JP2000310166A - Outboard motor loaded with 4-cycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly arrange an intake branch pipe and a paper separator tank, considering the output or function by arranging the intake branch pipe of an intake manifold on one advancing directional side of a cylinder block, and arranging the paper separator tank on the other advancing directional side. SOLUTION: An engine 14 comprises a paper separator tank 106 for separating the fuel vapor gas within a fuel supplying passage on the other advancing directional side of a cylinder block 20, which is opposite to one advancing directional side of the cylinder block 20 where the intake branch pipe 62 of an intake manifold 58 is arranged. According to this, the intake branch pipe 62 and the paper separator tank 106 can be properly arranged, considering the output or function. In this outboard motor 2, a compact engine with high output can be realized.

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-stroke engine, and more particularly, to a compact and high-power four-stroke engine capable of realizing a weight distribution and an even balance of appearance. The present invention relates to an outboard motor equipped with a cycle engine.

[0002]

2. Description of the Related Art In an outboard motor equipped with a four-cycle engine, there is a type in which unburned gas generated by the engine is collected in an intake system and reburned. For example, in a four-cycle engine, blow-by gas in a crankcase and vapor gas in a vapor separator are collected in an intake system and reburned.

[0003] Japanese Unexamined Patent Publication No. Hei 3 (1994) discloses a technique for recovering unburned gas generated in an engine into an intake system and reburning it.
Japanese Unexamined Patent Publication (Kokai) No. 172570/1990 discloses an example. As disclosed in this publication, as shown in FIG.
A carburetor 212 is disposed between each of the branch pipes 208 of the intake manifold 206 of the engine 204 and the surge tank 210, and the blow-by gas supply pipe 214 is provided in the surge tank 210 upstream of the carburetor 212. Are provided in communication.

[0004]

In an outboard motor equipped with a four-cycle engine, an intake manifold of an intake manifold is provided as an intake passage communicating with each cylinder to separate fuel vapor gas in a fuel supply path. A vapor separator tank is provided.

However, in the outboard motor, since the engine is arranged in the engine case, there is a problem that it is difficult to arrange the intake manifold and the vapor separator tank which are large parts in a well-balanced manner.

Therefore, in the outboard motor, proper arrangement of each intake branch pipe of the intake manifold of the engine is hindered, and there is a disadvantage that the output is affected. There is an inconvenience that is impaired.

[0007]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides an engine case comprising a lower case and an upper case. A crankcase having a cylinder block formed by stacking a plurality of cylinder blocks, a crankshaft having a shaft axis oriented in the vertical direction on the front side in the traveling direction of the cylinder block, and a valve train on the rear side in the traveling direction of the cylinder block. A cylinder head provided with a mechanism is disposed respectively, and via an intake valve and an exhaust valve on one side and the other side in a direction intersecting the traveling direction of each combustion chamber formed between each cylinder and the cylinder head, respectively. To open the intake port and the exhaust port, and a downstream end is attached to the cylinder head on one side in the traveling direction of the cylinder block to communicate with each intake port. In an outboard motor equipped with a four-cycle engine, an intake manifold having an intake branch pipe is provided, and an exhaust passage communicating with the exhaust port is provided on the other side in the traveling direction of the cylinder block. The pipes are arranged in parallel in the vertical direction in accordance with the plurality of cylinders, and the respective downstream end portions of the respective intake branch pipes adjacent to the intake port of the cylinder head, which are oriented in a direction substantially perpendicular to the advancing direction in a plan view, are arranged at respective downstream ends. An injector for injecting fuel is disposed in the intake port, and each of the intake branch pipes on the upstream side of the injector is bent in a substantially right angle direction so as to be directed forward in the traveling direction. Along the front in the traveling direction along with the upstream end of each intake branch pipe converges to a single surge tank to constitute the intake manifold, A throttle body equipped with a throttle valve is continuously provided substantially along the crankcase on the upstream side of the surge tank of the intake manifold, and travels in the upstream intake passage of the throttle body at a position forward of the front end of the crankcase in the traveling direction. The four-stroke engine is characterized in that it is open to the atmosphere in a direction substantially perpendicular to the direction of the cylinder block. On the other side of the direction, a vapor separator tank for separating the fuel vapor gas in the fuel supply path is provided, and in the vapor separator tank,
The throttle body is provided with a float and a filter, and the throttle body is provided with an opening at an upstream end for opening into an engine case, and the opening is provided at a position below the throttle body. The body is provided with an opening at the upstream end that opens into the engine case, and this opening is provided at a position in front of the crankcase that is furthest away from an air intake provided at the upper rear of the upper case. And

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An outboard motor according to the present invention has an intake manifold provided with an intake manifold pipe on one side in the traveling direction of a cylinder block and a vapor separator tank on the other side in the traveling direction. The branch pipe and the vapor separator tank can be appropriately arranged in consideration of the output and function, respectively.By installing the vapor separator tank on the other side in the traveling direction, the size and flexibility can be increased, The opening at the upstream end of the throttle body is provided at the lower position in the engine case and at the front position of the crankcase which is furthest away from the air intake provided at the upper rear of the upper case. This makes it difficult for water droplets contained in the air to reach the opening.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 show an embodiment of the present invention. 7 and 8, reference numeral 2 denotes an outboard motor. The outboard motor 2 includes a drive shaft housing 8 below an engine case 7 including a lower case 4 and an upper case 6.
And a gear case 10, and are mounted on a hull (not shown) by a mounting unit 12 mounted in front of the drive shaft housing 8 in the traveling direction.

As shown in FIGS. 1 to 6, the outboard motor 2 includes, in an engine case 7, a cylinder block 20 formed by vertically stacking a plurality of substantially horizontal cylinders 26 whose axes are directed in the traveling direction. A crankshaft 2 having an axial center directed vertically in front of the cylinder block 20 in the traveling direction.
Four-cycle engine 14 in which a crankcase 24 provided with a cylinder 2 and a cylinder head 32 provided with a valve operating mechanism 39 on the rear side in the traveling direction of the cylinder block 20 are provided.
It is equipped with. The outboard motor 2 drives the drive shaft 16 by the engine 14, converts the rotation direction by a gear (not shown), and directs the propeller 18 to the rear in the traveling direction.
Drive.

The engine 14 includes a cylinder block 2
The crankshaft 22 is supported by the crankcase 24 so that the crankshaft 22 is oriented substantially vertically to zero. Cylinder block 20
In this embodiment, a plurality of, in this embodiment, four cylinders 26 whose cylinder axis center lines are directed substantially in the horizontal direction are arranged in a substantially vertical direction, and each has a built-in piston 28. The pistons 28 are connected to the crankshaft 22 through connecting rods 30, respectively.

A cylinder head 32 is mounted on the cylinder block 20, and a head cover 34 is attached to the cylinder head 32. The cylinder head 32 is provided with an intake port 36 and an exhaust port 38 communicating with the combustion chamber formed between each cylinder 26 and the cylinder head 32 on one side and the other side in a direction intersecting the traveling direction. The intake port 36 and the exhaust port 38 are provided with an intake valve 40 and an exhaust valve 42 constituting a valve train 39. The intake valve 40 and the exhaust valve 42 are opened and closed by an intake rocker arm 44 and an exhaust rocker arm 46, as shown in FIG. Intake rocker arm 44 and exhaust rocker arm 46
Is swung by a cam shaft 48 supported by the cylinder head 32.

The engine 14 has a crank pulley 50 mounted on a crankshaft 22 protruding from the cylinder block 20 and the crankcase 24 above the centerline of the crankshaft. In the engine 14, a cam pulley 52 is attached to a cam shaft 48 protruding from the cylinder head 32 and the head cover 34 above the cam shaft center line. A timing belt 54 is wound around the crank pulley 50 and the cam pulley 52. Reference numeral 56 denotes a generator.

The engine 14 is provided with an intake manifold 58 located on one side of the cylinder block 20 in the traveling direction. The intake manifold 58 includes a surge tank 60 serving as a collecting portion and a plurality of intake branch pipes 62 branched from the surge tank 60, and has a tank intake passage 64 and an intake branch passage 66. The downstream side of each intake branch pipe 62 is connected and provided by a manifold side mounting portion 68. Manifold-side mounting portion 6 at downstream end of each intake branch pipe 62
Reference numeral 8 is attached to the head-side attachment portion 70 of the cylinder head 32, and communicates each branch intake passage 66 with each intake port 36 on one side in the traveling direction of the cylinder head 32.

Accordingly, on one side of the cylinder block 20 in the traveling direction, a poor number of intake branch pipes 62 each having a downstream end attached to the cylinder head 32 and communicating with each intake port 36.
Is provided. Further, on the other side of the cylinder block 20 in the traveling direction, an exhaust port 3
A branch exhaust passage 96, which is an exhaust passage communicating with 8, is provided. The branch exhaust passage 96 communicates with the collective exhaust passage 98 and is discharged by an exhaust pipe (not shown).

The intake manifold 58 has a plurality of intake branch pipes 62 arranged in parallel in the vertical direction in accordance with a plurality of cylinders, and the intake manifolds 62 advance in a plan view of the intake branch pipes 62 close to the intake port 36 of the cylinder head 32. A fuel injection valve 72, which is an injector for injecting fuel into each intake port 36, is provided at a downstream end portion oriented in a direction substantially perpendicular to the direction. The fuel injection valve 72 is mounted on an injection valve mounting portion 74 provided on the manifold side mounting portion 68 at a position close to the cylinder head 32, and a control unit 13 described later.
Connected to 0. The fuel injection valve 72 includes a controller 130
The operation is controlled to inject fuel into the intake port 36. Reference numeral 76 is a fuel distribution pipe.

The intake manifold 58 is provided with the fuel injection valve 7.
The cylinder block 2 is bent in a substantially right angle direction so that each intake branch pipe 62 upstream of the cylinder block 2 is directed forward in the traveling direction.
0 and extend upstream along the side wall of the suction branch pipe 62 in the traveling direction.
It is configured to converge to zero. A single throttle body 80 is mounted on the upstream side of the surge tank 60 via a spacer 78, and a cylindrical throttle guide 82 is mounted on the upstream side of the throttle body 80. A filter 84 is provided at the upstream end of the throttle guide 82.
Is installed.

The guide intake passage 8 of the throttle guide 82
6, the body intake passage 88 of the throttle body 80, and the spacer intake passage 90 of the spacer 78 are sequentially communicated and communicate with the tank intake passage 64. A throttle valve 92 is provided in the body intake passage 88.
The spacer intake passage 90 upstream of the throttle body 82 is opened to the atmosphere at a position forward of the front end of the crankcase 24 in a direction substantially perpendicular to the traveling direction at a position forward of the crankcase 24, and a north opening value 93 is provided. . This opening 9
3 is provided at a lower position in the engine case 7. The opening 93 is provided at a position in front of the crankcase 24 which is furthest away from an air intake 95 provided at the upper rear side of the upper case 4. Note that in FIG.
Is a spark plug.

As shown in FIGS. 1 and 2, the engine 14 has a breather chamber 100 in a head cover 34. The blow-by gas, which is unburned gas leaked into the crank chamber 102 in the crank case 24, is guided to the breather chamber 100. The breather chamber 100 is provided with a blow-by gas extraction pipe 104.

As shown in FIG. 1 and FIG. 2, the engine 14 has a traveling direction of the cylinder block 20 opposite to the traveling direction of the cylinder block 20 in which the intake branch pipe 62 of the intake manifold 58 is disposed. On the other side, a vapor separator tank 10 for separating fuel vapor gas in the fuel supply path
6 are provided. In the vapor separator tank 106,
A float 108 and a filter 110 are built in, and a vapor gas extraction pipe 112 is provided.

The throttle guide 82 is provided with a blow-by gas intake pipe 114 for blow-by gas, which is unburned gas generated by the engine 14, and a vapor gas intake pipe 116 for vapor gas, which is unburned gas. The blow-by gas intake pipe 114 and the vapor gas intake pipe 116 are provided above the guide intake passage 86 so as to be directed downward.

The blow-by gas inlet pipe 114 is connected to the blow-by gas outlet pipe 104 of the breather chamber 100 by a blow-by gas supply pipe 118. Thus, the guide guide passage 86 is provided in the throttle guide 82.
Blow-by gas supply pipe 11
8 are provided in communication with each other, and the breather chamber 100 is communicated with the blow-by gas passage 120 of the blow-by gas supply pipe 118. The blow-by gas supply pipe 118 is
Piping is performed so as to be inclined downward from the breather chamber 100 toward the throttle guide 82.

The vapor gas intake pipe 116 is connected to a vapor gas exhaust pipe 112 of the vapor separator 106 by a vapor gas supply pipe 122. Thus, the guide guide passage 86 is provided in the throttle guide 82.
A vapor gas supply pipe 122 is provided so as to communicate upward and downward, and a vapor separator 106 is communicated with a vapor gas passage 124 of the vapor gas supply pipe 122. The vapor gas supply pipe 122 is formed so as to be inclined downward from the vapor separator 106 toward the throttle guide 82.

The throttle guide 82 is provided with a mounting boss 126 facing the guide intake passage 86. The mounting boss 126 is provided with an intake air temperature sensor 128 for detecting the intake air temperature facing the guide intake passage 86. The intake air temperature sensor 128 is
30. The control unit 130 calculates the fuel injection amount based on the operation state detected by various sensors (not shown), corrects the fuel injection amount based on the intake air temperature detected by the intake air temperature sensor 128, and controls the operation of the fuel injection valve 72. I do.

Next, the operation will be described.

When the engine 14 of the outboard motor 2 is operated, the intake air taken into the surge tank 60 of the intake manifold 58 from the throttle guide 82 via the throttle body 80 is distributed to each branch pipe 62 and the fuel injection valve 72 is provided. Is sucked into the cylinder 26 from the intake port 36 as an air-fuel mixture together with the fuel injected by the cylinder. The air-fuel mixture in the cylinder 26 is ignited by a spark plug 94 and burned, and the exhaust gas 38
Is more exhausted.

The engine 14 has an intake manifold 5
A throttle guide 82 is provided further upstream than a throttle body 80 provided upstream of the surge tank 60 of FIG. Since the function of the throttle guide 82 is to guide intake air to the throttle body 80, no mechanical strength is required. Therefore, the throttle guide 82
Can be formed of a material such as rubber or synthetic resin having flexibility and elasticity.

When the engine 14 is operating, blow-by gas, which is unburned gas, introduced into the breather chamber 100 of the head cover 34 is supplied to the guide intake passage 86 of the throttle guide 82 through the blow-by gas passage 120 of the blow-by gas supply pipe 118. Is done. When the engine 14 is operating, the vapor gas, which is the unburned gas of the vapor separator 106, is supplied to the guide intake passage 86 of the throttle guide 82 through the vapor gas passage 124 of the vapor gas supply pipe 122.

The blow-by gas and the vapor gas, which are the unburned gas supplied to the guide intake passage 86 by the blow-by gas supply pipe 118 and the vapor gas supply pipe 122, flow into the guide intake passage 86 in which the intake of the throttle guide 82 flows quickly without stagnation. By providing the communication, the unburned gas can be sufficiently recovered.

Further, the blow-by gas supply pipe 118 and the vapor gas supply pipe 122 are provided so as to communicate with the blow-by gas passage 120 and the vapor gas passage 122 so as to be directed upward above the guide intake passage 86 and downward.
Moreover, the blow-by gas supply pipe 118 is connected to the breather chamber 10.
By piping so as to incline downward from 0 to the throttle guide 82 and by piping the vapor gas supply pipe 122 so as to incline downward from the vapor separator 106 toward the throttle guide 82, even if blow-by gas or vapor gas is liquefied. There is no accumulation.

Therefore, even if the blow-by gas or vapor gas generated in the engine 14 is liquefied, the passage can be prevented from being clogged, and these gases can be collected well in the intake system.

When the engine 14 is operating, the intake air temperature sensor 128 inputs the intake air temperature to the control unit 130.
The control unit 130 calculates the fuel injection amount based on the operation state detected by various sensors (not shown), corrects the fuel injection amount based on the intake air temperature detected by the intake air temperature sensor 128, and controls the operation of the fuel injection valve 72. I do.

The intake air temperature sensor 128 is a throttle guide 82 which can be formed of a material having flexibility and elasticity.
Guide intake passage 86 in which intake air flows quickly without stagnation
The engine 1
It is possible to detect the temperature of the intake air flowing without stagnating toward 4. Further, the intake air temperature sensor 128 is hardly susceptible to vibration propagation or thermal influence from the engine 14 by being attached to the throttle guide 82 which can be formed of a flexible or elastic material.

For this reason, the intake air temperature sensor 128 can be attached without taking measures against vibrations or heat, and the intake air temperature sensor 128 can accurately detect the intake air temperature. Thereby, the control unit 130 can appropriately correct the intake air temperature of the fuel injection amount by the fuel injection valve 72.

In the outboard motor 2, the intake branch pipe 62 of the intake manifold 58 is disposed on one side in the traveling direction of the cylinder block 20, and the vapor separator tank 106 is disposed on the other side in the traveling direction. The intake branch pipe 62 and the vapor separator tank 106 can be appropriately arranged in consideration of output and function, respectively. Therefore, this outboard motor 2
Can realize a compact and high-powered engine.

By arranging the vapor separator tank 106 on the other side in the traveling direction of the outboard motor 2, the float 108 and the filter 110 can be provided with flexibility in size. Therefore, this outboard motor 2
, The vapor separator tank 106 in which the float 108 and the filter 110 are installed can be actually installed in the engine case 7, and the outboard motor 2 that is compact as a whole can be realized.

In the outboard motor 2, an opening 93 at the upstream end of the throttle body 80 is provided at an air intake 95 provided at a lower position in the engine case 7 and at an upper rear side of the upper case 6.
Is provided at a position in front of the crankcase 24 which is furthest away from the water, it is possible to make it difficult for water droplets contained in the air to reach the open 93 ports. For this reason, this outboard motor 2
Even if external water jumps in from the air inlet 95, the engine 2 is not sucked and the output does not decrease.

[0038]

As described above in detail, according to the present invention, the intake manifold and the vapor separator tank are distributed to one side and the other side in the traveling direction of the cylinder block, respectively, so that the intake branch pipe and the vapor separator tank are respectively provided. It can be arranged appropriately in consideration of output and function. For this reason, this outboard motor 2 can realize a compact and high-output engine.

In this outboard motor, the interior of the float or the filter can be realized by giving a degree of freedom to the size of the vapor separator tank provided on the other side in the traveling direction.
For this reason, in this outboard motor, the vapor separator tank in which the float and the filter are installed can be actually provided in the engine case, and a compact outboard motor can be realized as a whole.

Further, in this outboard motor, it is possible to make it difficult for water droplets contained in the air taken in from the air inlet to reach the opening at the upstream end of the throttle body. Therefore, even if external water jumps in from the air intake, the outboard motor is not sucked into the engine and the output does not decrease.

[Brief description of the drawings]

FIG. 1 shows an outboard motor according to an embodiment of the present invention.
It is an expanded sectional view by a line.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG.

FIG. 3 is a partially cutaway front view of the engine.

FIG. 4 is a partially cutaway side view of the engine.

FIG. 5 is a sectional view taken along line 4-4 in FIG. 1;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 8;

FIG. 7 is a side view of the outboard motor.

FIG. 8 is a rear view of the outboard motor.

FIG. 9 is an exploded perspective view of an engine of an outboard motor showing a conventional example.

[Explanation of symbols]

 2 Outboard motor 7 Engine case 14 Engine 20 Cylinder block 32 Cylinder head 34 Head cover 36 Intake port 38 Exhaust port 58 Intake manifold 60 Surge tank 62 Intake branch pipe 64 Tank intake passage 66 Intake branch passage 72 Fuel injection valve 78 Spacer 80 Throttle body 82 Throttle guide 86 Guide intake passage 88 Body intake passage 90 Spacer intake passage 92 Throttle valve 100 Breather chamber 106 Vapor separator tank

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // F02B 67/00 B63H 21/26 EG K F02M 35/10 102B 301P (72) Inventor Mitsuhiko Ota Shizuoka No. 300 Takatsukacho, Hamamatsu-shi, Japan Suzuki Co., Ltd. (72) Inventor Nobuyuki Shomura 300, Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Jiro Saiga 300, Takatsuka-cho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd.

Claims (5)

[Claims] 1. A cylinder block formed by vertically stacking a plurality of substantially horizontal cylinders whose axes are directed in a traveling direction in an engine case composed of a lower case and an upper case. A crankcase having a crankshaft whose axis is directed vertically, and a cylinder head having a valve operating mechanism at the rear side in the traveling direction of the cylinder block. An intake port and an exhaust port are opened via an intake valve and an exhaust valve on one side and the other side in a direction intersecting with the traveling direction of each combustion chamber formed between the head and one side in the traveling direction of the cylinder block. An intake manifold having a plurality of intake branch pipes attached to the cylinder head at the downstream end and communicating with each intake port is disposed,
In an outboard motor equipped with a four-stroke engine having an exhaust passage communicating with the exhaust port on the other side in the traveling direction of the cylinder block, the intake branch pipes may be vertically adjusted in accordance with the plurality of cylinders. And an injector for injecting fuel into each of the intake ports is disposed at a downstream end portion of each of the intake branch pipes adjacent to the intake port of the cylinder head and oriented in a direction substantially perpendicular to a traveling direction in plan view. The intake branch pipes on the upstream side of the injector are extended substantially forward along the side wall of the cylinder block while being curved in a substantially perpendicular direction so as to be directed forward in the traveling direction. The upstream end of the intake branch pipe is converged to a single surge tank to constitute the intake manifold, and the intake manifold is provided upstream of the surge tank in the intake manifold. A state in which a throttle body having a throttle valve is continuously provided substantially along the rank case, and an upstream intake passage of the throttle body is directed substantially perpendicular to the traveling direction at a position forward of the front end of the crankcase in the traveling direction. An outboard motor equipped with a four-stroke engine, which is open to the atmosphere. 2. The four-stroke engine separates a fuel vapor gas in a fuel supply path into the other side in the traveling direction of the cylinder block opposite to one side of the cylinder block in which the intake branch pipe is disposed. The outboard motor equipped with the four-stroke engine according to claim 1, wherein a vapor separator tank is provided. 3. The outboard motor according to claim 2, wherein a float and a filter are provided inside the vapor separator tank. 4. The throttle body according to claim 1, wherein the throttle body has an opening at an upstream end for opening into an engine case, and the opening is provided at a lower position in the engine case. Outboard motor with cycle engine. 5. The crank body according to claim 1, wherein the throttle body has an opening at an upstream end for opening into an engine case, and the opening is furthest away from an air intake provided at an upper rear side of the upper case. An outboard motor equipped with the four-stroke engine according to claim 1, provided at a position.