JP3520985B2 - Watercraft engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine for a marine vessel, and more particularly to an improvement in the layout structure of an exhaust system and an intake system, which can be made compact when the entire engine is mounted on a hull.

[0002]

2. Description of the Related Art Conventionally, as an engine unit for a watercraft, a series engine in which a plurality of cylinders are arranged in series so that the cylinder axes are parallel to each other, a V-type engine in which each cylinder axis is arranged in a V-shape, etc. There are various types. In the case of this type of particularly small watercraft, the mounting space of the engine unit is limited, and it is demanded to make the engine unit compact when mounted on the hull.

[0003]

However, in the case of the above-mentioned in-line engine, there is a problem that the total height of the engine tends to be high, and in the case of the V-type engine, since the cylinder axis is inclined to the outside of the hull, the total height of the engine is Although it is advantageous in reducing the height, there is a problem that the size in the width direction of the hull tends to increase. In particular, when it is attempted to secure the pipe length necessary for improving the output in the exhaust system, there is a problem that the mounting space in the width direction tends to expand depending on the layout of the exhaust system.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an engine for a marine vessel which can reduce a required space when mounted on a hull and can secure a required exhaust pipe length. I am trying.

[0005]

According to a first aspect of the present invention, there is provided an engine for a marine vessel, which is mounted inside a hull with a crankshaft oriented in the front-rear direction of a hull and rotationally drives a propulsion unit arranged at the rear of the hull. exhaust system, after extending forward from the exhaust port is extended to the rear, is formed so as to surround the front side of the gas cylinder axis when viewed in the cylinder axis direction, the intake system is an engine
It is extended from the intake port of, and when viewed in the crankshaft direction
The front extension part or the rear extension part of the exhaust system.
Is the intake system axis (including extension) and cylinder axis (extension)
It is arranged so that it passes through the space sandwiched between
It is characterized in that that.

According to a second aspect of the present invention, in the first aspect, when viewed in the crankshaft direction, a portion of the exhaust system between the front extending portion and the rear extending portion intersects with the cylinder shaft. It is characterized in that it is arranged in.

The invention of claim 3 is the same as that of claim 1 or 2.
Te, when viewed in the crankshaft direction, the cylinder axis is inclined in the hull lateral outward, the intake system is disposed on the upper side of the inclined cylinder axis (including the extension), the exhaust system It is characterized in that it is arranged so as to pass through both the lower side and the upper side of the inclined cylinder axis (including the extension line).

According to a fourth aspect of the present invention, in an engine for a watercraft which is mounted inside the hull with a crankshaft directed in the longitudinal direction of the hull and rotationally drives a propulsion unit arranged at the rear of the hull, the cylinder axis is the lateral direction of the hull. The intake system is inclined outward, the intake system is extended from an intake port formed on the upper side of the inclination of the engine, and the exhaust system is provided with an expansion chamber (muffler) connected to the exhaust port and extended in the front-rear direction. When viewed in the crankshaft direction, the expansion chamber is arranged so as to pass through a space sandwiched between the cylinder shaft (including the extension line) and the intake system axis (including the extension line). It has a feature.

The invention of claim 5 is any one of claims 1 to 4.
In the above, the engine is a V-type engine in which the first and second cylinder shafts form a V bank, and the intake system is arranged in the V bank space between the first and second cylinders, and the exhaust system is Is arranged below the inclination of the first and second cylinders.

In the present invention, the space surrounded by the axis of the intake system and the cylinder axis means the space sandwiched between the axis B and the cylinder axis A in FIG. The upper side and the lower side of the inclined cylinder axis mean the upper side and the lower side of the cylinder axis A in FIG.

[0011]

According to the invention of claim 1, since the exhaust system is formed so as to extend forward from the exhaust port and then extend rearward, and is formed so as to surround the front side of the cylinder shaft, Compared to the case where it is extended forward or backward, the length of the exhaust pipe becomes longer by the portion surrounding the cylinder shaft, and since the exhaust pipe is positioned so as to surround the cylinder, the bend radius of the pipe can be increased. , You can secure a long exhaust pipe length while suppressing exhaust resistance without expanding the mounting space.
The engine performance can be improved.

Further, when viewed in the crankshaft direction, sandwiched de the exhaust system of the forward extending portion or rearward extending portion of the intake system of axes (including the extended line) and the cylinder axis (including extension) Since it is arranged so as to pass through the open space, a part of the exhaust system can be arranged by utilizing the empty space between the intake system and the cylinder shaft, and also from this point, the expansion of the mounting space can be prevented.

According to the second aspect of the invention, when viewed in the crankshaft direction, the portion between the front extension portion and the rear extension portion of the exhaust system is arranged so as to intersect with the cylinder shaft. Therefore, the portion between them also contributes to securing the length of the exhaust pipe, and as a result, the exhaust pipe length can be secured while suppressing the exhaust resistance without expanding the mounting space.

According to the third aspect of the invention, when viewed in the crankshaft direction, the cylinder shaft is tilted outward in the left-right direction of the hull, and the intake system is arranged above the tilted cylinder shaft, and the exhaust gas is discharged. Since the system is arranged so as to pass through both the lower side and the upper side of the tilted cylinder axis, while suppressing the engine overall height by the tilt of the cylinder axis, the intake system can be arranged by utilizing the empty space on the upper side of the tilt, Further, by utilizing the lower side and the upper side of the slope, it is possible to avoid the expansion of the mounting space while ensuring the pipe length of the exhaust pipe.

According to the invention of claim 4, when viewed in the crankshaft direction, the cylinder shaft is tilted outward in the left-right direction of the hull, the intake system is arranged on the upper side of the tilt, and the expansion chamber (muffler) of the exhaust system is provided. Since it is arranged so as to pass through the space sandwiched by the cylinder axis (including the extension line) and the axis line of the intake system (including the extension line), the inclination of the cylinder axis suppresses the overall height of the engine and You can use the empty space to place the expansion chamber of the exhaust system,
The expansion of the mounting space can be avoided.

According to the invention of claim 5, since the engine is a V-type engine in which the first and second cylinder shafts form a V bank, the inventions of claims 1 to 5 can be preferably applied, and The effect can be surely realized.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 6 are views for explaining an engine for a watercraft according to an embodiment of the present invention.
2, FIG. 3, and FIG. 4 are a rear view, a partial cross-sectional plan view, a partial cross-sectional side view and a plan view, respectively, of the engine mounted on the surface-traveling ship of this embodiment, and FIGS. It is a side view and a top view. 3 and 4, the left side of the drawings is the front of the hull.

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 structure in which a lid plate-shaped deck 6 is mounted on a so-called bathtub-shaped hull 5 and both are hermetically joined by a gunnel 7. A hatch 8 is mounted above the engine 3 of the deck 6 so as to be openable and closable forward with a front end hinge 8a as a fulcrum, and an opening and closing lid 9 for storing goods is attached to the hatch 8 so as to be openable and closable forward. . Here, in particular, the engine 3 of the hull 2
When viewed in cross section, the inner space of the portion where is arranged is highest at the center in the left-right direction of the hull and is lower as it is offset to the left and right outside.

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 allow the marine vessel to travel. It is designed to steer 1 left and right. 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 arranged in a tunnel-shaped arrangement space 2a formed in the rear portion of the hull 2, an impeller 14 arranged 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 mounted on the hull so that the crankshaft faces the longitudinal direction of the hull, and the axes of the left and right cylinder bores 17a and 17b, that is, the cylinder axis A forms a V bank, a two-axis V-type four cylinder. It is a two-cycle engine. In the present invention, the cylinder axis A means the cylinder bore 17
a, 18b The axis of itself and the extension lines above and below are included.

The engine 3 includes a crankcase 16 consisting of an upper case 16a and a lower case 16b, and left and right cylinder blocks 17 and 18 arranged on the upper case 16a to form a V bank. Cylinder heads 19 mounted on the cylinder blocks 17 and 18,
20 and the bracket 49 portion of the crankcase 16 is fixed to the hull 5 via the damper 48.

The above left and right cylinder blocks 17, 18
Two cylinder bores 17b and 18b are formed in each of the left and right cylinder bores 17b and 18b.
Are opposed to each other without being offset in the crankshaft direction. The pistons 21 and 22 slidably inserted into the cylinder bores 17b and 18b are connected to the crankshafts 25 and 26, which are independently spaced from each other via the connecting rods 23 and 24, left and right. There is. 20
a is a spark plug.

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. A flywheel magnet type generator 33 is attached to the front end of the crankshaft 26 on the right side, 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.

Two intake ports 16c are formed in the V bank 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. A carburetor 37 is connected to each of the intake ports 16c via a cab joint 36, and a common intake-side silencer 38 is connected to the front and rear carburetors 37. In this way, the intake system for supplying the air-fuel mixture to the engine is formed so that its axis B extends vertically upward in the V-bank space. In the present invention, the axis B of the intake system includes the axis of the intake system itself and the extension lines extending upward and downward.

Further, the exhaust ports 17a and 18a opened to the lower outside of the cylinder blocks 17 and 18 are provided with an exhaust manifold 44, an exhaust pipe 43, and a muffler (expansion chamber) 4 respectively.
5, and an exhaust device (exhaust system) 47 including a water lock 46 communicates with the above-mentioned propulsion unit 4 arrangement space 2a.

Here, the exhaust manifold 44 is disposed at a lower side portion of the engine 3, and has branch pipe portions 44a and 44a extending downward from the front and rear exhaust ports 17a and 17a or 18a and 18a, and the branch pipe portions. Tubes 44a, 44
It has a merging portion 44b that leads to the front while merging a.

Further, the exhaust pipe 43 has a rising portion 43a extending upward from the front end of the joining portion 44b of the exhaust manifold 44, and the rising portion 43a is seen from the front of the hull in the crankshaft direction. It is inclined so as to intersect with the axis A of the cylinder bores 17b and 18b, and to be closer to the center of the hull as it goes upward.

The exhaust pipe 43 is connected to the rising portion 4
3a, the bent portion 43 is bent backward and extends.
The muffler 45 is connected to c. This muffler 45
Is arranged so as to pass through the space above the cylinder heads 19 and 20 on the side of the intake system.

The rising portion 43a and the muffler 45 have cooling jackets 43b and 45a on their outer circumferences. The water lock 46 is provided to prevent water from flowing back from the exhaust pipe 43 at the time of overturning.

As shown in FIG. 3, the exhaust system of the engine of the present embodiment is viewed in the direction perpendicular to the crankshaft from the exhaust ports 17a and 18a, and the exhaust manifold 44 (front extending portion). By the rising portion 43a (a portion between the front extending portion and the rear extending portion), and extends upward from the bent portion 43c,
The muffler 45 (rear extension portion) extends rearward.
Further, the exhaust system, when viewed in the cylinder axis A direction,
Is formed in a curved shape so as to surround the front side of the.

The intake system of the present embodiment is linearly extended upward from the intake port 16c facing the V-bank internal space, and when viewed in the crankshaft direction, the exhaust system extends rearward. Installation portion, that is, the bent portion 43c and the muffler 4
Reference numeral 5 is arranged so as to pass through a space sandwiched between the axis B of the intake system and the cylinder axis A.

Further, in the engine 3 of this embodiment, when viewed in the crankshaft direction, the cylinder axis A is inclined outward in the lateral direction of the hull, and the intake system is arranged above the inclined cylinder axis A. The exhaust system is configured so that the front extending portion passes below the inclined cylinder axis A and the rear extending portion passes above.

Furthermore, in this embodiment, the rearward extending portion (muffler or the like) passes through a space sandwiched between the cylinder axis A and the intake system axis B when viewed in the crankshaft direction. It is arranged.

Next, the function and effect of this embodiment will be described.
When the engine 3 starts, the rotation of the crankshafts 25, 25 is transmitted via the drive gears 30, 31 and the output gear 32 to the output shaft 2
8, 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.

At this time, the outside air is sucked into the engine 3 from the intake system in the V bank, and the exhaust air is exhausted from the exhaust manifold 44 to the exhaust pipe 4 of the exhaust device 47.
3, the muffler 45, and the water lock 46, and the sheet is discharged into the propulsion unit 4 arrangement space 2a.

In this embodiment, the cylinder axis of the engine 3 is tilted to the outside of the hull, so that the overall height of the engine can be reduced. In addition, the rising portion 43a of the exhaust device 47
Is extended from the lower side of the engine to the upper side so as to intersect with the cylinder axis, and the muffler 45 is extended to the rear side on the upper side of the engine. Therefore, the engine peripheral portion of the exhaust device 47 can be arranged within the engine width, and the cylinder is tilted. It is possible to avoid expanding the width of the case.

Further, since the intake system is arranged in the V bank of the engine, the dead space can be effectively used, the expansion of the arrangement space by the intake system can be avoided, and the intake system can be prevented from expanding. Intrusion of water can be suppressed. 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 exhaust system includes exhaust ports 17a and 18a.
Since the structure extends from the front to the rear and extends to the rear and is formed to surround the front side of the cylinder axis A, a long exhaust pipe length can be secured without expanding the mounting space, and engine performance can be improved.

When viewed in the crankshaft direction, the rearward extending portion of the exhaust system, that is, the bent portion 43c and the muffler 4
Since 5 and the like are arranged so as to pass through the space sandwiched by the axis B of the intake system and the cylinder axis A, a part of the exhaust system can be arranged by utilizing the empty space between the intake system and the cylinder axis. Also from this point, it is possible to prevent the mounting space from expanding.

When viewed in the crankshaft direction, the portion between the front extension portion and the rear extension portion of the exhaust system, that is, the rising portion 43a is arranged so as to intersect with the cylinder axis A. The rising portion 43a also contributes to securing the length of the exhaust pipe, and as a result, it is possible to secure the length of the exhaust pipe while avoiding expansion of the mounting space.

When viewed in the crankshaft direction, the cylinder axis A is tilted outward in the lateral direction of the hull, the intake system is arranged above the tilted cylinder axis A, and the exhaust system is tilted. Since it is arranged so as to pass through both the lower side and the upper side of the axis A, the intake system can be arranged by utilizing the empty space on the upper side of the slope, and the pipe length of the exhaust pipe can be secured by using the lower side and the upper side of the slope. It is possible to avoid expansion of the mounting space.

Furthermore, when viewed in the crankshaft direction,
Since the exhaust system muffler (expansion chamber) 45 is arranged so as to pass through the space sandwiched between the cylinder axis A and the intake system axis B, the exhaust system muffler 45 is utilized by utilizing the empty space on the upper side of the inclination.
It can be arranged, and the expansion of the mounting space can be avoided.

In the above embodiment, the case of the V-type engine is illustrated, but the present invention is not limited to the V-type engine, and an upright parallel engine in which the cylinder axis extends in the vertical direction or a tilted parallel engine in which the cylinder axis is inclined outward. It can also be applied to engines.

[Brief description of drawings]

FIG. 1 is a rear view of an engine for a marine vessel according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional plan view of the engine of the embodiment.

FIG. 3 is a partial cross-sectional side view of the engine of the above embodiment.

FIG. 4 is a plan view of the engine of the embodiment.

FIG. 5 is a side view of the above-mentioned water surface traveling ship.

FIG. 6 is a plan view of the upper traveling ship.

[Explanation of symbols]

1 water traveling ship 2 hull 3 engine 16c intake ports 17a, 18a exhaust ports 25, 26 crankshafts 43c, 45 bent parts, muffler (rear extension part) 43a rising part (between front extension part and rear extension part) Part) 44 Exhaust manifold (front extension part) A Cylinder axis B Intake system axis

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02M 35/16 F02M 35/10 102V (56) Reference JP-A-4-201797 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) F01N 7/08 B63H 11/08 B63H 21/14 F01N 7/12 F02M 35/116 F02M 35/16

Claims (5)

(57) [Claims] 1. An engine for a marine vessel which is mounted inside a hull with a crankshaft directed in the longitudinal direction of a hull and rotationally drives a propulsion unit arranged at the rear of the hull, wherein an exhaust system extends forward from an exhaust port. After that, it is extended rearward and is formed so as to surround the front side of the cylinder axis when viewed in the cylinder axis direction, and the intake system extends from the intake port of the engine.
When viewed in the rank axis direction, the front extension of the exhaust system
The minute or rear extension part is the axis of the intake system (including the extension line).
)) And the cylinder axis (including extension)
An engine for a marine vessel, which is characterized by being arranged like this . 2. A portion of the exhaust system between the front extending portion and the rear extending portion intersects with the cylinder shaft (including an extension line) when viewed in the crankshaft direction. An engine for a marine vessel, which is characterized in that 3. The cylinder shaft according to claim 1 or 2, when viewed in the crankshaft direction, the cylinder shaft is inclined outward in the left-right direction of the hull, and the intake system includes the inclined cylinder shaft (including an extension line). An engine for a marine vessel, which is disposed on an upper side, wherein the exhaust system is disposed so as to pass through both the lower side and the upper side of the inclined cylinder shaft (including an extension line). 4. In an engine for a watercraft which is mounted inside a hull with a crankshaft directed in the longitudinal direction of the hull and rotationally drives a propulsion unit arranged at the rear of the hull, the cylinder axis is inclined outward in the lateral direction of the hull. The intake system extends from an intake port formed on the upper side of the slope of the engine, and the exhaust system includes an expansion chamber (muffler) connected to the exhaust port and extended in the front-rear direction. When viewed in the axial direction, it is arranged so as to pass through a space sandwiched by the cylinder axis (including the extension line) and the axis line of the intake system (including the extension line), and thus the water traveling Ship engine. 5. The engine according to any one of claims 1 to 4, wherein the engine is a V-type engine having first and second cylinder shafts forming a V bank, and the intake system is provided between the first and second cylinders. An engine for a watercraft, wherein the engine is arranged in a V bank space, and the exhaust system is arranged below a tilt of the first and second cylinders.