JPH0942013A - Control method for fuel injection type internal combustion engine of outboard motor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a control method and apparatus for an internal combustion engine for a ship, which can achieve ignition timing and fuel injection control that always provide an optimum combustion state regardless of whether the engine is a 2-cycle engine or a 4-cycle engine. A trim angle detecting means corresponding to an installation angle of an outboard mounting portion including a propeller shaft is provided, an opening of an exhaust pipe is provided in the outboard mounting portion, and based on an engine speed and a throttle opening degree. In a control method of an electronically controlled internal combustion engine, which calculates a basic control amount of ignition timing and fuel injection, and calculates a correction amount for the basic control amount based on detection data of various operating states, a trim is used as the detection data of the operating state. Contains angle data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for controlling ignition timing and fuel injection in an outboard motor.

[0002]

2. Description of the Related Art In an electronically controlled fuel injection type internal combustion engine, ignition timing and fuel are controlled in order to obtain an optimum combustion state corresponding to various operating states such as throttle opening, engine speed, engine temperature and intake negative pressure. The injection amount is controlled.

Such an electronically controlled internal combustion engine is also used as an internal combustion engine for ships such as outboard motors. In the outboard motor, the main exhaust port of the exhaust pipe is provided near the propeller shaft to discharge the exhaust into the water.

[0004]

However, in an outboard motor in which the main exhaust port of the exhaust pipe is provided near the propeller shaft, if the trim angle, which is the relative angle of the outboard motor body to the hull, increases, The water level drops and the back pressure on the engine decreases. Therefore, in an outboard motor of a two-cycle engine, the air-fuel ratio changes to the lean side if the intake air amount in the scavenging exhaust stroke increases while the fuel supply amount is constant, and an optimal combustion state cannot be obtained. Also, in an outboard motor of a four-cycle engine, if the intake valve and the exhaust valve overlap in a low lift portion, the intake air is affected by the back pressure from the exhaust pipe and the air-fuel ratio changes similarly to achieve optimum combustion. The state cannot be obtained.

In the case of an internal combustion engine using a carburetor, the fuel intake amount is automatically increased in accordance with the decrease in intake negative pressure due to the increase in intake air amount, so that the air-fuel ratio is maintained substantially constant. This can be dealt with by performing the ignition timing advance control in response to the change in the pre-ignition mixture amount that is increased. However, even if this is applied to the fuel injection type internal combustion engine as it is, if the calculated fuel injection amount does not follow the change of the intake air amount, the optimum combustion state cannot be obtained.

The present invention has been made in view of the above problems of the prior art, and is for a marine vessel capable of achieving ignition timing and fuel injection control that always provide an optimum combustion state regardless of whether the engine is a 2-cycle engine or a 4-cycle engine. An object of the present invention is to provide a control method and apparatus for an internal combustion engine.

[0007]

In order to achieve the above object, according to the present invention, an engine equipped with an ignition device and a fuel injection device, a propeller, a propeller shaft for driving the propeller to receive engine output, and an exhaust gas of the engine. The outboard motor body having an exhaust port for discharging the outboard into the water and a support bracket for tiltably supporting the outboard motor body with respect to the body, and the inclination angle of the outboard motor body with respect to the support bracket. Control of the fuel injection type internal combustion engine of the outboard motor, which is used in the outboard motor having the trim angle detecting means for detecting the trim angle, and controls the ignition timing and the fuel injection amount according to the engine speed and the engine load. In the method, the amount of fuel injection is increased as the trim angle changes and the exhaust port position approaches the water surface based on the detection result of the trim angle. To provide a control method for a fuel injected internal combustion engine of the machine.

In a preferred embodiment, the fuel injection amount is obtained as a basic control amount on the basis of an engine speed and an engine load, and a correction amount or a correction coefficient for the basic control amount is obtained on the basis of a trim angle. It is characterized in that a correction amount is added to the basic control amount or the basic control amount is multiplied by a correction coefficient to obtain.

In another preferred embodiment, when the trim angle changes in the back pressure decreasing direction, the ignition timing is corrected so as to be advanced.

In a further preferred embodiment, the correction control amount is switched stepwise according to the change of the trim angle, and the correction amount switching position when the trim angle is increasing is greater than the correction amount switching position when the trim angle is decreasing. The feature is that the correction calculation is performed so as to have a large hysteresis.

A further preferred embodiment is characterized in that the trim angle for switching the correction amount of the ignition timing and the trim angle for switching the correction amount of the fuel injection are the same.

Further, in the present invention, an engine equipped with an ignition device and a fuel injection device, a propeller, a propeller shaft for driving the propeller to receive engine output, and an exhaust port for discharging engine exhaust into water are arranged. And a trim angle detecting means for detecting a trim angle which is a tilt angle of the outboard motor body with respect to the support bracket. In a control device for a fuel injection type internal combustion engine of an outboard motor that is used for an outboard motor that is placed and controls the ignition timing and the fuel injection amount according to the engine speed and engine load, the trim angle is detected based on the detection result of the trim angle. An outboard boat characterized in that the fuel injection device is driven and controlled so that the fuel injection amount increases as the angle changes and the exhaust port position approaches the water surface. To provide a control device for a fuel injected internal combustion engine.

[0013]

Operation: The trim angle is detected, and the corrected ignition timing corresponding to the trim angle with respect to the basic ignition timing is calculated. in this case,
The correction amount is calculated so that the ignition timing is advanced stepwise as the trim angle increases. Chattering is prevented by providing a hysteresis characteristic that makes the switching position of the correction amount different in the increasing and decreasing directions of the trim angle.

Similarly, for fuel injection, a corrected injection time corresponding to the trim angle with respect to the basic injection time is calculated.
In this case, as in the case of the ignition timing, the correction amount is calculated so that the fuel is increased stepwise as the trim angle increases. In addition, chattering is prevented by changing the correction amount switching positions in the increasing and decreasing directions of the trim angle.

By making the switching point of the correction control calculation according to the trim angle the same for the ignition timing and the fuel injection, the control corresponding to the optimum combustion state based on both correction amounts is always achieved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an external view of a two-machine outboard motor for a ship to which the present invention is applied. As shown in the figure, the outboard motors 406-1 and 40-1 including two engines at the stern of the hull 405.
6-2 is attached. This is a structure for obtaining sufficient propulsive force on the sea, and for enabling navigation even if one of the outboard motors is out of order and ensuring return to the port.

When two outboard motors are cruising as described above, the two engines are operated in a running state. When performing drive control of the two-engine engine, each engine needs to be able to operate independently, and therefore each engine has a drive control device. Each control device detects various operating states such as engine speed, throttle opening, accelerator position, so-called load such as intake pipe negative pressure, intake air temperature, exhaust gas oxygen concentration, shift position, etc., and based on this detection information. ,
The optimum air-fuel ratio, the fuel injection amount, the injection timing, the ignition timing, etc. at that time are calculated according to a predetermined control program, and the engine is drive-controlled based on the calculated values. In this case, the control program has a detection information read routine and a main routine in which a plurality of calculation routines for calculating each control amount based on the read detection information are arranged in accordance with a predetermined sequence. Arithmetic processing is performed.

FIG. 2 is a block diagram of the drive operation system for the throttle and gear shift of one of the two outboard motors. The outboard motor main body 38 is mounted on the tilt shaft 3 with respect to the hull 36 via a bracket 37a and a clamp bracket 37b.
The trim angle θ can be changed around 05. 30
6 is a variable trim angle actuator, and 39 is a trim angle sensor. The trim angle θ indicates how much the direction of the central axis of the propeller 10 is inclined from the ship bottom. When the trim angle is 0 °, that is, when the central axis of the propeller 10 is parallel to the bottom of the outboard motor, the outboard motor is generally formed so that the front edge of the outboard motor body 38 is aligned with the vertical line. The relative angle θ with respect to the line may be called a trim angle.

A shift lever 50 having a cam 51 at its end
Is connected to the link bar 53 in the cowling via a pivot piece 52. The cam 51 is for shifting a clutch connecting the engine and the propeller shaft. A pin 55 is provided so as to project from the end of the link bar 53. The pin 55 is slidably mounted as shown by an arrow A in the long hole guide 54 fixed in the cowling.

On the other hand, a remote control box 56 for gear shift and throttle operation is provided inside each outboard motor 406-.
Two are provided for 1,406-2. This remote control box 56 is provided with the shift cable 5 for the outboard motor body 38.
7, throttle cable 58 and electric signal cable 5
It can be connected via three cables of 9. The shift cable 57 is connected to the pin 55 of the above-mentioned link bar 53 in the cowling. The remote control box 56 is provided with an operation lever 60, which is operated to move forward or backward from the neutral position (N) to slide the pin 55 in the elongated hole ring 54 via the shift cable 57. As a result, the link bar 53 moves in parallel, and the pivot piece 52 at the base portion thereof is rotated as shown by arrow B. As a result, the shift lever 50 rotates about its axis, and the cam 51 rotates to connect the crankshaft and the forward gear or the reverse gear via the dog clutch. The operating lever 60 is further moved in the F direction (during forward travel) or the R direction (during reverse travel) from the forward or backward shift operation completion position, that is, the throttle valve fully closed position, so that the inside of the outboard motor 38 is passed through the throttle cable 58. The engine throttle valve operates in the fully open direction. The shift cable 57 is provided with a shift cut switch (not shown). This is because when the dog clutch is disengaged from the gear during high-load operation, the meshing surface pressure between the clutch and the gear becomes very large, so that the cable is heavily loaded. The shift cut switch is for detecting an excessive clutch engagement pressure by detecting the elastic deformation amount of the cable due to this load, and lowering the engine rotation to facilitate clutch switching. Such a shift cut switch may be provided inside the cowling or inside the remote control box.

The remote control box 56 is further provided with a falling water detection switch (not shown). This water drop detection switch is, for example, connected to a wire tied to the body of an occupant, and when the occupant drops water, the switch is operated to stop the engine and immediately stop the ship. The remote control box 56 is also provided with an independent engine stop operation switch (not shown).

FIG. 3 is a detailed view of the engine around one of the V-type 6-cylinder engines mounted on each of the above-mentioned two-engine outboard motors.

As shown in FIG. 3, in the crank chamber 22,
The intake port 80 communicating with the intake manifold 24 opens. The intake port 80 is provided with the reed valve 23. The intake manifold 24 is provided with an injector 26 and a throttle valve 25. Intake manifold 24
An intake air temperature sensor 32 is provided in the. Further, on the outside of the intake manifold 24, the throttle valve 25 is provided with a throttle opening sensor 15 (see FIG. 4).

The fuel supplied to the injector 26 is stored in the fuel tank 63. This fuel tank 63
The fuel inside is sent to the sub tank 67 by the bottom pressure fuel pump 64 through the water separation and dust removal filter 66. The fuel in the sub-tank 67 is sent to the injector 26 of each cylinder via the distribution pipe by the high-pressure fuel pump 65, and the fuel is injected into the intake manifold 24 at a controlled injection amount and injection timing as will be described later, and a predetermined air-fuel ratio is obtained. To form a mixture of. The high-pressure fuel that has not been injected by the injector 26 passes through the return pipe 70 and the sub-tank 6
Recovered to 7. A pressure regulator 69 is provided on the return pipe 70 to keep the injection pressure of the injector 26 constant. Thereby, the fuel injection amount can be controlled by controlling the injection time by opening the injector 26.

FIG. 4 shows the details of the drive control system including the detection means for detecting various operating states of the outboard motor including the aforementioned engine and the means for driving the fuel injection and the ignition. This example represents one control system of an outboard motor equipped with two 6-cylinder engines for ships.

Six cylinder detecting means # 1 to # 6 are arranged around the crankshaft and generate a trigger signal for executing an event interrupt (TDC interrupt) for each cylinder executed in the main routine. This is configured so that, for example, a signal is emitted at the moment when the piston of each cylinder is located at the top dead center or before this by a predetermined angle (crank angle). Therefore, in this embodiment, 60 times during one rotation of the crankshaft.
One cylinder detection signal (TDC signal) for each cylinder #
The data are sequentially sent to the arithmetic processing unit from 1 to # 6. In this event interruption flow, the countdown of the ignition output is permitted and the fuel injection is performed based on the control calculation result for each cylinder obtained during the main routine.

The crank angle detecting means emits an angle pulse which serves as a base for ignition timing control, and emits a pulse signal corresponding to the number of teeth of the ring gear engaged with the crankshaft. For example, 4 in 1 rotation corresponding to 112 gear teeth
If it is configured to emit 48 pulses, the crankshaft rotates 0.8 degrees for each pulse.

The throttle opening detecting means 15 issues an analog voltage signal according to the opening of the throttle valve 25 provided in the intake manifold 24. The arithmetic processing unit A / D-converts this analog signal and performs arithmetic processing such as map reading.

More specifically, the link of the throttle wire connected to the above-mentioned throttle lever 60 (FIG. 2) is connected to one end of the valve shaft of the throttle valve 25.
A resistance sliding sensor is attached to the opposite end of the valve shaft. The valve shaft rotates according to the opening of the throttle valve, and the resistance value of the sensor changes. This change in resistance value is extracted as a voltage change and used as a detection signal of the throttle opening.

The following trim angle detecting means to intake air temperature detecting means are for correcting the control amount according to the change in the environment with respect to the operating condition of the engine. The trim angle detection means detects the mounting angle of the outboard motor. The E / G temperature detecting means attaches a temperature sensor to the cylinder block of each cylinder (or a specific reference cylinder) to detect the temperature of that cylinder.
The atmospheric pressure detecting means is provided at an appropriate position in the cowling. The intake air temperature detecting means 32 is provided at an appropriate position on the intake passage. The atmospheric pressure and the intake air temperature directly affect the volume of air, and the arithmetic processing unit performs a correction operation for the control amount such as the air-fuel ratio according to the detected values of the atmospheric pressure and the intake air temperature.

The burnt gas detecting means is a predetermined cylinder, for example, #
It is an oxygen concentration sensor (O2 sensor) provided in one cylinder. Feedback control of the fuel injection amount and the like is performed according to the detected oxygen concentration.

The knock detecting means 34 detects abnormal combustion in each cylinder. When knocking occurs, the ignition timing is shifted to the retard side or the fuel is set to the rich side to eliminate knocking. Prevent engine damage.

The oil level detecting means is provided with level sensors in both the sub tank 67 in the cowling and the main tank 63 in the ship.

The thermoswitches, one each provided on the left and right banks of the V-shaped bank, are composed of fast-responsive sensors such as a bimetal type temperature sensor, and detect the temperature rise of the engine due to abnormalities in the cooling system, etc. Perform misfire control to prevent it. The above-mentioned engine temperature detecting means is provided in the cylinder block and is used for correcting the control amount of the fuel injection. However, this thermoswitch is required to have a quick response in order to immediately cope with the temperature rise of the engine. .

The shift cut switch is for detecting the tension of the shift cable for switching the clutch and facilitating the switching of the dog clutch directly connected to the propeller.

The operating state detecting means is for detecting the operating state of the other outboard motor, and includes the cylinder deactivation operating detecting means, the two-engine operating state detecting means and the DES.
A detection means is included. The DES detecting means detects the DES which is a signal for notifying when the other engine is in the misfire operation state due to an abnormality in the two-engine operation. That is, when the engine of one of the outboard motors is performing misfire control due to lack of oil, temperature rise, etc., in a vessel of the type in which two outboard motors are arranged in parallel at the stern, that means From DES output means
Is output to detect this DES and detect this misfire operation state. By detecting this DES, the other engine is similarly subjected to misfire control so that the operating states of both engines are the same and the traveling balance is maintained.

The two-engine operating state detecting means is for detecting whether or not the other outboard motor is in the two-vehicle operating state in which the other outboard motor is operating at the same time. It is to detect whether or not the engine of the other outboard motor is in the cylinder deactivated operation state under the two-engine operating state. When the engine of one of the outboard motors is in the cylinder deactivated operation, a cylinder deactivation signal is output from that engine, and when this signal is detected, the other engine also performs the cylinder deactivated operation and both outboard motors are operated. Try to maintain a good running balance.

The battery voltage detection means detects the battery voltage and corrects and controls the injection amount based on this voltage because the opening / closing speed of the valve changes and the discharge amount changes due to the change of the drive power supply voltage of the injector. Used for.

The starter switch detecting means is for detecting whether or not the engine is in the starting operation. If the engine is in the starting state, the fuel is made rich and the control for the starting operation is performed.

The two types of E / G stop switch detection means are an engine stop operation switch and a water drop detection switch. Among them, the water drop detection switch detects the water drop of an occupant and immediately starts the engine. Control to stop. These two types of E / G stop switch detecting means are shown as one E / G stop switch detecting means for convenience in the drawing.

Based on the input signals from the respective detecting means as described above, each control amount is calculated in the arithmetic processing unit, and the fuel injection means # 1 on the output side (right side in FIG. 4) is calculated based on the calculation result. To # 6, ignition means # 1 to # 6, a fuel pump and an oil pump are drive-controlled. It should be noted that the fuel injection means and the ignition means are an injector and an ignition plug, respectively, and are controlled in order independently for each cylinder.

In order to execute the calculation in such an arithmetic processing unit, as shown in the figure, the arithmetic processing unit has a non-volatile memory such as a ROM storing a control program, a map and the like and each detection signal and the detection signal. A volatile memory such as a RAM for storing temporary data for calculation based on

Next, referring to FIG. 5, the ignition timing control and the fuel injection control of the outboard motor engine to which the present invention is applied will be described. FIG. 5 is a block diagram showing a configuration for executing such a control flow. Each block is
It is incorporated as an arithmetic processing circuit in the arithmetic processing device shown in FIG.

The cylinder discriminating means 201 is a cylinder detecting means # 1.
To # 6 (FIG. 4), the cylinder number is determined based on the input signal from each cylinder. The cycle measuring means 1000 measures the time interval of the input signal from each cylinder based on the detection signal from this cylinder detecting means, and multiplies this by 6 to calculate the time (cycle) of one rotation. The engine rotation speed calculation means 203 calculates the reciprocal of this cycle to obtain the rotation speed. The throttle opening reading means 204 reads the opening with an analog voltage signal corresponding to the throttle opening.

The throttle opening signal from the throttle opening reading means 204 is A / D converted, and the rotation speed signal from the E / G rotation speed calculating means 203 and the start information from the starter switch are used as the basic ignition timing calculating means 210. And is sent to the basic fuel injection calculation means 211, and the ignition timing and the fuel injection amount of the reference cylinder # 1 are calculated using the three-dimensional map in each of the normal operation mode and the start mode. The engine speed signal and the throttle opening signal are further sent to the cylinder-by-cylinder ignition timing correction value calculating means 208 and the cylinder-by-cylinder fuel injection amount correction value calculating means 209, and the basic ignition timings for the remaining cylinders # 2 to # 6. And a correction value for the basic injection amount is calculated by map calculation for each cylinder.

On the other hand, trim angle reading means 205, engine temperature reading means 206 and atmospheric pressure reading means 2
Reference numeral 07 denotes a detection signal from each detection means (FIG. 4), which is sent to the ignition timing correction value calculation means 212 and the fuel injection amount correction value / correction coefficient calculation means 213, and the correction value according to each operating state. And a correction coefficient is calculated. In this case, regarding the ignition timing correction value, the number of angles of the correction advance angle (or the retard angle) to be added to the value of the basic ignition advance angle is obtained by a map stored in advance for each type of read data. As for the correction coefficient of the fuel injection amount, a value corresponding to the operating state is obtained from the map data stored in advance.

Although not shown in the drawings, the ignition timing correction and the fuel injection amount correction may be performed by further inputting the intake temperature detection data to the respective calculation means 212, 213 to perform the correction based on the intake temperature. The fuel injection amount correction value / correction coefficient calculation means 213 is normally operated from the start operation mode based on the start start information from the starter SW and the engine speed information or the temperature information from the E / G (engine) temperature detection means. Information on the elapsed time of the timer that starts from the time of shifting to the operation mode is also input. In the fuel injection amount correction value / correction coefficient calculation means 213, a correction coefficient by which the basic injection amount is multiplied and a correction value other than the cylinder-specific correction value,
That is, the post-starting correction value and the transitional correction value corresponding to the passage of time from the time when the starting operation mode is changed to the normal operation mode are calculated.

The calculation outputs of the ignition timing correction value calculation means 212 and the fuel injection amount correction value / correction coefficient calculation means 213 are
It is inputted to the ignition timing correction means 214 and the fuel injection amount correction means 215, respectively, where the correction value is added to the basic ignition timing, the calculated value of the basic fuel injection is multiplied by the correction coefficient, and the post-starting correction value and the transient value are added. The time correction value is added to calculate the ignition timing of the # 1 cylinder and the control amount of the fuel injection.

The ignition timing of the reference cylinder # 1 and the control amount of the fuel injection are input to the cylinder-specific ignition timing correction means 216 and the cylinder-specific fuel injection amount correction means 217, where the corrected ignition timing of the # 1 cylinder is used. And # 2 to # 6 by adding the control correction amount by the cylinder-by-cylinder ignition timing correction amount calculation means 208 and the cylinder-by-cylinder fuel injection amount correction value calculation means 209 to the # 2 and # 6 cylinders.
The ignition timings of the cylinders up to 6 and the control amount of the fuel injection amount are calculated.

Based on the ignition timing and the fuel injection control amount for each of the cylinders # 1 to # 6 calculated in this way, the ignition output means 218 determines the value of the angle of ignition advance for each cylinder. Set the calculated control amount with a timer,
The fuel output means 219 sets a crank angle corresponding to the valve opening time with a timer.

FIGS. 6 and 7 are flowcharts of the overall control of the respective engines of the two-engine outboard motor according to the embodiment of the present invention. This flowchart is a flow of a main routine showing a sequence program of the entire control process incorporated in the CPU of the control device (arithmetic processing device) of each engine.

When the main switch is turned on and the power is turned on to start the engine operation, each processing circuit in the control processing device is first initialized after a predetermined reset time (step S11).

Next, at step S12, the operating state is judged and the result is held in the memory. Here, ON / OFF information of the main switch, ON / OFF of the starter SW read by using the starter SW detection means of FIG.
Information, and engine speed information calculated from the time interval of the detection signal from the cylinder determination means, the start determination to determine whether or not the starting state, throttle opening information read from the throttle opening detection means, engine speed information, Sudden acceleration / deceleration calculated from the operating condition information, which is the operating condition information of the other outboard motor read by the operating condition detecting means, or abnormal condition information such as overheating or oil shortage described below, or time change of throttle opening information. Cylinder deactivation decision whether to deactivate a specific cylinder based on information etc.,
Judgment whether to perform feedback control of oxygen concentration mainly based on throttle opening information and engine speed information,
And mainly based on the same two pieces of information, a determination as to whether control data is learned and stored under specific control conditions, an over-revolution determination as to whether excessive rotation is based on engine speed information, a throttle opening information, an engine Overheat judgment of whether or not it is in an overheat state based on the rotation speed information and the temperature information by the engine (E / G) temperature detection means or a thermo SW which is a more specific means thereof,
Based on the throttle opening information, the engine speed information, and the remaining oil amount information from the oil level detecting means, it is determined whether or not the remaining oil amount is small.
In the case of an excessive rotation state, an overheat state and a state where the residual oil amount is small, misfire control is performed as described below. In step S12, further, based on the throttle information, the crank angle information, the O2 sensor information, or the pulsar information from the pulsar coil which is a kind of crank angle detecting means,
Fail judgment of whether or not the above information is missing or abnormal, a judgment as to whether or not it is in a two-machine operating state in which other outboard motors are also operating based on the operating state information, a cylinder deactivation state signal Is used to determine whether the other outboard motor is in the cylinder deactivated operation state, and whether or not the other outboard motor is in the misfire control state corresponding to the abnormality based on DES (a signal notifying the misfire control state corresponding to the abnormality). The two-machine operating state determination consisting of three determinations, the rapid acceleration / deceleration determination based on the time change of the throttle opening information as described above, the shift cut SW which operates during the shift operation from the high speed rotation state A shift cut determination is made based on the ON / OFF information as to whether or not the shift cut state is set.

Such a determination is made based on various information such as the detection information from the sensor read in the previous routine and the calculation result.

Next, in step S13, it is determined whether or not the routine work of loop 1 is performed. YE
If it is S, the process proceeds to step S14 and the switch information is read. Here, information from the E / G stop switch detecting means, the main switch, the starter switch detecting means, and the thermo SW is read. Then, in step S15, the information from the knock sensor (knock detection means) and the throttle sensor (throttle opening detection means) is read. After the information reading by the loop 1 is completed, the process proceeds to step S16, and it is determined whether or not the routine work of the loop 2 is performed.

The arithmetic processing unit sets the processing flag 1 of the loop 1 to 1 at 4 ms intervals by hardware or software, and sets the processing flag 2 of the loop 2 to 1 at 8 ms intervals.

FIG. 8 shows such loop 1 and loop 2
4 is a flowchart of a timer interrupt for executing the. Such a timer is set in the initialization step S11. While the routines of the loops 1 and 2 are being executed, the flag is set and the timer for the next routine is set.

Returning to FIG. 6, in step S13, flag 1 is checked, and if it is 1, steps S14 and S15 are executed. Note that the flag 1 is cleared and becomes 0 at the same time when the process proceeds to step S14. When it is confirmed that the flag 1 is 0 in step S13, the process proceeds to step S16, and it is checked whether the flag 2 is 1. If the flag 2 is 1, the process proceeds to step S17 and the flag 2 is cleared to 0 at the same time. If the flag 2 is 0 in step S16, the process returns to step S12.

In step S17, the oil level is detected, and the shift cut switch that is activated when the tension is large is turned on or off depending on the tension of the shift cable that is large during the shift operation from the high rotation state.
The state is detected, and the two-engine running signal, the cylinder deactivation state signal, and the DES signal are detected. Further, in step S18, atmospheric pressure information, intake air temperature information, trim angle information, engine temperature information, battery voltage information, and oxygen concentration information in exhaust gas are atmospheric pressure detection means, intake air temperature detection means, trim angle detection means, E / G (engine) temperature detecting means, battery voltage detecting means, and O ₂ sensor. The A / F information before combustion is calculated based on the oxygen concentration information.

Next, in step S19, misfire control is performed. This is because, in the operation state determination in step S12 described above, the engine is in an abnormal state such as over-rotation, overheat at a predetermined throttle opening and engine speed, oil empty, or the other engine is in an abnormal state from the read information. The fuel control is performed so that the misfire of a specific cylinder is performed when the determination result that there is is present. Further, in the cylinder-by-cylinder correction in step S24 described below, misfire fuel control is output to output to the memory that the misfire control state is in order to halve the fuel injection amount of the cylinder in which the misfire occurs. Next, the fuel pump and the oil pump are drive-controlled based on the determination whether the engine is rotating and the information from the oil tank level sensor (step S20). For fuel, the fuel pump is driven when the engine is rotating, the fuel pump is stopped when the engine is stopped, and for oil, the pump is driven when the amount in the oil tank is small. The oil consumption is reduced by replenishing oil from the oil tank, or by lowering the engine speed when the onboard tank is empty.

Next, in step S21, the cylinder deactivation determination result is determined. This is a determination step for selecting the map of the arithmetic processing when it is determined in the above-described operating state determination step S12 that the cylinder deactivation operation is performed under the predetermined condition. If it is not the cylinder deactivated operation, the basic calculation of the ignition timing and the injection time and the correction calculation for each cylinder are performed using the normal operation map for the normal all cylinder operation (step S22). It is also determined whether or not the engine is in the misfire control state, and when in the misfire control state, the injection time is supplied to the misfire cylinder so as to supply the same amount of fuel as the fuel injection amount to the other ignition cylinders or a fuel reduced by a predetermined ratio. Is set. As a result, the fuel is supplied even in the misfire control from the time when the throttle opening and the engine speed are equal to or higher than a predetermined value, so that the piston and the like can be cooled by the heat of vaporization and damage can be prevented. In the cylinder deactivated operation state, the ignition timing and the injection time are calculated and the correction calculation for each cylinder is performed by using the cylinder deactivated map for the cylinder deactivated operation in which a specific cylinder is deactivated (step S24). Next, step S23 in FIG.
At, the correction values for the basic ignition timing and the fuel injection are calculated according to the operating conditions such as the atmospheric pressure and the trim angle.
Subsequently, in step S25, a correction value associated with the feedback control of the oxygen concentration is calculated. At this time, the learning determination of the calculation information and the activation determination of the O2 sensor are performed. Further, in step S26, a correction value for the control amount is calculated based on the detection signal from the knock sensor to prevent engine seizure and the like.

Next, in step S27, the basic ignition timing and the control amount of the fuel injection are multiplied by the correction coefficient and the correction value is further added or multiplied by the correction coefficient to obtain the optimum ignition timing, injection time and injection timing. Calculate After that, in step S290, the calculation of the engine pre-stop control is performed. This is a control for stopping the ignition and continuing the fuel injection for a predetermined time in consideration of restart when the engine is determined to be in the stopped state by turning off the main switch or the engine stop switch in step S12. It is a routine. With the above, the routine of the loop 2 is ended, and the process returns to the original operation state determination step S12.

FIG. 9 shows the flow of the TDC interrupt routine. A marker is fixed to the crankshaft, which causes each cylinder detecting means to output a signal notifying that the piston is at the top dead center in each cylinder when sequentially passing near each cylinder detecting means. The TDC interrupt is a routine interrupted by the main routine at any time based on the input of the TDC signal from each cylinder by the cylinder detecting means # 1 to # 6.

First, the number of the cylinder to which the signal is input is determined (step S28). Next, by comparing the cylinder number with the cylinder number of the previous input signal, it is determined whether the engine is rotating normally or reversely with respect to the rotation direction to be operated (step S29). If it is reversed, the engine is immediately stopped (step S33). If the engine is running in the normal direction, for example, the time interval between the cylinders # 1 and # 2 is counted and multiplied by 6 to calculate the cycle of engine rotation (step S30). Subsequently, the reciprocal of this cycle is calculated to calculate the rotation speed (step S31). When this rotation speed is lower than a predetermined rotation speed,
The engine is stopped (steps S32, 33).

Next, at step S34, it is judged if the input TDC interrupt signal is from a specific reference cylinder # 1. If the signal is from the reference cylinder # 1, it is determined whether or not the cylinder deactivation operation is being performed (step S3).
5) If the cylinder deactivation operation is in progress, it is determined whether or not the pattern of cylinders to be deactivated should be changed (step S37),
The pattern is switched (step S38) or the process proceeds to step S39 as it is without switching, and the cylinder deactivation operation information by ignition control is set. When the interrupt signal is not from # 1 (step S34) or when the cylinder deactivation operation is not in progress (step S35), the cylinder deactivation information is left as it is or the cylinder deactivation information is cleared (step S36) and the process proceeds to step S39 to deactivate the cylinder by ignition control. Set the driving information. The ignition pulse of the cylinder to be ignited is set based on this ignition cut-off cylinder information (step S40).

The details of this ignition pulse set are shown in FIG. The ignition timing obtained by the calculation is converted into the crank angle 60 degrees before TDC, that is, how many times it becomes a reference in the V-type 6-cylinder engine, and divided by 0.8 to be rounded to the pulse number. T of the cylinder that becomes TDC 60 degrees before
When the DC signal is input, the data of the rounded pulse number is held in the timer that constitutes the ignition output means 218, and at the same time, the number of pulses that is held each time the pulse from the crank angle detecting means reaches the timer. When the number of held pulses becomes 0, the ignition output means 218
Sparks the spark plug 19.

This embodiment is intended for a 6-cylinder V-type 2-bank engine, for example, and is an odd-numbered cylinder (# 1,
3, 5) are arranged in the left bank and even-numbered cylinders (# 2,
4 and 6) are arranged in the right bank. A separate timer is provided for each bank in order to control these cylinders for each bank. When setting the number of crank angle pulses corresponding to the ignition timing in these timers, as shown in the figure, first determine whether the cylinder number is an even number or an odd number, and depending on whether it is an even number or an odd number, set the ignition timing data to the corresponding bank. (In the figure, the odd bank is timer 3 and the even bank is timer 4), and the ignition cylinder number is set.

After that, for the deactivated cylinder for which the ignition control is misfiring, the cylinder for which the fuel injection amount is reduced for the fuel injection control is set as the cylinder deactivation information for the fuel injection control (step S41 in FIG. 9), and the misfire is deactivated for the ignition control. The injection time corresponding to the fuel injection amount reduced from the fuel injection control amount calculated for each cylinder, and the injection time corresponding to the fuel injection control amount calculated for the other cylinders, for each cylinder. The pulse is set (step S42).

When measuring the above-mentioned engine cycle, if there is an input signal (TDC signal) from one cylinder, the TDC interrupt shown in FIG.
The period measurement timer starts counting the number of constant frequency pulses at the time of inputting the TDC signal, and the TD of the next cylinder
When the C signal is input, it is reset and the counting of the next cylinder is started. In this case, when the count value exceeds a predetermined value, an overflow occurs and the count is reset. The timer overflow interrupt is executed at the time when this overflow occurs, that is, when it is detected that the cycle of the crank angle of 60 degrees is the low speed rotation for a predetermined time or longer.

FIG. 11 shows this overflow interrupt. When an overflow occurs, the number of times is first stored and it is determined whether the engine is in the starting operation state. If the operating mode is the starting state, the engine rotation is low due to the overflow, and the operation is continued.
If it is not in the start mode, it is determined whether or not the TDC signal pulse has been missed, that is, the TDC signal pulse has not been transmitted due to some trouble, and whether the overflow is detected by normal signal transmission without pulse omission. If the engine is running at low speed, stop the engine. If there is a missing pulse, it is determined whether or not the overflow detection is the second time, and if it is the second time, the engine is stopped because the rotation speed is too low. As a result, the engine is always stopped when there is an abnormality in the signal transmission system at low speed.

FIG. 12 shows an interrupt routine of the timers 3 and 4 corresponding to each bank for setting the ignition timing of each cylinder. When an engine rotation signal (TDC signal) is input from each cylinder, the timers 3 and 4 start counting down, and an interrupt is performed due to an underflow. First, the cylinder deactivation information indicating whether the engine is in the cylinder deactivation operation for a predetermined low rotation speed or less and the misfire information indicating whether the ignition is misfired by detecting overheat or overrevolution (overspeed) are read.
After that, when the misfire is caused by the cylinder deactivation information or the misfire information, the ignition processing routine is not performed, so that the spark plug is not discharged even at the timing set by the timer, and the phase is delayed by 120 °. The ignition timing of the cylinder is read from the memory, the timing is set in the timer, and the process directly returns to the main flow. If you do not want to misfire, read the number of the cylinder to be ignited, and pulse (H) from the ignition output port of the ignition drive circuit of that cylinder.
I) is output to discharge the spark plug. The ignition time corresponds to the pulse width and is set by a timer, or a loop that requires a predetermined number of times for execution is executed to obtain the required pulse width. After the elapse of this predetermined ignition time, the signal from the ignition output port is set to LOW, and the discharge of the spark plug is completed. Further, if the ignition drive circuit is LOW active, the logic is the reverse of the above.

The above is the mechanical structure of the outboard motor engine to which the present invention is applied, the system structure of the entire control system, and the flow of its operation.

FIG. 13 is an explanatory flowchart of the engine control method according to the present invention. As shown in (a), the correction calculation of the present invention is performed in the correction calculation step S23 of the main routine shown in FIG. As one of the series of correction calculation routines, the correction based on the trim angle is performed (see FIG. 1).
2 (b)). In the trim angle correction calculation routine, the ignition timing correction calculation is first performed, and then the fuel injection correction calculation is performed, as shown in FIG.

FIG. 14 is a flowchart of the ignition timing correction calculation. First, in step S1411, it is determined whether the area is a correction area. This is because the influence of back pressure fluctuation due to the change in trim angle becomes large especially at low rotation speed and low load.
This is because a correction calculation based on the trim angle is required when the engine speed is in a predetermined low rotation range and the throttle opening is in a predetermined low opening range. If the operating condition is within the correction range, the process advances to step S1413 to calculate a correction advance value of the ignition timing based on the trim angle data, as described later. If it is out of the range of the correction region, the ignition timing is calculated according to a normal routine by using the correction coefficient as a constant without a correction without correcting the trim angle (step S1).
412).

FIG. 15 is a flow chart of the fuel injection amount correction calculation. First, in step S1414, it is determined whether the area is a correction area. This is because, as in the case of the ignition timing correction described above, the influence of the back pressure fluctuation due to the change in the trim angle becomes large especially in the low rotation speed and the low load state, so that the engine speed is in the predetermined low rotation speed region and the throttle opening is set. This is because the correction calculation based on the trim angle is necessary when the degree is in a predetermined low opening range. If the operating state is within the correction range, step S1
Proceeding to 416, as will be described later, the correction increase value of the fuel injection amount is calculated based on the trim angle data. If it is outside the range of the correction region, the correction by the trim angle is not performed, and the injection amount is calculated according to a normal routine using the correction coefficient as a predetermined constant without correction (step S1415).

Next, the calculation of the ignition timing and the control amount of the fuel injection will be described in more detail. First, a basic control amount is calculated for the ignition timing and the injection amount. This is performed in step S22 of the main routine (FIG. 6) (step S24 when the cylinder is deactivated), and is calculated using the three-dimensional map based on the engine speed and the throttle opening for the reference cylinder # 1. After that, the cylinders # 2 to # 6 are corrected, and the basic control amounts of all the cylinders # 1 to # 6 are map-calculated. Next, in step S23 of the main routine (FIG. 7), correction calculation is performed based on the trim angle data. The trim angle data is data obtained by reading the detection data of the trim angle sensor and storing it in the RAM in step S18 of the main routine.

Regarding the correction calculation based on such a trim angle, an example of the calculation formulas for the ignition timing and the injection time at the time of starting and thereafter is as follows.

At the time of starting: (1) Ignition timing Ast = Astb + Aatrm Ast: Starting ignition timing Astb: Basic ignition timing at starting Aatrm: Trim angle correction ignition timing (2) Injection time Tst = Tstb × TINJC + Tv TINJC = C1 × C2 × C3 × C4 Tst: injection time at start Tstb: basic injection time at start TINJC: injection time correction coefficient Tv: invalid injection time C1: engine temperature correction coefficient C2: atmospheric pressure correction coefficient C3: intake air temperature correction coefficient C4: trim angle Correction coefficient After start: (1) Ignition timing As = Am + Ac Ac = Aecy + Ate + Apatm + Atrns + Aatrm As: Ignition timing Am: Basic ignition timing Ac: Corrected ignition timing Aecy: Cylinder corrected ignition timing Ate: Engine temperature correction ignition timing Apatm: Atmospheric pressure correction Ignition timing Atrns: Corrected ignition timing during transient (during rapid acceleration / deceleration) Aatrm: Trim angle corrected ignition timing However, As ≤ Asfst (calculated As , If the retard side) than Asfst and As = Asfst (Asfst: Correction ignition timing limit value after starting) (2) injection time TINJ = TINJS × TINJC + (TINJB + TL) × C + TL +
TINV + Tecy + Tfst + Ttrns TINJC = C1 × C2 × C3 × C4 TINJ: Injection time TINJB: Basic injection time TINV: Invalid injection time Tecy: Cylinder correction injection time Tfst: Start-up correction injection time Ttrns: Transient correction (during rapid acceleration / deceleration) Time TINJC: Injection correction coefficient C: O2 feedback correction coefficient C1: Engine temperature correction coefficient C2: Atmospheric pressure correction coefficient C3: Intake air temperature correction coefficient C4: Trim angle correction coefficient TL: Learning correction injection time However, correction after start and transient During the hour correction, C = 0 is set and O2 feedback correction is not performed. This is because if the control for alternately changing the air-fuel ratio to rich lean in the O2 feedback control is performed, proper output and combustion state cannot be obtained at the time of increasing correction after starting and during transition. Further, when the engine temperature is low and C1 is equal to or higher than a predetermined value, the O2 feedback correction is not similarly performed. In the learning correction control, in the learning region of a predetermined engine speed and throttle opening, when the learning region is exited and the learning region is reentered, the control is performed using the data of the previous calculation result to shorten the calculation process. Planned. Note that the invalid injection time is for correcting the opening / closing time of the injector valve depending on the battery voltage, so that it is corrected according to the battery voltage.

16A and 16B are graphs showing changes in the correction ignition timing and the injection amount correction coefficient with respect to changes in the trim angle. As shown in (A), the ignition timing is advanced stepwise at a predetermined switching point as the trim angle increases. In this case, as shown in the figure, the control calculation is performed with a hysteresis of, for example, 1.5 degrees so as to shift the switching point when the trim angle changes in the increasing direction and the switching point when the trim angle changes in the decreasing direction. To do. This corrected ignition timing calculation amount is added (advanced) to the basic injection timing as shown in the above-described calculation formula.

Similarly, with respect to the injection amount, as shown in FIG. 6B, the injection amount is increased stepwise at a predetermined switching point as the trim angle increases. In this case, as shown in the figure, the control calculation is performed with a hysteresis of, for example, 1.5 degrees so as to shift the switching point when the trim angle changes in the increasing direction and the switching point when the trim angle changes in the decreasing direction. To do. This injection amount correction coefficient is multiplied by the basic injection amount as shown in the above-mentioned arithmetic expression. It is desirable that the ignition timing and the injection amount are switched at the same switching point with respect to the trim angle. This is because there is only one optimal combustion condition under the same operating condition, and the corresponding ignition timing and injection amount are matched.

As the engine load detecting means, the throttle opening detecting means is used, and it is considered that the engine load is large or small depending on the magnitude of the throttle opening. However, a means for detecting the tilt angle of the strut lever 60 is arranged. The magnitude of the engine load may be directly detected from the tilt angle. Further, a means for detecting the air amount or an intake pressure sensor may be provided in the middle of the intake passage 24 to determine the magnitude of the engine load from the air amount or the intake pressure and the engine speed.

[0082]

As described above, in the present invention, in a two-cycle or four-cycle outboard motor,
When calculating the ignition timing and the control amount of fuel injection, the correction calculation is performed based on the trim angle, so the optimum control amount is always calculated corresponding to the back pressure change according to the change of the trim angle, and the operation is performed. Optimal combustion conditions are achieved depending on the conditions. In particular, reliable combustion is achieved at low speed and low load, which is greatly affected by back pressure, fluctuations in rotation are prevented, and the risk of engine stalls is eliminated, ensuring reliability during marine operation.

[Brief description of drawings]

FIG. 1 is an external view of a two-engine outboard motor to which the present invention is applied.

FIG. 2 is a structural explanatory view of a throttle lever of an outboard motor to which the present invention is applied.

FIG. 3 is a configuration diagram including a fuel system of the outboard motor of the present invention.

FIG. 4 is a structural explanatory diagram of a drive control system of a two-engine outboard motor.

5 is a control block diagram of the control system of FIG.

FIG. 6 is a flowchart of a main routine in a control sequence of an internal combustion engine to which the present invention is applied.

FIG. 7 is a continuation of the flowchart of FIG.

8 is a flowchart of a timer interrupt routine in the flowchart of FIG.

9 is a flowchart of a TDC interrupt routine in the flowchart of FIG.

FIG. 10 is a flowchart of an ignition pulse setting routine.

FIG. 11 is a flowchart of a timer overflow interrupt routine.

FIG. 12 is a flowchart of a timer interrupt routine for each bank.

FIG. 13 is an explanatory diagram of a trim angle correction flow according to the present invention.

FIG. 14 is a flowchart of ignition timing calculation by trim angle correction according to the present invention.

FIG. 15 is a flowchart of a fuel injection amount calculation by trim angle correction according to the present invention.

FIG. 16 is an explanatory diagram of hysteresis at a control amount switching point in trim angle correction according to the present invention.

[Explanation of symbols]

210: basic ignition timing calculation means, 211: basic fuel injection amount calculation means, 214: ignition timing correction means, 215: fuel injection amount correction means.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display F02P 5/15 F02P 5/15 B

Claims (6)

[Claims] 1. An outboard engine having an engine equipped with an ignition device and a fuel injection device, a propeller, a propeller shaft for driving the propeller to receive engine output, and an exhaust port for discharging engine exhaust into water. A boat including a main body of the outboard motor and a support bracket that supports the main body of the outboard motor so as to be tiltable with respect to the main body, and a trim angle detecting means for detecting a trim angle that is a tilt angle of the main body of the outboard motor with respect to the support bracket is arranged. In the control method of the fuel injection type internal combustion engine of the outboard motor, which is used for the outboard motor and controls the ignition timing and the fuel injection amount according to the engine speed and engine load, the trim angle changes based on the detection result of the trim angle. A fuel injection type internal combustion engine control method for an outboard motor, wherein the fuel injection amount is increased as the exhaust port position approaches the water surface. 2. The fuel injection amount obtains a basic control amount based on an engine speed and an engine load, while a correction amount or a correction coefficient for the basic control amount is obtained based on a trim angle, and the basic control amount is obtained. The control method for a fuel injection type internal combustion engine for an outboard motor according to claim 1, wherein a correction amount is added or the basic control amount is multiplied by a correction coefficient. 3. The fuel injection type internal combustion engine for an outboard motor according to claim 1, wherein the ignition timing is corrected so as to be advanced when the trim angle changes in the back pressure decreasing direction. Control method. 4. A hysteresis such that the correction control amount is switched stepwise according to the change of the trim angle, and the correction amount switching position in the increasing trim angle direction is larger than the correction amount switching position in the decreasing trim angle direction. The method for controlling a fuel injection type internal combustion engine for an outboard motor according to claim 1, wherein the correction calculation is performed so that 5. The control of a fuel injection type internal combustion engine of an outboard motor according to claim 4, wherein the trim angle for switching the correction amount of the ignition timing and the trim angle for switching the correction amount of the fuel injection are the same. Method. 6. An outboard outboard having an engine equipped with an ignition device and a fuel injection device, a propeller, a propeller shaft for driving the propeller to receive engine output, and an exhaust port for discharging engine exhaust into water. A ship including a main body of the outboard motor and a support bracket that supports the main body of the outboard motor so as to be tiltable with respect to the hull, and a trim angle detecting means for detecting a trim angle that is a tilt angle of the main body of the outboard motor with respect to the support bracket is arranged. The trim angle changes based on the trim angle detection result in the control device for the fuel injection type internal combustion engine of the outboard motor, which is used in the outboard motor and controls the ignition timing and fuel injection amount according to the engine speed and engine load. The fuel injection system of the outboard motor is characterized in that the fuel injection device is driven and controlled so that the fuel injection amount increases as the exhaust port position approaches the water surface. Institutions of the control device.