JP3531847B2 - Fuel pump drive system for fuel injection type internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pump drive system for a fuel injection type internal combustion engine, and more particularly to a drive circuit structure for connecting a battery and a motor.

[0002]

2. Description of the Related Art In a fuel supply system for an electronically controlled internal combustion engine, fuel is pressurized and supplied by a fuel pump (fuel pump) in order to inject fuel from an injector. As this fuel pump, it is necessary to use a fuel pump capable of supplying the fuel flow rate at the time of maximum engine rotation. In this case, when the engine load is low and the engine speed is low, excess fuel is circulated by the fuel pressure regulator. When the fuel is recirculated in this way, the temperature of the fuel rises, which may cause vaporization. Therefore, in a four-cycle engine for automobiles, the drive current of the fuel pump is switched according to the engine speed so that the fuel pressure according to the operating state is obtained, and when the load is low, the drive current is reduced to reduce the flow rate. It is controlled to make it smaller. Such switching of the drive current is performed by inserting a resistor in series with the motor on the power supply line. In this case, a transistor is used as the switch means, but a large current flows directly into the transistor when there is an abnormality such as a short circuit in the wire harness before and after the motor or a motor lock in the fuel pump, so a fuse should be inserted on this power line to connect the transistor. Need to be protected.

When the fuel is circulated at a low load as described above, or when the fuel is circulated in order to reduce the load on the fuel pump when the fuel flow path is clogged and the fuel pressure exceeds a certain pressure, A slightly higher blocking current than normal flows through the pump motor. In addition, a high inrush voltage temporarily flows immediately after the fuel pump is turned on. The peak value of this inrush voltage is almost equal to the lock current when the motor is locked.

On the other hand, in a marine internal combustion engine such as an inboard / outboard motor or an outboard motor, a two-cycle engine which is small in size and light in weight and has a relatively large output with respect to a displacement is currently available due to a special situation of being used on water. Mainly used.

[0005]

However, in an outboard motor of a two-cycle engine or the like, at present, sufficient development has not been made for the flow control of the excess fuel and the current control, and particularly vapor generation at low rotation speed is not achieved. However, if the flow control structure of the conventional 4-cycle engine is simply diverted, a problem remains in terms of protection of the current control circuit and reliability of operation. Especially in outboard motors,
It is necessary to reliably return to the port due to its reliable operation and protective function. In addition, when configuring the control circuit of the fuel pump, the distance from the main switch installed on the remote control box in the ship to the pump motor in the stern outboard motor is long, so the battery power is supplied to the fuel pump motor via the main switch. If an attempt is made to supply the voltage, there will be problems such as a large voltage drop due to the long wiring. In this case, if a signal circuit is configured using a relay, high waterproofness is required, and it is necessary to add an anti-vibration device to prevent malfunction due to the engine signal, resulting in a complicated structure and a large scale. The cost also rises.

The present invention has been made in view of the above points, and properly controls the flow rate of the fuel pump in accordance with the operating condition to ensure reliable operation and circuit protection, and to operate the battery without using a relay. It is an object of the present invention to provide a fuel pump drive device for a fuel injection type internal combustion engine, which achieves a highly reliable function by eliminating wasteful power consumption due to the voltage drop of the battery and cost of long wiring.

[0007]

In order to achieve the above object, according to the present invention, there is provided a fuel pump drive device for a fuel injection type internal combustion engine in which a main switch and a fuse are provided on a wiring connecting a battery and a fuel pump motor. , The capacity of the fuse is not less than the blocking current of the fuel pump motor and not more than the inrush current ,
On the ground side, the first switch circuit with a small resistance value and the resistance value
And a second switch circuit with a large
Switching control means for the first and second switch circuits is provided,
This switching control means is
When the value is equal to or more than the predetermined value, the first switch circuit is turned on and the
The second switch circuit when the engine speed is below a specified value.
Is turned on, the switching control means,
When the second switch circuit is in the ON state, it periodically switches
It is designed to turn on the first switch circuit for a fixed time.
That made the offer a fuel pump driving apparatus for a fuel injection type internal combustion engine according to claim.

[0008]

[0009]

The present invention further provides a battery and fuel pump.
Install the main switch and the fuse on the wiring connecting to the motor.
Pump drive device for a fuel injection type internal combustion engine provided with a valve
The fuse capacity to the fuel pump mode.
Above the blocking current and below the inrush current,
On the ground side of the pump motor, connect the first switch with a small resistance value.
H circuit and a second switch circuit with a large resistance value in parallel
And a switching control for these first and second switch circuits.
Control means is provided, and this switching control means is provided at the time of starting and
The first switch circuit when the engine speed is above a specified value
Is turned on, and if the engine speed is below a specified value,
Two switch circuits are configured to be turned on, and two switch means are provided in series on the drive power supply line for supplying the battery voltage to the fuel pump motor, and these two switch means are turned on / off depending on whether the main switch is turned on or off. There is provided a fuel pump drive device for a fuel injection internal combustion engine, characterized in that the battery and each switch means are connected by a signal line for operating, and the main switch is provided on the signal line.

[0011]

[Function] Since the capacity of the fuse on the power supply line connecting the battery and the fuel pump motor is not less than the blocking current and not more than the inrush current, the fuse is reliably flowed back while the fuse is reliably locked when the fuel pump is locked. And the drive circuit is protected.

By connecting two parallel circuits having different resistances to the fuel pump motor, the drive current flowing through this motor can be switched in two stages. A switch composed of, for example, a transistor is provided on each circuit, and one of the switches is turned on according to the engine speed. The low resistance switch is turned on at engine start and high engine speed, and the high resistance switch is turned on at low engine speed. As a result, a large current can be made to flow at the time of start-up when a rush current flows or at a high rotation speed where the flow rate is large, and at the time of a low rotation speed, the resistance can be increased to reduce the drive current and the flow rate can be decreased to reduce the reflux amount. .

When an abnormality such as a motor lock occurs during low speed operation, a large current flows, but at the time of low speed, a large resistance is connected, so the current is limited and becomes small, and the fuse may not blow. When such low rotation operation continues, by turning on the switch of low resistance regularly, when an abnormality such as motor lock occurs,
A large current flows without being limited to a high resistance, and the fuse is surely blown, so that heat generation of the motor and the resistance is prevented.

On the power supply line connecting the battery and the fuel pump motor, two switches made of, for example, transistors are provided in series. An on / off signal of the main switch is transmitted to these switches via a signal line to control the supply of power to the fuel pump motor. A CPU for stopping the motor, for example, according to the operating state is further connected to one of the switches. By providing the double switch means in this way, it is possible to reliably shut off the power supply even if a malfunction of the CPU or a short circuit of the other switch occurs when the main switch is turned off.

[0015]

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. 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 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. 2, 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. A throttle opening sensor 15 is provided on the throttle valve 25 outside the intake manifold 24.

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 low-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. 3 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. Thirty
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 movement) or the R direction (during backward movement) 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 amount of elastic deformation 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, a switch 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. 4 shows the details of the drive control system including the detecting means for detecting various operating states of the outboard motor including the engine and the means for driving the fuel injection and the ignition. This example represents one control system of an outboard motor equipped with a two-cylinder 6-cylinder engine.

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, ignition and fuel injection are performed based on the control calculation result for each cylinder determined during the main routine.

The crank angle detecting means emits an angular 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 emits 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 is for detecting abnormal combustion in each cylinder. When knocking occurs, ignition is shifted to the retard side or 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 provided on each of 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 of the cooling system, etc. Perform misfire control to prevent it. The engine temperature detecting means described above 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. The means is 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 DES is output from the DES output means, and is for detecting the DES and detecting the 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 battery voltage detecting 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 driving power supply voltage of the injector. Used for.

The starter switch detecting means is for detecting whether 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 detecting 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 each cylinder is independently controlled in order.

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 including a ROM storing a control program, a map and the like and respective detection signals and the detection signals. A volatile memory such as a RAM for storing temporary data for calculation based on

Next, the ignition timing control and fuel injection control of the outboard motor engine to which the present invention is applied will be described with reference to FIG. 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 calculation means 208 and the cylinder-by-cylinder fuel injection amount correction value calculation 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 reads the detection signals from the respective detection means (FIG. 4) and sends them to the ignition timing correction value calculation means 212 and the fuel injection amount correction coefficient calculation means 213, and the correction values and correction coefficients according to each operating state. To calculate. In this case, as for 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 from 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, the ignition timing correction and the fuel injection amount correction may be performed by inputting the detected temperature data of the intake air into the respective calculation means 212, 213 to perform the correction based on the intake air temperature. The fuel injection amount correction value / correction coefficient calculation unit 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 unit. 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 and fuel injection control amount of the reference cylinder # 1 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.

On the basis of the ignition timing and the fuel injection control amount for each of the cylinders # 1 to # 6 calculated as described above, the ignition output means 218 determines the value of the angle of the ignition advance angle 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 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 crank angle pulse train read from the crank angle detection means, a start determination for determining whether or not a starting state, throttle opening information read from the throttle opening detection means, engine speed information, Operating state information that is the operating state information of the other outboard motor that is read by the operating state detection means, or the following overheat, abnormal state information such as oil shortage,
Alternatively, the cylinder deactivation judgment as to whether or not the specific cylinder should be deactivated based on the rapid acceleration / deceleration information calculated from the time change of the throttle opening information, etc., mainly the feedback control of the oxygen concentration based on the throttle opening information and the engine speed information is performed. Whether or not to perform, mainly based on the same two pieces of information, whether or not to control and learn the control data in the case of a specific control condition, based on the engine speed information over-revolution determination of whether there is an excessive rotation, Overheat determination based on the throttle opening information, the engine speed information, and the temperature information by the engine (E / G) temperature detecting means or a thermo SW which is a more specific means, overheat determination, throttle opening information, engine Based on the number of revolutions information and the remaining oil amount information by the oil level detection means, the remaining oil Carry out the amount is less whether the oil empty judgment. 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, it is determined whether or not the information is missing or abnormal. Failure judgment, whether the two outboard motors are in operation with other outboard motors operating based on the operating status information, and whether the other outboard motor is in cylinder deactivation operating status based on the cylinder deactivation signal , And DE
Two-engine operating state determination consisting of three determinations of whether the other outboard motor is in the misfire control state corresponding to the abnormality by S (signal for notifying the misfire control state corresponding to the abnormality), and the throttle opening information described above. It is possible to judge whether the vehicle is in rapid acceleration / deceleration based on the change with time, or whether it is in the shift cut state based on the ON / OFF information of the shift cut SW that operates during the shift operation from the high speed rotation state. Done.

Such a judgment 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, step S14 and step 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 is turned on and off which operates in accordance with the tension of the shift cable which is large during the shift operation from the high rotation state, and which is turned on when the tension is large.
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, there is an abnormal state such as over-rotation, overheat at a predetermined throttle opening degree and engine speed, oil empty, or the like from the read information, or another engine is in an abnormal state. 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 executed to output to the memory that the misfire control state is in order to halve the fuel injection amount of the cylinder to be misfired compared to the other cylinders. 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 either replenishing the oil from the oil tank or reducing the engine speed.

Next, in step S21, the cylinder deactivation determination result is determined. This is a determination step for selecting a map for arithmetic processing when it is determined in the operation state determination step S12 described above that the cylinder deactivation operation is performed in the predetermined low load and low rotation state. If it is not the cylinder deactivation 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 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 using the cylinder deactivation map for the cylinder deactivated operation in which a specific cylinder is deactivated (step S24).

Next, in step S23 of FIG. 7, correction values for basic ignition timing and fuel injection are calculated according to operating conditions such as atmospheric pressure and 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.

Next, in step S27, the basic ignition timing and the fuel injection control amount are multiplied by a correction coefficient, and a correction value is further added or multiplied by the correction coefficient to determine 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 only in consideration of the restart and continuing the fuel injection for a predetermined time when it is determined that the engine is in a 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 from # 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. In the V-6 engine, 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, 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. In order to control these cylinders for each bank, each bank has a separate timer. 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, with respect to the deactivated cylinder that causes misfire in the ignition control, the cylinder in which the fuel injection amount is decreased in the fuel injection control is set as the cylinder deactivation information due to the fuel injection control (step S41 in FIG. 9), and the misfire deactivated in 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 engine cycle described above, 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. A timer overflow interrupt is executed at the time when this overflow occurs, that is, when it is detected that the crank angle of 60 degrees is a low speed rotation that is 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 pulse of the TDC signal is missing, that is, the TDC signal pulse is not 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 has been detected for the second time. Even if the overflow has been detected for 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 are interrupted. First, the cylinder deactivation information indicating whether or not the engine is in the cylinder deactivation operation for a state of a predetermined low speed or less and the misfire information regarding whether or not to ignite the ignition due to detection of overheat or overrev (overspeed) are read. After this, a timer value corresponding to the ignition timing is set in the timer 3 or 4 corresponding to the cylinder number. After that, when the misfire is performed based on the cylinder deactivation information or the misfire information, the ignition process 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. When not causing misfire, the number of the cylinder to be ignited is read, and a pulse (HI) is output from the ignition output port of the ignition drive circuit of the cylinder at the timing set by the timer 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 changed to LO.
Then, 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 configuration of the outboard motor engine to which the present invention is applied, the system configuration of the entire control system, and the flow of its operation.

FIG. 13 is a circuit diagram showing a part of the fuel pump drive system according to the embodiment of the present invention. Battery 10
A fuse 1003 is provided on a power supply line 1020 that connects the positive side of 01 to the fuel pump (F / P) motor 1002. The power supply line 1020 is used for the fuel pump motor 100.
2 is branched into two lines at a point b on the ground side, one line is connected to the A side transistor 1006 of the ECU 1005 via the input port 8, and the other line has a resistance value R.
EC from the input port 9 via the current limiting resistor 1004 of
It is connected to the U side B-side transistor 1007. Each of the A-side and B-side transistors has a power supply line 1020.
Switch, and one of them is selected to be turned on. Each of the transistors 1006 and 1007 is connected to a CPU (not shown), and the CPU selects the transistor 1006 having no resistance to turn it on when the engine speed is equal to or higher than a predetermined speed and turns on the other resistor when the speed is lower than the predetermined speed. Transistor 10 connected to 1004
Turn on 07.

In such a circuit configuration, the fuse 1
The capacity of 003 is not less than the blocking current of the fuel pump motor 1002 and not more than the inrush current.

FIG. 14 is an explanatory diagram of this fuse capacity. FIG. 4A is a graph of the fusing characteristic of the fuse capacity I0, where the horizontal axis represents time and the vertical axis represents current value. Also, (B)
The figure is a characteristic diagram of the motor current, where the horizontal axis represents time and the vertical axis represents current value. As shown in (B), the inrush current IPEAK flows immediately after the motor is turned on. This IPEAK is almost equal to the abnormal current when the motor is locked. The blocking current I1 when the excess fuel is recirculated is a value somewhat higher than the current when the motor is normal. In such a current characteristic, the fuse capacitance I0
Is set so that I1 <I0 <IPEAK. The blown region of the fuse having such a capacitance I0 is shown in FIG. As can be seen from the figure, even if a normal rush current flows temporarily, the fuse does not blow within the predetermined time T. On the other hand, if a current close to IPEAK continues to flow for time T or longer due to motor lock or the like, the fuse is blown. Also,
The fuse does not blow even if the blocking current I1 continues to flow.

By using the fuse having such characteristics, the fuel pump can be driven without being cut off by the current due to the normal motor operation, and the circuit can be surely blown to protect the circuit when an abnormal current flows.

FIG. 15 shows a B in which the resistor R is connected to the A-side transistor 1006 having a small resistance shown in FIG.
9 is a flowchart of a switching operation in a circuit having a side transistor 1007. This flow is shown in FIG.
The details of the fuel pump control step S20 shown in FIG. First, in step S1801, it is determined whether or not the starter switch is in the on state, that is, whether or not the cranking operation is being performed, and whether or not the starter switch is within a predetermined time t0 from on to off.
During cranking or after turning off the starter switch t0
If it is within the time, the A-side transistor 1006 is turned on and the B-side transistor 1007 is turned off (step S1802). As a result, the motor can be started without limiting the normal inrush current.

T0 after the starter switch is turned off
When the time has elapsed, the process proceeds to step S1803, and it is determined whether or not the condition is a condition in which the engine should be stopped. The condition for stopping the engine is, for example, when the main switch is turned off, when the engine reverses at the time of starting, or when water falls. If the engine is stopped, both transistors A on the B side 10
Both 06 and 1007 are turned off to stop the fuel supply (step S1804).

If the engine stop condition is not satisfied, the routine proceeds to step S1805, where the engine speed is the predetermined N.
(Rpm) or more to determine. If N or more,
The A-side transistor 1006 is turned on and the B-side transistor 1007 is turned off (step S1806). As a result, a large amount of current can be supplied to increase the amount of supplied fuel during high load and high rotation. The engine speed is N
If the following is true, the B-side transistor is turned on and the A-side transistor is turned off (step S1807). As a result, it is possible to limit the current flowing through the motor when the load is low and the rotation is low to reduce the flow rate and reduce the reflux resistance.

FIG. 16 is a time chart of the embodiment shown in FIG. As shown in the figure, the A-side transistor circuit having a small resistance is used at the time of engine start (during a predetermined time t0 after the starter switch is ON and OFF), and thereafter, if the rotation speed is high according to the engine rotation speed. An A-side transistor circuit, and a B-side transistor circuit having a large resistance if the rotation speed is low is used. In the above-described embodiment, the A-side transistor is turned on at the time of starting until the time t0 after the starter switch is turned off, but instead of this, a predetermined value after the starter switch is turned on. A is the start time until the time t0 'elapses.
The side transistor may be controlled to be turned on.

FIG. 17 is a flow chart of another embodiment of the present invention, and FIG. 18 is its time chart.

This embodiment is the same as the embodiment of FIG. 15 up to step S1805 for determining whether the engine speed is N or more in the above-mentioned flowchart of FIG. If the engine speed is N or more, the A-side transistor is turned on and the B-side transistor is turned off as in the above embodiment (step S1806).

The present embodiment is characterized in that when the engine speed is less than N, the B side is turned on and the A side is turned on at a constant cycle. That is, when the engine speed is not N or more in step S1805,
First, the timer is started (step S1808,
1809). Next, this timer count value is T1 (see FIG.
8 time t1) is determined (step S1)
810). If T1 or less, that is, the engine speed is N
If the time since it dropped below has not reached t1,
The B-side transistor is turned on and the A-side transistor is turned off (step S1811).

If the timer exceeds T1, the process advances to step S1812, and the timer count value is T2 (see FIG.
8 time t2) or less. If it has not reached T2, the A-side transistor is turned on and the B-side transistor is turned off until T2 is reached (step S181).
4). When T2 is reached, step S1812 becomes NO, the process proceeds to step S1813, and the timer is reset.
Then, the B-side transistor is turned on and the A-side transistor is turned off (step S1811).

According to the above flow, as shown in the time chart of FIG. 18, when the engine speed is equal to or lower than the predetermined value, the B-side transistor is first turned on, and thereafter, it is constant based on the time t1 and t2 set by the timer. The A-side transistor can be turned on for a certain period of time in a cycle.

FIG. 19 is a layout diagram of a fuel supply system for an outboard motor according to an embodiment of the present invention. Battery 100 on board
1 is installed, and the main switch 1010 is provided in the cockpit. Fuel pump 1002 and control unit (ECU)
1005 is provided in the cowling 1011 of the outboard motor. The plus (+) side of the battery 1001 is connected to the main switch 1010 and the fuel pump 100 is connected to the fuel pump 100 through the port 2 and the port 3 of the ECU as described later.
2 motors.

FIG. 20 is a circuit diagram of the fuel supply device having the above arrangement. The (+) side of battery 1001 is connected to the second port of ECU 1005 via power supply line 1012. Further, the (+) side of the battery 1001 is connected to the first port of the ECU via the signal line 1015.
The main switch 1010 is provided on the signal line 1015. The (−) side of the battery 1001 is the E of the outboard motor.
Connected to the 5th port of CU and grounded. ECU
Signal line 1015 connected to the first port of the ECU
It is branched into two, and one is connected to the transistor 1013 via the interface 1016. The other branched signal line is the power supply circuit 1017 and the CPU 101.
8 to another transistor 1014. These transistors 1013 and 1014 are arranged in series on the power supply line 1012 via the second, third and fourth ports. A fuel pump motor 1002 is connected on the power supply line between the 3rd and 4th ports.

In such a circuit configuration, when the main switch 1010 is turned on, this on operation is transmitted to the ECU via the signal line 1015, and the power supply circuit 101
In response to this, 7 enables control by the ECU to start. The CPU 1018 turns on the transistor 1014 based on the ON signal of the main switch 1010 unless another engine stop condition is satisfied. Further, the interface circuit 1016 turns on the transistor 1013 based on the ON signal of the main switch 1010. As a result, the power supply line 1012 connecting the battery 1001 and the fuel pump motor 1002 is closed and the motor 1002 is driven. When the main switch 1010 is turned off, the interface 1016 and the CPU 1018 turn off the transistors 1013 and 1014, respectively.
The power supply from 001 is stopped. By thus providing the two transistors 1013 and 1014 forming the switch in series on the power supply line, the engine is surely stopped by the OFF operation of the main switch 1010, the malfunction of the CPU 1018 and the second operation. Even if a short circuit occurs between the third and third ports, the power can be reliably cut off and the fuel pump can be stopped. Further, since the power switch line on which a large current flows and the signal line on which a minute current flows are separated from each other and the main switch is provided on the signal line, the length of the power line is shortened and the adverse effect such as voltage drop is eliminated.

FIG. 21 shows the fuse 1003 shown in FIG. 13 and the parallel transistor 100 of the A / B switching mechanism.
It is a circuit diagram of the structure which integrated the drive circuit which has 6,1007 in the circuit of FIG. That is, the fuse 1003 is provided on the power supply line 1012 and the CPU is provided with the above-mentioned A side and B.
This is a configuration in which the side transistors 1006 and 1007 are connected. As described above, the CPU selects one of the A-side and B-side transistors to turn it on according to the engine speed. The other configurations and effects are the same as those of the circuit of FIG.

[0089]

As described above, according to the present invention, the capacity of the fuse on the power supply line connecting the battery and the fuel pump motor is not less than the blocking current and not more than the inrush current.
When the fuel pump is locked, the fuse is surely blown to protect the drive circuit while reliably performing the fuel recirculation action. In addition, the fuel pump motor has a different resistance.
By connecting two parallel circuits, the drive current flowing through this motor can be switched in two stages. This allows
It is possible to flow a large current at the time of start-up where a rush current flows or at a high rotation with a large flow rate, and at the time of low rotation, it is possible to increase the resistance to reduce the drive current and reduce the flow rate to reduce the reflux amount.

Further, by connecting a large resistance during low rotation operation to reduce the current and periodically turning on a switch having a low resistance, a large current is high when an abnormality such as a motor lock occurs. The heat is prevented from being generated by the motor and the resistor because the fuse is surely blown without being restricted by the resistor.

Further, by providing two switches in series on the power supply line connecting the battery and the fuel pump motor, malfunction of the CPU and short circuit of the other switch occur when the main switch is turned off. However, the power can be surely cut off.
Further, since the power switch line on which a large current flows and the signal line on which a minute current flows are separated from each other and the main switch is provided on the signal line, the length of the power line is shortened and the adverse effect such as voltage drop is eliminated.

[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 configuration diagram including a fuel system of the outboard motor of the present invention.

FIG. 3 is a structural explanatory view of a throttle lever of an outboard motor to which the present invention is applied.

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 a circuit diagram of essential parts of a fuel supply device according to an embodiment of the present invention.

FIG. 14 is an explanatory diagram of fuse blowing characteristics according to an example of the present invention.

FIG. 15 is a flowchart of fuel pump drive control according to the embodiment of the present invention.

16 is a time chart of the embodiment of FIG.

FIG. 17 is a flowchart of another embodiment of the present invention.

FIG. 18 is a time chart of the embodiment of FIG.

FIG. 19 is a layout configuration diagram of a fuel supply device according to the present invention.

FIG. 20 is a circuit diagram of a fuel supply device according to an embodiment of the present invention.

FIG. 21 is a circuit diagram of a fuel supply device according to another embodiment of the present invention.

[Explanation of symbols]

201: cylinder discriminating means, 203: engine speed calculating means, 205: trim angle reading means, 210: basic ignition timing calculating means, 211: basic fuel injection amount calculating means, 2
14: Ignition timing correction means, 215: Fuel injection amount correction means, 218: Ignition output means, 219: Fuel output means, 1
001: battery, 1002: fuel pump motor, 10
03: fuse, 1004: current limiting resistor, 1006
1007: transistor, 1010: main switch,
1012: power supply line, 1013, 1014: transistor, 1015: signal line.

Claims (2)

(57) [Claims] 1. In a fuel pump drive device for a fuel injection type internal combustion engine, wherein a main switch and a fuse are provided on a wiring connecting a battery and a fuel pump motor, a capacity of the fuse is greater than or equal to a blocking current of the fuel pump motor. A first switch circuit having a small resistance value and a second switch circuit having a large resistance value in parallel on the ground side of the fuel pump motor. Switching control means is provided, and the switching control means turns on the first switch circuit at the time of starting and when the engine speed is above a predetermined value, and when the engine speed is below a predetermined value, the second switch circuit. Is configured to be turned on, and the switching control means is configured such that, when the second switch circuit is in the on state, the switching control means periodically turns on the first switch for a predetermined time. The fuel pump driving apparatus for a fuel injected internal combustion engine, characterized in that it is configured to turn on the switch circuit. 2. In a fuel pump drive device for a fuel injection type internal combustion engine, wherein a main switch and a fuse are provided on a wiring connecting a battery and a fuel pump motor, the capacity of the fuse is greater than or equal to a blocking current of the fuel pump motor. A first switch circuit having a small resistance value and a second switch circuit having a large resistance value in parallel on the ground side of the fuel pump motor. Switching control means is provided, and the switching control means turns on the first switch circuit at the time of starting and when the engine speed is above a predetermined value, and when the engine speed is below a predetermined value, the second switch circuit. And two switch means in series on the drive power supply line for supplying the battery voltage to the fuel pump motor. However, the fuel is characterized in that the battery and each of the switch means are connected by a signal line for operating these two switch means in response to ON / OFF of the main switch, and the main switch is provided on this signal line. Fuel pump drive for injection type internal combustion engine.