JP2003148159A - Outboard motor mounted with four-cycle multi-cylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an outboard motor compact by arranging engine parts in an engine case without interference to other parts. SOLUTION: In this outboard motor mounted with a four-cycle multi-cylinder engine, an intake port and an exhaust port are opened to one side and the other side in a moving direction of a cylinder block of each combustion chamber formed between a cylinder and a cylinder head of a cylinder block arranged in an engine case. An intake manifold having a plurality of branch pipes is arranged on one side in a moving direction of the cylinder block, and an exhaust passage is arranged on the other side in the moving direction of the cylinder block. A portion swelling rearward in the moving direction is sealed by a breather plate from a camshaft side, so as to form a breather chamber at the upper portion of a cylinder head cover. An engine part projecting rearward in the moving direction is arranged to the cylinder head cover at the lower portion of the breather chamber at the swelling portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outboard motor equipped with a four-cycle multi-cylinder engine, and more particularly to a four-cycle multi-cylinder with a crankshaft oriented vertically in an engine case including a lower case and an upper case. The present invention relates to an outboard motor equipped with an engine.

[0002]

2. Description of the Related Art Propulsion devices for ships are roughly classified into three types, namely, an inboard engine (inboard engine), an inboard / outboard engine (inboard / outdrive engine), and an outboard motor (outboard engine), depending on the arrangement.

Outboard motors are often used in small ships and are mounted outside the stern of the hull. In this outboard motor, an engine is arranged in the upper part, and a drive mechanism is mounted in the lower part of the engine, and the hull is turned by rotating the entire outboard motor in the left-right direction.

Many engines equipped with a two-cycle engine are often found, but recently,
4-cycle engine Multi-cylinder 4 especially when displacement increases
Some are equipped with a cycle engine.

In such a four-cycle engine, an intake manifold intake pipe for guiding intake air to each cylinder and a surge tank are attached to the side of the cylinder as an intake device, and an intake / exhaust valve is operated in the cylinder head. Since the engine has a valve mechanism and engine parts such as engine accessories, the entire engine tends to be larger than the two-cycle engine. This tendency becomes stronger especially in the case of multiple cylinders.

[0006]

By the way, the outboard motor is
Since the engine is covered by the engine case, intake branch pipes, intake manifolds, surge tanks, and other intake system parts, camshafts, intake and exhaust valves are added as the functional parts that increase with the 4-cycle multi-cylinder as described above. A space for arranging the valve operating mechanism such as the above, the breather device, and the engine accessory parts such as the pump is necessarily restricted.

Further, if the engine case becomes larger than necessary, when the outboard motor is mounted on the hull as described above, the mounting work becomes troublesome due to the increase in weight and the size increase. In addition, if the engine case including the lower case and the upper case becomes large, the work of removing and installing the engine case at the time of engine maintenance becomes difficult, and the outboard motor becomes inconvenient to use.

[0008]

Therefore, in order to eliminate the above-mentioned inconveniences and disadvantages, the present invention proposes that in the engine case including the lower case and the upper case, the axial center is oriented in the traveling direction. A cylinder block formed by stacking a plurality of horizontal cylinders in the vertical direction, a crankcase having a crankshaft in which a shaft center is vertically oriented inward in the forward direction of the cylinder block, and a moving direction of the cylinder block. A cylinder head having a valve mechanism including a camshaft, an intake valve, and an exhaust valve is provided on the rear side, and a cylinder head cover covering the rearmost portion of the cylinder head is provided, and between each cylinder and the cylinder head. The intake port and the exhaust port are opened at one side and the other side in the traveling direction of each formed combustion chamber through an intake valve and an exhaust valve, respectively, and the cylinder block is opened. In an outboard motor equipped with a four-cycle multi-cylinder engine in which an intake manifold having a plurality of intake branch pipes is disposed on one side in the traveling direction of, and an exhaust passage is disposed on the other side in the traveling direction of the cylinder block, An upper portion of the cylinder head cover is closed by a breather plate that closes a portion that bulges rearward in the traveling direction from the side of the camshaft to form a breather chamber, and a portion below the breather chamber that further bulges out. The cylinder head cover is provided with an engine component that is projected rearward in the traveling direction.

According to a second aspect of the present invention, the intake branch pipes are arranged in parallel in the vertical direction according to the number of the plurality of cylinders, and the intake branch pipes upstream of the intake port of the cylinder head are advanced. While being bent in a substantially right-angled direction so as to be directed to the front in the direction of the cylinder, the front end of the intake branch pipe is converged in the surge tank while extending substantially forward along the side wall at a distance from the cylinder block in the traveling direction. The intake manifold is configured, and the axial lengths of a plurality of intake branch pipes that connect the intake port and the surge tank are made different from each other in a side view, and the length of the lowermost intake branch pipe in a side view is determined. It is characterized in that the uppermost intake branch pipe is set rearward and downward longer than the side view thereof, and a space is provided between the intake branch pipe and the cylinder block.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An outboard motor equipped with a four-cycle multi-cylinder engine according to the present invention has an upper portion of a cylinder head cover which is closed by a breather plate which closes a portion which bulges rearward in the traveling direction from a camshaft side. While partitioning the breather chamber with, the cylinder head cover at the lower part of the breather chamber in the part that bulges out, by arranging the engine parts projecting to the rear side in the traveling direction,
A space is created between the cylinder head cover at the lower part of the portion that bulges rearward in the traveling direction and the engine case that faces the cylinder head cover, and it is possible to use this space to arrange engine parts.

[0011]

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

1 to 8 show an embodiment of the present invention. 3 to 6, 2 is an outboard motor, and 4 is a middle unit. An outboard motor holding portion 6 for mounting the outboard motor 2 on a hull (not shown) is provided in front of the middle unit 4 of the outboard motor 2 in the traveling direction (on the right side in FIG. 7). A tilt shaft 8 for tilting the outboard motor 2 is attached to the outboard motor holding portion 6.

Further, in the middle unit 4, FIG.
As shown in, the drive shaft 10 is axially supported in the vertical direction. An oil pan 12 is arranged on the upper side near the drive shaft 10, and an exhaust tube 14 is arranged on the lower side.

The drive shaft 10 applies a driving force of a crank shaft 34 of an engine 36, which will be described later, to a gear case 16.
It is transmitted to a propeller 18 directed rearward (left side in FIG. 4) in the traveling direction via an internal gear (not shown).

A gear case 16 is attached to the lower portion of the middle unit 4. A gear (not shown) connected to the lower end of the drive shaft 10 is accommodated in the gear case 16. A propeller 18 connected to the gear (not shown) is rotatably attached to the gear case 16.

Further, on the upper part of the middle unit 4,
The engine case 20 is attached. The engine case 20 is composed of a lower case 22 and an upper case 24. The upper case 24 has a recessed upper rear portion, and an air intake 26 that opens upward (upper side in FIG. 7) is formed in this recessed portion.

Furthermore, a cover portion 28 having a substantially L-shaped cross section is attached to the recessed portion. The cover portion 28 is formed with an opening portion 30 that opens to the rear portion (left side in FIG. 7) when attached to the recessed portion.

A four-cycle multi-cylinder engine (hereinafter referred to as "engine") 36 having a crankshaft 34 is disposed in the engine housing portion 32 formed in the engine case 20.

As shown in FIG. 1 and FIG. 7, the engine 36 includes a plurality of substantially horizontal first to fourth axial centers oriented in the traveling direction in an engine case 20 composed of a lower case 22 and an upper case 24. A crankcase having a cylinder block 38 formed by vertically stacking cylinders 48-1 to 48-4, and a crankshaft 34 having an axial center vertically oriented in front of the cylinder block 38 in the traveling direction. Crankshaft holding part 44 and cylinder block 3
8, the cam shaft 88, the intake valve 62, the exhaust valve 8
A cylinder head 40 provided with a valve operating mechanism consisting of two and a cylinder head cover 42 covering the rearmost portion of the cylinder head 40 are arranged.

That is, the cylinder block 38 of the engine 36 is arranged at a substantially central portion of the engine accommodating portion 32. A cylinder head 40 provided with a valve mechanism and a cylinder head cover 4 covering the valve mechanism are provided on the rear side (left side in FIG. 1) of the cylinder block 38 in the traveling direction.
2 and 1 are installed in sequence.

On the front side (right side in FIG. 1) of the traveling direction of the cylinder block 38, a crankshaft 34 whose axial center is vertically oriented by a crankshaft holding portion 44 is pivotally supported. The cylinder block 38 is provided with an engine water jacket 46 that cools the engine 36.

As shown in FIG. 7, in the cylinder block 38, a plurality of substantially horizontal first to fourth cylinders 48-1 to 48-4 whose axes are oriented in the traveling direction are vertically stacked. Is formed. The first to fourth cylinders 48-1 to 48-4 include the first to fourth pistons 50-1.
.About.50-4 are arranged so as to be reciprocally movable.

The first to fourth pistons 50-1 to 50-
4 are connected to the crankshaft 34 via first to fourth connecting rods 52-1 to 52-4, respectively.

Here, the first to fourth cylinders 48-1 to 48-4
Since 8-4 has the same shape, it is the second shape shown in FIG.
Only the cylinder 48-2 will be described and the description of the first, third and fourth cylinders 48-1, 48-3 and 48-4 will be omitted.

The engine 36 includes a cylinder head 4
A combustion chamber 54 is formed by 0, the second piston 50-2, and the second cylinder 48-2.

An intake port 56 communicating with the combustion chamber 54 is formed on one side (lower side in FIG. 1) in a direction intersecting the traveling direction of the cylinder head 40. An intake branch passage 68 formed by a second intake branch pipe 66-2 of an intake manifold 64, which will be described later, which constitutes the intake device, communicates with the intake port 56. This intake port 56
An injector 58 for injecting fuel into the intake port 56 is disposed at the downstream end of the second intake branch pipe 66-2 close to the intake port 56. The intake port 60 of the intake port 56 is opened and closed by an intake valve 62 that constitutes a valve mechanism.

The intake manifold 64 is disposed upstream of the first to fourth intake branch pipes 66-1 to 66-4 and the first to fourth intake branch pipes 66-1 to 66-4. And a surge tank 70. A throttle body 72 is arranged on the upstream side of the surge tank 70.

An exhaust port 74 communicating with the combustion chamber 54 is formed on the other side (upper side in FIG. 1) in the direction intersecting the traveling direction of the cylinder head 40. The exhaust port 74 has an exhaust branch portion 76 which is an exhaust passage arranged on the other side in the traveling direction of the cylinder block 38.
And the exhaust collecting portion 78 are communicated with each other. The exhaust port 80 of the exhaust port 74 is opened and closed by an exhaust valve 82 that constitutes a valve mechanism. An ignition plug 84 is attached to the cylinder head 40 in a substantially central portion of the combustion chamber 54 with a slight inclination.

A valve operating chamber 86 is formed by the cylinder head 40 and the cylinder head cover 42 at the rear side (left side in FIG. 7) of the cylinder head 40 in the traveling direction. A cam shaft 88 for operating the intake / exhaust valves 62 and 82, which constitute the valve operating mechanism, is disposed in the valve operating chamber 86. Intake / exhaust cams 90A and 90B are fixedly mounted on the cam shaft 88.

A breather plate 92 is attached to the cylinder head cover 42 on the rear side (left side in FIG. 1) of the cylinder head 40 in the direction of travel to define a breather chamber 94. That is, as shown in FIG. 7, the upper portion of the cylinder head cover 42 is closed by a breather plate 92 that closes a portion that bulges to the rear side in the traveling direction (left side in FIG. 7) from the cam shaft 88 side to define a breather chamber 94. Is forming. The cylinder head cover 4 at the lower portion of the breather chamber 94 at the bulging portion
In Fig. 2, engine parts are arranged so as to project to the rear side in the traveling direction.

In the outboard motor 2 having the engine 36 mounted therein, the first to fourth intake branch pipes 66-1 to 66-1 of the intake manifold 64 provided on one side in the direction intersecting with the traveling direction of the cylinder block 38. At the engine 36 side part of 66-4,
Water jacket 9 for cooling intake air, which is an engine part
6 is provided.

More specifically, as shown in FIGS. 1, 2 and 8, a plate-shaped first connecting portion 98-1 for connecting the first and second intake branch pipes 66-1 and 66-2 is provided. , A plate-shaped second connecting portion 9 for connecting the second and third intake branch pipes 66-2, 66-3
8-2 and a plate-shaped third connecting portion 98-3 for connecting between the third and fourth intake branch pipes 66-3, 66-4, and the first to fourth intake branch pipes 66-1. 66-4 are integrally connected by the first to third connecting portions 98-1 to 98-3.

The first to fourth intake branch pipes 66-1 to 6-6 are also provided.
As shown in FIG. 1, the front and rear ends of the engine 6-6 and the first to third connecting portions 98-1 to 98-3 are separated from each other by a predetermined distance in plan view and are substantially parallel to each other in the vertical direction, and the engine 36.
The first and second protrusions 100-1 and 1 that protrude toward the side
00-2 is formed, and the first and second protrusions 100-1 and
100-2 to the first to fourth intake branch pipes 66-1 to 66
-4 and the first to third connecting portions 98-1 to 98-3 are integrally formed. First to fourth intake branch pipes 66-1 to 66-4 located at the upper and lower ends of the first and fourth intake branch pipes 66-1 to 66-4.
-4, as shown in FIG. 8, the engine 3 is separated from the engine 3 by a predetermined distance and is substantially parallel in the horizontal direction.
The third and fourth protrusions 100-3 and 100-4, which protrude toward the 6 side and connect the upper and lower ends of the first and second protrusions 100-1 and 100-2, are integrally formed. .
First to fourth intake branch pipes 66-1 to 66-4 and first to third
Connecting parts 98-1 to 98-3 and first to fourth protruding parts 100-
1 to 100-4 form a concave space that opens toward the engine 36 side. The third and fourth protrusions 1
00-3, 100-4, the cooling water pipe mounting portion 10
4, 104 are provided respectively.

Further, the first to the first sides which are open sides of the concave space
A plate-shaped water jacket cover 102 that engages with the tip portions of the fourth protrusions 100-1 to 100-4 is provided,
Engine 36 side portions of the first to fourth intake branch pipes 66-1 to 66-4 and first to third connecting portions 98-1 to 98-3.
Of the engine 36 and the first to fourth protrusions 100-1
˜100-4 and the water jacket cover 102 form a water jacket 96 which is a large capacity engine component for intake air cooling.

A water jacket 96 for cooling the intake air
The cooling water therein is supplied through a cooling water circulation path different from the normal cooling water circulation path for cooling the engine.

Next, the operation will be described.

The outboard motor 2 includes the first to fourth intake branch pipes 66-1 to 66-4 and the first intake manifold 64 which constitute the intake manifold 64.
-Third connecting parts 98-1 to 98-3 and first to fourth protruding parts 1
00-1 to 100-4 and water jacket cover 10
2 and the first to fourth intake branch pipes 66-1 to 66-
A water jacket 96, which is an engine component, is provided in a space on the engine 36 side portion of No. 4. When the outboard motor 2 is driven, the cooling water is supplied to the water jacket 96 provided in the engine 36 side portion of the first to fourth intake branch pipes 66-1 to 66-4 forming the intake manifold 64. Therefore, the temperature of the intake manifold 64 is prevented from rising due to the heat of the engine 36 side, and the intake charging efficiency is prevented from decreasing.

As a result, the intake manifold 64 has a simple structure without complicating the structure of the intake manifold 64, and the first to fourth intake branch pipes 66- of the intake manifold 64 are provided.
The water jacket 96 can be easily formed in 1 to 66-4, and the manufacturing cost of the intake manifold 64 can be kept low, which is economically advantageous.

Further, the water jacket 96 is
~ Engine 36 side parts of the fourth intake branch pipes 66-1 to 66-4, engine 36 side parts of the first to third connecting parts 98-1 to 98-3, and first to fourth protruding parts 100- 1-100
-4 and the water jacket cover 102, it is possible to prevent the temperature of the intake manifold 64 from rising due to heat on the side of the engine 36, improve the intake charging efficiency, and be advantageous in practical use. By not providing a water jacket between the engine case 20 and the intake manifold 64 on the side of the four intake branch pipes 66-1 to 66-4 separated from the engine 36, a gap between the engine case 20 and the intake manifold 64 is provided. The size of the engine case 20 can be reduced and the engine case 20 can be made compact.

Further, the first to fourth intake branch pipes 66-1 to 6-6
6-4 part of the engine 36 and the first to third connecting parts 98
By forming the water jacket 96 for cooling the intake air having a large capacity by the engine 36 side parts of -1 to 98-3, the first to fourth protruding parts 100-1 to 100-4 and the water jacket cover 102. , The first to fourth
Intake branch pipes 66-1 to 66-4 and water jacket 9
The contact area with 6 can be enlarged, and the intake air can be reliably cooled.

Furthermore, by supplying the cooling water in the water jacket 96 for cooling the intake air through a cooling water circulation path different from the ordinary cooling water circulation path for cooling the engine, the intake air can be controlled independently of the temperature control of the engine 36. The temperature can be controlled, which is practically advantageous.

A breather chamber 94 is formed by partitioning a portion of the outboard motor 2 above the cylinder head cover 42, which bulges rearward in the traveling direction, by a breather plate 92 that closes the camshaft 88 side. There is. In the cylinder head cover 42 at the lower portion of the breather chamber 94 at the bulging portion, the engine component is arranged so as to project rearward in the traveling direction, so that the cylinder at the lower portion of the portion bulging rearward in the traveling direction. Head cover 42 and engine case 2 facing the cylinder head cover 42
A space is created between the lower case 22 and the lower case 22, and it is possible to arrange engine parts by utilizing this space.

Therefore, in the outboard motor 2, the engine parts can be arranged in the engine case 20 without interfering with other parts, so that the engine case 20 can be prevented from being upsized and the outboard motor 2 can be avoided. 2 compactness can be achieved.

[0044]

As described above, in the outboard motor of the present invention, a space is created between the cylinder head cover at the lower portion of the portion bulging rearward in the traveling direction and the engine case facing the cylinder head cover, This space can be used to arrange engine parts.

Therefore, in the outboard motor of the present invention, the engine parts can be arranged in the engine case without interfering with other parts, so that the engine case can be prevented from increasing in size and the outboard motor of the outboard motor can be prevented. It can be made compact.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line I-I of FIG. 7 showing an embodiment of the present invention.

FIG. 2 is an enlarged side view of a main part of the outboard motor.

FIG. 3 is a front view of an outboard motor.

FIG. 4 is a left side view of the outboard motor.

FIG. 5 is a rear view of the outboard motor.

FIG. 6 is a right side view of the outboard motor.

7 is a cross-sectional view taken along the line VII-VII of FIG.

8 is a sectional view taken along line VIII-VIII in FIG.

[Explanation of symbols]

2 outboard motor 20 engine case 22 lower case 24 upper case 32 Engine compartment 34 crankshaft 36 engine 38 cylinder block 40 cylinder head 42 Cylinder head cover 44 Crankshaft holder 62 intake valve 82 Exhaust valve 88 cam shaft 92 Breather plate 94 Breather Room

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 35/16 B63H 21/26 Z (72) Inventor Mitsuhiko Ota 300 Takatsuka-cho, Hamamatsu-shi, Shizuoka Suzuki Stock Company (72) Inventor Nobuyuki Shomura 300, Takatsuka-cho, Hamamatsu City, Shizuoka Prefecture Suzuki Stock Company (72) Inventor Hidehiko Yoshioka 300, Takatsuka-cho, Hamamatsu City, Shizuoka Prefecture Suzuki Stock Company (72) Inventor Jiro Saiga Hamamatsu, Shizuoka Prefecture 300, Takatsuka-cho, Yokohama-shi Suzuki Stock Company F-term (reference) 3G015 AA01 AA03 AA05 AA07 AB01 BE03 CA05

Claims (2)

[Claims] 1. A cylinder block, which is formed by stacking a plurality of substantially horizontal cylinders whose axes are oriented in the traveling direction in the vertical direction in an engine case consisting of a lower case and an upper case, and a front side in the traveling direction of the cylinder block. A crank case having a crank shaft having an axial center oriented vertically; a cylinder head having a valve mechanism including a cam shaft, an intake valve, and an exhaust valve at a rear side in the traveling direction of the cylinder block; A cylinder head cover for covering the rearmost portion of the cylinder head is provided, and an intake valve and an exhaust valve are provided on one side and the other side in the traveling direction of each combustion chamber formed between each cylinder and the cylinder head, respectively. The intake port and the exhaust port are opened, and an intake manifold having a plurality of intake branch pipes is arranged on one side in the traveling direction of the cylinder block. In an outboard motor equipped with a four-cycle multi-cylinder engine in which an exhaust passage is arranged on the other side in the direction of travel of the lock, an upper portion of the cylinder head cover is provided with a portion that bulges rearward in the direction of travel in the camshaft. The breather plate that closes from the side defines the breather chamber, and the bulging portion of the breather chamber has a cylinder head cover below the breather chamber, and an engine component protruding rearward in the traveling direction is arranged. An outboard motor equipped with a 4-cycle multi-cylinder engine. 2. The intake branch pipes are arranged in parallel in the vertical direction according to the number of the plurality of cylinders, and the intake branch pipes upstream of an intake port of the cylinder head are directed forward in the traveling direction. While bending in a substantially right angle direction, the intake manifold is configured by converging the upstream end of the intake branch pipe to a surge tank while extending the front side in the traveling direction substantially along the side wall at a distance from the cylinder block, The axial lengths of the plurality of intake branch pipes connecting the intake port and the surge tank are made different from each other in the side view, and the length of the lowermost intake branch pipe in the side view is set to that of the uppermost intake branch pipe. The four-stroke multi-cylinder according to claim 1, wherein the four-stroke multi-cylinder is set to be rearward and longer than a length in a side view, and a space is provided between the intake branch pipe and the cylinder block. An outboard motor equipped with an engine.