JPH09126019A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent rapid increase of the engine rotational speed even when the engine rotational speed is changed from the low engine rotational speed range to the high engine rotational speed range. SOLUTION: In an engine control device provided with an engine rotational speed detecting means 11 to detect the engine rotational speed and a main control part 9 to control the engine rotational speed, the main control part 9 operates the increase ratio of the engine rotational speed based on the detected value obtained from the engine rotational speed detecting means 11, and when the increase ratio of the engine rotational speed exceeds the prescribed value, the main control part 9 has the engine rotational speed suppression control function to control the suppression of the engine rotational speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device, and more particularly to an engine control device for controlling the rotational speed of an engine used in an outboard motor of a ship or the like.

[0002]

2. Description of the Related Art Conventionally, there have been the following engine control devices for controlling the number of revolutions of an engine in order to prevent deterioration of the engine due to excessive rotation.
That is, the engine speed is constantly detected, and the engine speed is controlled so as not to rise above a predetermined value.

More specifically, when the engine is under a certain load, for example, when the ship is sailing on the water surface in a steady state, the engine speed is
Maintain a constant value based on load for navigation and engine power. Then, in order to accelerate the ship, the throttle is opened, the engine speed increases, and the speed of the ship also increases.

On the other hand, when the ship is turning or when the screw connected to the engine is exposed to the air from the water surface for some reason, the load applied to the engine is suddenly reduced, and the engine speed may be rapidly increased. . At this time, in the conventional engine control device, the upper limit of the engine speed (overrev limiter speed) is set in advance, and when the predetermined speed is reached, the energization to the spark plug is cut off. . Therefore, the engine speed is maintained near a predetermined value.

[0005]

However, in the above conventional example, the following inconveniences have occurred. That is, according to the above-described conventional example, the engine speed is maintained near the allowable speed when overspeed occurs. However, when the engine output is considerably high when the ship is traveling and the load is suddenly reduced from the state where the engine load is large, the engine speed instantaneously reaches the overspeed prevention set speed. Then, although the rotation speed is maintained by the rotation speed suppression control, the load increases again after the ship has passed over waves or jumped.

That is, since the cycle of heavy load state → light load state → heavy load state is repeated, there is a problem that a large force fluctuation is applied to the engine and the engine is deteriorated depending on its magnitude and frequency. In particular, the engine of a ship, unlike an automobile or the like, poses a problem because the throttle operated by the driver is usually fixed at a fixed position.

Further, in the above-mentioned conventional example, the engine speed is only controlled so as not to exceed a certain upper limit value, so that the engine speed is not controlled in the low speed region and the medium speed region. Therefore, in the low and medium speed range, when the attitude of the hull is changed or the screw connected to the engine is exposed from the water surface based on the trim control of the outboard motor or the like, the rotational speed rapidly increases due to a sudden decrease in load. Therefore, when the screw again enters the water surface, the load suddenly increases, and the propulsive force is applied to the ship. As a result, there is an inconvenience that the riding comfort of the ship deteriorates.

[0008]

It is an object of the present invention to improve the above-mentioned disadvantages of the conventional example, and particularly to prevent a rapid increase in the engine speed even in a low speed range (low speed range) to a high speed range (high speed). It is an object of the present invention to provide an engine control device that can do the above.

[0009]

In order to achieve the above-mentioned object, in the invention according to claim 1, a rotation speed detecting means for detecting the rotation speed of the engine, and a main control portion for controlling the rotation speed of the engine are provided. In the engine control device provided with, the main control unit calculates the increase rate of the engine speed based on the detection value obtained from the rotation speed detection means, and the increase rate of the engine speed becomes equal to or higher than a predetermined value. In this case, the main control unit has a rotational speed suppression control function for suppressing the rotational speed of the engine.

With the above construction, first, the engine speed detecting means provided in the engine control device always detects the engine speed and transmits the engine speed data to the main control section. Then, the main control unit calculates the degree of increase in the rotation speed per unit time (rotation speed increase rate) based on the rotation speed data. That is, the data obtained by differentiating the rotation speed with respect to time is calculated.

Then, the main control section compares the above-described rotation speed increase rate with the rotation speed increase rate reference value stored in the main control section. At this time, if the calculated rotation speed increase rate exceeds the reference value, the main control unit suppresses the rotation speed of the engine. Specifically, the power supply to the ignition plug is cut off or the throttle provided in the suction pipe is closed.

From the above, even if the engine speed increase rate exceeds a predetermined value even in the low engine speed region, the main control unit presumes that this is an abnormal situation and positively rotates the engine. Suppress and control the number. As a result, appropriate engine control can be performed over a wide range from the low speed range to the high speed range.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the drawings. First, as shown in FIG. 8, the configuration of the control system of the engine control device 1 includes a microcomputer 3, an input / output interface 5, and the like. Main control unit 9 equipped with 7
And a rotation speed detecting means 11 for detecting the rotation speed of the engine.
A throttle opening detector 13 for detecting the opening of the throttle valve, and an intake air amount detector 15 for detecting the amount of air taken into the engine.

In addition to the above, the engine control device 1 is
Various actuators 17 for controlling the engine speed are provided. Specifically, the actuator 17 includes an ignition mechanism equipped with an ignition plug and the like, and a throttle valve 19 for adjusting the intake air amount as shown in FIG.
And a step motor 21 for driving the motor. Further, means for changing the fuel supply amount, means for changing the ignition timing, and the like are also conceivable.

Here, the above-mentioned throttle valves 19 and 25
More specifically, the main throttle valve 25 and the sub-throttle valve 19 are provided inside the throttle body 23 incorporated in the engine of the outboard motor. The main throttle valve 25 is adapted to be opened and closed by the operation of the throttle lever by the boat operator.
Further, the sub-throttle valve 19 has a throttle body 23.
When the intake air amount is controlled to control the engine speed, it is opened and closed by a step motor 21 attached to the sub-throttle valve 19.

Next, a method of controlling the rotation speed by the engine control device according to this embodiment will be described with reference to FIG.

First, when the ship is traveling, the rotation speed data from the rotation speed detecting means 11 is constantly transmitted to the main control section 9,
Then, it is calculated as the actual rotation speed N [rpm] in the main controller 9 (S1). Here, the rotation speed detection means 11
Is a rotary encoder (not shown) arranged at one end of the output shaft of the engine control device 1. The rotary encoder generates one pulse each time the engine makes one revolution, and the counter circuit formed in the main control unit 9 counts the number of pulses and replaces it with the number of revolutions. It has become.

Next, the main control section 9 compares the engine speed N calculated by the above-mentioned method with the control start speed A stored in the main control section 9 (S2). The control start rotation speed A is a value set for not performing the rotation speed suppression control in the low rotation speed region, and is appropriately determined according to the characteristics of the ship. When the detected rotation speed N is lower than the control start rotation speed A [rpm], the rotation speed suppression control is not performed and the process returns to the start stage of the control flow in FIG. 1. On the other hand, the detected rotation speed N is the control start rotation speed A.
If it exceeds, then the flow proceeds to the rotational speed suppression control.

When the engine speed N exceeds the control start speed A, the main control section 9 always
The engine speed N that is changing every moment is stored in the engine speed storage means (S3). This is for calculating the reference value of the rotational speed to be controlled when performing the rotational speed suppression control described later. Therefore, when the rotational speed suppression control is subsequently started, the rotational speed of the engine immediately before that time is stored as the control reference rotational speed B [rpm].

Next, the main controller 9 also calculates the rotation speed increase rate at that time. Specifically, this represents the amount of change in the number of revolutions per unit time, and is the number of revolutions N [rpm] differentiated by the time [t]. In this embodiment,
Since the engine speed suppression control is performed on the basis of the engine speed increase rate, it is important to calculate the engine speed increase rate. Hereafter, the rate of increase in the number of revolutions is expressed as
Expressed by

Then, the above-mentioned rotational speed increase rate ΔN / Δt
Does not exceed the reference value C, it is determined that the vehicle is in a normal traveling state, and the rotation speed suppression control is not performed (S4). This reference value C is obtained in relation to the output characteristics of the engine and the shape of the hull. Specifically, when an engine that produces a large output is mounted on a small ship,
Even during normal sailing, the rate of increase in engine speed becomes large. On the other hand, when an engine with a small output is mounted on a large ship, the rate of increase in engine speed becomes small. However, since the engine speed increase rate when the load is not applied to the engine becomes extremely large, the reference value C of the engine speed increase rate can be easily determined by experiments or the like.

On the other hand, the rotation speed increase rate ΔN / Δt is the reference value C.
When it exceeds, it is presumed that some inconvenience has occurred in the ship or the engine, and the main control unit 9 starts the warning display for calling the driver's attention and also starts the rotation speed suppression control ( S5). Here, as the warning to the driver, for example, a case where a warning light provided on the control panel is turned on or a warning buzzer is turned on can be considered.

Next, the rotation speed increase rate ΔN / Δt is the reference value C.
A specific method for controlling the rotation speed suppression when the value exceeds the above will be described in detail.

First, when the rotational speed suppression control is started, the main control section 9 cuts off the power supply to the spark plug mounted on the engine. At this time, when the engine is equipped with a plurality of cylinders, the ignition cut control is performed at the next ignition timing in the ignition plug of one cylinder, for example. In this case, the ignition cut control is not limited to one cylinder. From the above, the combustion is not performed in all or part of the cylinders of the engine, and the output is reduced. As a result, the number of revolutions of the engine does not increase any more, and an abnormal increase in the number of revolutions is effectively prevented.

Here, the concrete method of the rotational speed suppression control is not limited to the above-described energization cutoff,
For example, the same effect can be obtained when the fuel supply is cut off or when the throttle valve shown in FIG. 8 is controlled to be closed. In this case, the main control unit 9 outputs a control signal to the step motor 21 to open and close the sub-throttle valve of the throttle body when performing the rotational speed suppression control based on the control of the intake air amount ( (See FIG. 9).

Then, the main control section 9 resets the variable X to zero. This variable X is a variable used to determine the number of rotation speed suppression control described later, and is initially set to zero (S6).

Subsequently, the main control section 9 counts the elapsed time from the start of the rotation speed suppression control by the timer (S7), and subsequently, the engine rotation speed N [rpm] is equal to the control start rotation speed B described above. It is determined whether or not the sum exceeds a predetermined value D (S8). This predetermined value D is the control reference speed B
To control the engine speed within a fixed range.

Here, the reference value C of the above-mentioned rotation speed increase rate
And the value of D must be set according to the characteristics of the engine and the hull. Further, these values do not have to be fixed, and, for example, as shown in FIG. 2, different values can be set according to the value of the control reference rotational speed B immediately before the rotational speed suppression control. .

Further, when the fixed time has not elapsed since the start of the rotation speed suppression control, when the main control portion 9 determines that the rotation speed N of the engine exceeds the value of B + D, the main control portion 9 does not change. The rotation speed suppression control is continued repeatedly.

When the engine speed N is lower than the value of B + D by continuously performing the engine speed suppression control, the engine speed suppression control is canceled (S9), and the normal control is performed. Is resumed. That is, when the rotational speed suppression control is performed once, it is determined whether the rotational speed is B + D or higher or lower until the control is released and the normal control is resumed. Return the power to the unit as usual.

At this time, the main control section 9 determines the number of times of rotation speed suppression control based on the value of the variable X described above. That is,
When the first rotation speed suppression control is performed, the variable X
The value of is set to zero, which is the initial value. Then, the control number reference value E, which is the reference value of the number of rotation speed suppression control, is compared with X (S10). Here, the control count reference value E
Is usually set to a sufficient number of times considered necessary for the ship to return from a special sailing state to a normal sailing state.

From the above, since a positive positive number is set for E, X is a value smaller than E. Then, following the above, 1 is added to X (S11), and the value of X becomes 1 this time. Then, it is further determined whether or not a fixed time has elapsed from the start of the rotation speed suppression control, and if it has not elapsed, the same rotation speed comparison is performed as described above (S
8), control is repeated. When the start and release control of the rotation speed suppression control is performed a predetermined number of times E, the value of X becomes E + 1 in the next control process, the rotation speed suppression control is completely released, and the normal control is performed. Return.

Also, during the rotational speed suppression control, when the driver does not notice the warning display and opens the throttle, the normal output increases, and even when the normal load condition is restored, the above-mentioned standard is satisfied. The rotation speed may not be lower than B + C. Therefore, the control returns to the normal control after the elapse of the fixed time set by the timer (S12). However, even in this case, if the rotation speed suppression control is unconditionally released, the rotation speed may suddenly increase, so that the rotation speed suppression control is gradually returned to the normal control (S12).

Next, a specific example of control by the engine control device 1 configured as described above will be described with reference to FIGS. 3 to 5. Here, FIG. 3 is a diagram showing the relationship between the throttle opening and the engine speed in the acceleration region and the steady region at the time of traveling of the ship equipped with the engine according to the present embodiment.

First, in FIG. 3, the throttle is opened and fixed at a fixed position. Along with this, the engine speed increases and the ship is also accelerated. At this time,
When the vessel is operating normally, the rotation speed smoothly rises to a steady state (two-dot chain line in the figure). On the other hand, as shown in the figure, when the screw is exposed from the water surface due to a change in posture due to some reason on the ship,
The engine speed rises sharply.

In the conventional control, the upper limit M of the rotation speed is M.
Is set, but no control is performed in the rotational speed range between them. Therefore, the engine has an upper limit speed M
The rotational speed suppression control is performed only when the temperature reaches the value (dotted line in the figure). For this reason, the engine speed unnecessarily increases, and the navigation of the ship becomes unstable in some cases.

On the other hand, in the engine control device according to this embodiment, the rotation speed suppression control is performed not only in the vicinity of the upper limit rotation speed M of the engine but also in the entire rotation speed region above the control start rotation speed A. That is, when the engine speed rapidly increases in the acceleration range in the figure, the rate of increase in engine speed ΔN / Δt at that time is calculated. When the calculated value of the rotation speed increase rate ΔN / Δt exceeds a predetermined value C, it is determined that the engine speed is abnormal, and the engine speed is controlled to be suppressed as described above (solid line in the figure). ). Therefore,
According to the engine control device of the present embodiment, there is almost no separation from the engine speed during normal traveling,
The rotation speed is controlled appropriately. This also applies to the case where the screw is exposed due to the influence of waves or the like and the engine speed sharply rises during traveling in the steady region.

Next, FIG. 4 is a diagram showing another example of the rotational speed suppression control in the acceleration region in FIG. This figure 4
According to the above, when the rotational speed suppression control of the present invention is started during the operation of the throttle, the throttle is opened during the control and the output has already increased even when the load applied to the engine returns to normal. In some cases, the rotation speed does not fall below B + D. In such a case, a warning display or the like may be displayed to prompt the driver to return the throttle. However, when the load decreases during turning or jumping, the rotation speed rises in a short time. Therefore, after a certain time (W in the figure) has elapsed from the start of the rotation speed suppression control by the timer,
It is also effective to completely release the control.

Further, in the case of the above control, the output is too large when the control is released, depending on how the throttle is opened,
Since the engine speed may increase, it is also effective to gradually return from the engine speed suppression control to the normal control (Y in the figure). As a result, the hull accelerates smoothly and the riding comfort is improved.

FIG. 5 is a diagram showing a change in the rotation speed when the rotation speed suppression control is continuously performed (Z in the drawing). As in the case described above, the alternate long and short dash line represents the conventional case. In the above control, the solid line indicates the control according to the present embodiment. In the conventional rotational speed suppression control, as shown in the figure, the upper limit rotational speed M is used as a reference, and when the upper limit rotational speed is simply exceeded, the energization to the spark plug is cut off. It is designed to control.

On the other hand, in the rotational speed suppression control of this embodiment,
Immediately before the rotational speed suppression control, the rotational speed B [rpm] of the engine
Then, control is performed using the sum of a certain predetermined value D [rpm] as a reference value. For example, if the engine speed is B = 3000 [rp
m], it is assumed that the engine speed sharply increases.
Then, the predetermined value of the rotational speed at this time D = 300 [rpm]
Suppose that Under this condition, B + D or 33
The rotation speed suppression control is performed based on 00 [rpm]. Specifically, in the area shown in FIG. 5, the rotation speed suppression control is performed. On the other hand, normal control is performed in the area shown in the figure. With this, although it includes small fluctuations,
The engine is controlled around 3300 [rpm].

As described above, according to the present embodiment, when the degree of change ΔN / Δt of the engine speed, which has increased due to the sudden decrease in the load when the throttle opening is constant, exceeds the reference value C described above. Is calculated by adding the sum of the engine speed B before rising and a certain predetermined value D to calculate the reference speed, and when the throttle opening is constant, the engine speed is the reference speed B + D.
Every time it exceeds the limit, the engine speed is reduced by performing ignition cut, etc., so it is possible to perform finer engine speed suppression control than the conventional one, and to increase the engine speed by the conventional overspeed prevention setting rotation. The number of revolutions can be suppressed to be considerably lower than the number (see FIG. 6). In other words,
Not only in the high rotation speed range, but also in the low rotation speed range, it is possible to positively suppress a rapid increase in the rotation speed.

As described above, it is possible to prevent the engine speed from rapidly increasing (over-rotation) when the load on the hull of the vessel equipped with the outboard motor or the outboard motor screw is suddenly reduced, and at the same time, when the over-rotation occurs It is possible to prevent a problem that a large load is applied to the engine, and as a result, it is possible to prevent deterioration of the engine.

Further, according to this embodiment, it is possible to prevent the engine speed from rapidly increasing (excessive rotation), so that it is possible to improve the riding comfort of the ship. In addition, when the ship is turning, which requires a certain amount of handle operation force by the ship operator, it is not necessary to operate the throttle lever as in the related art, and thus the feeling of maneuvering of the ship can be improved.

Further, since the above-mentioned effects can be obtained only by modifying a part of the system such as changing the control program of the main control section, the cost is preferable.

[0046]

The present invention is constructed and functions as described above, and according to the invention of claim 1, the main control unit monitors the engine speed, and the engine speed increase rate is a predetermined value. If the engine speed is exceeded, the engine speed is controlled to be suppressed, so that the engine speed is appropriately controlled not only in the high speed region but also in the low to medium speed region, and as a result, the engine is always maintained in the allowable speed region. It produces the excellent effect of

Further, according to the present invention, the rapid increase of the rotation speed can be effectively suppressed even in the low rotation speed region.
The excellent effect that the riding comfort of the ship is improved even when traveling at low and medium speeds is produced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flowchart of a rotation speed suppression control in the present embodiment.

FIG. 2 is a chart showing a map of a rotation speed increase rate C and a predetermined value D at each rotation speed of the engine.

FIG. 3 is a diagram showing a relationship between time and engine speed under various conditions when accelerating with a constant throttle.

FIG. 4 is a diagram showing a relationship between time and an engine speed in an acceleration region.

FIG. 5 is a diagram showing a relationship between time and engine rotation speed when the rotation speed is maintained and controlled within a predetermined range.

6A and 6B are views showing a case where a screw installed in the engine is exposed from the water surface, FIG. 6A shows a state of turning, FIG. 6B shows a state of trim control, and FIG. [Fig. 3] is a diagram showing a state where the hull is receiving waves.

FIG. 7 is an enlarged view showing the engine during the trim control disclosed in FIG. 6 (b).

FIG. 8 shows a system block diagram of the present embodiment.

9 is a cross-sectional view showing a throttle mechanism provided in an intake pipe, FIG. 9 (a) is an upper cross-sectional view, and FIG. 9 (b) is a lateral cross-sectional view.

[Explanation of symbols]

 1 Engine Control Device 9 Main Control Unit 11 Rotation Speed Detection Means A Control Start Rotation Speed B Control Reference Speed C Reference Speed Rise Reference Value

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Claims (1)

[Claims] 1. An engine control device comprising: a rotation speed detecting means for detecting the rotation speed of an engine; and a main control portion for controlling the rotation speed of the engine, wherein the main control portion is obtained from the rotation speed detecting means. The rate of increase of the engine speed is calculated based on the detected value, and when the rate of increase of the engine speed is equal to or higher than a predetermined value, the main control unit controls the engine speed to be suppressed. An engine control device having a number suppression control function.