JP3747803B2 - Outboard motor with 4-cycle V-type engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an outboard motor equipped with a 4-cycle V-type engine, and more particularly to an outboard motor equipped with a 4-cycle V-type engine characterized by the layout of intake and exhaust devices.
[0002]
[Prior art]
In order to make the engine compact, there is a V-type engine in which a pair of cylinder blocks are arranged to face the V-type. In particular, since outboard motors are required to be light and compact, those using V-type engines are increasing.
[0003]
Since the outboard motor houses the engine and the intake / exhaust device in the engine case, various attempts have been made particularly on the layout of the intake / exhaust device.
[0004]
As an example, there is a structure of an intake / exhaust device disclosed in Japanese Patent Laid-Open No. 6-264757. The layout of this intake / exhaust device is such that an exhaust port is formed toward the inside of the V bank, an exhaust passage communicating with the exhaust port is provided below the V bank, and an intake port and the intake port are provided outside the V bank. An intake passage communicating with the port is provided.
[0005]
[Problems to be solved by the invention]
However, in the intake / exhaust device layout described above, the intake device protrudes particularly in the width direction of the engine, so that it is not sufficiently compact.
[0006]
In addition, the above-described layout of the intake / exhaust device makes it difficult to replace the spark plug, resulting in poor maintainability.
[0007]
The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide an outboard motor equipped with a compact 4-cycle V-type engine.
[0008]
Another object of the present invention is to provide an outboard motor equipped with a 4-cycle V-type engine with improved maintainability.
[0009]
[Means for Solving the Problems]
An outboard motor equipped with a four-cycle V-type engine according to the present invention has a cylinder head, a cylinder block, and a crankcase as described in claim 1 in order to solve the above-described problems. The crankshaft is disposed in the crankcase and the piston is slidable in the direction perpendicular to the crankshaft in the cylinder formed in the cylinder block. The reciprocating stroke of the piston is converted into the rotational motion of the crankshaft by inserting it into the piston and connecting the piston and the crankshaft, while these cylinder blocks are arranged by arranging the pair of cylinder blocks in a V shape. Water-cooled 4-cycle V-type engine with V banks formed between blocks Is formed in the cylinder head, and an inlet manifold is disposed in a space formed by the V bank and the engine cover. The inlet manifold, the cylinder head, and the The combustion chamber formed at the joint with the cylinder block is communicated with the intake port, while the inlet manifold is connected to the throttle body disposed above the engine and between the V banks , and the cylinder block and the A silencer is arranged in a space formed by a crankcase and the engine cover, and the silencer and the throttle body are connected by a connecting pipe arranged on the cylinder block .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a longitudinal sectional view of an engine of an outboard motor to which the present invention is applied, and FIG. 2 is a sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. As shown in FIGS. 1 to 3, the engine 2 of the outboard motor 1 is a water-cooled four-cycle V-type four-cylinder engine, for example, and is installed on the engine holder 3. The engine 2 is configured by combining a cylinder head 4, a cylinder block 5, a crankcase 6, and the like, and forms a V bank 7 between the cylinder blocks 5 by arranging the pair of cylinder blocks 5 in a V shape. The engine 2 is covered with an engine cover 8 around and above the engine 2.
[0012]
In the crankcase 6 of the engine 2, a crankshaft 9 that is vertically arranged so as to face the vertical direction is rotatably supported. A cylinder 10 is formed in the cylinder block 5. A piston 11 is slidably inserted into the cylinder 10 in a direction perpendicular to the crankshaft 9, and the piston 11 and the crankshaft 9 are connected by a connecting rod 12. The reciprocating stroke of the piston 11 is converted into the rotational motion of the crankshaft 9.
[0013]
The engine 2 includes an intake device 13 and an exhaust device 14. The intake device 13 includes an introduction pipe 15 that introduces fresh air from the outside, a silencer 16 that reduces the introduction sound and pulsation of air, a connection pipe 18 that connects the silencer 16 and a throttle body 17 that adjusts the amount of air, a throttle An inlet manifold 19 that distributes air from the body 17 to each cylinder 10 and a combustion chamber 20 that is formed in the cylinder head 4 and formed at the joint between the cylinder head 4 and the cylinder block 5 communicate with the inlet manifold 19. It is comprised from the intake port 21 to be made.
[0014]
The exhaust device 14 is formed in the cylinder head 4 and includes an exhaust port 22 that communicates with the combustion chamber 20 and an exhaust passage 23 that is formed in the cylinder block 5 and communicates with the exhaust port 22. 2, the left side from the center of the engine 2 mainly shows the exhaust device 14, and the right side shows the intake device 13.
[0015]
As shown in FIG. 2, the exhaust passage 23 is formed in the innermost valley portion 24 of the V bank 7, and the inlet manifold 19 is vertically moved in the space 25 formed by the outside, that is, the V bank 7 and the engine cover 8. Arranged in the direction. As shown in FIG. 1, the inlet manifold 19 extends upward, and its upstream end is above the engine 2 and downstream of the throttle body 17 disposed between the V banks 7 in plan view (see FIG. 2). Connected to.
[0016]
A silencer 16 and an introduction pipe 15 are arranged in a space 26 formed by the cylinder block 5 and the crankcase 6 and the engine cover 8. The upstream side of the throttle body 17 and the downstream side of the silencer 16 are connected by a connecting pipe 18 disposed on one cylinder block 5.
[0017]
In the cylinder head 4, a valve operating device 30 including a camshaft 27, an intake valve 28, an exhaust valve 29 and the like is provided. A spark plug 31 is screwed to the center of the combustion chamber 20 from the outside of the V bank 7 of the cylinder head 4. Further, a fuel injector 32 is mounted from the inside of the V bank 7 and is arranged so as to inject fuel into the intake port 21 upstream of the intake valve 28. When a carburetor is provided instead of the fuel injector 32, the carburetor is disposed at a connection portion between the inlet manifold 19 and the intake port 21 (not shown).
[0018]
Next, the operation of this embodiment will be described.
[0019]
An exhaust passage 23 constituting the exhaust device 14 is formed in the valley portion 24 closest to the innermost side of the V bank 7, and the intake device 13 is configured in a space 25 formed outside thereof, that is, the V bank 7 and the engine cover 8. By arranging the inlet manifold 19, the intake device 13 does not protrude in the width direction of the engine 2 unlike the conventional one, and the engine 2 can be made compact.
[0020]
Further, unlike the prior art, the intake port 21 and the inlet manifold 19 communicating with the intake port 21 are not provided outside the V bank 7, that is, in the space 26 formed by the cylinder block 5 and the crankcase 6 and the engine cover 8. Therefore, the space 26 can be used effectively, and the silencer 16 and the introduction pipe 15 can be arranged.
[0021]
Similarly, since the spark plug 31 can be mounted from the outside of the V bank 7 of the cylinder head 4, the spark plug 31 can be easily replaced and the maintainability is improved.
[0022]
【The invention's effect】
As described above, according to the outboard motor equipped with the 4-cycle V-type engine according to the present invention, the intake device does not protrude in the width direction of the engine, and the engine can be made compact.
[0023]
In addition, the spark plug can be easily replaced, and the maintainability is improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an engine of an outboard motor showing an embodiment of an outboard motor equipped with a 4-cycle V-type engine according to the present invention.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
3 is a cross-sectional view taken along line III-III in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outboard motor 2 4-cycle V-type engine 4 Cylinder head 5 Cylinder block 6 Crankcase 7 V bank 8 Engine cover 9 Crankshaft 10 Cylinder 11 Piston 13 Intake device 16 Silencer (intake device)
17 Throttle body (intake device)
18 Connection pipe (intake device)
19 Inlet manifold (intake device)
20 Combustion chamber 21 Intake port (intake device)
22 Exhaust port (exhaust device)
23 Exhaust passage (exhaust system)
25 Space formed by V bank and engine cover 26 Space formed by cylinder block and crankcase and engine cover

Claims (1)

A cylinder head, a cylinder block, and a crankcase are installed on the engine holder, and the periphery and upper part thereof are covered with an engine cover. A crankshaft is disposed in the crankcase, and is formed in the cylinder block. A reciprocating stroke of the piston is converted into a rotational motion of the crankshaft by inserting the piston into the cylinder slidably in a direction perpendicular to the crankshaft and connecting the piston and the crankshaft. In an outboard motor equipped with a water-cooled 4-cycle V-type engine in which a V bank is formed between the cylinder blocks by arranging the cylinder blocks in a V shape, an intake port is formed in the cylinder head, and V bank and engine cover An inlet manifold is disposed in a space formed by the engine, and the inlet manifold communicates with a combustion chamber formed at a joint portion between the cylinder head and the cylinder block via the intake port, while the inlet manifold is connected to the engine. A silencer is disposed in a space formed by the cylinder block, the crankcase, and the engine cover, and is connected to the throttle body disposed above and between the V banks . The silencer and the throttle body are connected to the cylinder. An outboard motor equipped with a 4-cycle V-type engine, which is connected by a connecting pipe arranged on a block .

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