JP2010013982A - Fuel injection control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain high controllability of fuel injection control when a power distribution period to an ignition coil 24a overlaps with an injection period in a fuel injection control device electrically operating a fuel injection valve 18 using electric power from a battery 60. <P>SOLUTION: Voltage of the battery 60 is applied to a capacitor 66 for injection through a diode 64. The capacitor 66 for injection is made to serve as an exclusive power supply for an ECU 62 and the fuel injection valve 18. That is, the capacitor 60 for injection is not affected even if the voltage of the battery 60 is fluctuated during the power distribution period to the ignition coil 24a. When operating the fuel injection valve 18, the ECU 62 calculates ineffective injection time based on the detected value Vi of the voltage of the capacitor 66 for injection. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel injection control device that performs fuel injection control of an internal combustion engine by electrically operating a fuel injection valve using electric power from a power feeding means.

  An electromagnetic solenoid is well known as an electronically controlled actuator mounted on a fuel injection valve of an internal combustion engine. By energizing the electromagnetic solenoid, the nozzle needle of the fuel injection valve can be displaced to open the fuel injection valve. Here, the valve opening time of the fuel injection valve is set based on the command value of the injection amount for the fuel injection valve. This is because the actual amount of fuel injected from the fuel injection valve is determined according to the opening time of the fuel injection valve.

  By the way, there is a response delay between the timing of starting energization of the electromagnetic solenoid and the timing of actually starting fuel injection after the fuel injection valve is opened. Therefore, conventionally, the valve opening time calculated from the command value of the injection amount for the fuel injection valve is corrected by the invalid injection time which is the time for compensating for the shortage of the actual injection amount due to the response delay. Has also been put to practical use. Specifically, in view of the fact that the response delay amount changes depending on the voltage of the battery that supplies power to the electromagnetic solenoid, it has been put into practical use to calculate the invalid injection time based on the detected value of the battery voltage. Yes.

There are other fuel injection control devices described in, for example, the following Patent Documents 1 and 2.
JP-A-6-43400 Japanese Patent Laid-Open No. 10-299551

  By the way, even if the fuel injection control is performed by operating the fuel injection valve based on the injection time corrected by the invalid injection time, a phenomenon in which the air-fuel ratio becomes lean occurs in a predetermined operating state of the internal combustion engine. It has been found by the inventors. Therefore, the inventors have conducted various experiments to investigate this factor, and as a result, the fuel injection period and the energization period to the ignition coil may overlap depending on the operating state of the internal combustion engine. Found out to be lean. That is, during the energization period to the ignition coil, a large amount of battery power is consumed by the ignition coil, so that the battery voltage decreases. For this reason, when the energization period to the ignition coil overlaps with the fuel injection period, the detected value of the battery voltage used for calculating the invalid injection time is higher than the actual battery voltage during the fuel injection period. Therefore, the invalid injection time is calculated to be shorter than an appropriate value, and the actual fuel injection amount is insufficient.

  In addition, not only when the energization period to the ignition coil and the fuel injection period overlap, but generally, the power of the power supply means is excessively consumed, so that the voltage of the power supply means is calculated as the invalid injection period. If there is a difference between the time and the time of fuel injection, the controllability of the fuel injection control may be reduced.

  The present invention has been made to solve the above-mentioned problems, and its object is to maintain high controllability of the fuel injection control when the fuel injection valve is electrically operated using the electric power from the power supply means. It is an object of the present invention to provide a fuel injection control device that can do this.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  According to a first aspect of the present invention, there is provided a fuel injection control device that performs fuel injection control of an internal combustion engine by electrically operating a fuel injection valve using electric power from a power supply means, wherein the fuel injection valve and the power supply means And a blocking unit that prevents a voltage fluctuation of the power feeding unit from being propagated to the fuel injection valve side due to power consumption of a predetermined on-vehicle electric load other than the fuel injection valve, and the blocking unit Valve opening time calculation means for calculating the valve opening time of the fuel injection valve based on the voltage on the fuel injection valve side, and operation means for operating the fuel injection valve based on the calculated valve opening time. It is characterized by providing.

  In the above invention, since the blocking means is provided, fluctuations in the voltage on the fuel injection valve side of the blocking means in the electrical path that electrically connects the power feeding means and the fuel injection valve can be preferably blocked. For this reason, by calculating the valve opening time of the fuel injection valve based on this voltage, it is possible to inject the intended amount of fuel with high accuracy, and to maintain high controllability of the fuel injection control.

  The predetermined on-vehicle electric load may be used as an ignition means for the internal combustion engine. Furthermore, the predetermined on-vehicle electric load may be an electric load other than the fuel injection valve and the fuel injection control device.

  According to a second aspect of the present invention, in the first aspect of the present invention, the blocking means is connected to a diode having a forward direction from the power supply means side to the fuel injection valve side and a cathode side of the diode. And power storage means for storing the power of the power supply means.

  In the said invention, the electric power of an electrical storage means is not consumed by predetermined vehicle-mounted electric loads other than a fuel injection valve. For this reason, even if the voltage of the power supply means varies due to the power consumption of a predetermined electric load, the voltage of the power storage means is not affected. For this reason, in the said invention, a prevention means can be comprised simply and appropriately.

  According to a third aspect of the present invention, in the first aspect of the invention, the blocking means includes a constant voltage circuit that generates a constant voltage lower than the voltage of the power supply means by using the voltage of the power supply means. It is characterized by comprising.

  In the above invention, since the constant voltage circuit generates a constant voltage lower than that of the power supply means, the output voltage of the constant voltage circuit is stable regardless of voltage fluctuation of the power supply means. For this reason, in the said invention, a prevention means can be comprised simply and appropriately.

  In addition, since the output voltage of the constant voltage circuit is assumed to be constant, the valve opening time calculation means takes into account the value assumed as the output voltage in advance without referring to the detection value of each output voltage. Thus, the valve opening time may be calculated.

  According to a third aspect of the present invention, the constant voltage circuit has a breakdown voltage that is lower than a voltage assumed as a voltage of the power supply means, and the voltage of the power supply means passes through a resistor. A Zener diode applied to the cathode side, and a transistor having a forward direction from the power supply means side to the fuel injection valve side and a base connected to the cathode of the Zener diode. May be a feature.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the ignition means of the internal combustion engine is of a full transistor type.

  In the full transistor type, a large amount of power is consumed during the energization period of the ignition coil. In particular, the power consumption per unit time at this time tends to be larger than the power consumption per unit time during the storage period of the capacitor in the CDI method. For this reason, it is easy to cause a rapid voltage fluctuation of the power supply means. Therefore, if the valve opening time is calculated based on the voltage detection value of the power supply means, the detection value used for the calculation and the voltage of the power supply means during the fuel injection period may be greatly different. For this reason, the said invention becomes a thing with especially high utility value of the invention of Claims 1-3.

  Here, the ignition means is included in the predetermined in-vehicle electric load.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the internal combustion engine is a single cylinder.

  In a single-cylinder internal combustion engine, the frequency of non-stationary power consumption, such as power consumption for ignition, is less than that of a multi-cylinder engine, resulting in non-stationary power consumption. The voltage fluctuation of the power feeding means tends to be particularly noticeable. For this reason, the said invention becomes a thing with especially high utility value of the invention of Claims 1-4.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, the internal combustion engine is mounted on a motorcycle.

  In a motorcycle, the voltage of the power feeding means tends to vary particularly easily due to the power consumption of the on-vehicle electric load. For this reason, the said invention has especially high utility value of the invention of Claims 1-5. In addition, if the said motorcycle is a small motorcycle, the utility value of the invention of Claims 1-5 will become still higher.

(First embodiment)
Hereinafter, a first embodiment in which a power generation control device according to the present invention is applied to a power generation control device for a motorcycle will be described with reference to the drawings.

  FIG. 1 shows the system configuration of this embodiment.

  The illustrated internal combustion engine 10 is of a single cylinder. Specifically, the internal combustion engine 10 is an intake port type spark ignition internal combustion engine. A throttle valve 16 that is mechanically operated by an accelerator grip 14 is provided upstream of the intake passage 12 of the internal combustion engine 10. A throttle sensor 15 that detects the opening of the throttle valve 16 (throttle opening θ) is provided near the throttle valve 16. An intake pressure sensor 17 that detects the pressure in the vicinity of the throttle valve 16 in the intake passage 12 is provided. A fuel injection valve 18 is provided downstream of the intake passage 12. The fuel injection valve 18 uses an electromagnetic solenoid 18a as an electronically controlled actuator, and opens when the electromagnetic solenoid 18a is energized by turning on the switching element 18b. Thereby, fuel (for example, gasoline) is injected into the intake passage 12.

  The intake passage 12 is communicated with the combustion chamber 22 by the opening operation of the intake valve 20. A spark plug 24 protrudes from the combustion chamber 22. In the present embodiment, a full transistor type ignition device is illustrated as an ignition means including the ignition plug 24. This is because the switching element 24b is connected to the primary side coil of the ignition coil 24a and the loop circuit of the battery 60, the switching element 24b and the primary side coil is closed by turning on the switching element 24b. 60 is an ignition device in which electric power of 60 is supplied to the primary coil, thereby causing ignition discharge. That is, after energy is stored in the primary coil by supplying power to the primary coil, the primary coil is interrupted by turning off the switching element 24b, thereby generating a high voltage in the secondary coil. This is an ignition device that generates a discharge spark between both electrodes of the spark plug 24.

  The mixture of the intake air and fuel in the combustion chamber 22 is used for combustion by the spark discharge. This combustion energy is converted into mechanical energy that displaces the piston 26, and as a result, the output shaft (crankshaft) of the internal combustion engine 10 is rotated. The air-fuel mixture used for combustion is discharged into the exhaust passage 30 as exhaust gas as the exhaust valve 28 is opened.

  The rotor 40b of the AC generator 40 is directly connected to the crankshaft. The AC generator 40 is an 8-pole generator. And the protrusion part 42 is provided in the outer periphery of the rotor 40b for every predetermined angle (here 30 degree CA is illustrated). That is, the outer periphery of the rotor 40b constitutes a timing rotor for detecting the rotation angle of the crankshaft. Although not shown, it is desirable that the flywheel be integrally formed in addition to the crankshaft and the AC generator 40.

  The stator 40a of the AC generator 40 is connected to an output terminal. One of the output terminals is grounded, and the other is connected to the regulator 50. The regulator 50 selectively extracts a negative current from the alternating current output from the AC generator 40 and outputs the negative current to the vehicle lamp 48, and an on-vehicle electric device other than the lamp 48 by selectively extracting the positive current. And a function of supplying the load.

  Specifically, one end of the lamp 48 is grounded, and the other end is connected to the anode of the diode 52. The cathode side of the diode 52 is connected to the output terminal of the AC generator 40. As a result, the negative current of the AC generator 40 can be supplied to the lamp 48.

  On the other hand, the output terminal of the AC generator 40 is also connected to the anode of the thyristor 54. The cathode side of the thyristor 54 is connected to the on-vehicle electric load such as the ignition coil 24a as well as the battery 60. A voltage control circuit 56 is connected to the gate of the thyristor 54. The voltage control circuit 56 has a function of turning off the thyristor 54 when the voltage on the cathode side of the thyristor 54 exceeds a predetermined value.

  The system according to the present embodiment further includes an electronic control unit (ECU 62). The ECU 62 controls the internal combustion engine 10 and controls actuators such as the fuel injection valve 18 and the ignition coil 24a based on output signals from the crank angle sensor 44, the throttle sensor 15 and the intake pressure sensor 17 that detect the rotation angle of the crankshaft. To operate. That is, the fuel injection valve 18 is opened by turning on the switching element 18b. In addition, after the switching element 24b is turned on, the ignition timing is reached and the spark discharge is generated by turning it off.

  FIG. 2 shows a process related to the combustion control among the processes performed by the ECU 62.

  The injection end timing calculation unit B10 calculates a valve closing command timing (fuel injection end timing) for the fuel injection valve 18 with a parameter indicating the operating state of the internal combustion engine 10 as an input. Here, as the input parameters, it is desirable to include a parameter indicating the load of the internal combustion engine 10 and the rotational speed. In the present embodiment, an example is shown in which the opening (throttle opening θ), the intake pressure, and the rotation speed of the throttle valve 16 as parameters indicating the load are used as input parameters. The fuel injection end timing that is variably set according to the input parameters is preliminarily adapted so as to be an optimal timing or the like in order to improve the exhaust characteristics.

  The ignition timing calculation unit B12 calculates a timing (ignition timing) at which spark discharge is generated with a parameter indicating the operating state of the internal combustion engine 10 as an input. In other words, the timing for ending energization of the primary coil of the ignition coil 24a is calculated. Here, as the input parameters, it is desirable to include a parameter indicating the load of the internal combustion engine 10 and the rotational speed. In the present embodiment, an example is shown in which the intake pressure and the rotation speed as parameters indicating the load are used as input parameters. Here, not only the energization end timing for the primary coil of the ignition coil 24a but also the energization start timing is calculated.

  The injection amount calculation unit B14 calculates an injection amount as a command value for the fuel injection valve 18 with a parameter indicating the operating state of the internal combustion engine 10 as an input. Here, as the input parameters, it is desirable to include a parameter indicating the load of the internal combustion engine 10 and the rotational speed. In the present embodiment, an example is shown in which the throttle opening θ and intake pressure as parameters indicating the load, and the rotation speed are used as input parameters.

  The injection time calculation unit B16 converts the injection amount calculated by the injection amount calculation unit B14 into the valve opening time (injection time TAU) of the fuel injection valve 18. The injection time TAU is a time for which energization to the electromagnetic solenoid 18a is continued by turning on the switching element 18b.

  The injection start timing calculation unit B18 is based on the injection end timing calculated by the injection end timing calculation unit B10 and the injection time TAU calculated by the injection time calculation unit B16. Start time). In other words, the timing for switching the switching element 18b from the off state to the on state is calculated.

  By the way, when the energization operation for the electromagnetic solenoid 18a is started by turning on the switching element 18b, the current flowing through the electromagnetic solenoid 18a gradually increases due to the inductance component of the electromagnetic solenoid 18a. For this reason, the force which displaces the nozzle needle of the fuel injection valve 18 to the valve opening side gradually increases after energization is started. Here, when the voltage applied to the electromagnetic solenoid 18a is reduced, the degree of gradual increase of the force after the start of energization is reduced, and as a result, the fuel injection amount is reduced. That is, when the voltage applied to the electromagnetic solenoid 18a decreases, the amount of fuel actually injected from the fuel injection valve 18 decreases even if the energization time is the same.

  Therefore, in the present embodiment, the controllability of the fuel injection control is maintained high by the following configuration. That is, as shown in FIG. 1, the injection capacitor 66 is provided as a power source dedicated to the ECU 62 and the fuel injection valve 18. The voltage of the battery 60 is applied to the positive electrode side of the injection capacitor 66 via a diode 64 whose forward direction is the direction from the battery 60 side to the injection capacitor 66 side. Further, the negative electrode side of the injection capacitor 66 is grounded. Thereby, the injection capacitor 66 is charged to a value lower than the voltage of the battery 60 by a voltage drop amount in the diode 64. In particular, the diode 64 prevents the charge of the injection capacitor 66 from flowing out to the on-vehicle electric load other than the ECU 62 and the fuel injection valve 18. For this reason, even if the voltage of the battery 60 temporarily decreases due to an increase in the power consumption of the in-vehicle electric load other than the ECU 62 and the fuel injection valve 18, the voltage of the injection capacitor 66 is temporarily synchronized with this. It does not show any significant decline.

  Then, the ECU 62 calculates the fuel injection time TAU based on the detected value Vi of the voltage of the injection capacitor 66. This will be described below.

  FIG. 3 shows a procedure for calculating the fuel injection time TAU according to the present embodiment. This process is repeatedly executed by the ECU 62, for example, at a predetermined crank angle cycle.

  In this series of processing, first, in step S10, the fuel injection amount is calculated based on the rotation speed and the intake pressure. In the subsequent step S12, the fuel injection base time τB is calculated based on the fuel injection amount. The fuel injection base time τB is an energization time (injection time) for actually injecting the fuel amount calculated in step S10 when the voltage applied to the fuel injection valve 18 (electromagnetic solenoid 18a) is a reference value. ). In the subsequent step S14, the detection value Vi of the voltage of the injection capacitor 66 is acquired. Here, the detection value Vi is repeatedly sampled at a predetermined time period, and the latest sampling value is acquired here.

  In the subsequent step S16, the invalid injection time Tv is calculated based on the detection value Vi. The invalid injection time Tv is a correction amount for correcting the injection time TAU so that the fuel amount actually injected is the same regardless of the voltage applied to the fuel injection valve 18 (electromagnetic solenoid 18a). Here, as shown in the figure, the invalid injection time Tv is set shorter as the detection value Vi becomes higher. And the decreasing speed of the invalid injection time Tv with respect to the increase in the detection value Vi is set to become smaller as the detection value Vi increases.

  In the subsequent step S18, the fuel injection time TAU is calculated based on the fuel injection base time τB and the invalid injection time Tv. This process may be a process in which the fuel injection time TAU is obtained by adding the invalid injection time Tv to the fuel injection base time τB.

  In addition, when the process of step S18 is completed, this series of processes is once complete | finished.

  Thus, in this embodiment, by calculating the invalid injection time Tv based on the detected value Vi of the voltage of the injection capacitor 66, the voltage value used for calculating the invalid injection time Tv and the fuel by the fuel injection valve 18 are calculated. It can be suitably avoided that the voltage actually applied to the fuel injection valve 18 at the time of injection is different. This can be realized because the power source of the ECU 62 and the fuel injection valve 18 is configured independently of the power source for other electric loads (battery 60). That is, during the energization period of the ignition coil 24a, a large amount of power is consumed by the battery 60, so that the voltage of the battery 60 rapidly decreases. On the other hand, in this embodiment, since the fuel injection timing and the ignition timing are variably set according to the operating state of the internal combustion engine 10, these periods may overlap. If these periods overlap, the voltage of the battery 60 at the time of fuel injection may be excessively low with respect to the voltage VB of the battery 60 at the time of calculation of the invalid injection time Tv. In this case, the actual fuel injection time TAU becomes excessively short with respect to the time required to inject the fuel amount calculated in step S10, and the actual injection amount may be insufficient. .

  On the other hand, in this embodiment, by using the voltage of the injection capacitor 66, it is not affected by a sudden drop in the voltage of the battery 60 due to ignition. For this reason, the voltage value used when calculating the invalid injection time Tv and the voltage value actually applied to the fuel injection valve 18 at the time of fuel injection can be suitably matched. For this reason, the fuel injection time TAU can be set with high accuracy, and as a result, the controllability of the fuel injection control can be kept high.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) The injection capacitor 66 is provided with a diode 64 for preventing the outflow of electric charge from the injection capacitor 66 to the other in-vehicle electric load side so that the injection capacitor 66 is a power source dedicated to the ECU 62 and the fuel injection valve 18. Based on the voltage of 66, the invalid injection time Tv was calculated. Thereby, the injection time TAU can be calculated with high accuracy.

  (2) As the ignition means of the internal combustion engine 10, a full transistor type was used. In this case, a large amount of power is consumed during the energization period of the primary coil of the ignition coil 24a. In particular, the power consumption per unit time at this time tends to be larger than the power consumption per unit time during the storage period of the capacitor in the CDI method. For this reason, a rapid voltage fluctuation of the battery 60 tends to occur at the ignition timing. Therefore, the significance of using the injection capacitor 66 as a power source for the ECU 62 and the fuel injection valve 18 is particularly significant.

  (3) The internal combustion engine 10 is a single cylinder. For this reason, since the number of times the electric power of the battery 60 is consumed by ignition in one combustion cycle is smaller than that of a multi-cylinder one, the amount of fluctuation in the voltage of the battery 60 due to ignition increases. For this reason, it is particularly significant to ensure the controllability by performing the fuel injection control using the detected value Vi of the voltage of the injection capacitor 66.

  (4) A motorcycle was adopted. In a motorcycle, the voltage of the battery 60 tends to vary particularly easily due to the power consumption of the in-vehicle electric load. For this reason, the utility value of the injection capacitor 66 is particularly high.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 4 shows the system configuration of this embodiment. In FIG. 4, members corresponding to those shown in FIG. 1 are given the same reference numerals for the sake of convenience.

  As shown in the figure, in this embodiment, a constant voltage circuit 70 that generates a constant voltage lower than the voltage VB of the battery 60 is provided, and this is used as a power source dedicated to the ECU 62 and the fuel injection valve 18. Specifically, the constant voltage circuit 70 includes an NPN-type bipolar transistor (transistor 72), the collector of which is connected to the battery 60 side, and the emitter of which is connected to the fuel injection valve 18 side. The collector and base of the transistor 72 are connected via a resistor 74. Further, the base of the transistor 72 is connected to the cathode side of the Zener diode 76. The anode side of the Zener diode 76 is grounded.

  Here, the breakdown voltage of the Zener diode 76 is set to a predetermined voltage (for example, “8V”) lower than the voltage VB (for example, “12V”) of the battery 60. The predetermined voltage is set to be equal to or lower than a lower limit value of a voltage assumed when the voltage VB of the battery 60 is rapidly decreased due to an increase in power consumption of the in-vehicle electric load. Thereby, a breakdown voltage is always applied to the base of the transistor 72. The resistor 74 is set to a value that can suppress the current consumption of the Zener diode 76. According to such a configuration, when the switching element 18 b is turned on, the transistor 72 is also turned on, and current flows from the battery 60 side to the fuel injection valve 18 side via the transistor 72. In addition, at this time, a breakdown voltage (specifically, a voltage having a value obtained by subtracting the voltage drop between the base and the emitter from the breakdown voltage) is applied to the fuel injection valve 18 stably. . For this reason, high controllability of the fuel injection control can be maintained regardless of whether the ignition timing and the injection period overlap.

  According to this embodiment described above, the following effects can be obtained in addition to the effects according to the effects (2) to (4) of the first embodiment.

  (5) A constant voltage circuit 70 that generates a constant voltage lower than the voltage of the battery 60 using the voltage of the battery 60 is provided, and this is used as a power source for the fuel injection valve 18 and the ECU 62. Thereby, even if it is a case where the voltage of the battery 60 falls rapidly due to the increase in the power consumption of the vehicle-mounted electric load, the controllability of the fuel injection control can be maintained high.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  The constant voltage circuit that generates a constant voltage lower than the voltage VB of the battery 60 is not limited to that illustrated in FIG. For example, a PNP bipolar transistor may be used as the transistor 72. In this case, the emitter is connected to the battery 60. Further, for example, instead of the Zener diode 76, one or a plurality of diodes having a ground side as a cathode side may be provided, and the power of the battery 60 may be supplied to the one or the plurality of diodes via a constant current diode. Good. In this case, the voltage on the cathode side of the constant current diode can be a constant voltage.

  In the first embodiment, the power source of the ECU 62 is the injection capacitor 66. However, the present invention is not limited to this, and may be the battery 60, for example. Even in this case, if the ECU 62 calculates the invalid injection time Tv based on the detected value Vi of the voltage of the injection capacitor 66, the same effects as those of the first embodiment can be obtained.

  In the second embodiment, the invalid injection time Tv is calculated each time based on the detected value Vi of the output voltage of the constant voltage circuit (the voltage on the emitter side of the transistor 72), but the present invention is not limited to this. That is, since the output voltage of the constant voltage circuit is considered to be constant, the invalid injection time Tv may be set in advance based on the voltage determined from the characteristics of the constant voltage circuit. Furthermore, conversion means for converting the fuel injection amount into the injection time TAU in consideration of the invalid injection time Tv assumed in advance from the output voltage of the constant voltage circuit may be constructed. According to this, since it is only necessary to perform the process of directly converting the fuel injection amount into the injection time TAU, the calculation load of the ECU 62 can be reduced.

  In the second embodiment, the power source of the ECU 62 is the constant voltage circuit 70. However, the present invention is not limited to this, and may be, for example, the battery 60. Even in this case, if the ECU 62 calculates the injection time TAU based on the output voltage of the constant voltage circuit 70, the same effect as that of the second embodiment can be obtained.

  The parameters for calculating the fuel injection amount are not limited to those illustrated in FIG. For example, only one of the throttle opening θ and the intake pressure PM may be used as a parameter indicating the load. Further, in addition to the parameters indicating the rotation speed and the load, a parameter indicating the temperature may be referred to. Here, the parameter indicating the temperature includes a detected value of the intake air temperature, a detected value of the temperature of the cooling water of the internal combustion engine 10, and the like.

  The parameters for calculating the ignition timing are not limited to those illustrated in FIG. For example, it may be calculated based on the rotational speed and the throttle opening θ. Further, there are two modes: a mode that is calculated based on the rotational speed and the intake pressure, and a mode that is calculated based on the rotational speed and the throttle opening, and one of these two modes is selected depending on the operating state of the internal combustion engine 10. May be used to switch whether to calculate the ignition timing. Furthermore, when calculating the ignition timing, a correction process corresponding to an increase or decrease in the required torque for the internal combustion engine 10 or a correction process based on atmospheric pressure may be performed.

  The regulator 50 is not limited to that illustrated in FIG. For example, instead of the thyristor 54, a transistor may be used as an opening / closing means for opening / closing between the AC generator 40 and the electric load. Further, for example, the negative current output from the AC generator 40 may not be used at all. In this case, since the power source of the lamp 48 is the battery 60, when the lamp 48 is turned on by the user, the voltage of the battery 60 may drop rapidly. For this reason, when the invalid injection time Tv is calculated based on the detected value of the voltage VB of the battery 60, the voltage value used for the calculation may be different from the voltage value in the fuel injection period. Therefore, the application of the present invention is effective.

  The AC generator 40 is not limited to an eight-pole type, and the number of poles may be arbitrary. Further, the AC generator 40 is not limited to the one provided with a permanent magnet.

  In each of the above embodiments, the full-transistor type is used as the ignition means. However, the present invention is not limited to this. A so-called capacitor discharge type (CDI) may be used in which the charge of the capacitor is discharged to the ignition coil by making a closed loop by turning on the switching element. Even in this case, the voltage VB of the battery 60 tends to decrease during the capacitor charging period. For this reason, in the case where the timing for charging the capacitor and the valve opening period of the fuel injection valve 18 overlap, the voltage VB of the battery 60 used to calculate the invalid injection time Tv and the valve opening period Since the voltage VB may be different, the application of the present invention is effective.

  In the above invention, it is possible to prevent the influence of the temporary decrease in the voltage of the battery 60 due to the power consumption required for ignition from reaching the voltage applied to the fuel injection valve 18. Intended but not limited to this. For example, in a water-cooled engine, when a radiator fan is started, an inrush current flows through a DC motor that drives the fan, and power consumption temporarily becomes excessive. For this reason, in this case, the voltage of the battery 60 may drop rapidly. Therefore, from the viewpoint of preventing this influence, in the first and second embodiments, the power source of the DC motor that drives the radiator fan is the anode side of the diode 64 or the input side of the constant voltage circuit 70. Is valid.

  Other than that, the internal combustion engine is not limited to a single cylinder, and may be a multi-cylinder. The vehicle is not limited to a battery-mounted type, and may be a so-called battery-less vehicle that does not assume that a battery is mounted on the vehicle at the time of product shipment. In this case, a capacitor that stores electric power generated by the generator serves as a power source for the in-vehicle electrical component as a power supply means. Even in this case, the application of the present invention is effective because there is a risk that the voltage of the capacitor is greatly reduced during a period in which power necessary for ignition is consumed.

1 is a system configuration diagram according to a first embodiment. FIG. The block diagram which shows a part of process of the combustion control concerning the embodiment. The flowchart which shows the procedure of the calculation process of the fuel injection time concerning the embodiment. The system block diagram concerning 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 18 ... Fuel injection valve, 60 ... Battery (one embodiment of electric power feeding means), 62 ... ECU (one embodiment of a fuel injection control apparatus), 64 ... Diode, 66 ... Capacitor.

Claims (6)

In a fuel injection control device that performs fuel injection control of an internal combustion engine by electrically operating a fuel injection valve using electric power from a power supply means,
A voltage variation of the power supply means that is provided between the fuel injection valve and the power supply means and that is caused by power consumption of a predetermined on-vehicle electric load other than the fuel injection valve is prevented from being propagated to the fuel injection valve side. Blocking means to
A valve opening time calculating means for calculating a valve opening time of the fuel injection valve based on a voltage on the fuel injection valve side of the blocking means;
A fuel injection control device comprising: operating means for operating the fuel injection valve based on the calculated valve opening time.   The blocking unit includes a diode whose forward direction is the direction from the power supply unit side to the fuel injection valve side, and a power storage unit that is connected to the cathode side of the diode and stores the electric power of the power supply unit. The fuel injection control device according to claim 1, wherein the fuel injection control device is configured.   2. The fuel injection according to claim 1, wherein the blocking means comprises a constant voltage circuit that generates a constant voltage lower than the voltage of the power supply means by using the voltage of the power supply means. Control device.   The fuel injection control apparatus according to any one of claims 1 to 3, wherein the ignition means of the internal combustion engine is of a full transistor type.   The fuel injection control device according to any one of claims 1 to 4, wherein the internal combustion engine is a single cylinder.   The fuel injection control device according to any one of claims 1 to 5, wherein the internal combustion engine is mounted on a motorcycle.

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