JP3344406B2 - Outboard motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle guide for an outboard motor, and more particularly to a method of recovering unburned gas generated in an engine into an intake system without clogging even if the gas is liquefied. In addition, the intake air temperature sensor can be attached without requiring any anti-vibration measures or heat measures, and the intake air temperature sensor can accurately detect the intake air temperature, and the intake air temperature correction of the fuel injection amount by the fuel injection valve can be performed. The present invention relates to a throttle guide for an outboard motor that can be properly performed.

[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-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.
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]

However, in the outboard motor disclosed in the above publication, a blow-by gas pipe 214 is provided so as to communicate with a surge tank 210 having a lower intake flow rate than an evaporator 212. Therefore, there was a problem that the blow-by gas could not be collected well.

[0005] Some 4-cycle engines have a fuel injection valve. The fuel injection amount of the fuel injection valve is
It is necessary to correct it by the intake air temperature.

However, there is a problem that the intake air temperature sensor for detecting the intake air temperature cannot accurately detect the intake air temperature depending on the mounting position. For this reason, when the intake air temperature sensor is mounted at an inappropriate position, the intake air temperature cannot be accurately detected, and there is a disadvantage that the intake air temperature correction of the fuel injection amount cannot be properly performed.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides an outboard motor equipped with a four-cycle engine having a fuel injection valve in order to eliminate the above-mentioned disadvantages. A throttle body is provided on the upstream side, and a throttle guide is provided on the upstream side of the throttle body. The throttle guide communicates with a gas supply pipe for unburned gas generated by the engine so as to be directed downward above the guide intake passage. And an intake air temperature sensor for detecting an intake air temperature facing the guide intake passage.

[0008]

According to the structure of the present invention, the throttle guide is provided further upstream than the throttle body provided upstream of the surge tank in the intake manifold of the engine. Since the function of this throttle guide is to guide intake air to the throttle body, no mechanical strength is required.

The throttle guide is provided with a gas supply pipe for an unburned gas generated in the engine so as to be directed downward above the guide intake passage. As described above, since the gas supply pipe for the unburned gas is provided in communication with the guide intake passage through which the intake air flows quickly without stagnation, the unburned gas can be sufficiently recovered. Further, since the gas supply pipe for the unburned gas is provided so as to be directed upward and downward above the guide intake passage, there is no accumulation even if the unburned gas is liquefied.

Further, an intake air temperature sensor for detecting an intake air temperature facing the guide intake passage is attached to the throttle guide which can be formed of the flexible or elastic material. As described above, the intake air temperature sensor is provided so as to face the body intake passage through which the intake air flows quickly without stagnation, so that the temperature of the intake air flowing toward the engine can be detected. Further, the intake air temperature sensor is attached to a throttle guide which can be formed of a material having flexibility and elasticity, so that it is less susceptible to vibration propagation and thermal influence from the engine.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail 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 is covered with an engine cover 4, an under cover 6, a drive shaft housing 8, and a gear case 10 and a hull (not shown) by a mounting unit 12.
Attached to

The outboard motor 2 is equipped with a four-cycle engine 14 as shown in FIGS. The outboard motor 2 drives the drive shaft 16 by the engine 14 and changes the rotation direction by a gear (not shown) to drive the propeller 18.

As shown in FIGS. 5 and 6, the engine 14 is supported by a crankcase 24 with a crankshaft 22 directed substantially vertically in a cylinder block 20. The cylinder block 20 includes a plurality of cylinder shaft center lines oriented substantially in the horizontal direction.
The two cylinders 26 are disposed substantially vertically, 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 each cylinder 26. Intake port 36 and exhaust port 3
8, an intake valve 40 and an exhaust valve 42 are provided. 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.

As shown in FIGS. 4 and 5, the engine 14 is provided with an intake manifold 58 located on one side. The intake manifold 58 is provided with a surge tank 6 serving as a collecting part.
0 and a plurality of branch pipes 62 branched from the surge tank 60, the tank intake passage 64 and the branch intake passage 6.
6 is provided. The downstream side of each branch pipe 62 is provided by being connected by a manifold side mounting portion 68. The manifold side mounting portion 68 is mounted on the head side mounting portion 70 of the cylinder head 32, and communicates each branch intake passage 66 with each intake port 36.

Each of the branch pipes 6 is provided in the intake manifold 58.
2 is provided with a fuel injection valve 72. The fuel injection valve 72 is
It is attached to an injection valve attachment portion 74 provided on the manifold side attachment portion 68 at a position close to the cylinder head 32, and is connected to a control unit 130 described later. Fuel injection valve 72
The operation of the intake port 36 is controlled by the control unit 130.
Inject fuel into Reference numeral 76 is a fuel distribution pipe.

In the outboard motor 2 equipped with such an engine 14, a single throttle body 80 is attached to a surge tank 60 on the upstream side of the intake manifold 58 via a spacer 78, and the throttle body 80 is provided. A cylindrical throttle guide 82 is attached and provided on the upstream side. At the upstream end of the throttle guide 82, a filter 84 is attached.

Guide intake passage 8 of 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.

In FIG. 4, reference numeral 94 denotes a spark plug, and reference numeral 96 denotes a branch exhaust passage communicating with each exhaust port 38. The branch exhaust passage 96 communicates with the collective exhaust passage 98 and is discharged by an exhaust pipe (not shown).

The engine 14 has a breather chamber 100 in a head cover 34 as shown in FIGS. 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 FIGS. 1 to 4, the engine 14 is provided with a vapor separator 106 on the opposite side to the intake manifold 58 for separating unburned vapor gas. The vapor separator 106 incorporates a float 108 and a filter 110, and is provided with a vapor gas outlet tube 112.

The throttle guide 82 is provided with a blow-by gas intake pipe 114 for blow-by gas, which is unburned gas generated in 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 inlet pipe 116 is connected to a vapor gas outlet 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 operating, 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, the unburned gas blow-by 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 unburned blow-by gas and vapor gas supplied to the guide intake passage 86 by the blow-by gas supply pipe 118 and the vapor gas supply pipe 122 pass through 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 downward above the guide intake passage 86.
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 the vapor gas generated in the engine 14 is liquefied, the passages are not clogged, and these gases can be satisfactorily collected 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.

Therefore, the intake air temperature sensor 128 can be mounted 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.

[0039]

As described above in detail, according to the present invention, the function of the throttle guide provided further upstream of the throttle body provided upstream of the surge tank of the intake manifold of the engine is to control the intake air by the throttle. Because it leads to the body, no mechanical strength is required. For this reason, the throttle guide can be formed of a material having flexibility and elasticity.

Further, since the gas supply pipe for the unburned gas is provided in communication with the guide intake passage through which the intake of the throttle guide flows quickly without stagnation, the unburned gas can be sufficiently recovered. Further, since the gas supply pipe for the unburned gas is provided so as to be directed upward and downward above the guide intake passage, there is no accumulation even if the unburned gas is liquefied. For this reason, even if the unburned gas generated in the engine is liquefied, the unburned gas can be favorably collected in the intake system without clogging.

Further, the intake air temperature sensor is provided so as to face a guide intake passage in which the intake of the throttle guide, which can be formed of a material having flexibility or elasticity, flows quickly without stagnation, so that it is suitable for the engine. The temperature of the intake air flowing through can be detected. Further, the intake air temperature sensor is attached to a throttle guide which can be formed of a material having flexibility and elasticity, so that it is less susceptible to vibration propagation and thermal influence from the engine. For this reason, the intake air temperature sensor can be attached without the need for anti-vibration measures and thermal measures, and the intake air temperature sensor can accurately detect the intake air temperature, and correct the intake air temperature correction of the fuel injection amount by the fuel injection valve. Can be made.

[Brief description of the drawings]

FIG. 1 is a partially broken front view of an engine of an outboard motor showing an embodiment of the present invention.

FIG. 2 is a partially cutaway side view of the engine.

FIG. 3 is a sectional view taken along line III-III in FIG. 4;

FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 6;

FIG. 5 is an enlarged sectional view taken along line VV in FIG. 6;

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

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 14 Engine 20 Cylinder block 32 Cylinder head 34 Head cover 36 Intake port 38 Exhaust port 48 Camshaft 58 Intake manifold 60 Surge tank 62 Branch pipe 64 Tank intake passage 66 Branch intake passage 72 Fuel injection valve 76 Fuel distribution pipe 78 Spacer Reference Signs List 80 throttle body 82 throttle guide 84 filter 86 guide intake passage 88 body intake passage 90 spacer intake passage 92 throttle valve 100 breather chamber 102 crank chamber 106 vapor separator 118 blow-by gas supply pipe 120 blow-by gas passage 122 vapor gas supply pipe 124 vapor gas passage 128 intake Temperature sensor 130 control unit

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02B 67/00 F02B 67/00 R F02D 35/00 360F F02M 25/08 N F02D 35/00 360 29/00 C F02M 25/08 35/16 Z 29/00 35/10 301P 35/16 B63H 21/26 G (72) Inventor Nobuyuki Shomura 300 Takatsuka-cho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Hidehiko Yoshioka Takatsuka-cho, Hamamatsu-shi, Shizuoka 300 Suzuki Co., Ltd. (72) Inventor Jiro Saiga 300, Takatsukacho, Hamamatsu-shi, Shizuoka Prefecture Suzuki Co., Ltd. (56) References JP-A-3-172570 (JP, A) JP-A-60-4492 ( JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02M 35/10-35/16 B63H 21/26 F02B 67/00

Claims (1)

(57) [Claims] 1. An outboard motor equipped with a four-cycle engine equipped with a fuel injection valve, wherein the engine is provided with a surge tank and a plurality of intake branch pipes on one side in a direction intersecting the traveling direction of the outboard motor. A throttle body is provided upstream of the surge tank of the intake manifold, a throttle guide is provided upstream of the throttle body, and a gas supply pipe for unburned gas generated by the engine is provided in the throttle guide. An outboard motor characterized in that an outboard motor is provided above and in communication with the guide intake passage so as to be directed downward, and an intake air temperature sensor that detects intake air temperature is provided facing the guide intake passage.