JP3535193B2 - Watercraft - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine vessel that drives a propulsion device by an output shaft of the engine to drive the propulsion device. More specifically, the propulsion device operates at a high output speed while operating the engine at a high output speed. The present invention relates to improvements in a crankshaft structure of an engine that can be rotated and a driving force transmission structure.

[0002]

2. Description of the Related Art Conventionally, the above-mentioned engines for watercraft are
There is a method in which a crankshaft is used as an output shaft without changing the speed as it is, and a propeller shaft (transmission shaft) connected to the output shaft is used to rotate a jet pump (propulsion device) to generate a propulsive force. In order to improve the maximum speed of this type of watercraft, it is common to increase the output of the engine to increase the amount and pressure of water ejected rearward from the jet pump.

The method of increasing the engine speed is the easiest and cheapest method for improving the output of the engine. However, if the engine speed, that is, the speed of the jet pump is too high, water is sucked into the impeller section. There is a problem that the cavitation phenomenon occurs in which the amount of air does not catch up with the amount of jetting and bubbles are generated, and the pump efficiency decreases. Even in the case of a type of propulsion machine equipped with a screw unlike the jet pump, the same phenomenon as above occurs on the suction side of the screw.

As a method for solving the above problems, a transmission is arranged between the output shaft of the engine and the jet pump so that the jet pump operates at a high output speed while the engine rotates at a high output speed. A method of rotating can be adopted.

[0005]

However, when the dedicated transmission is provided between the output shaft of the engine and the jet pump as described above, the structure becomes complicated, the boat weight increases, and the cost increases. The problem occurs.

The present invention has been made in view of the above problems of the prior art, and does not reduce pump efficiency due to the cavitation phenomenon, and also causes problems such as structural complexity, increased boat weight, and increased cost. It is an object of the present invention to provide a watercraft capable of increasing the speed of a boat without any trouble.

[0007]

According to a first aspect of the present invention, there is provided a gear on which a propeller mounted on a rear portion of a hull is driven by an output shaft of the engine so as to travel on the water. ， The cylinder axis of the second cylinder forms V bank,
And the first crankshaft of the first cylinder and the second crank of the second cylinder
Link axis and 2-axis V-type engine disposed so as to be parallel to the output shaft, the first mounted on the first crankshaft
The first drive gear and the second drive gear mounted on the second crankshaft are meshed with the output gear mounted on the output shaft.

According to a second aspect of the present invention, in the first aspect, the propeller shaft is connected to the output shaft via a rubber coupling, and the gear transmission mechanism is arranged between the coupling and the crankshaft. It has a feature. According to a third aspect of the present invention, a generator is mounted on the front end portion of the first crankshaft, the drive gear is on the rear end side of the first and second crankshafts, and the output gear is the output shaft. It is characterized in that they are arranged respectively.

According to a fourth aspect of the present invention, a propulsion unit disposed at the rear of the hull is driven by an output shaft of the engine to drive the propulsion unit on the water to drive the marine vehicle to the water.
The cylinder axes of the first and second cylinders form a V bank and the first cylinder
A two-axis V-type engine in which a first crankshaft of a cylinder and a second crankshaft of a second cylinder are arranged in parallel with the output shaft, and intake is performed in a V bank between the first and second cylinders. A system is provided, and an opening / closing lid is provided above the intake system of the hull.

[0010]

According to the marine vessel of the present invention, the engine is a two-shaft V type engine, and the first and second drive gears mounted on the first and second crankshafts are mounted on the output shaft. Since it meshes with the output gear, the propulsion machine can be rotated at the maximum efficiency rotation speed while rotating the engine at the maximum output rotation speed by appropriately selecting the gear ratio between the first and second drive gears and the output gear. As a result, the efficiency of the propulsion device is not lowered due to the cavitation phenomenon, and the boat speed can be increased. In this case, since the gears that connect the crank shaft and the output shaft are used for gear shifting, there is no need to provide a dedicated gear shifting device, and the structure is not complicated, the weight of the boat is increased, and the cost is not increased. .

According to the watercraft of the second aspect of the present invention, since the engine rotation passing through the gear transmission mechanism is transmitted to the propeller shaft through the rubber coupling, the rotation speed of the rubber coupling is lower than the engine rotation speed. Therefore, the rubber coupling can be prevented from being damaged by centrifugal force.
Further, according to the watercraft of the invention of claim 3, the generator is mounted on the front end portion of the first crankshaft, the drive gear is provided on the rear end side of the first and second crankshafts, and the output gear is provided. Since the output shafts are attached to the output shafts respectively, the output shafts can be shortened and the engine can be made compact because there is no need to place the engine in front in order to avoid interference between the generator and the coupling. The degree of freedom of can be increased.

According to the watercraft of the fourth aspect of the present invention, the engine is a two-axis V-type engine, and the V between the first and second cylinders is V.
Since the intake system is installed in the bank and the opening / closing lid is provided above the intake system of the hull, the intake system can be installed by effectively utilizing the empty pace of the engine, and maintenance and inspection can be facilitated.
In this case, since it is a two-axis V-type engine, it is possible to secure a sufficient space for disposing the intake system while reducing the bank sandwiching angle to make the engine width compact.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 are views for explaining a seaplane according to an embodiment of the present invention, and FIGS. 1 and 2 are a rear view, a plan view, and a view of an engine mounted on the seaplane of this embodiment. 3 and 4 are a side view and a plan view of the watercraft.

In the figure, reference numeral 1 denotes a watercraft, which is a hull 2 and an engine 3 housed and mounted in the hull 2.
And a propulsion unit 4 driven by the engine 3.

The hull 2 is a box-shaped vessel having a so-called bathtub-shaped hull 5 on which a lid-plate-shaped deck 6 is mounted and which are hermetically joined by a gunnel 7. A hatch 8 is mounted on the deck 6 above the engine 3 so as to be openable and closable forward with a front end hinge 8a as a fulcrum. There is. A steering handle 10 is disposed at the rear of the hatch 8, and the steering handle 10 swings a jet port 11 of the propulsion unit 4 which will be described later to the left and right to move the floating vessel 1 to the left and right. To steer. A saddle type seat 12 is mounted behind the steering handle 10 of the hull 2.

The propulsion unit 4 has a suction duct 13 disposed in an arrangement space 2a formed in a tunnel shape in the rear portion of the hull 2, an impeller 14 disposed in the middle of the duct 13, and a rear end portion thereof. The jet outlet 11 is arranged so as to be swingable from side to side, and the impeller 14 is driven by a propeller shaft 15. In addition, the above arrangement space 2
a is opened toward the rear end of the hull, and the suction port 13a of the suction duct 13 is opened at the bottom surface of the hull 2.

The engine 3 is a two-shaft V-type four-cylinder engine, and is provided with a crankcase 16 consisting of an upper case 16a and a lower case 16b, and a V bank on the upper case 16a. Left and right cylinder blocks 17, 18 and the respective cylinder blocks 17, 18
Cylinder heads 19 and 20 mounted on the. Two cylinder bores 17b and 18b are formed in each of the left and right cylinder blocks 17 and 18, and the left and right cylinder bores 17b and 18b are arranged to face each other without being offset in the crankshaft direction. The pistons 21 and 22 slidably inserted in the cylinder bores 17b and 18b are connected to the connecting rod 23 and
It is connected to the crankshafts 25 and 26 via 24.

The crankshafts 25 and 26 are arranged in parallel with each other at the mating portion of the upper case 16a and the lower case 16b, and are rotatably supported by bearings 27 arranged on the mating surface. There is. Further, a flywheel magneto type generator 33 is attached to the front end of the right crankshaft 26, and the front side of the generator 33 is attached to the right side of the front wall of the crankcase 16.
It is surrounded by 3a.

An output shaft 28 is inserted and disposed below the left and right crankshafts 25 and 26 in parallel with the crankshafts 25 and 26, and the front and rear ends of the output shaft 28 are located near the bearing 2.
It is rotatably supported by 9. The front end of the output shaft 28 is located near the middle of the front and rear cylinder bores, and the rear end projects rearward of the crankcase 16. The output shaft 28 is attached to the propeller shaft at the protruding end. A joint 34 for connecting to 15 is attached.

Drive gears 30 and 31 are mounted and fixed to the rear ends of the crankshafts 25 and 26, respectively.
Reference numerals 0 and 31 mesh with an output gear 32 mounted and fixed to the rear portion of the output shaft 28. And the above-mentioned gears 30 to 32
Is a cover 35 attached to the rear wall of the crankcase 16.
It is surrounded by. Here, the gear ratio between the drive gears 30 and 31 and the output gear 32 is appropriately set so that the impeller 14 can be rotated at a high efficiency rotation speed while rotating the engine at a high output rotation speed. In the case of the engine of the present embodiment, the gear ratio is set to 1 because the high output speed and the high efficiency speed are the same.

Further, two intake ports 16c are formed in the V bank inside portion formed by the left and right cylinder heads 17 and 18 of the upper cover 16a. before this,
The rear intake port 16c communicates with the left and right independent crank chambers via the left and right independent intake passages. Further, reed valves 39 and 40 for preventing backflow are arranged in the respective intake passages. Further, a carburetor 37 common to two cylinders facing each other through a gab joint 36 is provided at each of the intake ports 16c.
, And a common intake-side silencer 38 is connected to the front and rear carburetors 37. This constitutes an intake system that supplies a mixture of air and fuel to the engine.

The exhaust manifold 4 is attached to the exhaust ports 17a and 18a of the cylinder blocks 17 and 18, respectively.
3, 44 are connected to each of the exhaust manifolds 4
Reference numerals 3 and 44 denote the above-mentioned arrangement space 2 for the propulsion unit 4 via the muffler 45, the water lock 46, and the exhaust pipe 47.
It communicates with the inside of a. The muffler 45 is located on the left and right sides of the cylinder blocks 17 and 18, and has a box shape extending in the longitudinal direction of the hull. Further, the water lock 46 is for preventing water from flowing back to the engine from the exhaust pipe 47 at the time of overturning. Furthermore, the exhaust pipe 47 extends rearward above the cylinder heads 19 and 20.

Next, the function and effect of this embodiment will be described. When the engine 3 starts, the rotation of the crank shafts 25, 25 is transmitted to the output shaft 28 via the drive gears 30, 31 and the output gear 32.
And the output shaft 28 drives the impeller 14 of the propulsion unit 4 via the propeller shaft 15. Then, the water is sucked into the suction duct 13, the pressure is increased by the impeller 14 portion, and then the water is jetted rearward from the jet port 11, whereby a propulsive force is obtained, and the marine vessel 1 advances.

Thus, in this embodiment, the crankshaft 2
Drive gears 30, 31 and output gear 32
Since it is transmitted to the output shaft 28 via the engine, the engine speed that gives a high output can be shifted to a highly efficient impeller speed and transmitted, the occurrence of the cavitation phenomenon can be suppressed, and the boat speed can be increased efficiently. Can be improved.

In the present embodiment, the gear shift 30 is used to connect the crankshafts 25 and 26 with the output shaft 28.
Since it is realized by utilizing .about.32, it is not necessary to separately provide a dedicated transmission, and therefore the structure can be simplified, the boat weight can be reduced, and the cost can be reduced.

Further, since the engine 3 is a two-axis V-type engine, it is not necessary to offset the opposing cylinder bores 17b and 18b of the left and right cylinder blocks 17 and 18 in the axial direction, and the engine can be made compact accordingly. Further, since the intake conditions for the left and right crank chambers are the same, uneven intake amounts can be prevented. Furthermore 1 axis 2
Parts can be shared with the cylinder engine, and cost can be reduced from this point as well.

Further, in this embodiment, since the intake system is arranged in the V bank, the intake port of this intake system is located in the upper part of the inside of the hull 2, and the invasion of water from the intake system is suppressed. be able to. Further, since the intake system is arranged in the V bank, the intake system can be arranged by effectively utilizing the dead space of the engine, and the engine can be made compact. In this case, since the two-axis V-type engine is used, the space between the crankshafts can be widened and the space between the crankshafts can be made smaller while the space between the crankshafts can be made large while ensuring a large space. Further, the generator 33 is arranged at the front end of the right crankshaft 26, and
Since 0 to 32 are arranged on the rear end side of the crankshaft, the output shaft 2
8 can be shortened, and the engine can be made compact because it is not necessary to dispose the engine in front in order to avoid interference between the generator 33 and the coupling 34.

Furthermore, in this embodiment, since the hatch 8 is provided above the V bank of the engine so as to be openable and closable, maintenance and inspection of the engine 3 can be facilitated.

In the above embodiment, the drive gears 30, 3 are
Although the case where the gear ratio between 1 and the output gear 32 is 1 has been described,
It goes without saying that this gear ratio can be set to a value other than 1 as appropriate, and it is desirable to increase the number of teeth of the output gear 32 to reduce the engine rotation speed and transmit it to the propeller shaft.

[0030]

As described above, according to the watercraft according to the invention of claim 1, the two-shaft V-type engine is adopted, and the first and second crankshafts and the output shaft are provided with the drive gear and the output gear. Since the driving gear can be rotated at a high output speed by rotating the engine at a high output speed by appropriately setting the gear ratio of the drive gear to the output gear, the structure is complicated. It has the effect of suppressing the cavitation phenomenon and efficiently increasing the boat speed while avoiding the increase in weight, the increase in weight, and the increase in cost.

Further, according to the watercraft according to the second aspect of the present invention, since the gear transmission mechanism is arranged on the input side of the rubber coupling, the rotational speed of the coupling is reduced and the coupling of the coupling is reduced. Deformation due to centrifugal force can be prevented. According to the invention of claim 3, the generator is provided at the front end portion of the first crankshaft, and the drive gear is provided at the rear end side of the first and second crankshafts.
Since the output gears are attached to the force shafts respectively, the engine can be made compact.

According to the watercraft of the fourth aspect of the present invention, the engine is a two-axis V type engine, and the V between the first and second cylinders is V.
Since the intake system is arranged in the bank and the opening / closing lid is provided above the intake system of the hull, the empty space of the engine can be effectively utilized and maintenance and inspection can be facilitated.

[Brief description of drawings]

FIG. 1 is a rear view of an engine used in a watercraft according to an embodiment of the present invention.

FIG. 2 is a plan view of the engine of the embodiment.

FIG. 3 is a side view of the above-described water-based traveling ship of the embodiment.

FIG. 4 is a plan view of the above-mentioned waterborne vessel of the embodiment.

[Explanation of symbols]

1 Water Traveling Ship 2 Hull 3 Engine 8 Hatch (Opening / Closing Lid) 14 Impeller (Propulsion Machine) 25, 26 Crankshaft 28 Output Shaft 30, 31 Drive Gear 32 Output Gear 33 Generator 34 Coupling 36, 37, 38 Cab Joint, Vaporizer, air cleaner (intake system)

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-3-295789 (JP, A) JP-A-6-239292 (JP, A) JP-A-5-105190 (JP, A) JP-A-61- 67695 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B63H 23/06 B63H 11/08 B63H 21/14

Claims (4)

(57) [Claims] 1. A marine vessel traveling on water by driving a propulsion unit disposed at the rear of the hull with an output shaft of the engine, wherein the engine is a cylinder bank of the first and second cylinders is a V bank. None and the first crankshaft of the first cylinder and
A two- shaft V-type engine arranged so that the second crankshaft of the second cylinder is parallel to the output shaft, and the first crank
First drive gear mounted on the shaft and the second crankshaft
A watercraft in which the second drive gear mounted on the output shaft is meshed with the output gear mounted on the output shaft. 2. The propeller shaft according to claim 1, wherein a propeller shaft is connected to the output shaft via a rubber joint, and the first and second drive gears and the output gear are provided between the joint and the crankshaft. A watercraft comprising a transmission mechanism including the following. 3. The generator according to claim 1, wherein a generator is mounted on a front end portion of the first crankshaft, and the drive gear is on the rear end side of the first and second crankshafts. A watercraft in which the output gears are respectively arranged on the output shafts. 4. A marine vessel traveling on water by driving a propulsion unit arranged at the rear of the hull by an output shaft of the engine, wherein the engine is a cylinder bank of the first and second cylinders is a V bank. None and the first crankshaft of the first cylinder and
A two- shaft V-type engine is provided in which the second crankshaft of the second cylinder is arranged in parallel with the output shaft.
An onboard watercraft, wherein an intake system is provided in a V bank between cylinders, and an opening / closing lid is provided above the intake system of the hull.