JP3674728B2 - Outboard motor with 2-cycle internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an outboard motor including a two-cycle internal combustion engine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an outboard motor is mounted on a ship, and a two-cycle internal combustion engine having an O ₂ sensor for detecting the oxygen concentration of a cylinder is provided on the upper portion of the outboard motor. Is supplied to the fuel supply system, and the breather hose attached to the oil tank is attached to the intake silencer.
[0003]
[Problems to be solved by the invention]
Thus, in an internal combustion engine mounted on an outboard motor, a breather hose is usually attached to the oil tank and its tip is attached to an intake silencer in order to suppress fluctuations in the internal pressure of the oil in the oil tank. The inside of the intake silencer communicates with the inside of the oil tank. Since the intake silencer communicates with the outside and intake air can freely enter and exit, the pressure inside the intake silencer is the same as the atmospheric pressure, so the oil tank internal pressure is stable, and the oil pump discharge is stable as a signal. Obtained. Moreover, when the oil in the oil tank overflows and overflows from the breather hose, it can be recovered in the internal combustion engine without being accumulated in the intake silencer and leaking outside.
[0004]
In the case of an internal combustion engine having an O ₂ sensor, attached to the O ₂ sensor by the oil amount is excessive, the characteristics of the sensor that functions of the O ₂ sensor is reduced, and oil overflow the oil tank, the breather hose If it overflows, the amount of oil becomes excessive and the function of the O ₂ sensor deteriorates.
[0005]
The present invention has been made in view of such a point, and even when the oil in the oil tank overflows and overflows from the breather hose, the two-cycle internal combustion system prevents the function of the O ₂ sensor from being deteriorated due to excessive oil amount. The purpose is to provide an outboard motor equipped with an engine.
[0006]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the invention according to claim 1 is provided with a two-cycle internal combustion engine having an O ₂ sensor for detecting the oxygen concentration of the cylinder, and the oil disposed in the two-cycle internal combustion engine. In an outboard motor comprising a two-cycle internal combustion engine in which oil is supplied from a tank to a fuel supply system and a tip of a breather hose attached to the oil tank is attached to an intake silencer,
The intake silencer has a resonance box, and the tip of the breather hose is attached to a place other than the resonance box,
The tip of the breather hose is at a position lower than the lower end of the intake passage of the cylinder having the O ₂ sensor and higher than the upper end of the intake passage of the lowermost cylinder,
A drain hose is attached to the lower end of the intake silencer, and the end of the drain hose is connected to the downstream side of the throttle valve .
Even if the oil in the oil tank overflows and overflows from the breather hose , attaching the tip of the breather hose to a place other than the resonance box will adversely affect the function of the resonance box of the intake silencer. preventing, and O ₂ oil that overflows from the intake passage of the cylinder having the sensor so as not to flow into the oil can be prevented degradation of the performance of the O ₂ sensor by adhering to the O ₂ sensor.
[0008]
Further, by attaching the tip of the breather hose to a position higher than the upper end of the intake passage of the lowermost cylinder, it is possible to prevent water accumulated in the lower portion of the intake silencer from being sucked into the oil tank.
[0009]
In addition, by attaching a drain hose to the lower end of the intake silencer and connecting the tip of this drain hose to the downstream side of the throttle valve, it is possible to prevent water collected in the lower part of the intake silencer from being sucked into the oil tank. I can .
[0010]
The invention according to claim 2 is characterized in that an oil tank is disposed on a side portion of the two-cycle internal combustion engine, and the breather hose is disposed on a side where the oil tank is disposed, and is connected to the intake silencer. . The breather hose is arranged on the side where the oil tank is arranged and connected to the intake silencer, so that the breather hose can be shortened and can be easily piped from the side of the two-cycle internal combustion engine.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an outboard motor equipped with a two-cycle internal combustion engine of the present invention will be described below. 1 is a view showing a state in which an outboard motor is mounted on a ship, FIG. 2 is a view showing a configuration of the outboard motor, FIG. 3 is a side view of the internal combustion engine, and FIG. 4 is a plan view in which a part of the internal combustion engine is broken. 5 is a cross-sectional view taken along line V-V in FIG. 4, FIG. 6 is a side view in which a part of the internal combustion engine is broken, FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. It is sectional drawing of a part.
[0012]
The ship 1 is floated on the water surface 2, and the arrow Fr indicates the forward direction of the ship 1. An outboard motor 4 is detachably attached to the rear part of the hull 3 of the ship 1. The outboard motor 4 includes a clamp bracket 6 that is detachably attached to the rear portion of the hull 3, a swivel bracket 8 that is pivotally supported by the clamp bracket 6 via a pivot shaft 7, and the swivel A hydraulic cylinder 9 for rotating the bracket 8 in the vertical direction and a propulsion unit 10 supported by the swivel bracket 8 are provided.
[0013]
The propulsion unit 10 has a case 12 supported by the swivel bracket 8, and an internal combustion engine 13 is attached to the upper portion of the case 12, and a cowling 14 that covers the internal combustion engine 13 from above is provided. A power transmission shaft 15 having a substantially vertical axis is provided in the case 12 below the internal combustion engine 13, and the shaft center extends in the front-rear direction at the lower end of the case 12 and is connected to the power transmission shaft 15. A propeller shaft 16 is rotatably supported, and a propeller 17 is attached to the propeller shaft 16.
[0014]
A fuel tank 41 is disposed in the hull 3, and the fuel tank 41 is connected to a fuel supply device 39 via a manual low-pressure fuel pump 48 and a tube 50. The internal combustion engine 13 is a water-cooled two-cycle V-type six-cylinder crankshaft vertical engine, and has a crankcase 20 supported by a case 12. A crankshaft 21 whose axis is substantially vertical is freely rotatable in the crankcase 20. It is supported by. The crankcase 20 is provided with a cylinder body 22 constituting each cylinder so as to form a V shape. Cylinder holes 23 are formed in the cylinder body 22 for each cylinder, and pistons 24 are slidably fitted into the cylinder holes 23. The pistons 24 are connected to the crankshaft 21 by connecting rods 25.
[0015]
In addition, the crankcase 20 is formed with an intake port 27 for communicating with the inside and outside of the crankcase 20 for each cylinder. An intake device 26 that opens to the atmosphere in the cowling 14 is connected to the intake port 27. The intake device 26 includes an intake pipe 28 communicating with an intake port 27 and an intake silencer 32 attached to an upstream end portion of the intake pipe 28. The intake silencer 32 has an intake port 32a.
[0016]
As shown in FIG. 3, the intake pipe 28 and the intake silencer 32 have a recess 32b formed in an annular shape in the attachment portion of the intake silencer 32, while a protrusion 28a is formed in an annular shape in the attachment portion of the intake pipe 28. The intake silencer 32 effectively functions as an intake chamber, and is configured to be able to reduce the intake noise and engine noise.
[0017]
The intake port 28b of the intake pipe 28 and the intake port 32a of the intake silencer 32 are formed in substantially the same plane L1, and the intake flow is reversed in the intake silencer 32. As shown in FIG. 4, the air sucked from the suction port 32a of the intake silencer 32 is reversed in the intake silencer 32 toward the suction port 28b of the intake pipe 28, so that the air may contain moisture. Even if it exists, entry into the crank chamber 33 side is prevented. A net member 302 is provided on the entire surface of the intake silencer 32 on the side of the intake port 32a. The net member 302 can prevent foreign matter from entering the intake silencer 32.
[0018]
In the intake silencer 32, partition walls 310 and 311 are formed and resonance box portions 312 and 313 are provided. Resonance boxes 312 and 313 are provided using the space in the intake silencer 32 to mute the sound, the space for arranging the resonance boxes 312 and 313 can be easily secured, and the number of parts can be reduced.
[0019]
An injector 37 is disposed in the intake pipe 28 so that the nozzle 37a faces the intake passage 30 and fuel is injected from the nozzle 37a at a predetermined timing. The head of the injector 37 is located in the recess 32 b of the intake silencer 32. In this way, the injector 37 is surrounded by the intake silencer 32 and the fuel system electrical component 320, and the injector 37 can be prevented from being attacked by water or from being hit by foreign matter.
[0020]
The intake pipe 28 and the intake silencer 32 communicate with each other to form an intake passage 30, and outside air from the outside of the intake silencer 32 passes through the intake port 32 a, the intake passage 30, and the intake port 27 and enters the interior of the crankcase 20. It can flow into the crank chamber 33. Each intake port 27 is provided with a reed valve 29, and each intake pipe 28 is provided with a throttle valve 31 for adjusting the cross-sectional area of the intake passage 30 by manual operation. In each cylinder body 22, a space surrounded by the cylinder body 22 and the piston 24 is a combustion chamber 34, and a spark plug 35 is disposed so as to face the combustion chamber 34.
[0021]
Each injector 37 attached to each cylinder of each intake pipe 28 is a solenoid open / close type that is opened / closed by magnetic force, and allows fuel to be injected into the intake passage 30 upstream of the reed valve 29. Each injector 37 is provided with a fuel supply device 39 for supplying fuel. The fuel supply device 39 has a fuel rail 38 that allows the upstream ends of the injectors 37 to communicate with each other. A vapor separator tank 42 is attached to the side wall of the cylinder body 22 so that fuel can be supplied to the vapor separator tank 42. A manual low-pressure fuel pump 48 and a diaphragm-type low-pressure fuel pump 49 are provided, and a tube 50 and a filter 51 are interposed between the low-pressure fuel pumps 48 and 49.
[0022]
Further, the fuel supply device 39 is provided with a high-pressure fuel pump 52 that pressurizes the fuel in the vapor separator tank 42 to a high pressure and supplies it to the fuel rail 38. The high-pressure fuel pump 52 is connected to the fuel rail 38 by a pipe 53, and the fuel in the vapor separator tank 42 is pressurized by driving the high-pressure fuel pump 52, and passes through the pipe 53 and the fuel rail 38 to each injector 37. Supplied. The fuel rail 38 is connected to the upper portion of the vapor separator tank 42 via a pipe 54 and a regulator valve 59, and the fuel pressure supplied to each injector 37 is regulated to a predetermined high pressure by the regulator valve 59. The injector 37 injects fuel based on this pressure.
[0023]
An oil tank 75 is disposed in the vicinity of the cylinder body 22, and oil in the oil tank 75 is supplied into the vapor separator tank 42 by the oil pump 76, where it is mixed with fuel and passes through the injector 37. The internal combustion engine 13 is lubricated by being supplied to the combustion chamber 34. An O ₂ sensor 70 is attached in the vicinity of one cylinder # 1 among the six cylinders of the cylinder body 22.
[0024]
The O ₂ sensor 70 is attached as shown in FIG. The insert 400 is press-fitted into the side wall of the uppermost cylinder of the cylinder body 22 to form a passage 400a communicating with the cylinder hole 23, and the holder 402 is fastened and fixed to the side wall by a bolt 403 via a seal member 401. ing. An O ₂ sensor 70 is attached to the bolt 403, and a detection portion 70 a of the O ₂ sensor 70 communicates with the cylinder hole 23 from the passage 400 a of the insert 400 through the passage 402 a of the holder 402. The holder 402 and the O ₂ sensor 70 are covered with a cover 410.
[0025]
The oil tank 75 is disposed above the filter 51, and a breather hose 500 is attached to the oil tank 75, and a distal end portion 500 a of the breather hose 500 is attached to the intake silencer 32. In order to suppress fluctuations in the internal pressure of the oil tank 75 due to the up and down of the oil level, a breather hose 500 is attached to the oil tank 75, and its tip 500a is attached to the intake silencer 32. Communicate.
[0026]
The tip portion 500a of the breather hose 500 is lower than the lower end of the intake passage 30 of the uppermost cylinder having the O ₂ sensor 70, as shown in FIG. At positions L3 and L4. Thus, even when the oil in the oil tank 75 overflows and overflows from the breather hose 500, the oil overflowing from the intake passage 30 of the cylinder having the O ₂ sensor 70 is prevented from flowing in, so that the oil is in the O ₂ sensor. The functional deterioration of the O ₂ sensor 70 due to adhering to the detection unit 70a of the 70 can be prevented.
[0027]
In addition, the intake silencer 32 has resonance boxes 312 and 313, and the tip portion 500a of the breather hose 500 is attached to a place other than the resonance box. By attaching the tip 500a of the breather hose 500 to a place other than the resonance box, the breather hose 500 is prevented from adversely affecting the functions of the resonance boxes 312 and 313.
[0028]
In addition, an oil tank 75 is disposed on the side of the two-cycle internal combustion engine 13, and a breather hose 500 is disposed on the side where the oil tank 75 is disposed and connected to the intake silencer 32, so that the breather hose 500 can be shortened. Moreover, piping can be easily made from the side of the two-cycle internal combustion engine 13.
[0029]
The tip end portion 500a of the breather hose 500 is attached to a position L5 higher than the upper end of the intake passage 30 of the lowermost cylinder, and the water accumulated in the lower portion of the intake silencer 32 can be prevented from being sucked into the oil tank 75.
[0030]
One end portion 510 a of the drain hose 510 is attached to the lower end of the intake silencer 32, and the tip end portion 510 b of the drain hose 510 is connected to the downstream side of the throttle valve 31. By connecting the front end portion 510b of the drain hose 510 to the downstream side of the throttle valve 31, the water accumulated in the lower portion of the intake silencer 32 due to the negative pressure of the intake passage 30 is sucked, so that the water is sucked into the oil tank 75. Can be prevented.
[0031]
Next, fuel injection control will be described. Detection signals from various sensors indicating the operating state of the internal combustion engine 13 and the states of the outboard motor 4 and the ship 1 are input to the control device 68. That is, as a sensor, a crank angle sensor 90 that detects the rotation angle (rotation speed) of the crankshaft 21, a crank chamber pressure sensor 91 that detects the pressure in the crankcase 20, and the pressures in the cylinders # 1 to # 6 are detected. cylinder pressure sensor 92 to, exhaust pressure sensor for detecting the exhaust pressure of the intake air passage intake air temperature sensor 93 for detecting the temperature of 30, an engine temperature sensor 94 for detecting the temperature of the cylinder body 22, the respective cylinders # 1 ~ # 6 95, a throttle opening sensor 96 that detects the opening of the throttle valve 31, a cooling water temperature sensor 97 that detects the temperature of the cooling water, an engine vibration sensor 98 that detects the frequency of the internal combustion engine 13, and a mount height of the internal combustion engine 13. An engine mount height detection sensor 99 for detecting the height, and a neutral sensor 100 for detecting the neutral state of the power transmission device 80 of the outboard motor 4. , A trim angle detection sensor 101 for detecting the vertical rotation position of the outboard motor 4, a ship speed sensor 102 for detecting the speed of the ship 1, a ship attitude sensor 103 for detecting the attitude of the ship 1, and an atmospheric pressure for detecting the atmospheric pressure. A sensor 104 and an oil level sensor 105 are provided, and an O ₂ sensor 70 is provided in the vicinity of the cylinder # 1 .
[0032]
The control device 68 computes the detection signals of these various sensors and transmits the control signals to the spark plug 35, the injector 37, the throttle valve 31, and the ISC 89. In the air-fuel ratio control, the fuel injection amount is controlled by feedback control based on the detection signal (voltage value) of the O ₂ sensor 70. When the air-fuel ratio changes from the lean side to the rich side, the fuel injection amount is controlled to decrease.By this control, the air-fuel ratio gradually changes to the lean side, and when the air-fuel ratio changes from the rich side to the lean side, the fuel injection amount is changed. By controlling so as to increase, the fuel injection amount is controlled so that the theoretical air-fuel ratio (air excess ratio λ = 1) is averaged. In this embodiment, the fuel injection amount is controlled so that the theoretical air-fuel ratio becomes the theoretical air-fuel ratio by feedback control for the cylinder # 1 , and the air-fuel ratio of the cylinder # 1 is used for the remaining cylinders # 2 to # 6. Control is performed to correct the fuel injection amount in accordance with the states of # 2 to # 6 .
[0033]
【The invention's effect】
As described above, in the first aspect of the present invention, the intake silencer has a resonance box, the tip of the breather hose is attached to a place other than the resonance box, and the tip of the breather hose is a cylinder having an O ₂ sensor. Even if the oil in the oil tank overflows and overflows from the breather hose, the tip of the breather hose resonates. By installing in a place other than the box, the breather hose is prevented from adversely affecting the function of the resonance box of the intake silencer, and the oil overflowing from the intake passage of the cylinder having the O ₂ sensor is prevented from flowing. It is possible to prevent the functional deterioration of the O ₂ sensor due to adhesion to the O ₂ sensor.
[0035]
Further, since the tip of the breather hose is attached at a position higher than the upper end of the intake passage of the lowermost cylinder, it is possible to prevent water accumulated in the lower part of the intake silencer from being sucked into the oil tank.
[0036]
Further, since the tip end portion of the drain hose is connected to the downstream side of the throttle valve, it is possible to prevent water accumulated in the lower portion of the intake silencer from being sucked into the oil tank.
[0037]
According to the second aspect of the present invention, the breather hose is disposed on the side where the oil tank is disposed and connected to the intake silencer. Therefore, the breather hose can be shortened and can be easily piped from the side of the two-cycle internal combustion engine.
[Brief description of the drawings]
FIG. 1 is a diagram showing a state in which an outboard motor is mounted on a ship.
FIG. 2 is a diagram showing a configuration of an outboard motor.
FIG. 3 is a side view of the internal combustion engine.
FIG. 4 is a plan view in which a part of the internal combustion engine is broken.
5 is a cross-sectional view taken along line V-V in FIG.
FIG. 6 is a side view in which a part of the internal combustion engine is broken.
7 is a cross-sectional view taken along line VII-VII in FIG.
FIG. 8 is a cross-sectional view of an intake pipe portion.
[Explanation of symbols]
1 ship 4 outboard motor 13 internal combustion engine 32 intake silencer 70 O ₂ sensor 75 oil tank 500 breather hose 500a tip of breather hose 500

Claims (2)

A two-cycle internal combustion engine having an O ₂ sensor for detecting the oxygen concentration of the cylinder is provided. Oil is supplied from an oil tank arranged in the two-cycle internal combustion engine to a fuel supply system, and a tip of a breather hose attached to the oil tank In an outboard motor having a two-cycle internal combustion engine with a portion attached to an intake silencer,
The intake silencer has a resonance box, and the tip of the breather hose is attached to a place other than the resonance box,
The tip of the breather hose is at a position lower than the lower end of the intake passage of the cylinder having the O ₂ sensor and higher than the upper end of the intake passage of the lowermost cylinder,
An outboard motor equipped with a two-cycle internal combustion engine, wherein a drain hose is attached to a lower end of the intake silencer, and a leading end of the drain hose is connected to a downstream side of a throttle valve . 2. The two-cycle according to claim 1 , wherein an oil tank is arranged on a side portion of the two-cycle internal combustion engine, and the breather hose is arranged on a side where the oil tank is arranged and connected to the intake silencer. An outboard motor equipped with an internal combustion engine.

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