JPH04325735A - Internal combustion engine controlling device for outboard motor - Google Patents

Abstract

PURPOSE:To prevent rapid increasing of a rotational speed so as to improve stability and the life of an internal combustion engine by controlling the internal combustion engine so as to restrict the rotational speed when it is detected by a floation detector that a screw is floated on a water surface. CONSTITUTION:An internal combustion engine controlling device for an outboard motor is provided with a rotational speed detector for detecting the rotational speed (R) of an internal combustion engine, a floation detector 8 for outputting a floation signal (F) when the screw of the internal combustion engine is floated on a water surface, and a control circuit 6 for operating the control parameter of the internal combustion engine on the basis of the signal thereof. When the floation signal (F) is inputted from the floation detector 8 to the control circuit 6, a driving signal (A) is outputted to an actuator 7 by the rotational speed controlling means of the control circuit 6 so as to control reduction in output of the internal combustion engine 1. Or a throttle detector for detecting a throttle opening alpha is provided, and upper limit rotational speed is calculated at all times according to the throttle opening alpha at the time of operation. When the rotational speed of the internal combustion engine 1 is exceeds the upper limit rotational speed, it is judged that the screw is floated so as to restrict the rotational speed.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to a control device for an internal combustion engine used in an outboard motor, and more particularly to an internal combustion engine control device for an outboard motor that prevents runaway rotation when the screw of the internal combustion engine rises from the water surface. It is something.

0002

2. Description of the Related Art FIG. 4 is a side view showing the appearance of a general internal combustion engine for an outboard motor. The screw, 3, which is rotationally driven by the internal combustion engine 1 via the fixed part 1a,
This is the hull to which the

FIG. 5 is a block diagram showing a general internal combustion engine control device for an outboard motor. In the figure, 4 indicates an internal combustion engine 1.
5 is a rotation detector provided on the camshaft or crankshaft to detect the rotation speed R; 5 is a throttle detector that detects the throttle opening α corresponding to the accelerator operation amount of the internal combustion engine; 6 is a rotation speed R and the throttle opening; A control circuit that operates control parameters of the internal combustion engine based on various signals including the degree α; 7 is an internal combustion engine 1 driven by a drive signal A from the control circuit 6;
actuator.

Note that the rotation detector 4 generates a crank angle reference position signal synchronized with the rotation of the internal combustion engine 1, and outputs a crank angle reference position signal to the control circuit 6.
is being entered. Further, various signals indicating the operating state of the internal combustion engine are inputted to the control circuit 6 from various detectors (not shown). Further, the actuator 7 includes various drive control elements related to the internal combustion engine 1, such as a fuel pump, an ignition coil, a throttle, and a starting motor.

Next, the operation of a conventional internal combustion engine control system for an outboard motor will be explained with reference to FIGS. 4 and 5. The control circuit 6 generates a drive signal A based on various signals including rotational speed R, throttle opening α, crank angle reference position signal, and various operating conditions, and controls the actuator 7 (for example, fuel pump and ignition coil). and calculates and controls fuel injection timing and ignition timing. Further, the throttle opening degree α is determined according to the gear position, etc., and the air supply flow rate is adjusted to control the internal combustion engine 1 to a desired rotation speed.

By the way, in the case of the internal combustion engine 1 for an outboard motor,
During normal driving, the hull 3 swings on the water surface, so the screw 2 may float above the water surface. In particular, since the internal combustion engine 1 is operated with an appropriate inclination in the direction of the arrow around the fixed portion 1a, the screw 2 is likely to float above the water surface. If the screw 2 rises to the surface of the water, the rotational speed R of the internal combustion engine 1 will rapidly increase due to the sudden decrease in load, causing the engine to run out of control, and the internal combustion engine 1 will be damaged due to overspeeding and the sudden increase in load when re-entering the water surface. This will shorten your lifespan.

Therefore, conventionally, the upper limit permissible rotation speed of the internal combustion engine 1 is set in advance, and control is performed so that the upper limit permissible rotation speed is not exceeded to prevent the internal combustion engine 1 from running out of control. However, when the screw 2 floats up, the rotational speed always increases to the upper limit permissible rotational speed, so that sufficient safety cannot be ensured and the life of the internal combustion engine 1 cannot be improved.

[0008]

[Problems to be Solved by the Invention] As described above, the conventional internal combustion engine control device for outboard motors has a fixed upper limit allowable rotation speed, so if the screw 2 floats at low rotation speeds, the rotation speed will be reduced. There is a risk that the number of screws may increase rapidly and run out of control, which is not an effective countermeasure against screw floating, and there is a problem that safety cannot be ensured and the life of the internal combustion engine 1 cannot be improved.

[0009] This invention was made to solve the above-mentioned problems, and by limiting the rotational speed of the internal combustion engine when the screw rises above the water surface, a sudden increase in the rotational speed can be prevented. An object of the present invention is to obtain an internal combustion engine control device for an outboard motor that improves safety and the life of the internal combustion engine.

0010

[Means for Solving the Problems] An internal combustion engine control device for an outboard motor according to the present invention includes a rotation detector that detects the rotation speed of the internal combustion engine, and a surfacing signal that outputs a surfacing signal when the screw of the internal combustion engine rises from the water surface. A levitation detector that outputs, a control circuit that operates control parameters of the internal combustion engine based on various signals including the rotation speed and levitation signals, an actuator that is driven by a drive signal from the control circuit, and a control circuit that is included in the control circuit. and rotation speed limiting means for limiting the rotation speed in response to a levitation signal.

[0011] Further, an internal combustion engine control device for an outboard motor according to another aspect of the present invention includes: a rotation detector for detecting the rotation speed of the internal combustion engine; a throttle detector for detecting the throttle opening of the internal combustion engine; A control circuit that operates control parameters of the internal combustion engine based on various signals including rotation speed and throttle opening, an actuator that is driven by drive signals from the control circuit, and an actuator that is included in the control circuit and operates according to the throttle opening. The engine is equipped with upper limit rotation speed calculating means for generating an upper limit rotation speed, and rotation speed limiting means included in the control circuit and limiting the rotation speed when the rotation speed exceeds the upper limit rotation speed.

0012

[Operation] In the present invention, when the floating of the screw is detected, the rotational speed of the internal combustion engine is limited to prevent a sudden increase in the rotational speed.

[0013] In another aspect of the present invention, the upper limit rotation speed is always calculated according to the throttle opening degree during operation,
When the rotational speed of the internal combustion engine exceeds the upper limit rotational speed, it is determined that the screw is floating, and the rotational speed is limited to prevent runaway due to a sudden increase in the rotational speed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a control circuit according to an embodiment of the present invention, where 7, R, α, and A are the same as described above. Further, the structure of the internal combustion engine 1 and the entire device is as shown in FIGS. 4 and 5.

In FIG. 1, 61 is an input interface for receiving various signals including the rotational speed R, throttle opening α, and other operating conditions, 62 is a microcomputer for receiving various signals via the input interface 61, and 63 is a microcomputer for receiving various signals via the input interface 61. This is an output interface for sending the drive signal A generated from the microcomputer 62 to the actuator 7.

Reference numeral 8 denotes a levitation detector that outputs a levitation signal F to the input interface 61 when the screw 2 of the internal combustion engine 1 rises from the water surface, and is a levitation detector that detects a resistance change between electrodes or a floating switch. It has become. In this case, the microcomputer 62 in the control circuit 6 includes rotation speed limiting means for limiting the rotation speed R in response to the levitation signal F.

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be explained with reference to the flowchart in FIG. 2 and FIGS. 4 and 5. FIG. 2 shows the processing procedure of the microcomputer 62. First, the rotation speed R of the internal combustion engine is detected (step S1).

Next, it is determined whether or not the levitation signal F is input from the levitation detector 8, that is, whether or not the screw 2 is floating (step S2). , the output of the internal combustion engine 1 is reduced according to the rotational speed R at that time, and the rotational speed R is limited to prevent runaway (
Step S3).

The rotational speed limit amount at this time may be calculated from the rotational speed R immediately before the levitation signal F is input, or may be stored in advance as a table map. Further, the output reduction control of the internal combustion engine 1 is performed by various methods using the drive signal A to the actuator 7. For example, reduce the fuel discharge amount of the fuel pump, shift the energization timing of the ignition coil to the retarded side, or
This is done by reducing the throttle opening degree α.

In the above embodiment, the levitation state of the screw 2 was determined based on the levitation signal F from the levitation detector 8. You may judge. In this case, the control circuit 6
The microcomputer 62 inside includes an upper limit rotation speed calculation means that generates an upper limit rotation speed RM according to the throttle opening degree α, and a rotation speed limiter that limits the rotation speed R when the rotation speed R exceeds the upper limit rotation speed RM. means.

FIG. 3 is a flowchart showing the operation of another embodiment of the present invention that can determine the floating state of the screw 2 based on the rotational speed R and the throttle opening α, and steps S1 and S3 are the same as described above. This is the step. First, the rotation speed R (step S1) and the throttle opening α
is detected (step S11), and the upper limit rotational speed RM corresponding to the throttle opening degree α at that time is determined from RM=f(α) (step S12).

Next, the detected rotational speed R and the calculated upper limit rotational speed RM are compared, and the rotational speed R is determined to be the upper limit rotational speed RM.
is exceeded (RM<R) (step S1
3). If it is determined that the rotation speed R exceeds the upper limit rotation speed RM, it is recognized that the screw 2 has floated, and the rotation speed R is limited (step S3). The rotational speed limit amount at this time may be calculated according to the rotational speed R as described above,
The rotation speed may be limited to be equal to or less than the upper limit rotation speed RM calculated in step S12.

As a result, even when the load suddenly changes due to the floating of the screw, the internal combustion engine 1 does not overspeed.
Safety is ensured, and damage to the internal combustion engine 1 can be prevented in advance and reliably.

[0024]

As described above, according to the present invention, there are provided a rotation detector for detecting the rotation speed of an internal combustion engine, a levitation detector for outputting a levitation signal when the screw of the internal combustion engine rises from the water surface, and a levitation detector for detecting the rotation speed of an internal combustion engine. a control circuit that operates control parameters of an internal combustion engine based on various signals including a number and a levitation signal; an actuator that is driven by a drive signal from the control circuit; When the floating of the screw is detected, the engine speed is restricted to prevent a sudden increase in the engine speed, thereby improving safety and the life of the internal combustion engine. This has the effect of providing an internal combustion engine control device for an outboard motor with improved performance.

According to another aspect of the present invention, there is provided a rotation detector for detecting the rotation speed of the internal combustion engine, a throttle detector for detecting the throttle opening of the internal combustion engine, and a rotation detector that detects the rotation speed and the throttle opening. A control circuit that operates control parameters of the internal combustion engine based on various signals, an actuator that is driven by drive signals from the control circuit, and an upper limit rotation that is included in the control circuit and generates an upper limit rotation speed depending on the throttle opening. Equipped with a numerical calculation means and a rotation speed limiting means that is included in the control circuit and limits the rotation speed when the rotation speed exceeds the upper limit rotation speed, and constantly calculates the upper limit rotation speed according to the throttle opening degree during operation. This internal combustion engine control system for outboard motors improves safety and the life of the internal combustion engine by determining that the screw is floating when the rotation speed exceeds the upper limit rotation speed and limiting the rotation speed. There is an effect that can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a control circuit according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of the microcomputer in FIG. 1;

FIG. 3 is a flowchart showing a processing procedure of a microcomputer according to another embodiment of the present invention.

FIG. 4 is a block diagram showing a general internal combustion engine control device for an outboard motor.

FIG. 5 is a side view showing a general internal combustion engine for an outboard motor.

[Explanation of symbols]

1 Internal combustion engine 4 Rotation detector 5 Throttle detector 6 Control circuit 7 Actuator 8 Levitation detector 62 Microcomputer R Rotation speed α Throttle opening degree F Levitation signal A Drive signal S1 Step S2 of detecting the rotation speed Determine the levitation of the screw Step S3 Step S12 to limit the rotation speed Step S13 to calculate the upper limit rotation speed Step S13 to determine whether the rotation speed exceeds the upper limit rotation speed

Claims (2)

[Claims] 1. A rotation detector that detects the rotation speed of an internal combustion engine; a levitation detector that outputs a levitation signal when the screw of the internal combustion engine rises from the water surface; The engine includes a control circuit that operates control parameters of the internal combustion engine based on a signal, and an actuator that is driven by a drive signal from the control circuit, and the control circuit limits the rotation speed in response to the levitation signal. An internal combustion engine control device for an outboard motor, characterized in that it includes rotation speed limiting means. 2. A rotation detector that detects the rotation speed of the internal combustion engine, a throttle detector that detects the throttle opening of the internal combustion engine, and a rotation detector that detects the rotation speed of the internal combustion engine based on various signals including the rotation speed and the throttle opening. The control circuit includes a control circuit that operates control parameters of the engine, and an actuator driven by a drive signal from the control circuit, and the control circuit includes upper limit rotation speed calculation means that generates an upper limit rotation speed according to the throttle opening. and rotation speed limiting means for limiting the rotation speed when the rotation speed exceeds the upper limit rotation speed.