JP2002188494A - Engine control device - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide an engine control device that prevents a change in engine speed at a switching point of opening and closing a throttle valve. In an engine in which a solenoid valve is provided in an intake device to control an intake air amount by duty control, a throttle valve provided inside a throttle body constituting the intake device is turned on when fully closed. When a fully closed switch is provided, and when the fully closed switch is switched from ON to OFF (step 2), the duty of the solenoid valve is maintained at the current duty (step 3). The setting was made so that the adjustment value did not change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an engine control device.

[0002]

2. Description of the Related Art Some engines are provided with a solenoid valve in an intake system of the engine to control the amount of intake air by duty control or the like in order to improve idling stability and startability.

[0003] The solenoid valve of such an engine is controlled such that when the throttle valve is fully closed, the engine speed is equal to the target engine speed except in the case of starting and dash port mode.

On the other hand, when the throttle valve is not fully closed, the duty is controlled on a predetermined map,
It is adjusted so that there is no time delay in the dashpot control etc. at the time of sudden full closing operation.

[0005] Even in the fully closed state, the adjustment is made within a range that does not cause problems such as startability of the engine, rotation drop during dashpot control, and engine stall.

[0006]

However, the above-mentioned adjustment is not always performed, but is performed only at the time of engine inspection or when a problem occurs. Accordingly, a difference occurs between the air amount adjusted in advance due to a change in friction and the like and the air amount actually required by the engine.

For example, if the sensor used for control is a fully-closed switch that is turned on when the throttle valve provided inside the throttle body is fully closed, the rotation speed feedback works when fully closed, and there is no problem. When the fully-closed switch is OFF, that is, when the throttle valve is slightly opened, the duty is controlled on the predetermined map as described above.
At the point where N / OFF is switched, the engine speed may increase or decrease.

For example, when the duty when the fully closed switch is ON and the feedback is performed is set to be higher than the duty when the fully closed switch is OFF, the switching point (O
(N → OFF), the amount of air decreases, and the engine speed suddenly decreases.

Further, when the throttle valve is slowly returned, there is a possibility that the amount of air becomes small before the fully closed switch is turned on and the engine stalls.

On the other hand, when the duty when the fully-closed switch is ON and feedback is set to be lower than the duty when the fully-closed switch is OFF, the switching point of the fully-closed switch (O
In the case of (N → OFF), there is a possibility that a problem such as an increase in the amount of air and an abrupt increase in the engine speed may occur.

Even when a throttle sensor that detects the opening of the throttle valve is used for control instead of the fully closed switch that operates when the throttle valve opens and closes, an idle zone is set in this sensor. The same symptoms occur.

The present invention has been made in consideration of the above circumstances, and has as its object to provide an engine control device that prevents a change in engine speed at a switching point of opening and closing a throttle valve.

[0013]

According to the present invention, there is provided an engine control device for solving the above-mentioned problems.
As described in the above, in an engine in which an intake device is provided with a solenoid valve to control the amount of intake air by duty control, when the throttle valve provided inside the throttle body constituting the intake device is fully closed. A fully-closed switch that operates ON is provided, and when the fully-closed switch is switched from ON to OFF, the duty of the solenoid valve is maintained at the current duty, and the adjustment value of the solenoid valve is switched when the fully-closed switch is switched. Is set not to change.

Further, in order to solve the above-described problem, as described in claim 2, the gradient (change) of the map is offset so as to pass through the held duty value while keeping the same.

Further, in order to solve the above-mentioned problems,
As described in claim 3, the adjustment value when the fully closed switch is switched from ON to OFF is reflected on the map when the fully closed switch is OFF.

Further, in order to solve the above-mentioned problem, as set forth in claim 4, the offset is based on the engine speed and the adjustment value when the fully-closed switch is switched from ON to OFF. This is performed by a method of determining the difference from a similar grid point of the map.

Then, in order to solve the above-mentioned problem,
As set forth in claim 5, upper and lower limits are set for the offset amount.

Further, in order to solve the above-mentioned problem, as set forth in claim 6, the engine is an engine for an outboard motor in which a crankshaft is provided vertically.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a right side view of an outboard motor to which the present invention is applied. The outboard motor 1 includes an engine holder 2 and is mounted on a transom 4a of a hull 4 via a bracket 3 attached to the engine holder 2.

The engine holder 2 has an exhaust passage and a drain passage (both not shown), which will be described later, formed therein, and an engine 5 is installed above the exhaust passage and the drain passage. The crankshaft 6 is provided vertically inside the engine 5 so as to be oriented substantially vertically. Further, a drive shaft housing 8 is installed below the engine holder 2 via an oil pan 7 in which an exhaust passage and a drain passage (both not shown) described later are formed. Then, the periphery of the engine 5 is covered with the engine cover 9.

A drive shaft 10 connected to the lower end of the crankshaft 6 extends downward in the oil pan 7 and the drive shaft housing 8, and a bevel gear in a gear case 11 provided below the drive shaft housing 8. 12 and propeller shaft 13
Is configured to drive the propeller 14 via the.

Further, a shift device 15 for shifting the rotation direction of the propeller shaft 13 and the propeller 14 to forward, reverse or neutral by remote control is provided in the gear case 11. Shift device 1
A shift rod 16 extends upward from 5 and is connected to a link mechanism 17 provided in the engine cover 9.

On the other hand, the water intake 1
The cooling water such as seawater or lake water taken in from the water intake 18 is pumped toward the engine 5 through a cooling water pipe 20 by a water pump 19 driven by a drive shaft 10. Then, the cooling water sent toward the engine 5 cools various parts in the engine 5 and then is discharged to the outside together with the exhaust gas.

FIG. 2 is an enlarged right side view of the engine 5 shown in FIG. 1, and FIG. 3 is a system diagram of the engine 5. As shown in FIG. As shown in FIGS. 1 to 3, the engine 5
For example, it is a water-cooled four-cycle four-cylinder engine, and is configured by arranging a cylinder head 21, a cylinder block 22, a crankcase 23, and the like in a lateral direction.

A cylinder 24 (cylinder) is formed in a cylinder block 22 of the engine 5. Further, a combustion chamber 25 is formed in the cylinder head 21 so as to match the cylinder 24, and a spark plug 26 is connected from the outside thereof.
A piston 27 is slidably inserted into the cylinder 24. Although not shown in detail, the piston 27 and the crankshaft 6 are connected by a connecting rod 28. Then, the reciprocating stroke of the piston 27 is converted into the rotational movement of the crankshaft 6. further,
Although not shown in detail, a flywheel magneto 29 is attached to the upper end of the crankshaft 6 integrally with the crankshaft 6.

In the cylinder head 21, an intake port 30 and an exhaust port 31 connected to the combustion chamber 25 are formed.
A fuel injector 32 for injecting fuel into the intake port 30 is attached to the cylinder head 21 from outside. In the cylinder head 21, an intake valve 33 and an exhaust valve 3 for opening and closing both ports 30, 31 are provided.
A valve train 35 such as 4 is also arranged and covered by a cylinder head cover 36.

An electric component 37, an intake device 38, and an exhaust device 39 are arranged around the engine 5. The intake device 38 mainly includes a silencer 40, a throttle body 41, an intake manifold 43 having a surge tank 42 and a plurality of intake pipes extending from the surge tank 42 to each cylinder. They are arranged collectively on one side of the cylinder block 22.

On the other hand, the exhaust device 39 is arranged on the opposite side of the intake device 38, and the electrical components 37 are also arranged on the same side as the exhaust device 39. The exhaust device 39 has an exhaust manifold 44, which is supported on the side of the cylinder head 21 and the side of the engine holder 2.

A water jacket 45 is formed around the cylinder 24 in the cylinder block 22 and around the combustion chamber 25 of the cylinder head 21. An exhaust passage 46 is formed in the exhaust manifold 44 to connect the exhaust port 31 of the cylinder block 22 to an exhaust passage (not shown) formed in the engine holder 2 and the oil pan 7. Jacket 4
7 is formed.

A cooling water outlet (not shown) of the water jacket 45 formed in the cylinder block 22 is disposed above the cylinder block 22, and a drain hose 48 connected to the cooling water outlet extends downward. The downstream end of the drain hose 48 is connected to a cooling water drain passage (not shown) formed in the engine holder 2 and the oil pan 7, and discharges the cooling water into the drive shaft housing 8.

An electrical component holder 49 is disposed on the side of the engine 5 in front of the exhaust manifold 44, and a control unit 50 for controlling the engine 5 is provided therein. A rectifier / regulator 51 is arranged between the exhaust manifold 44 and the electrical component holder 49.

Further, for example, a cylinder temperature sensor 52 for detecting a cylinder temperature is provided on the side of the cylinder block 22 above the rectifier / regulator 51, and a manifold temperature for detecting the temperature of the exhaust manifold 44 is also provided on the side of the exhaust manifold 44. A sensor 53 is provided.

Further, an ignition coil 54a for the second and third cylinders from the top is provided above the side surface of the cylinder head cover 36, and an ignition coil 54b for the first and fourth cylinders from the top is provided below. Each is provided.

The link mechanism 17 of the shift device 15
In the vicinity, a neutral switch 55 for detecting whether the shift position is neutral is provided.

As shown in FIG. 3, a crank angle sensor 56 for detecting the rotation angle of the crankshaft 6 is provided near the outer peripheral surface of the flywheel magneto 29. Also,
A fully closed switch 6 in which a throttle valve 59 provided inside the throttle body 41 is turned ON when fully closed.
0 is provided.

Further, the surge tank 42 disposed between the throttle valve 59 and the intake port 30 adjusts the amount of air during idling to control the start of the engine 5 and to control the number of revolutions when the throttle valve 59 is fully closed. And an IAC solenoid valve 57 for performing dashpot control and the like. The solenoid valve 57 can change the intake air amount of the engine 5 independently of the operation of the throttle valve 59.

Since the required basic air amount differs depending on the variation of the engine 5, the surge tank 42 is provided with an air bypass screw 58 for adjusting the basic air amount. Like the solenoid valve 57, the air bypass screw 58 can change the intake air amount of the engine 5 independently of the operation of the throttle valve 59.

FIG. 4 is a block diagram of the engine system shown in FIG. As shown in FIG. 4, information obtained from each sensor and switch is sent to the control unit 50. Specifically, after the rotation angle of the crankshaft 6 is A / D (analog / digital) converted from the crank angle sensor 56, the rotation angle is sent to the rotation speed detecting unit 61, and the data of the engine rotation speed obtained here is obtained. The data is sent to the calculation unit 62.

The position information of the throttle valve 59 in the throttle body 41 is transmitted from the fully closed switch 60 to A / A.
After the D conversion, the data is sent to the fully closed position determination section 63, and the position data of the throttle valve 59 obtained here is calculated by the calculation section 6.
Sent to 2.

Further, the shift position information of the shift device 15 is transmitted from the neutral switch 55 to the shift position determination section 6.
4, and the obtained position data of the shift device 15 is sent to the calculation unit 62.

Further, from the cylinder temperature sensor 52 and the manifold temperature sensor 53, the temperature information of the cylinder 24 and the exhaust manifold 44 is sent to the temperature detecting section 6.
5, and the temperature data of the cylinder 24 and the exhaust manifold 44 obtained here is sent to the calculation unit 62.

The information obtained from each sensor and switch is calculated by a calculation unit 62, and appropriate control signals are sent to a solenoid control unit 66, an ignition control unit 67, and a fuel injection control unit 68 to output the air amount during idling. , The fuel injector 32 for injecting fuel into the intake port 30, and the ignition coils 54a and 54b for igniting the spark plug 26.

By the way, the initial setting of the engine 5 is such that the duty of the solenoid valve 57 does not change when the fully closed switch 60 is turned on and off (when the amount of air passing through the passage changes or does not change or opens to the extent). That is, the matching is performed so that the rotation of the engine 5 does not fluctuate, but the matching adjusted in advance is deviated due to poor maintenance of the air bypass screw 58, deterioration over time, deterioration of lubricating oil, change in friction, and the like. In such a case, the rotation drop of the dashpot control may be early or late, or the rotation of the engine 5 may suddenly increase or decrease while the throttle valve 59 is slightly opened. Is equipped with an air amount control device for the solenoid valve 57 for solving the above-mentioned problems. It is.

FIG. 5 is a flowchart showing the flow of control performed by the air amount control device. 6 shows a first embodiment of the basic map when the fully closed switch 60 is OFF, and FIG. 7 shows a second embodiment of the basic map when the fully closed switch 60 is OFF. FIG. 8 is a timing chart of this control.

First, it is determined whether or not the fully closed switch 60 is ON, that is, whether or not the throttle valve 59 is fully closed (step 1 in FIG. 5).
If 0 is ON, then the fully-closed switch 60 is turned ON and OFF.
It is determined whether the mode has been switched to F (step 2 in FIG. 5).

When the fully closed switch 60 is switched from ON to OFF, the duty (D
%), And the rotation speed at the time of the switching is Necrp.
m (step 3 in FIG. 5).

Next, D which is actually shifted to Duty (Db%) of the basic map set to Necrpm (f (Nec)) of the map when the fully closed switch 60 is OFF.
uty (Dc%), and the difference (Db−Dc)
Is detected. Then, the absolute value of this difference (| Db-Dc
It is determined whether or not |) is within the upper and lower limit values (B%) of the duty offset (step 4 in FIG. 5).

If the upper and lower limits of the duty offset (B
%) Or more, the offset of the Duty map is regulated within the upper and lower limits (± B%) (Step 5 in FIG. 5).

On the other hand, the upper and lower limits of the duty offset (B
%), The entire map is offset by the difference (Duty = f (Ne) + (Db-Dc))
(Step 6 in FIG. 5).

Then, until the fully-closed switch 60 is turned on, control is performed while the map when the fully-closed switch 60 is off is offset.

For example, as shown in FIG. 6, 1250 rpm which is the offset reference point (when ON → OFF) of the map
Duty (Db%) of the basic map at (= Nec) is 6
5%, and the actually shifted Duty (Dc%) is 50%.
%, The upper and lower limit (B%) of the offset is 20%
Then, the offset value becomes 15%. If the upper and lower limit (B%) of the offset is 10%, the offset value is 10%.

In the first and second embodiments, the rotation speed (Ne) of the offset reference point (when ON → OFF) of the map is used.
Although c) is set to 1250 rpm, it may be set to any rotational speed depending on the engine.

When the fully closed switch 60 is switched from ON to OFF, the duty (D
%) At the current Duty, and the retained Du
By adjusting the gradient (change) of the map so as to pass through the ty value while keeping the same, the adjustment value of the solenoid valve 57 does not change when the fully-closed switch 60 is switched. A sudden change in the engine speed is prevented.

Further, since the gradient (change) of the map is offset while keeping the same, both the rise and the fall of the engine speed are equivalent to the normal change, and there is no change in the operability.

Further, the fully-closed switch 60 is turned from ON to OF.
The adjustment value when switching to F is set to the fully closed switch 60OFF
By reflecting the time on the map, the fully closed switch 60
The behavior of the engine speed due to the opening / closing operation of the throttle valve 59 after the OFF state can be made similar to the behavior in the normal state.

Furthermore, the offset point is determined by the difference between the engine speed and the adjustment value when the fully-closed switch 60 is switched from ON to OFF and a similar grid point of the basic map, and the offset point is set to the speed feedback. Be sure to be larger than the air adjustment value at the time. As a result, the possibility of engine stall is significantly reduced.

Since the upper and lower limit values are set for the offset amount, it is necessary to switch the fully-closed switch 60 from ON to OFF immediately after the engine 5 is started or during the dashpot. Since the offset with the larger value is not performed, the rotation of the engine does not suddenly decrease or does not stop decreasing.

In the above-described embodiment, an example in which the present invention is applied to the engine 5 of the outboard motor 1 has been described. However, any engine that controls the amount of intake air using a solenoid valve may be used in an automobile or an automatic transmission. It can also be applied to engines for motorcycles and the like.

[0060]

As described above, according to the engine control device of the present invention, in the engine in which the intake valve is provided with a solenoid valve to control the intake air amount by duty control, The throttle valve provided inside the throttle body is provided with a fully-closed switch that is turned ON when the throttle valve is fully closed. When the fully-closed switch is switched from ON to OFF, the duty of the solenoid valve is changed to the duty of the current duty. Since the adjustment value of the solenoid valve is set so as not to change when the fully closed switch is switched, the rapid change of the engine speed during the delicate opening / closing operation of the throttle valve is prevented.

Further, since the gradient (change) of the map is offset while maintaining the same duty so as to pass the held Duty value, the map itself moves in accordance with the basic air amount, and both rise and fall of the engine speed are performed normally. Becomes equivalent to change,
The same operability as usual can be secured.

Further, the fully-closed switch is turned from ON to OF.
Set the adjustment value when switching to F to the fully closed switch OFF
Since the time map is reflected, the behavior of the engine speed by the opening / closing operation of the throttle valve after the fully closed switch is turned off can be made similar to the behavior in the normal state.

Further, the offset is determined by the method of determining the engine speed and the adjustment value when the fully-closed switch is switched from ON to OFF by the difference between the same grid point of the basic map and the engine. Reduces the possibility of stalls.

Since the upper and lower limits are set for the offset amount, even when the fully closed switch is switched from ON to OFF immediately after the engine is started or during a dashpot, the rotation of the engine suddenly decreases or decreases. There is no problem such as no longer running.

[Brief description of the drawings]

FIG. 1 is a right side view of an outboard motor showing an embodiment of an engine control device according to the present invention.

FIG. 2 is an enlarged right side view of an engine portion of the outboard motor shown in FIG.

FIG. 3 is a system diagram of the outboard engine shown in FIG. 1;

FIG. 4 is a block diagram of the engine system shown in FIG. 3;

FIG. 5 is a flowchart showing a control flow.

FIG. 6 is a table showing a first embodiment of a basic map when a fully closed switch is OFF.

FIG. 7 is a table showing a second embodiment of the basic map when the fully closed switch is OFF.

FIG. 8 is a timing chart of control.

[Explanation of symbols]

Reference Signs List 1 outboard motor 5 engine 15 shift device 32 fuel injector 41 throttle body 50 control unit 52 cylinder temperature sensor 53 manifold temperature sensor 54a, 54b ignition coil 55 neutral switch 56 crank angle sensor 57 IAC solenoid valve 58 air bypass screw 59 throttle valve 60 Fully-closed switch of throttle valve B Upper and lower limit value of Duty offset D Duty of solenoid valve Dub of basic map at offset reference point of Db map
ty Dc Duty Ne engine speed actually shifted Offset reference point of the Nec map (from ON to OFF)
Rotation speed

Claims (6)

[Claims] In an engine in which a solenoid valve is provided in an intake device to control an amount of intake air by duty control, a throttle valve provided inside a throttle body constituting the intake device is turned off when a throttle valve is fully closed.
N-operated fully-closed switch is provided, and this fully-closed switch is
The engine is characterized in that, when switching from N to OFF, the duty of the solenoid valve is maintained at the current duty and the adjustment value of the solenoid valve does not change when the fully closed switch is switched. Control device. 2. The engine control device according to claim 1, wherein a gradient (change) of the map is offset while maintaining the same duty so as to pass through the held duty value. 3. The engine control device according to claim 1, wherein an adjustment value when the fully closed switch is switched from ON to OFF is reflected in a map when the fully closed switch is OFF. 4. The method according to claim 1, wherein the offset is determined by a method of determining the engine speed and the adjustment value when the fully-closed switch is switched from ON to OFF by a difference between similar grid points in a basic map. 4. The control device for an engine according to claim 2 or 3. 5. The engine control device according to claim 1, wherein upper and lower limits are set for the offset amount. 6. The engine control device according to claim 1, wherein the engine is an engine for an outboard motor having a crankshaft vertically provided therein.