JP2001152895A - Operation control method for outboard engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an outboard engine from going into a stall, when shifting is made so that a reversely directed thrust force is generated after closing of a throttle valve in order to decelerate or stop the ship. SOLUTION: This outboard engine is provided with a intake bypass passage fitted with an ISC valve and structured, so that the degree of opening of the intake bypass passage is made greater than the normal value in idling, if the existence of a ship is determined and after a throttle valve is closed upon determination of existence of any ship speed, and also the ignition timing is retarded, and thereby the idling speed at normal level is maintained, and when a shift IN from this condition to the reverse rotation side is determined, the ignition timing is advanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outboard motor in which an intake bypass passage bypassing a throttle valve is formed with respect to a main intake passage provided with a throttle valve, and an ISC valve is provided in the intake bypass passage. With respect to engines, especially in such outboard engines,
The present invention relates to an engine operation control method for preventing engine stall from occurring when decelerating or stopping a ship in a running state.

[0002]

2. Description of the Related Art In an outboard motor mounted on a small boat, an engine serving as a driving source is installed in a top cowling in an upper part of the fuselage, and a propeller serving as a propulsion device is mounted in a lower case in a lower part of the fuselage. A shift conversion mechanism for switching power transmission between neutral, forward and reverse is installed between a drive shaft connected to the crankshaft of the No. 1 and a propeller shaft which is a rotation shaft of the propeller.

In this shift conversion mechanism, a drive gear fixed to the lower end of a drive shaft is meshed with a forward gear and a reverse gear rotatably disposed on a propeller shaft, respectively, and is disposed between the forward gear and the reverse gear. By shifting the dog clutch to any of neutral, forward and reverse positions, the rotation of the forward gear or the reverse gear rotating in conjunction with the drive shaft is selectively transmitted to the propeller shaft via the dog clutch. (Or not at all).

On the other hand, in an engine installed in a top cowling of an outboard motor, as an intake passage from a surge tank to an engine combustion chamber, a main intake passage (intake pipe) provided with a throttle valve on the way is further provided. Conventionally, a structure is known in which an intake bypass passage is formed so as to bypass a throttle valve, and the opening degree of the intake bypass passage is controlled by an opening / closing control valve called an ISC (idle speed control) valve. .

[0005] An I for controlling the opening degree of the intake bypass passage.
The SC valve normally opens when the engine speed is lower than the target speed during idling and closes when the engine speed is higher than the target speed. By controlling the ISC valve to open (so-called dash pod control) when the throttle valve is suddenly closed, the engine stops due to an undershoot of the engine rotation, or the engine misfires due to a shortage of intake air. It prevents malfunctions such as engine rotation stop.

[0006]

In the case of a small boat equipped with an outboard motor as described above, when decelerating or stopping a boat in a running state, it is necessary to operate a brake like a vehicle running on the ground. Because the engine cannot rotate, the throttle valve in the main intake passage is closed to bring the engine to the idle state, the shift is returned to neutral, and then the gear is shifted in the reverse direction. By rotating the propeller to generate the decelerating force, a deceleration force is generated.

However, during the shift conversion for such a deceleration or stop operation, the rotational force generated in the propeller by the hull still propelled by inertia (rotational force in a direction opposite to the engine rotational direction). Shift I to the reverse side
At N, the engine is reversely transmitted from the propeller side to the engine side, so that the engine whose rotational force is reduced to the idle state receives a rotational force from the propeller in a direction opposite to the engine rotational direction, causing engine stall. There is a problem that there is a fear.

An object of the present invention is to solve the above-mentioned problems. Specifically, in an outboard motor engine having an intake bypass passage provided with an ISC valve,
It is an object of the present invention to prevent the engine from stalling when the shift conversion is performed so that the thrust in the reverse direction is generated after the throttle valve is closed in order to decelerate or stop the ship.

[0009]

According to the present invention, in order to solve the above-mentioned problems, an intake bypass passage is formed which bypasses a throttle valve with respect to a main intake passage provided with a throttle valve. ISC in the passage
In an outboard motor engine provided with a valve, the presence or absence of a boat speed is determined, and after the throttle valve is closed in a state where the boat speed is determined to be present, the opening degree of the intake bypass passage is set to a normal idle state. By increasing the opening degree and retarding the ignition timing, the idle rotation speed at the normal level is maintained, and the ignition timing is advanced when the shift IN from this state to the reverse rotation is determined. It is characterized by having done.

According to the above-described operation control method for an outboard motor engine, when the engine is idling with the throttle valve closed while the ship is stopped, normal idle control is performed, while When the engine is idling with the throttle valve closed to decelerate or stop the ship, the ignition timing is retarded to maintain the normal level of idling speed. Since more air is supplied than in the case, even when the engine receives reverse rotational force from the propeller at the time of the shift IN to the reverse rotation side, the ignition timing is advanced, and the engine is immediately turned on. There is no such thing as the engine stalling due to the increase of the rotational force.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an outboard motor operation control method according to the present invention will be described with reference to the drawings.

FIG. 1 schematically shows an example of an outboard motor provided with an engine to which the operation control method of the present invention is applied. The outboard motor 1 can be rotated in a horizontal direction by a swivel bracket 2. The upper part of the swivel bracket 2 is rotatably supported in the vertical direction with respect to the clamp bracket 4 by the horizontal tilt shaft 3, and the clamp bracket 4 is detachably fixed to the rear tail plate of the hull. It is mounted so as to be rotatable in the horizontal direction (steering direction) and the vertical direction (tilt direction) with respect to the hull.

The housing of the outboard motor 1 is composed of a top cowling 5, an upper case 6, and a lower case 7, and an engine 8 serving as a driving source is provided in the top cowling 5 in the upper part of the fuselage. The propeller 9 serving as a propulsion unit is rotatably mounted on the lower rear side of the lower case 7 at the lower part of the fuselage. Is provided with an oil pan 11 for temporarily storing lubricating oil used in the engine 8, and an exhaust pipe 12 extending from the engine 8 below the oil pan 11.
Exhaust gas discharged from the end of the lower case 7
An exhaust passage 13 is provided to guide the inside.

A power transmission drive shaft 14 connected to the lower end of the crankshaft of the engine 8 passes vertically through the upper case 6 while being isolated from the oil pan 11 and the exhaust passage 13. And the drive shaft 14 is connected to the engine 8
A water pump 15 for supplying cooling water to the motor is installed near the lower case 7 so as to be driven by the rotational force of the drive shaft 14.

A propeller shaft 16 which is a rotating shaft of the propeller 9 is passed through the lower case 7 in a horizontal direction, and the drive shaft 1 extended into the lower case 7 is provided.
The lower end of 4 is linked to a propeller shaft 16 via a shift conversion mechanism 17 including bevel gears 17a, 17b, 17c and a dog clutch 17d, and is shifted by rotation of a shift rod 18 extending in the vertical direction in parallel with the drive shaft 14. By operating the conversion mechanism 17, the rotational force is transmitted from the drive shaft 14 to the propeller shaft 16 in a state where it is converted into any one of neutral, forward, or reverse (not transmitted in neutral).

That is, the shift conversion mechanism 17 includes a drive gear 17a fixed to the lower end of the drive shaft 14.
A forward gear 17b rotatably disposed on the propeller shaft 16 and a reverse gear 17c are meshed with each other, and a dog clutch 17d slidably and non-rotatably mounted on the propeller shaft 16 is connected to the forward gear 17b. The dog clutch 17d is arranged between the reverse gear 17c and slides on the propeller shaft 16 in conjunction with the rotation of the shift rod 18 (the rotation of the cam surface at the lower end of the shift rod).

With such a shift conversion mechanism 17, the driver rotates the shift rod 18 around its axis by operating the remote control lever to move the dog clutch 17d, thereby allowing any one of the forward gear 17b and the reverse gear 17c. Or by preventing the rotation of the drive shaft 14 from being transmitted to the propeller shaft 16 via one of the forward gear 17b and the reverse gear 17c, The rotation of the drive shaft 14 is set to a neutral state in which the rotation is not transmitted to the propeller shaft 16.

FIG. 2 shows the engine 8 installed in the top cowling 5 of the outboard motor 1 as described above, schematically showing the intake system of the engine 8 viewed from above.
FIG. 3 shows a control system of the engine 8.

The engine 8 shown in FIG. 2 is a fuel injection type 4-cycle V-type multi-cylinder engine, and includes a surge tank 21.
An intake pipe 24 provided with a throttle valve 25 and a fuel injector 26 on the way is provided as a main intake passage as an intake passage extending from the air to a combustion chamber 23 having a spark plug 22. An intake bypass passage 27 is formed so as to bypass the intake passage 25, and in the middle of the intake bypass passage 27, an ISC serving as an open / close control valve for controlling the opening degree of the passage 27 is provided.
(Idle speed control) Valve 28 is provided.

As shown in FIG. 3, a throttle opening sensor 31 is provided for the rotation axis of the throttle valve 25 for the engine 8 having the intake bypass passage 27 provided with such an ISC valve 28. An engine speed sensor (pulsar coil) 32 is provided around the crankshaft, and a shift sensor 33 for detecting a shift conversion state, such as a shift position switch, for a rotation operation portion of the shift rod 18. Is installed.

As other sensors, a temperature sensor 34 for detecting the engine temperature, an intake pressure sensor 35 for detecting the air pressure in the intake pipe downstream of the throttle valve, and an oxygen concentration of the combustion gas are detected. Sensor 36 for detecting the temperature and pressure of the lubricating oil, an oil temperature sensor 38 for detecting the pressure of the lubricating oil, an atmospheric pressure sensor 39 for detecting the atmospheric pressure, and a trim for detecting the inclination angle of the outboard motor. The sensors 40 and the like are installed at appropriate places.

Each of these sensors is an EC with a built-in CPU, a timer, and a storage unit such as a RAM and a ROM.
U (engine control unit) 30. In the ECU 30, arithmetic processing is performed by the CPU based on the detection data input from each sensor and each map previously stored in the storage unit, and the result is controlled. The signal is output from the ECU 30 to the ignition plug 22, the fuel injector 26, and the ISC valve 28.

FIG. 4 is a flowchart showing an outline of an embodiment of the engine operation control method of the present invention implemented by the engine 8 of the outboard motor 1 as described above. In the cruising state of the hull provided with the outboard motor 1, it is determined that there is no boat speed if the cruising speed is below a predetermined speed, and it is determined that there is a boat speed if the cruising speed is above a predetermined speed, When it is determined that there is no boat speed, it is determined that the hull is already in a stopped state, and normal engine operation control is performed.

When it is determined that the boat speed is present, the throttle opening in that state is detected. When the throttle opening is not fully closed, it is determined that the cruising state is continued. To perform normal engine operation control
When the throttle opening is fully closed, it is determined that the operation of deceleration or stop has been started from cruising, and the ISC valve 28 is controlled so as to keep the opening of the intake bypass passage 27 large. In addition, by controlling the ignition timing of the ignition plug 22 to be retarded, the control is performed so that the engine 8 can maintain the normal idle rotation speed.

After determining that the throttle is fully closed in the state where the boat speed is present and starting the engine control as described above, the state where the boat speed is present is maintained until a predetermined time elapses.
When the predetermined time has elapsed, the determination that the boat speed is present is released, and when the shift IN to the reverse rotation side is determined while the boat speed is present (within the predetermined time), the ignition timing is advanced. are doing.

In the operation control method for an outboard motor engine as described above, the speed sensor is attached to the outboard motor 1 to determine the presence or absence of the boat speed, and the detected value of the actual running speed of the hull is obtained. Although it may be input to the ECU 30, in the present embodiment, the state where the engine speed is equal to or higher than the set value or the throttle opening is equal to or higher than the set value is determined without installing such a speed sensor. If it has continued for more than the time, it is determined that there is a boat speed.

In the present embodiment, the detection of the throttle opening is based on the detected value of the opening of the throttle valve 25 by the throttle opening sensor 31, but the air pressure in the intake pipe 14 downstream of the throttle valve 15 is measured. The detection value of the intake pressure sensor 35 to be detected may be used.

In the present embodiment, the determination of the shift IN to the reverse rotation side is based on the detection of the shift sensor 33 installed on the rotation operation portion of the shift rod 18, but the shift sensor is installed on the shift conversion mechanism 17. It is also possible to use not only a shift position switch but also an appropriate sensor such as a shift stroke sensor, and further, without using such a shift sensor, an engine speed sensor. If a sudden decrease in rotation speed below a certain rotation speed is detected from a signal, it may be determined that shift IN has been performed.

When the shift sensor is used, specifically, for example, (1) a neutral position switch is provided, and it is determined that the shift IN is in progress when the neutral position is deviated. (2) The forward position and the reverse position Is provided with a position switch, and a signal is used to determine whether the vehicle is going forward or backward. (3) A shift stroke sensor is provided so that the shift is going forward or backward. An appropriate method such as judging whether the user is about to enter is possible.

According to the operation control method for an outboard motor engine of the present embodiment as described above, normal idle control is performed when the throttle valve is closed and idle operation is performed in a state where the ship is stopped, When idle operation is performed with the throttle valve closed to decelerate or stop operation while the ship is running, the ignition timing is retarded to maintain the normal level of idle speed. Therefore, a larger amount of air is supplied than in the case of normal idling operation. Therefore, even when the engine receives reverse rotational force from the propeller at the time when the engine is shifted to the reverse rotation direction later, the ignition timing is not changed. Is advanced, the rotational force of the engine is immediately increased, and occurrence of engine stall can be prevented.

In the present embodiment, since the engine speed and the throttle opening are used as data to determine the presence or absence of the boat speed, the speed of the boat is not required without a speed sensor. The presence or absence can be determined.

Further, in the present embodiment, the determination that the boat speed is present is released when a predetermined time has elapsed from the state in which it is determined that the throttle is fully closed with the boat speed present. After that, if the shift conversion operation for deceleration or stop is not performed for some reason, the control automatically returns to the normal engine operation control.

The embodiment of the outboard motor operation control method according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment. Is a fuel injection type 4-cycle V-type multi-cylinder engine, but it is needless to say that the present invention is not limited to such an engine, but can be applied to other outboard motor engines.

[0034]

According to the method for controlling the operation of an outboard motor engine of the present invention as described above, in order to decelerate or stop the ship from the running state, the thrust in the reverse direction after closing the throttle valve. If the engine receives a rotational force in the opposite direction to the engine rotation direction from the propeller when the shift conversion is performed to generate the engine, the engine rotation force can be immediately increased accordingly and the engine stall occurs. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an outboard motor including an engine to which an operation control method according to the present invention is applied.

FIG. 2 is a top view showing an intake system of an engine installed in the outboard motor shown in FIG.

FIG. 3 is an explanatory diagram showing a control system of an engine installed in the outboard motor shown in FIG. 1;

FIG. 4 is a flowchart showing an outline of an operation control method for an outboard engine according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outboard motor 8 Engine 24 Intake pipe (main intake passage) 25 Throttle valve 27 Intake bypass passage 28 ISC valve

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Claims (3)

[Claims] An outboard motor having an intake bypass passage formed around a throttle valve with respect to a main intake passage provided with a throttle valve, and an ISC valve provided in the intake bypass passage. After the throttle valve is closed with the presence / absence determined and the boat speed is determined to be high, the opening of the intake bypass passage must be larger than the normal idle opening, and the ignition timing must be retarded. A method for controlling the operation of an engine for an outboard motor, the method comprising: maintaining an idle speed at a normal level, and advancing the ignition timing when a shift IN from this state to the reverse rotation is determined. 2. The engine speed is equal to or higher than a set value, or
2. The outboard motor engine operation control method according to claim 1, wherein when the state where the throttle opening is equal to or more than the set value has continued for a predetermined time or more, it is determined that there is a boat speed. 3. After the throttle valve is closed in a state where it is determined that there is a ship speed, the state of determination that there is a ship speed is maintained until a predetermined time elapses. The operation control method for an outboard motor engine according to claim 1 or 2, wherein the determination of presence is canceled.