JP3307080B2 - Fuel pump control device for 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 device for controlling a fuel pump for supplying fuel to a fuel injection device for an internal combustion engine.

[0002]

BACKGROUND OF THE INVENTION In devices driven by an internal combustion engine, it is sometimes necessary to be able to start and stop the engine without using key switches. For example, in a vehicle that travels on water, such as a water vehicle, a key switch that has a complicated structure to enable multi-stage operation because it dives into the water while traveling and water enters the vehicle. If used, there is a risk that a short circuit accident may occur at the key switch. In addition, in a leisure vehicle such as a water vehicle, it is difficult to insert and remove a troublesome key. Therefore, it is necessary to enable the engine to be started by a switch operation as simple as possible. Furthermore, if a key switch is used for a vehicle traveling on water, there is a risk that if the key is lost on the water, it will not be possible to return to the port. In these cases, it is necessary to start and stop the engine by a push button switch having a simple structure without using a key switch.

In order to enable starting and stopping of the engine without using a key switch, for example, a start switch and a stop switch, which are, for example, pushbutton switches, are provided. It is conceivable to stop the engine by pressing.

When starting and stopping the engine using a start switch and a stop switch, it is conceivable that a drive circuit around the electrical components is configured as shown in FIG. 6, for example. In FIG. 6, reference numeral 1 denotes a battery, and reference numeral 2 denotes a starter motor connected to both ends of the battery 1 via contacts 3a of a relay 3. The relay 3 has an exciting coil 3b, and the voltage of the battery 1 is applied to the exciting coil 3b via a start switch 4 composed of a push button switch. The exciting coil 3b is excited only while the start switch 4 is closed to close the contact 3a. Therefore, starter motor 2
Rotates only while the start switch 4 is closed.

[0005] Reference numeral 5 denotes a fuel pump connected to both ends of the battery 1 via a pump switch 6. Reference numeral 7 denotes a fuel injector for supplying fuel to the internal combustion engine.
The fuel is supplied to the injector 7 from. Reference numeral 8 denotes a magnet generator driven by the output shaft of the engine. The output of the magnet generator is applied to the fuel pump 5 via a diode 9 and the battery 1 is connected via the diode 9 and a pump switch 6. Are applied to both ends. A fuel injection control device 10 is provided to control the timing of giving an injection command to the injector 7 (fuel injection timing) and the injection time, and the output of the magnet generator 8 is applied to the power supply terminal of the fuel injection control device 10. I have. The fuel injection control device 10 includes a DC power supply unit that rectifies the AC output of the magnet generator 8 and outputs a DC constant voltage, and a CPU that is driven by the DC power supply unit. An injection command signal having a pulse width corresponding to time is given to the injector 7.

A stop switch 12 is a push button switch. The stop switch 12 is provided so that a part of the fuel injection control device 10 is grounded to stop the operation of the fuel injection control device.

Although the internal combustion engine is further provided with an ignition device, the illustration of the ignition device is omitted in FIG.

When the engine is started as shown in FIG. 6, the pump switch 6 is first closed and the fuel pump 5 is started.
To supply fuel to the injector 7. Next, the start switch 4 is closed and the starter motor 2 is rotated.
When the crankshaft of the engine rotates, the magnet generator 8 outputs a voltage, so that power is supplied to the fuel injection control device 10, which supplies an injection command signal to the injector 7. The injector 7 opens its valve only while the injection command signal is being supplied, injects fuel into the fuel injection space of the engine (for example, in the throttle body), and supplies a predetermined amount of fuel to the engine. After the engine has started, the start switch 4 is opened to stop energizing the starter motor 2. During operation of the engine, the battery 1 is charged by the output of the magnet generator 8 through the diode 9 and the pump switch 6.

When the engine is stopped, the stop switch 1
Close 2. When the stop switch 12 is closed, the operation of the fuel injection control device 10 stops, and the supply of the injection command signal to the injector 7 stops. As a result, the supply of fuel to the engine stops, and the engine stops. After the engine stops,
The pump switch 6 is opened to disconnect the fuel pump 5 from the battery 1 to prevent battery consumption.

[0010]

As shown in FIG. 6,
When the engine is started by closing the start switch 4, it is necessary to drive the fuel pump 5 by the battery 1 in order to surely inject the fuel at the time of the start operation. However, in this case, after the engine stops, it is necessary to disconnect the fuel pump 5 from the battery, so it is necessary to insert the pump switch 6 between the fuel pump 5 and the battery 1. Therefore, it is necessary to operate the two switches, the pump switch 6 and the start switch 4, at the time of starting the engine, and there is a problem that the operation becomes complicated and the advantage of omitting the key switch is lost.

After the engine stops, the pump switch 6
There is also a danger that the battery 1 will be consumed by forgetting to open the battery.

An object of the present invention is to enable the engine to be started only by operating a start switch composed of a self-return type switch such as a push button switch, and to automatically disconnect a fuel pump from a battery when the engine is stopped. It is an object of the present invention to provide a fuel pump control device for an internal combustion engine, which is capable of performing the following.

[0013]

SUMMARY OF THE INVENTION The present invention provides a power supply device having a magnet generator mounted on an output shaft and a battery charged by the magnet generator, a fuel injector, and a fuel injector. A fuel pump to supply
A fuel injection control device that is driven by an output of a DC power supply unit that outputs a DC voltage using a magnet generator as a power supply and controls an injector, a self-recovering start switch that is closed at startup, and a state in which the start switch is closed. The present invention relates to a fuel pump control device that includes a starter motor driven by an output of a battery, is supplied with fuel by an injector, and controls energization of a fuel pump of an internal combustion engine started by the starter motor.

In the present invention, in order to achieve the above object, a start switch state detecting means for detecting a state of a start switch, and a rotation state of the internal combustion engine can cause a magnet generator to generate an output for driving a fuel pump. An engine state detecting means for detecting whether or not the power generation is possible; and a start switch state detecting means and an engine state detecting means provided so as to be turned on and off, and the start switch state detecting means detects a closing of the start switch. And when the engine state detecting means is detecting the power generation enabled state, the output is turned on to apply the output of the power supply to the fuel pump, and the start switch state detecting means detects the opening of the start switch. When the engine state detecting means no longer detects a power generation enabled state in the state of being turned on, the fuel pump is turned off to disconnect the power supply from the fuel pump. It is provided and a drive for the switch.

[0015] The engine state detecting means may be configured to detect whether or not the engine is in a power generation enabled state, for example, based on an output voltage of a DC power supply unit of the fuel injection control device.

The engine state detecting means detects the rotational speed of the internal combustion engine, and detects that the engine is in a power generation enabled state when the rotational speed is detected to be equal to or higher than a set value. It can also be configured.

The starting switch state detecting means and the engine state detecting means may be realized by software using a CPU, or may be realized by a starting switch state detecting circuit and an engine state detecting circuit comprising a hardware circuit.
In this case, the start switch state detection circuit is configured by a circuit including a switch state detection transistor provided so that when the start switch is closed, a base current is supplied through the start switch with the output of the battery and the base switch is turned on. it can. Further, the engine state detection circuit can be configured by a circuit including an engine state detection transistor that detects an output voltage of the DC power supply unit of the fuel injection control device and conducts when the output voltage is established. In this case, the fuel pump driving switch includes an exciting coil provided to be excited when the switch state detecting transistor is conducting and when the fuel state detecting transistor is conducting, and the exciting coil includes: It can be constituted by a relay having a contact that closes when excited.

[0018]

With the above construction, when the start switch state detecting means detects the closing of the start switch, the pump drive switch is turned on to apply the output voltage of the power supply to the fuel pump. The fuel is supplied, and the fuel can be injected. When the starter motor is started and the magnet generator outputs a predetermined voltage, the fuel injection control device operates, so that the injector injects fuel to start the engine. During the operation of the engine, the engine state detecting means detects the power generation enabled state, so that the pump driving switch keeps the ON state and continues to supply power to the fuel pump. Therefore, the operation of the engine is performed without any trouble.

When the engine is stopped, the engine state detecting means does not detect the power generation enabled state, so that the pump driving switch is turned off and the fuel pump is disconnected from the power supply. Therefore, it can be prevented that the fuel pump is driven while the engine is stopped and the battery is consumed.

[0020]

FIG. 1 shows the overall configuration of a fuel pump control device for an internal combustion engine according to the present embodiment. In FIG. 1, reference numeral 1 denotes a battery, and 2 denotes a battery through a contact 3a of a relay 3.
A starter motor connected to both ends of the motor for driving the crankshaft when the engine is started, and a self-return type switch such as a push button switch (a switch that closes only while applying the operating force and opens when the operating force is removed) Start switch
The exciting coil 3b of the relay 3 is connected to both ends of the battery 1 via the start switch 4.

Reference numeral 5 denotes a fuel pump for supplying fuel from a fuel tank (not shown) to the injector 7. Reference numeral 8 denotes a magnet generator driven by the output shaft of the engine. Has been applied. In this example, the magnet generator 8 and the battery 1 charged by the magnet generator through the diode 9 constitute a power supply device for a fuel pump control device.

Reference numeral 10 denotes a fuel injection control device that operates using the magnet generator 8 as a power source. Reference numeral 12 denotes a stop switch composed of a self-returning type switch. The stop switch 12 connects a part of the fuel injection control device to ground. The engine is stopped by stopping the operation of the fuel injection control device. The fuel injection control device 10 includes a DC power supply unit that outputs a constant DC voltage using the magnet generator 8 as a power supply, and a CPU driven by the DC power supply unit, and controls the control conditions such as the ambient temperature and the atmospheric pressure. Accordingly, the fuel injection timing and the fuel injection time at each rotation speed are calculated, and an injection command signal having a pulse width corresponding to the calculated injection time at the calculated injection timing is given to the injector 7. The injector 7 is
While the injection command signal is being given, the valve is opened to inject fuel into the fuel injection space of the engine.

In the present invention, the output voltage of the power supply device is supplied to the fuel pump 5 through the fuel pump control device 20. The fuel pump control device 20, as shown in FIG.
Start switch state detecting means 21 for detecting the state of the start switch 4; and engine state detection for detecting whether or not the rotation state of the internal combustion engine is in a power generation enabled state in which the magnet generator can generate an output for driving the fuel pump. Means 22 and a pump driving switch 2 provided between the power supply device and the fuel pump 5.
3 is provided. The pump driving switch 23 is a switch that is turned on and off by the start switch state detecting means 21 and the engine state detecting means 22. When the start switch state detecting means 21 detects that the start switch 4 is closed, the pump driving switch 23 is operated. 22 is turned on when the power-generating state is detected, the output of the power supply device is applied to the fuel pump 5, and the engine-state detecting means is detected when the starting-switch state detecting means detects the opening of the starting switch. When the power supply no longer detects the power generation enabled state, the power supply device is turned off and the power supply device is disconnected from the fuel pump.

In the embodiment of FIG. 2, when the engine is started, when the start switch 4 is closed, the starter motor 2 rotates. At this time, the start switch state detecting means 21 detects the closing of the start switch, so that the pump driving switch 2
3 is turned on, and the output voltage of the battery 1 is applied to the fuel pump 5 through the pump driving switch 23.
As a result, the fuel pump 5 operates, and fuel is supplied to the injector 7. In addition, the rotation of the crankshaft of the engine causes the magnet generator 8 to output a voltage, and the voltage is supplied to the fuel injection control device 10. Therefore, the control device 10 supplies an injection command signal to the injector 7. The injector 7 opens its valve to inject fuel only while the injection command signal is being supplied, and supplies fuel to the engine. Further, a spark is generated in the spark plug by an ignition device (not shown), and the engine is ignited, so that the engine is started. When the engine is rotated by the starter motor and the magnet generator 8 generates a voltage necessary to drive the fuel pump,
Since the engine state detecting means 22 detects the power generation enabled state and holds the pump driving switch 23 in the ON state, the operation of the fuel pump is continued even if the start switch 4 is opened.

When the stop switch 12 is closed and the engine is stopped, the engine state detecting means 22 does not detect the power generation enabled state, so that the pump driving switch 23 is turned off and the fuel pump 5 is disconnected from the battery.

With the above configuration, the engine can be started only by performing the operation of closing the start switch, so that the starting operation can be simplified. Moreover, since the fuel pump can be disconnected from the power source after the engine stops, it is possible to prevent the battery from being consumed while the engine is stopped.

FIG. 3 shows a more specific embodiment of the present invention. In the example shown in FIG. 3, the pump driving switch 23 is formed of a relay having an exciting coil 23a and a contact 23b, and diodes 23c are connected in parallel to both ends of the exciting coil 23a. The contact 23b includes a movable contact b1 and fixed contacts b2 and b3. The movable contact b1 is connected to the movable contact b when the exciting coil 23a is not excited.
2 and contacts the fixed contact b3 when the exciting coil 23a is excited. The movable contact b1 is the exciting coil 23a
Is connected to the positive terminal of the battery 1 and a fuel pump 5 is connected between the fixed contact b3 and ground (the negative terminal of the battery). The fixed contact b2 is an idle contact, and when the movable contact b1 is in contact with the fixed contact b2, the fuel pump 5 is disconnected from the power supply. To both ends of the fuel pump 5, a diode D1 whose anode is directed to the ground side is connected.

Start switch 4 and exciting coil 3 of relay 3
a through the diode D2 to the connection point with the capacitor C1
Is connected, and the other end of the capacitor C1 is grounded. A series circuit of resistors R1 and R2 is connected in parallel to both ends of the capacitor C1, and the connection point of the resistors R1 and R2 is connected to the base of an NPN transistor Tr1 whose emitter is grounded. A capacitor C2 is connected in parallel between the base and the emitter of the transistor Tr1. In this example, the transistor Tr1, the resistors R1 and R2, the capacitors C1 and C2, and the diode D2 constitute a starting switch state detecting circuit 21 '.
Is realized.

The fuel injection control device 10 includes a DC power supply 10A for rectifying the output voltage of the magnet generator 8 and outputting a constant DC voltage, and a CPU 10B driven by the power supply. The injection timing and the injection time at each rotational speed are calculated in accordance with control conditions such as pressure and atmospheric pressure, and an injection command signal Vj having a pulse width corresponding to the calculated injection time at the calculated injection timing is generated. This injection command signal Vj
Is supplied to the injector, and the injector opens the valve to supply fuel to the engine only while the injection command signal is being supplied.

In this embodiment, the NP whose emitter is grounded
The base of the N-transistor Tr2 is connected to the output terminal of the DC power supply 10A via the resistor R3, the resistor R4 is connected between the base and the emitter of the transistor Tr2, and the Zener diode ZD1 is connected between the collector and the emitter.
The collector of the transistor Tr2 is connected to the collector of the transistor Tr1, and when the magnitude of the output voltage of the DC power supply unit 10A becomes greater than or equal to a set value, the transistor Tr2 conducts, and the exciting current flows to the exciting coil 23a through the transistor Tr2. It is flowing. An engine state detecting circuit 22 'is constituted by the transistor Tr2, the resistors R3 and R4, and the Zener diode ZD1, and this detecting circuit implements the engine state detecting means of FIG.

In the embodiment shown in FIG.
Is closed, the capacitor C1 is charged by the output voltage of the battery 1 through the diode D2, and a base current is applied to the transistor Tr1 by the voltage across the capacitor C1, so that the transistor Tr1 conducts. When the transistor Tr1 is turned on, a current flows through the exciting coil 23a, so that the movable contact b1 comes into contact with the fixed contact b3 to apply the output voltage of the battery 1 to the fuel pump 5. When the engine is started and the output voltage of the magnet generator 8 is established, the output voltage of the DC power supply unit 10A becomes equal to or higher than the set value, so that the transistor Tr2 is turned on (by detecting that the engine is in a power generation enabled state). ) Apply a current to the exciting coil 23a. Therefore, even after the start switch 4 is opened, the exciting coil 23a is kept in the excited state as long as the engine is rotating, and the fuel pump 5
Is continuously applied to the power supply.

When the stop switch (not shown in FIG. 3) is closed to stop the engine, the output voltage of the magnet generator 8 disappears, and the output voltage of the DC power supply 10A disappears. The transistor Tr2 at 22 'is turned off, and the exciting coil 23a is deenergized. As a result, the movable contact b1 comes into contact with the fixed contact b2, so that the fuel pump 5 is disconnected from the power supply. Therefore, it can be prevented that the fuel pump is driven while the engine is stopped and the battery is consumed.

In the example shown in FIG. 3, the fuel pump drive switch 23 is controlled by a hardware circuit. However, the switch 23 can be turned on / off by software using a CPU.

FIG. 4 shows a hardware configuration for controlling the fuel pump driving switch 23 using the CPU 10B of the fuel injection control device 10, and FIG. 5 shows controlling the fuel pump driving switch 23 using the CPU. 5 shows an example of a control algorithm in the case of performing the control. In this example, a collector-emitter circuit of the transistor Tr3 is inserted between the exciting coil 23a and the ground, and the base of the transistor Tr3 is
It is connected to the output port of PU10B. The potential at the connection point between the start switch 4 and the exciting coil 3b of the relay 3 and the output voltage of the DC power supply 10A are supplied to the CPU 10B.

In this example, it is first determined from the potential at the connection point between the start switch 4 and the exciting coil 3b whether or not the start switch is on, and when it is detected that the start switch is on, Fuel pump drive switch 23
Is closed. Next, the power supply unit 10 of the fuel injection control device 10
By reading the output voltage of A, it is determined whether or not the output voltage has been established (is not less than a set value). If the voltage has been established, the fuel pump driving switch 23 is kept in a closed state. When the engine stops and the output voltage of the power supply unit of the fuel injection control device disappears, the switch for driving the fuel pump is opened.

In the example shown in FIG. 5, the start switch state detecting means is realized by the process of determining whether the start switch is in the ON state, and the output voltage of the power supply unit of the fuel injection control device is established. The engine state detecting means is realized by the process of determining whether or not the engine is present.

In the above-described embodiment, it is determined whether or not the engine is in a state where the magnet generator can generate an output voltage for driving the pump from the output of the power supply unit of the fuel injection control device (power generation enabled state). However, when the output voltage of the magnet generator 8 is detected and the detected value becomes equal to or higher than a set value, it may be detected that the power generation is possible. Then, when the number of rotations is equal to or more than the set value, it may be detected that the power generation is possible.

In the above embodiment, the fuel pump drive switch 23 is constituted by a relay. However, this switch can be constituted by using a semiconductor switch element.

In the above-described embodiment, the stop switch stops the engine by stopping the operation of the fuel injection control device 10 by grounding a part of the fuel injection control device 10. However, the method of providing the stop switch is as follows. The invention is not limited to the above example. For example, a stop switch is connected to a part of the circuit of the ignition device for the internal combustion engine, and when the stop switch is closed, a part of the ignition device for the internal combustion engine is short-circuited or grounded. Thus, the ignition operation may be stopped.

[0040]

As described above, according to the present invention, starting switch state detecting means for detecting the state of the starting switch,
Engine state detecting means for detecting whether or not the engine is in a state in which a magnet generator can generate a pump driving voltage (power generation possible state); a fuel pump driving switch on / off controlled by these detecting means; When the closed state of the start switch is detected and the power generation possible state is detected, the fuel pump drive switch is turned on to apply the output of the power supply to the fuel pump, and the open state of the start switch is detected. When the power generation possible state is no longer detected in the state where it is set, the fuel pump drive switch is turned off and the power supply device is disconnected from the fuel pump,
The engine can be started only by operating a start switch composed of a self-return type switch such as a push button switch, and when the engine stops, the fuel pump can be automatically disconnected from the battery. Therefore, it is possible to prevent the battery from being consumed while the engine is stopped without complicating the operation at the time of starting.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram specifically showing a configuration of a fuel pump control device of the embodiment of FIG.

FIG. 3 is a circuit diagram showing a more specific embodiment of the present invention.

FIG. 4 is a circuit diagram showing a hardware configuration of an embodiment in which a fuel pump driving switch is controlled using a CPU.

FIG. 5 is a flowchart showing a control algorithm when a fuel pump driving switch is controlled using a CPU.

FIG. 6 is a circuit diagram showing a configuration example of a circuit that can be considered when driving a starter motor, a fuel injection control device, and a fuel pump without using a key switch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Starter motor 3 Relay 3a Contact 3b Excitation coil 4 Start switch 5 Fuel pump 7 Injector 8 Magnet generator 10 Fuel injection control device 12 Stop switch 20 Fuel pump control device 21 Start switch state detection means 22 Engine state detection means 23 Fuel Pump drive switch 23a Excitation coil 23b Contact Tr1 Switch state detection transistor Tr2 Engine state detection transistor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-3592 (JP, A) JP-A-2-271083 (JP, A) JP-A-64-53060 (JP, A) JP-A-5-530 321715 (JP, A) JP-A-55-87830 (JP, A) JP-A-3-206347 (JP, A) JP-A-57-145772 (JP, U) JP-A-57-172161 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 41/00-45/00

Claims (4)

(57) [Claims] 1. A power supply device comprising: a magnet generator attached to an output shaft; and a battery charged by the magnet generator; a fuel injector; a fuel pump for supplying fuel to the injector; A fuel injection control device that is driven by an output of a DC power supply unit that outputs a DC voltage using a magnet generator as a power source and controls the injector, a self-recovery start switch that is closed at startup, and the start switch that is closed A starter motor driven by the output of the battery while the fuel is supplied by the injector, and controls the energization of the fuel pump of the internal combustion engine started by the starter motor. Starting switch state detecting means for detecting a state of the starting switch; and An engine state detecting means for detecting whether or not the generator is in a power generation enabled state capable of generating an output for driving the fuel pump; and an on / off control provided by the start switch state detecting means and the engine state detecting means. And when the start switch state detecting means detects the closing of the start switch and when the engine state detecting means detects the power generation enabled state, the output of the power supply device is fueled. When the engine state detecting means no longer detects a power generation enabled state while the start switch state detecting means detects the opening of the start switch, the power supply apparatus is turned off and the power supply device is supplied to the fuel pump. A fuel pump control device for an internal combustion engine, comprising: a fuel pump drive switch separated from the fuel pump. 2. The fuel pump control for an internal combustion engine according to claim 1, wherein the engine state detecting means detects whether or not the engine is in a state capable of generating power from an output voltage of a DC power supply unit of the fuel injection control device. apparatus. 3. The engine state detecting means detects a rotational speed of the internal combustion engine, and detects that the engine is in a power generation enabled state when the rotational speed is detected to be equal to or higher than a set value. Item 2. A fuel pump control device for an internal combustion engine according to Item 1. 4. A power supply device comprising a magnet generator attached to an output shaft and a battery charged by the magnet generator, a fuel injector, a fuel pump for supplying fuel to the injector, A fuel injection control device that is driven by an output of a DC power supply unit that outputs a DC voltage using a magnet generator as a power source and controls the injector, a self-recovery start switch that is closed at startup, and the start switch that is closed A starter motor driven by the output of the battery while the fuel is supplied by the injector, and controls the energization of the fuel pump of the internal combustion engine started by the starter motor. When the start switch is closed, a base current is applied through the start switch at the output of the battery. A start switch state detection circuit including a switch state detection transistor provided so as to be conductive, and detecting an output voltage of a DC power supply unit of the fuel injection control device, and detecting a magnitude of the output voltage equal to or greater than a set value. An engine state detection circuit including an engine state detection transistor that conducts at a certain time, and an excitation coil that is excited when the switch state detection transistor is on and the fuel state detection transistor is on. A contact that closes when the exciting coil is excited, the contact comprising a fuel pump driving switch inserted between the battery and the fuel pump. Fuel pump control unit.