JP2865173B2 - Water jet propulsion system for small boats - Google Patents

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 device for a small boat, and more particularly, to a water jet propulsion device driven by an engine, which can be downsized as a whole including a drive system such as an engine. It relates to an intended water jet propulsion device.

[0002]

2. Description of the Related Art In recent small boats, a water jet type propulsion device is frequently used as a propulsion device.
A water propulsion system for a small boat of this type is disclosed in
No. 2396 and U.S. Pat.
No. 81303 is known.

In the former water jet propulsion system for a small boat, a pump housing is provided at a rear portion of a hull, and an impeller fixed to a rear end of an impeller shaft extending horizontally forward and backward is accommodated in the pump housing. The front end of the impeller shaft is connected to the engine mounted on the hull front.

[0004] In the latter type of water jet propulsion system for a small boat, an engine is arranged above a pump housing, and an upper end of an impeller shaft that penetrates upward from the pump housing and protrudes is connected to the engine via a gear mechanism.

[0005]

However, in the former water jet propulsion system for small boats, the pump housing, that is, the propulsion unit is disposed at the rear of the hull, and the engine is disposed at the front of the hull. Must be connected to each other, so that the extra space on the hull is reduced, and the layout freedom of other equipment is limited.

In the latter type of water jet propulsion system for a small boat, the engine is located above the pump housing, so that the size of the boat in the vertical direction cannot be avoided.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a small boat in which a propulsion device including an engine and a propulsion unit is miniaturized. The aim is also to allow great freedom.

[0008]

To achieve the above object, according to an aspect of this invention is mounted on a rear inner hull, over the nozzle portion of the rear for spouting water from the intake portion for sucking the water,
A pump housing that extends while curving back upward, is accommodated in the pump housing, and a impeller provided on the impeller shaft, an engine of this impeller within the hull
In a water jet propulsion device for a small boat that generates driving force by injecting water sucked from an intake portion through an intake portion through a nozzle portion, the impeller is disposed inside the pump housing.
And the impeller shaft is connected to the pump
Extend diagonally back along the curve in the jing,
End protruding upward from the pump housing
Straighten the engine in front of the curved section of the pump housing.
Face to face and tilt and place the engine crankshaft
Was extended obliquely rearward and upward from the engine body in front of and parallel to the impeller shaft, and the upper end of the impeller shaft and the upper end of the crankshaft were connected by a power transmission mechanism.

According to the present invention, the engine can be constituted by a four-stroke engine in which an oil pan is assembled to an engine body. In this embodiment, the oil pan is connected to a pump housing.
It is desirable to dispose it in front of the engine and obliquely below the engine body . In this aspect, when the bottom of the engine is supported on the hull by a pair of left and right anti-vibration mounts, it is desirable to arrange an oil pan between the anti-vibration mounts.

[0010]

[Function] The engine and the propulsion unit are arranged close to each other,
The assembled figure will be inclined to the rear of the hull. others
Of the engine and the propulsion unit
The law is small and the height is low. Furthermore, pump housing
The upper end of the impeller shaft protruding from the
Since the upper end is connected by a power transmission mechanism, the power transmission mechanism
Very small blockage of water flow in pump housing
No. Therefore, the propulsion unit has high propulsion efficiency.

In the case where the engine comprises a four-cycle engine, the oil pan is connected to a pump housing.
The oil pan can be prevented from interfering with other devices by disposing it in front of the engine and obliquely below the engine body . When the bottom of the engine is supported on the hull by a pair of right and left anti-vibration mounts, the oil pan can be disposed between the anti-vibration mounts to more effectively prevent interference with other devices.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show a watercraft propulsion system for a small boat according to an embodiment of the present invention. FIG. 1 is a plan view of the small boat, FIG. 2 is a sectional side view of the same, and FIG. 4 is a partially sectional side view of the water jet propulsion device, FIG. 5 is a partially enlarged plan sectional view of the water jet propulsion device, and FIG. 6 is a partially enlarged side sectional view of the water jet propulsion device. is there.

1 and 2, reference numeral 11 denotes a hull in which a hull (lower hull) 12 and a deck (upper hull) 13 are joined.
It is composed of a resin such as P. Partition wall 1 inside hull 11
Trunk room TR, center room CR according to 4,15
The engine room ER is divided into front and rear. The trunk room TR is a storage space, and the center room CR has a fuel tank 40 and an engine room E.
The engine 50 and the propulsion unit 60 are housed in R.

The deck 13 has openings 17 and 18 at the front and rear, respectively, and a concave cabin 16 which is open upward at the center. The front opening 17 is opened in the trunk room TR and is opened and closed by a lid 19, and the rear opening 18 is opened in the engine room ER and is opened and closed by a hood 20.

An opening 21 is formed in the bottom wall of the cabin 16, and a steering device 23 is mounted on the front wall. The opening 21 opens in the center room CR, and the cover member 24
To be opened and closed. The steering device 23 is configured by attaching a steering handle (operating stick) 25 or the like to the steering post 22, and the steering handle 25 or the like is connected to the propulsion unit 60 or the like by a cable or the like. The steering post 22 has its base end fixed to the front wall of the cabin 16 at a position deviated leftward and upward , and its tip extends obliquely rearward and upward . The tip of the steering post 22 (in front of the hull 11)
The steering handle 25 described above is tiltably attached to a rear end portion with respect to the rear, and the steering handle 25 is attached to a steering shaft 25 in the steering post 22.
Connect with a.

In the cabin 16, a driver's seat 26 and a passenger's seat 27 are provided independently of each other. The driver's seat 26 and the passenger's seat 27 are spaced apart from each other in front and rear and left and right, that is, staggered, and the driver's seat 26 is located behind the steering device 23 on the left side of the hull 11 and The passenger seat 27 is located on the right side of the hull 11.

As shown in FIGS. 3 and 4, the propulsion unit 60 includes a pump housing 61 in which an impeller 63 fixed to the lower end of an impeller shaft 62 is rotatably housed. The pump housing 61 is formed of a cylindrical member that curves gently backward and upward , and has an intake portion 64 that opens at the front end of the hull 12 at the bottom, and a rear end that opens at the stern of the hull 12. It is connected to the nozzle section 65. The pump housing 61 has an outer set plate 67 in which the periphery of the intake portion 64 is provided on the inner surface of the bottom of the hull 12.
It is fixed by the bolt which penetrated.

The nozzle portion 65 is formed integrally with the reverse body 66a and has a hole 12 formed at the stern of the hull 12.
f and opens right behind the hull 11. A steering nozzle 68 is attached to the rear end of the nozzle portion 65 so as to be rotatable in the left-right direction, and the flow of water jetted from the nozzle portion 65 is changed by the steering nozzle 68.

The reverse body 66a is bolted to the inner surface of the stern of the hull 12 together with the outer side reverse cover 66b with bolts. Circumferentially defines a reverse chamber 66. Joints 69a, 69 are provided on the left and right sides of the nozzle 65 in the reverse body 66a.
a is fixedly mounted, and the reverse pipes 69, 69 are connected to the joints 69a, 69a. The joints 69a, 69a open to the reverse chamber 66 and connect the reverse chamber 66 to the reverse pipes 69, 69.

The reverse cover 66b is fixed to the outer surface of the stern of the hull 12, and covers the steering nozzle 68 in the vertical and horizontal directions, that is, around the steering nozzle 68 except for the rear. An opening 66f is formed at the rear of the reverse cover 66b, and a reverse bucket 72 is attached to the rear of the reverse cover 66b so that the opening 66f can be opened and closed.

The steering nozzle 68 has a cylindrical shape whose diameter is reduced toward the rear, is accommodated in a reverse chamber 66, and is surrounded by a reverse cover 66b. The front end of the steering nozzle 68 fits with the outer periphery of the nozzle portion 65 of the pump housing 61, and the upper and lower ends of the front end are supported by the pump housing 61 so as to be rotatable about a vertical axis.

The steering nozzle 68 has chopper valves 70, 70 on the left and right sides, respectively, of the reverse pipe 6.
Openings 9 and 69 to the reverse chamber 66 are integrally formed so as to be openable and closable, and a cable 71 connected to the steering handle 25 is locked on the left side. The steering nozzle 68 responds to the steering of the steering handle 25 to change the flow direction of the water spouting from the nozzle portion 65, and to open the reverse pipes 69, 69 to the reverse chamber 66 with the chopper valves 70, 70. Open and close selectively.

The reverse pipes 69, 69 are respectively
It extends substantially obliquely left front and right front, and has a front end connected to the reverse nozzles 69b, 69b. Reverse nozzle 69b,
69b is fixed to the inner surface of the side of the hull 12 with bolts, and opens on the outer surface of the hull 12 so as to be directed obliquely forward. As described above, the openings of the reverse pipes 69, 69 to the reverse chamber 66 are opened and closed by the chopper valves 70, 70.

The reverse bucket 72 has a valve plate 72a capable of opening and closing the opening of a reverse cover 66b integrally formed between a pair of side plates 72b, 72b. Are rotatably connected to the left and right sides of the inner surface of the reverse cover 66b, respectively, around a horizontal axis. In the reverse bucket 72, a cable 73 is locked to a right side plate, and the cable 73 is connected to a forward / reverse switching lever of the control device 23. The reverse bucket 72 responds to the operation of the forward / reverse switching lever, and closes the opening 66f of the reverse cover 66b when moving backward (see FIG. 6).

The impeller shaft 62 is connected to the pump housing 61.
, And extends obliquely rearward , penetrates through a hollow pivot shaft 74 fixed to the upper part of the pump housing 61, and the upper end protrudes into the case 81. The impeller shaft 62 has the impeller 63 fixed to the lower end as described above, the upper part, the middle part and the upper end of the impeller 63 are supported by bearings, respectively. It is connected to 51.

As shown in FIG. 4, the belt transmission 80 is formed of a case 8 having a cover 81b joined to a main body 81a.
1 and a belt 84 is mounted between the driven pulley 82 and the drive pulley 83. The main body 81a of the case 81 has a lower rear portion of the pivot shaft 7 described above.
4 is supported via a mount. In this case 81, a hole 86 for taking in cooling air is formed in the cover 81b at a position above the drive pulley 83.

The driven pulley 82 is fixed to the upper end of the impeller shaft 62, and the drive pulley 83 is fixed to a rotating shaft 85 provided on the crankshaft 51 of the engine 50. The drive pulley 83 is provided with a cooling fan 83a at the upper part. This belt transmission 80
Transmits the power of the engine 50 to the impeller shaft 62.

The engine 50 is composed of a two-cylinder two-cycle engine, the bottom of which is disposed on the bottom of the hull 12 via a pair of left and right mounts 52, 52, and the rear of which is a pump housing 61.
Is mounted via a mount 53. This engine 5
0 is the cylinder head 5 with the crankcase 54 on the rear side.
5 is located on the front side, and the crankshaft 51 is mounted so as to extend obliquely rearward and upward in parallel with the impeller shaft 62 described above. The rotation shaft 85 is provided at the upper end of the crankshaft 51 coaxially and integrally rotatable as described above,
The flywheel 56 is fixed below the rotating shaft 85. The throttle valve of the engine 50 is connected to an accelerator grip (accelerator lever) of the control device 23.

In the water jet propulsion system for a small boat of this embodiment, the crankshaft 5 of the engine 50 is used.
1 is connected to the impeller shaft 62 of the propulsion unit 60 via a belt transmission device 80 so as to be able to transmit power.
Is driven and rotated by the impeller 63. As is well known, the propulsion unit 60 sucks water from the intake portion 64 by rotation of the impeller 63, and jets the sucked water from the nozzle portion 65 to generate a propulsive force.

In this water jet propulsion device, as shown in FIG. 4, an impeller shaft 62 having a lower end provided with an impeller 63 is extended obliquely rearward and upward from the pump housing 61, and the engine 50 is cranked. The shaft 51 is disposed immediately before and near the pump housing 61 so as to extend obliquely rearward and upward in parallel with the impeller shaft 62. Therefore, the dimension in the front-rear direction when the engine 50 and the propulsion unit 60 are assembled can be reduced, and the height of the engine 50 and the propulsion unit 60 can be reduced. Therefore, other devices, such as seats 26, 2
It is possible to reduce the restrictions on the layout of the engine 7 and the like from the engine 50 and the like, and to prevent the hull 11 from being enlarged vertically. As is clear from the above description, the present invention
The impeller 63 is arranged at a curved portion in the pump housing 61.
And the impeller shaft 62 is bent in the pump housing 61.
Extend diagonally back along the section
Protrude upward from the jing or 61 and extend as it is.
Gin 50 directly in front of the curved part of pump housing 61
The engine 50 crankshaft
To the front of the impeller shaft 62 and the impeller shaft 62
Extends obliquely rearward and upward from the engine body 54 in parallel with
And above the upper end of the impeller shaft 62 and the crankshaft 51.
Connected to the end by a belt transmission 80 as a power transmission mechanism
It is characterized by having done.

Next, water jet propulsion of another embodiment will be described.
The device will be described with reference to FIG. 7 according to the present invention U
FIG. 4 shows a side sectional view of another embodiment of the water jet propulsion device.
You. In this embodiment, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the engine 50 is constituted by a four-cycle engine. The engine 50 is also directly inclined and disposed in front of the curved portion of the pump housing 61, and an oil pan 57 is attached to a lower portion of a crankcase (engine body) 54. This oil pan 57
Of the pump housing 61 between the mounts 52
It is located forward and diagonally forward and downward of the engine body 54 .
As is well known, oil is stored in the oil pan 57.

In the engine 50, a crank pulley 58 is fixedly mounted on the crankshaft 51 below the flywheel 56. The timing belt 59 is wound around the crank pulley 58, and the timing belt 5
At 9, it is connected to a valve operating mechanism provided on the cylinder head 55 so that power can be transmitted. As is well known, the valve mechanism covers a cam shaft, a rocker arm head, and the like provided on the cylinder head 55 with a cover 55a, and a cam pulley 59a fixed to the cam shaft is provided with the timing belt 5 described above.
9 is wound.

In another embodiment , the engine 50
Although the oil pan 57 is indispensable in the four-stroke engine, the oil pan 57 is disposed between the mounts 52 and 52 below the crankcase 54. Therefore, the oil pan 5
The position 7 does not interfere, that is, a position that does not affect the layout of other devices, and the oil pan 57 does not increase the size of the engine 50.

[0035]

According to the first aspect of the present invention, the impeller is provided with a pump housing.
Place it on the curved part in the housing and align the impeller shaft with the pump housing.
Extend it diagonally back along the curved part in the housing,
The upper end protrudes upward from the pump housing
Extend the engine before the curved section of the pump housing
Directly facing and tilting the engine crankshaft
To the front of the impeller axis and parallel to the impeller axis.
Extend obliquely rearward and upward from the engine body and above the impeller shaft.
Connect the end and the upper end of the crankshaft with a power transmission mechanism.
Therefore, the engine and the propulsion unit were placed close to each other,
The assembled figure can be tilted to the rear of the hull. For this reason, the front-back dimension of the assembled state of the engine and the propulsion unit can be reduced, and the height can also be suppressed. Therefore, since the entire propulsion device including the engine and the propulsion unit is small, only a small arrangement space is required, and it is easy to arrange other equipment on a narrow hull. Further, since the upper end of the impeller shaft protruding from the pump housing and the upper end of the crankshaft are connected by the power transmission mechanism, the power transmission mechanism hardly obstructs water flow in the pump housing. Therefore, the propulsion unit has high propulsion efficiency.

According to a second aspect of the present invention, an oil pan in the case of using a four-cycle engine is provided in front of the pump housing.
The oil pan can be placed without affecting the overall size because it is located diagonally in front of and below the engine body.In addition, the oil pan does not interfere with other equipment and the layout of the equipment is not affected, Hardly ever.

According to a third aspect of the present invention, the lower portion of the engine is supported on the hull by a pair of left and right anti-vibration mounts, and the oil pan is disposed between the anti-vibration mounts. And the oil pan does not restrict the layout of other equipment
Or almost never.

[Brief description of the drawings]

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

FIG. 2 is a side sectional view of the small boat according to the present invention .

FIG. 3 is a plan view of a water jet propulsion device according to the present invention .

FIG. 4 is a side sectional view of a water jet propulsion device according to the present invention .

FIG. 5 is a partially enlarged plan sectional view of a water jet propulsion device according to the present invention .

FIG. 6 is a partially enlarged side sectional view of a water jet propulsion device according to the present invention .

FIG. 7 shows another water jet propulsion device according to the present invention .
Side sectional view of the embodiment of FIG.

[Explanation of symbols]

11 Hull, 50 Engine, 51 Crankshaft, 52 Mount (vibration-proof mount), 54 Crankcase (engine body), 57 Oil pan, 6
0 ... propulsion unit, 61 ... pump housing, 62 ...
-Impeller shaft, 63 ... Impeller, 64 ... Intake part, 65 ... Nozzle part, 80 ... Belt transmission (power transmission mechanism).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B63H 11/00 B63H 11/08

Claims (3)

(57) [Claims] 1. A mounted on the rear inside the hull, over water from sucking intake portion to the nozzle portion of the rear for spouting water, after
A pump housing extending upward while being curved upwardly, and an impeller housed in the pump housing and provided on an impeller shaft.The impeller is driven by an engine in the hull to move the impeller from the intake portion. In a watercraft propulsion system for a small boat that generates propulsion by injecting sucked water from a nozzle portion, the impeller is disposed on a curved portion in the pump housing.
And place the impeller shaft on a curved part in the pump housing.
Extend diagonally backward along the top of the pump housing , projecting upwards from the pump housing , and extend the engine directly in front of the curved section of the pump housing.
The engine crankshaft in front of the impeller shaft.
Parallel to the impeller axis and obliquely rearward and upward from the engine body
A water jet propulsion device for a small boat , wherein an upper end of the impeller shaft and an upper end of the crankshaft are connected by a power transmission mechanism. 2. The water jet propulsion system for a small boat according to claim 1, wherein said engine comprises a four-stroke engine in which an oil pan for storing oil is assembled to an engine body. In front of the pump housing and diagonally forward and downward of the engine body
Water jet propulsion system for a small boat, characterized in that arranged in. 3. The water jet propulsion device for a small boat according to claim 2, wherein a bottom portion of the engine is supported on the hull by a pair of anti-vibration mounts separated in a hull width direction. A water jet propulsion device for a small boat, wherein the oil pan is disposed on the water jet propulsion device.