JP2018155213A - Fuel injection control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection control device capable of accelerating excellent atomization of fuel by correcting an injection amount during fuel injection.SOLUTION: An injection amount calculation part (50) calculates an injection amount at intervals of predetermined time. A control part (10) corrects the calculated injection amount with a newly calculated injection amount during fuel injection by a fuel injection device (8). A target value at which the fuel injection is stopped is predetermined as a blow end angle (R1, R2) based upon a crank angle. A control part (10) starts fuel injection in timing when injection is performed by the calculated injection amount at the blow end angle (R1, R2). The control part (10) executes basic injection and additional injection executed after the basic injection during one cycle of an internal combustion engine. The additional injection is executed according to the amount obtained by subtracting an injection-completion amount by the basic injection from the injection amount calculated at the intervals of predetermined time.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fuel injection control device, and more particularly to a fuel injection control device that corrects a fuel injection amount based on a change amount of an engine load.

  2. Description of the Related Art Conventionally, in a fuel injection control device that determines a fuel injection amount in one cycle based on information such as engine speed, vehicle speed, and throttle opening, a configuration in which fuel injection is performed a plurality of times in one cycle. Are known.

  In Patent Document 1, two injection timings consisting of basic injection and additional injection are set during one cycle of the engine, and the engine load (mainly throttle grip opening) increases after basic injection. A fuel injection control device is disclosed in which the shortage is compensated by additional injection. Usually, the basic injection and additional injection are performed within the range in which the injected fuel can be drawn into the cylinder during the intake stroke. Specifically, the basic injection is performed after the intake valve is closed until the exhaust valve is opened. Is set within a predetermined range in which the injected fuel enters the cylinder after the intake valve is opened. In addition, due to the structure of the injector, some time is required until the injection can be resumed after stopping the injection, and if the basic injection and the additional injection are too close, it is difficult to obtain the correction effect. A predetermined interval is provided between the times.

JP-A-63-129141

  In the configuration of Patent Document 1, the calculation of the basic injection amount is performed only once immediately before the start of injection, and any load increased after this calculation is compensated for by additional injection. In this respect, since a certain amount of time is required for the injected fuel to reach an ideal atomized state, the additional injection that shortens the time from injection to ignition is as small as possible. Then, the subject that the injection quantity cannot be changed after the start of injection occurred.

  The objective of this invention is providing the fuel injection control apparatus which can accelerate | stimulate favorable atomization of a fuel by solving the subject of the said prior art and correct | amending the injection quantity during fuel injection.

  In order to achieve the above-mentioned object, the present invention performs at least one fuel injection in one cycle of an internal combustion engine by means of a fuel injection device (8) for controlling the injection amount according to the injection time and the fuel injection device (8). A fuel injection control apparatus comprising: a control unit (10) for controlling the fuel injection amount; and an injection amount calculation unit (50) for calculating an injection amount of the fuel injection based on at least information on an engine speed and a throttle valve opening. The calculation unit (50) calculates the injection amount every predetermined time, and the control unit (10) newly calculates the calculated injection amount during fuel injection by the fuel injection device (8). The first feature is that the correction is made according to the injection amount.

  Further, a target value for stopping the fuel injection is predetermined as a blow end angle (R1, R2) based on a crank angle, and the control unit (10) determines that the calculated injection amount is the blow end angle. The second feature is that the fuel injection is started at the timing when the injection is finished at the end angles (R1, R2).

  The control unit (10) executes basic injection and additional injection to supplement the basic injection during one cycle of the internal combustion engine, and the additional injection is performed based on an injection amount calculated every predetermined time. A third feature is that the process is executed by an amount obtained by subtracting the injected amount by injection.

  A fourth feature is that a prohibition section (C) for the additional injection is provided immediately after the completion of the basic injection.

  Further, when the injection amount calculated during the execution of the basic injection increases from the start time of the basic injection, the control unit (10) may pass the basic blow end angle (R1). A fifth feature is that the injection is continued.

  Further, the blow end angle (R1) of the basic injection is set to a first predetermined angle near the explosion bottom dead center (BDC1) of the internal combustion engine, and the blow end angle (R2) of the additional injection is set to the internal combustion engine. There is a sixth feature in that the fuel injection is forcibly terminated at the second predetermined angle after the exhaust top dead center (TDC2) and at the blow end angle (R2) of the additional injection.

  According to the first feature, the fuel injection device (8) that controls the injection amount according to the injection time, and the control unit that causes the fuel injection device (8) to perform at least one fuel injection during one cycle of the internal combustion engine ( 10) and an injection amount calculation unit (50) for calculating an injection amount of the fuel injection based on at least information on the engine speed and the throttle valve opening, the injection amount calculation unit (50 ) Calculates the injection amount every predetermined time, and the control unit (10) calculates the calculated injection amount according to the newly calculated injection amount during fuel injection by the fuel injection device (8). Therefore, by correcting the injection amount during fuel injection, changes in load such as increase in throttle valve opening and throttle grip opening that occurred during fuel injection are reflected in the currently executed fuel injection. So it becomes possible.

  According to the second feature, the target value for stopping the fuel injection is predetermined as the blow end angle (R1, R2) with reference to the crank angle, and the control unit (10) is configured to calculate the value. Since the fuel injection is started at the timing when the injected amount ends at the blow end angle (R1, R2), the injection calculated every predetermined time by changing the injection start timing according to the calculated injection amount It becomes easier to respond to changes in quantity.

  According to the third feature, the control unit (10) executes basic injection and additional injection to supplement the basic injection during one cycle of the internal combustion engine, and the additional injection is calculated at predetermined time intervals. The injection amount calculated every predetermined time is reflected in the injection in both the basic injection and the additional injection. Even when the load changes during the basic injection, it is possible to reduce the injection amount by the additional injection by dealing with the correction of the basic injection amount as much as possible. Thereby, the injected fuel is likely to be in an ideal atomized state, and ideal combustion is easily obtained.

  According to the fourth feature, since the additional injection prohibition section (C) is provided immediately after the completion of the basic injection, the injector constituting the fuel injection device is able to inject again after the injection is stopped. In some cases, a certain amount of time is required, and even if an injection command is given to this non-driveable section, correct injection is not performed. It is possible to configure so that no injection command is issued.

  According to a fifth feature, when the injection amount calculated during execution of the basic injection has increased from the start of the basic injection, the control unit (10) determines the blow end angle of the basic injection ( Since the injection is continued even after R1), if the load increases during the basic injection, it can be coped with by increasing the basic injection amount (extending the injection time). Thereby, it becomes possible to reduce the injection amount by additional injection.

  According to the sixth feature, the blow end angle (R1) of the basic injection is set to a first predetermined angle near the explosion bottom dead center (BDC1) of the internal combustion engine, and the blow end angle (R2) of the additional injection. ) Is set to a second predetermined angle after exhaust top dead center (TDC2) of the internal combustion engine, and fuel injection is forcibly terminated at the blow end angle (R2) of the additional injection, so that the basic injection and the additional injection By providing a predetermined interval between the two, it is possible to lengthen the correctable period and reflect the change in the load as much as possible in the injection amount. Also, by setting the blow end angle of the additional injection to a predetermined angle after exhaust top dead center that is close to the limit angle at which the injected fuel can be sucked into the cylinder, fuel injection at a position exceeding the limit angle is prohibited. be able to.

It is a block diagram which shows the structure of the fuel-injection control apparatus which concerns on this embodiment. It is a time chart (injection pattern 1) which shows the flow of operation | movement of a fuel-injection control apparatus. It is a time chart (injection pattern 2) which shows the flow of operation | movement of a fuel-injection control apparatus. It is a time chart (injection pattern 3) which shows the flow of operation | movement of a fuel-injection control apparatus. It is a flowchart which shows the procedure of fuel injection amount calculation control. It is a flowchart which shows the procedure of basic injection control. It is a flowchart which shows the procedure of additional injection control. It is a flowchart which shows the procedure of additional injection forced stop control.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a fuel injection control apparatus according to an embodiment of the present invention. The pulsar rotor 2 fixed to the crankshaft 1 of the engine is provided with 13 protrusions 2a provided at intervals of 22.5 degrees and a tooth notch 2a corresponding to three protrusions. The output signal from the pulse generator 3 is input to the phase detection unit 20 included in the ECU 10 as the control unit.

  The phase detector 20 detects the phase of the crankshaft 1 based on the crank pulse signal generated by the pulse generator 3. The stage assignment unit 30 divides one rotation of the crankshaft 1 into 16 at the output timing of the crank pulse, assigns a stage count (360 degrees) of “0” to “16” to each phase of the crankshaft 1, and When the stroke determination is completed, absolute stages (720 degrees stage) of “0” to “31” are assigned to each phase of one cycle (720 degrees) of the crankshaft. The engine speed calculation unit 40 calculates the engine speed based on the output signal of the phase detection unit 20.

  The opening degree of the throttle valve is calculated based on the opening degree of the throttle grip operated by the passenger. An output signal of the throttle valve opening sensor 6 that detects the opening of the throttle valve is input to the injection amount calculation unit 50. The output signal of the throttle grip opening sensor 5 may be input to the injection amount calculation unit 50.

  The injection amount calculation unit 50 includes an injection amount map 51 and a calculation interval timer 52. The injection amount calculation unit 50 applies information such as the engine speed, the throttle grip opening degree, the throttle valve opening degree, the vehicle speed, the gear stage number of the transmission, and the like to an injection amount map 51 that is a preset data map. Thus, the fuel injection amount is derived. The calculation interval timer 52 measures the elapsed time from the calculation of the fuel injection amount, that is, the derivation of the injection amount by the injection amount map 51. The injection amount calculation unit 50 according to the present embodiment is configured to derive the fuel injection amount every predetermined time (1 msec in the present embodiment) set in the calculation interval timer 52. The injection amount derived by the injection amount map 51 can be appropriately corrected according to the external air pressure, the cooling water temperature, the pressure of the fuel injection device 8, and the like. In addition, the derivation of the injection amount at every predetermined time can be started after the engine stroke determination is confirmed.

  Information from the stage allocation unit 30, the engine speed calculation unit 40, and the injection amount calculation unit 50 is input to the injection start time setting unit 60. The control unit 10 according to the present embodiment performs basic injection and additional injection performed at a timing after the basic injection during one cycle of the engine, and fuel necessary for the cycle is completely injected by the basic injection. If not, the shortage is injected by additional injection.

  The fuel injection device (injector) 8 controlled by the fuel injection control unit 7 is configured to inject fuel pressurized at a constant pressure by opening the solenoid valve. The injection amount is controlled by the duration of the opening operation.

  The injection start timing setting unit 60 stores a basic injection blow end angle R1 and an additional injection blow end angle R2. The injection start timing setting unit 60 includes an injection time setting timer 63 that sets the opening time of the solenoid valve, and an injection time storage memory 64 that stores the injected time. In addition to the injection amount calculated every 1 msec, the injection start timing setting unit 60 is based on the current absolute stage, engine speed, basic injection blow end angle R1, additional injection blow end angle R2, injection time, and injected time. Thus, the basic injection start timing and the additional injection start timing are set, and a control signal is output to the fuel injection control section 7.

  FIG. 2 is a time chart (injection pattern 1) showing the flow of operation of the fuel injection control apparatus according to the present embodiment. In this time chart, in order from the top, crank angle, crank pulse, absolute stage, valve timing of intake / exhaust valve, basic end point, and blow end angle as target values to stop additional injection, injection pattern, throttle grip opening and The timing of the injection amount calculation is shown.

  The valve timing is a fixed value determined by a cam profile that drives the intake and exhaust valves. The basic injection blow end angle R1 and the additional injection blow end angle R2 are fixed values stored in the control unit 10. The basic injection blow end angle R1 is set to a first predetermined angle (for example, 180 degrees) near the explosion bottom dead center BDC1, and the blow end angle R2 of the additional injection is a second predetermined angle after the exhaust top dead center TDC2. (For example, 420 degrees).

  As described above, the calculation of the injection amount (injection time) by the injection amount calculation unit 50 is repeatedly executed every 1 msec. The injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, calculates the time from the current crank angle to the basic injection blow end angle R1, and calculates the basic injection blow The time t1 at which the injection with the latest injection time ta just ends by calculating backward from the end angle R1 is set as the basic injection start timing. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts basic injection at the time t1 as the injection amount A1. The injection start time setting unit 50 updates the injected time stored in the injected time storage memory 64 as needed.

  Here, when the engine is rotating at 10,000 rpm, the crankshaft rotates 60 degrees during 1 msec. Even during such high rotation, the calculation of the injection amount is performed every 1 msec, so that the basic injection can be performed. The injection amount can be updated about 2 to 3 times. At present, the fuel injection device 8 and the control device are improved in performance, and the injection time can be controlled in units of μsec. In the example of FIG. 2, although the injection amount is calculated several times during basic injection, the engine load has not changed since the start of injection, so the injection amount A1 at the start of injection at the basic injection blow end angle R1 is It shows the state that blows.

  Next, at time t2 when the basic injection blow end angle R1 is reached, the basic injection is completed and the throttle grip opening degree starts to increase due to the driver's acceleration request. Such an increase in engine load after the end of basic injection is compensated by additional injection.

  The injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time until the additional injection blow end angle R2 is reached. Next, an additional injection time tb obtained by subtracting the injected time after the injection by the basic injection from the latest injection time is calculated. Then, the time t3 at which the additional injection time tb is calculated by back-calculating from the additional injection blow end angle R2 is set as the start time of the additional injection. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7, and starts additional injection at the injection amount B1 from time t3.

  In this figure, all the injections in one cycle are completed at the additional injection blow end angle reaching time t4, but the injection amount (injection time) is calculated by the injection amount calculation unit 50 even during the execution of the additional injection. Is repeatedly executed every 1 msec. As a result, in addition to the case where the required injection ends before reaching the additional injection blowing end angle R2 according to the change in the throttle grip angle, the necessary additional injection ends when the additional injection blowing end angle R2 is reached. There are cases where this is not done. However, in the present embodiment, the additional injection blow end angle R2 is set as an absolute injection end position so that the forced stop is performed even when the necessary injection has not ended.

  Further, immediately after the completion of the basic injection, a prohibition section C (for example, 0.5 msec) for prohibiting the start of additional injection is provided. According to this prohibition section C, the fuel injection device 8 that requires some time until it can be injected again after the stop of injection is configured so that an injection command for additional injection is not issued in this non-driveable section. Is possible.

  FIG. 3 is a time chart (injection pattern 2) showing the flow of operation of the fuel injection control apparatus according to the present embodiment. In the example of this figure, the injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time until the basic injection blow end angle R1 is reached. The time t10 at which the injection with the latest injection time tc is just blown from the blow end angle R1 is set as the basic injection start timing. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts basic injection from time t10.

  In the example of FIG. 3, the throttle grip opening degree starts to increase in response to the driver's acceleration request from time t10 when the basic injection is started. On the other hand, in this embodiment, since the calculation of the injection amount (injection time) is repeated every 1 msec, the basic injection amount can be corrected during execution of the basic injection. This makes it possible to extend the injection time until the latest injection amount A2 finishes blowing even after the basic injection blowing end angle R1 that should have ended at the beginning of basic injection, at time t11. The basic injection will end.

  Next, the injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time until the additional injection blow end angle R2 is reached. Then, the additional injection time td obtained by subtracting the injection completion time of the basic injection from the latest injection time is calculated backward from the additional injection blow end angle R2, and the time t12 at which the blow ends is set as the start time of the additional injection. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts additional injection at the injection amount B2 from time t12. Then, at time t13 when the additional injection blowing end angle R2 is reached, the additional injection is completed and all injections are completed.

  In the example of this figure, the injection amount in the additional injection is reduced by reflecting the correction of the injection amount in accordance with the throttle grip opening that increases with the start of the basic injection in the basic injection. That is, according to the fuel injection control device according to the present embodiment, even when the throttle grip opening degree increases during basic injection, the basic injection amount is increased as much as possible to reduce the injection amount due to additional injection. be able to. As a result, the injected fuel is likely to be in an ideal atomized state, and better combustion can be obtained.

  FIG. 4 is a time chart (injection pattern 3) showing the flow of operation of the fuel injection control apparatus according to the present embodiment. In the example of this figure, the injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time until the basic injection blow end angle R1 is reached. The time t20 at which the injection with the latest injection time te is just blown by calculating backward from the blow end angle R1 is set as the basic injection start timing. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts basic injection from time t21.

  In the example of this figure, the throttle grip opening degree starts to increase due to the driver's acceleration request from time t20 before time t21 at which basic injection is started. The injection start timing setting unit 60 sets the time t21 as the start timing of the basic injection in consideration of the increase in the throttle grip opening, but thereafter the throttle grip opening starts to decrease.

  Even in such a case, in this embodiment, since the calculation of the injection amount (injection time) is repeatedly performed every 1 msec, it is possible to correct the basic injection amount during execution of the basic injection. That is, even if the basic injection should have finished blowing at the start of the basic injection but before reaching the basic injection blowing end angle R1, the basic injection can be performed if the latest injection amount A3 has been blown by considering the injected time. The injection can be terminated. As a result, it is possible to prevent fuel that is excessive from being injected in the light of the latest situation and improve fuel efficiency. In the example of FIG. 4, the basic injection is completed at time t22 before time t23 when the basic injection blow end angle R1 is reached, and the throttle grip opening is not changed thereafter, so that the additional injection is not performed and the basic injection is performed. The state where all the injections are completed at the time t22 with the end of the operation is shown.

  Hereinafter, the procedure of the fuel injection control according to the present embodiment will be described using the flowcharts of FIGS. The injection amount calculated using the injection amount map is indicated as the target injection time T unless otherwise specified.

  FIG. 5 is a flowchart showing a procedure of fuel injection amount calculation control. In step S1, the engine speed is detected based on the output signal of the engine speed calculator 40. In step S2, the throttle grip opening degree is detected by the throttle grip opening degree sensor 5, and in step S3, the throttle valve opening degree is detected by the throttle valve opening degree sensor 6. In the subsequent step S4, the target injection time T is calculated by applying the numerical value of each parameter to the injection amount map 51. In step S5, based on the output signal of the calculation interval timer 52, it is determined whether or not 1 msec has elapsed since the previous injection amount calculation. If an affirmative determination is made, the process returns to step S1. If a negative determination is made in step S5, the process proceeds to step S6 to determine whether or not the engine has stopped. If an affirmative determination is made in step S6, the process returns to the determination in step S5. That is, the calculation of the injection amount is executed every 1 msec until the engine stops. If an affirmative determination is made in step S5, the series of control is terminated.

  FIG. 6 is a flowchart showing a procedure of basic injection control. In step S10, the engine speed is detected, and in step S11, an absolute stage is detected. In step S12, an estimated arrival time T1 up to the basic injection blow end angle R1 is calculated.

  In step S13, it is determined whether or not the calculated estimated arrival time T1 is equal to or less than the target injection time T. If an affirmative determination is made, the process proceeds to step S14 and basic injection is started. In subsequent step S15, it is determined whether or not the injected time T2 is equal to or longer than the target injection time T. If an affirmative determination is made, the process proceeds to step S16 to stop basic injection. On the other hand, if a negative determination is made in step S15, the process proceeds to step S17, and it is determined whether or not the target injection time T has been updated to the latest value by calculation every 1 msec. If a negative determination is made in step S17, the process returns to the determination in step S15.

  If an affirmative determination is made in step S17, the process proceeds to step S18, and it is determined whether or not the injected time T2 is equal to or longer than the updated target injection time T. If a negative determination is made in step S18, the process returns to step S17. If an affirmative determination is made, the process proceeds to step S16 to stop basic injection. In step S19, the additional injection prohibition timer is started, and a series of control is terminated.

  FIG. 7 is a flowchart showing a procedure of additional injection control. In step S20, it is determined whether or not the basic injection blow end angle R2 has been passed. If an affirmative determination is made in step S20, the process proceeds to step S21 to determine whether or not the count value of the additional injection prohibition timer has reached a predetermined value (for example, 0.5 msec). If a positive determination is made in step S21, the process proceeds to step S22. If a negative determination is made in steps S20 and S21, the process returns to the determinations in steps S20 and S21, respectively.

  In step S22, an additional injection time T3 is obtained by calculating T-T2 (target injection time T-injected time T2). In the subsequent step S23, an expected arrival time T4 up to the additional injection blow end angle R2 is calculated. In step S24, it is determined whether the calculated estimated arrival time T4 is equal to or less than the additional injection time T3. If an affirmative determination is made, the process proceeds to step S25 and additional injection is started. If a negative determination is made in step S24, the process returns to the determination in step S24.

  In the following step S26, it is determined whether or not T2 + T3 (injected time T2 + additional injection time T3) is equal to or longer than the target injection time T. If an affirmative determination is made, the process proceeds to step S27 to stop additional injection. On the other hand, if a negative determination is made in step S26, the process proceeds to step S28, in which it is determined whether or not the target injection time T has been updated to the latest value. If a negative determination is made in step S28, the determination returns to step S26.

  If an affirmative determination is made in step S28, the process proceeds to step S29, and it is determined whether or not T2 + T3 is equal to or longer than the updated target injection time T. If a negative determination is made in step S29, the process returns to step S28. On the other hand, if an affirmative determination is made, the process proceeds to step S27, where the additional injection is stopped, and the series of controls is terminated.

  FIG. 8 is a flowchart showing a procedure of additional injection forced stop control. In step S30, additional injection is being performed, and it is determined whether the process proceeds to step S31 and the additional injection blow end angle R2 has been reached. If a negative determination is made in step S31, the process returns to the determination in step S31. If an affirmative determination is made, the additional injection is forcibly stopped in step S32, and the series of controls is terminated. Thus, since the additional injection is forcibly stopped regardless of the updated injection time at the additional injection blow end angle R2, even if the additional injection amount is corrected to increase immediately before reaching the additional injection blow end angle R2, this increase correction is performed. Therefore, fuel can be prevented from being injected at a position exceeding the intake limit angle into the cylinder.

  As described above, according to the fuel injection control device of the present invention, the injection amount calculation unit 50 calculates the injection amount every predetermined time, and newly calculates the calculated injection amount during fuel injection by the fuel injection device 8. Since correction is performed based on the calculated injection amount, it is possible to reflect a change in load, such as an increase in the throttle grip opening generated during fuel injection, in the currently executed fuel injection. In addition, the target value for stopping the fuel injection is predetermined as the blow end angle based on the crank angle, and the fuel injection is started at the timing when the calculated injection amount finishes the injection at the blow end angle. By changing the injection start timing according to the injected amount, it becomes easy to cope with a change in the injection amount calculated every predetermined time. Further, the basic injection and the additional injection are executed during one cycle of the internal combustion engine, and the additional injection is executed by the amount obtained by subtracting the injected amount by the basic injection from the injection amount calculated every predetermined time. In both the injection and the additional injection, the injection amount calculated every predetermined time is reflected during the injection, and even when the load changes during the basic injection, the basic injection amount is corrected as much as possible. Thus, it is possible to reduce the injection amount by the additional injection. Thereby, the injected fuel is likely to be in an ideal atomized state, and ideal combustion is easily obtained.

  Engine configuration, valve timing, shape and structure of crank pulsar rotor and pulse generator, basic injection blow end angle and additional injection blow end angle setting, injection amount calculation interval, injection amount calculation start timing, injection amount The type and number of sensor information used for the calculation, the aspect of the injection amount map, and the like are not limited to the above embodiment, and various changes can be made. For example, the injection amount calculation interval may be set to change according to the engine speed. The fuel injection control device according to the present invention can be applied to various four-cycle engines including the fuel injection device.

  DESCRIPTION OF SYMBOLS 1 ... Crankshaft, 2 ... Crank pulser rotor, 3 ... Pulse generator, 5 ... Throttle grip opening sensor, 6 ... Throttle valve opening sensor, 7 ... Fuel injection control part, 8 ... Fuel injection apparatus, 10 ... ECU ( Control unit), 50 ... injection amount calculation unit, 51 ... injection amount map, 52 ... calculation interval timer, 60 ... injection start timing setting unit, R1 ... basic injection blow end angle, R2 ... additional injection blow end angle, 63 ... injection Time setting timer, 64 ... injection time storage memory, C ... additional injection prohibited section

The target value for stopping the fuel injection, the angle end Spray referenced to crank angle (R1, R2) are determined in advance as the control unit (10), the amount of the calculated injected Spray the The second feature is that the fuel injection is started at the timing when the injection is finished at the end angles (R1, R2).

Further, when the injection amount calculated during the execution of the basic injection increases from the start of the basic injection, the control unit (10) may pass the basic injection end angle (R1). A fifth feature is that the injection is continued.

Further, the injection end angle (R1) of the basic injection is set to a first predetermined angle near the explosion bottom dead center (BDC1) of the internal combustion engine, and the injection end angle (R2) of the additional injection is set to the internal combustion engine. There is a sixth feature in that the fuel injection is forcibly terminated at the second predetermined angle after the exhaust top dead center (TDC2) and at the injection end angle (R2) of the additional injection.

According to the second feature, the target value for stopping the fuel injection is determined in advance as the injection end angle (R1, R2) with reference to the crank angle, and the control unit (10) calculates the calculation value. Since the fuel injection is started at the timing when the injected amount ends at the injection end angle (R1, R2), the injection calculated at predetermined intervals by changing the injection start timing according to the calculated injection amount It becomes easier to respond to changes in quantity.

According to a fifth feature, when the injection amount calculated during execution of the basic injection has increased from the start of the basic injection, the control unit (10) determines the end angle of the basic injection ( Since the injection is continued even after R1), if the load increases during the basic injection, it can be coped with by increasing the basic injection amount (extending the injection time). Thereby, it becomes possible to reduce the injection amount by additional injection.

According to the sixth feature, the injection end angle (R1) of the basic injection is set to a first predetermined angle in the vicinity of the explosion bottom dead center (BDC1) of the internal combustion engine, and the injection end angle (R2) of the additional injection ) Is set to a second predetermined angle after the exhaust top dead center (TDC2) of the internal combustion engine, and the fuel injection is forcibly terminated at the injection end angle (R2) of the additional injection, so the basic injection and the additional injection By providing a predetermined interval between the two, it is possible to lengthen the correctable period and reflect the change in the load as much as possible in the injection amount. In addition, the injection end angle of the additional injection is set to a predetermined angle after exhaust top dead center that is close to the limit angle at which the injected fuel can be sucked into the cylinder, thereby prohibiting fuel injection at a position exceeding the limit angle. be able to.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a fuel injection control apparatus according to an embodiment of the present invention. The Parusarota 2 fixed to the crankshaft 1 of the engine is provided with thirteen protrusions 2a and the projections 3 min tooth missing portion 2 b of the provided 22.5 degree intervals, juxtaposed with Parusarota 2 The output signal from the pulse generator 3 is input to the phase detection unit 20 included in the ECU 10 as the control unit.

The injection start timing setting unit 60 stores a basic injection injection end angle R1 and an additional injection injection end angle R2. The injection start timing setting unit 60 includes an injection time setting timer 63 that sets the opening time of the solenoid valve, and an injection time storage memory 64 that stores the injected time. In addition to the injection amount calculated every 1 msec, the injection start timing setting unit 60 is based on the current absolute stage, engine speed, basic injection injection end angle R1, additional injection injection end angle R2, injection time, and injected time. Thus, the basic injection start timing and the additional injection start timing are set, and a control signal is output to the fuel injection control section 7.

FIG. 2 is a time chart (injection pattern 1) showing the flow of operation of the fuel injection control apparatus according to the present embodiment. In this time chart, in order from the top, crank angle, crank pulse, absolute stage, valve timing of intake and exhaust valves, injection end angle as a target value for stopping basic injection and additional injection, injection pattern, throttle grip opening and The timing of the injection amount calculation is shown.

The valve timing is a fixed value determined by a cam profile that drives the intake and exhaust valves. The basic injection end angle R1 and the additional injection end angle R2 are fixed values stored in the control unit 10. The basic injection end angle R1 is set to a first predetermined angle (for example, 180 degrees) near the explosion bottom dead center BDC1, and the injection end angle R2 of the additional injection is a second predetermined angle after the exhaust top dead center TDC2. (For example, 420 degrees).

As described above, the calculation of the injection amount (injection time) by the injection amount calculation unit 50 is repeatedly executed every 1 msec. Injection start timing setting unit 60, calculates the current crank angle based on the engine rotational speed and absolute stages, calculating the time from the current crank angle until reaching the angle R1 end Spray basic injection, Spray basic injection Set to the start timing of end basic injection. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts basic injection at the time t1 as the injection amount A1. The injection start time setting unit 60 updates the injected time stored in the injected time storage memory 64 as needed.

Here, when the engine is rotating at 10,000 rpm, the crankshaft rotates 60 degrees during 1 msec. Even during such high rotation, the calculation of the injection amount is performed every 1 msec, so that the basic injection can be performed. The injection amount can be updated about 2 to 3 times. At present, the fuel injection device 8 and the control device are improved in performance, and the injection time can be controlled in units of μsec. In the example of FIG. 2, although the injection amount is calculated several times during the basic injection, the engine load has not changed since the start of the injection, so the injection amount A1 at the start of the injection at the basic injection end angle R1 is It shows the state that blows.

Next, at the time t2 when the basic injection injection end angle R1 is reached, the basic injection ends and the throttle grip opening degree starts to increase due to the driver's acceleration request. Such an increase in engine load after the end of basic injection is compensated by additional injection.

The injection start time setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time until the additional injection injection end angle R2 is reached. Next, an additional injection time tb obtained by subtracting the injected time after the injection by the basic injection from the latest injection time is calculated. Then, the time t3 at which the additional injection time tb is calculated backward from the additional injection injection end angle R2 and just blown is set as the start time of the additional injection. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7, and starts additional injection at the injection amount B1 from time t3.

In this figure, all the injections in one cycle are completed at the additional injection end angle that reaches time t4, but the injection amount (injection time) is calculated by the injection amount calculation unit 50 even during the execution of the additional injection. Is repeatedly executed every 1 msec. As a result, in addition to the case where the required injection ends before reaching the additional injection end angle R2 according to the change in the throttle grip angle, the necessary additional injection ends when the additional injection end angle R2 is reached. There are cases where it is not. However, in the present embodiment, the additional injection injection end angle R2 is set as an absolute injection end position so that the forced injection is stopped even when necessary injection is not completed.

FIG. 3 is a time chart (injection pattern 2) showing the flow of operation of the fuel injection control apparatus according to the present embodiment. In the example of this figure, the injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time until the basic injection injection end angle R1 is reached. The time t10 at which the injection with the latest injection time tc is just blown by calculating backward from the injection end angle R1 is set as the basic injection start timing. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts basic injection from time t10.

In the example of FIG. 3, the throttle grip opening degree starts to increase in response to the driver's acceleration request from time t10 when the basic injection is started. On the other hand, in this embodiment, since the calculation of the injection amount (injection time) is repeated every 1 msec, the basic injection amount can be corrected during execution of the basic injection. This makes it possible to extend the injection time until the latest injection amount A2 finishes blowing even after the basic injection end angle R1 where the basic injection should have ended at the start of basic injection, at time t11. The basic injection will end.

Next, the injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time required to reach the additional injection end angle R2. Then, the additional injection time td obtained by subtracting the injection-completed time by the basic injection from the latest injection time is calculated backward from the additional injection end angle R2, and the time t12 at which the blowing ends is set as the start timing of the additional injection. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts additional injection at the injection amount B2 from time t12. Then, at time t13 when the additional injection injection end angle R2 is reached, the additional injection is completed and all injections are completed.

FIG. 4 is a time chart (injection pattern 3) showing the flow of operation of the fuel injection control apparatus according to the present embodiment. In the example of this figure, the injection start timing setting unit 60 calculates the current crank angle based on the engine speed and the absolute stage, and calculates the time until the basic injection injection end angle R1 is reached. The time t20 at which the injection with the latest injection time te is just blown back from the injection end angle R1 is set as the start timing of the basic injection. In response to this, the control unit 10 outputs a drive signal to the fuel injection control unit 7 and starts basic injection from time t21.

Even in such a case, in this embodiment, since the calculation of the injection amount (injection time) is repeatedly performed every 1 msec, it is possible to correct the basic injection amount during execution of the basic injection. That is, even when the basic injection should have finished blowing at the start of basic injection, even before reaching the basic injection end angle R1, if the latest injection amount A3 has been blown, the basic injection is completed. The injection can be terminated. As a result, it is possible to prevent fuel that is excessive from being injected in the light of the latest situation and improve fuel efficiency. In the example of FIG. 4, the basic injection is completed at time t22 before time t23 when the basic injection injection end angle R1 is reached, and the throttle grip opening is not changed thereafter. The state where all the injections are completed at the time t22 with the end of the operation is shown.

FIG. 5 is a flowchart showing a procedure of fuel injection amount calculation control. In step S1, the engine speed is detected based on the output signal of the engine speed calculator 40. In step S2, the throttle grip opening degree is detected by the throttle grip opening degree sensor 5, and in step S3, the throttle valve opening degree is detected by the throttle valve opening degree sensor 6. In the subsequent step S4, the target injection time T is calculated by applying the numerical value of each parameter to the injection amount map 51. In step S5, based on the output signal of the calculation interval timer 52, it is determined whether or not 1 msec has elapsed since the previous injection amount calculation. If an affirmative determination is made, the process returns to step S1. If a negative determination is made in step S5, the process proceeds to step S6 to determine whether or not the engine has stopped. When not being constant determined in step S6 returns to the determination in step S5. That is, the calculation of the injection amount is executed every 1 msec until the engine stops. If an affirmative determination is made in step S 6, the series of control is ended.

FIG. 6 is a flowchart showing a procedure of basic injection control. In step S10, the engine speed is detected, and in step S11, an absolute stage is detected. In step S12, an expected arrival time T1 up to the basic injection end angle R1 is calculated.

FIG. 7 is a flowchart showing a procedure of additional injection control. In step S20, it is determined whether or not the basic injection spray end angle R1 has been passed. If an affirmative determination is made in step S20, the process proceeds to step S21 to determine whether or not the count value of the additional injection prohibition timer has reached a predetermined value (for example, 0.5 msec). If a positive determination is made in step S21, the process proceeds to step S22. If a negative determination is made in steps S20 and S21, the process returns to the determinations in steps S20 and S21, respectively.

In step S22, an additional injection time T3 is obtained by calculating T-T2 (target injection time T-injected time T2). In the following step S23, an expected arrival time T4 up to the additional injection end angle R2 is calculated. In step S24, it is determined whether the calculated estimated arrival time T4 is equal to or less than the additional injection time T3. If an affirmative determination is made, the process proceeds to step S25 and additional injection is started. If a negative determination is made in step S24, the process returns to the determination in step S24.

FIG. 8 is a flowchart showing a procedure of additional injection forced stop control. In step S30, additional injection is being performed, and it is determined whether or not the process proceeds to step S31 to reach the additional injection end angle R2. If a negative determination is made in step S31, the process returns to the determination in step S31. If an affirmative determination is made, the additional injection is forcibly stopped in step S32, and the series of controls is terminated. Thus, additional since the injection spouting end angle R2 updates the injection time additional injection regardless forcibly stopped, add additional injection amount immediately before reaching the injection jetted end angle R2 is be increasing correction this increasing correction Therefore, fuel can be prevented from being injected at a position exceeding the intake limit angle into the cylinder.

As described above, according to the fuel injection control device of the present invention, the injection amount calculation unit 50 calculates the injection amount every predetermined time, and newly calculates the calculated injection amount during fuel injection by the fuel injection device 8. Since correction is performed based on the calculated injection amount, it is possible to reflect a change in load, such as an increase in the throttle grip opening generated during fuel injection, in the currently executed fuel injection. In addition, the target value for stopping the fuel injection is determined in advance as the injection end angle with reference to the crank angle, and the fuel injection starts at the timing when the calculated injection amount finishes the injection at the injection end angle. By changing the injection start timing according to the injected amount, it becomes easy to cope with a change in the injection amount calculated every predetermined time. Further, the basic injection and the additional injection are executed during one cycle of the internal combustion engine, and the additional injection is executed by the amount obtained by subtracting the injected amount by the basic injection from the injection amount calculated every predetermined time. In both the injection and the additional injection, the injection amount calculated every predetermined time is reflected during the injection, and even when the load changes during the basic injection, the basic injection amount is corrected as much as possible. Thus, it is possible to reduce the injection amount by the additional injection. Thereby, the injected fuel is likely to be in an ideal atomized state, and ideal combustion is easily obtained.

Engine configuration, valve timing, shape and structure of crank pulsar rotor and pulse generator, basic injection end angle and additional injection end angle setting, injection amount calculation interval, injection amount calculation start timing, injection amount The type and number of sensor information used for the calculation, the aspect of the injection amount map, and the like are not limited to the above embodiment, and various changes can be made. For example, the injection amount calculation interval may be set to change according to the engine speed. The fuel injection control device according to the present invention can be applied to various four-cycle engines including the fuel injection device.

DESCRIPTION OF SYMBOLS 1 ... Crankshaft, 2 ... Crank pulser rotor, 3 ... Pulse generator, 5 ... Throttle grip opening sensor, 6 ... Throttle valve opening sensor, 7 ... Fuel injection control part, 8 ... Fuel injection apparatus, 10 ... ECU ( Control unit), 50 ... injection amount calculation unit, 51 ... injection amount map, 52 ... calculation interval timer, 60 ... injection start timing setting unit, R1 ... basic injection end angle, R2 ... additional injection end angle, 63 ... injection Time setting timer, 64 ... injection time storage memory, C ... additional injection prohibited section

Claims (6)

A fuel injection device (8) that controls the injection amount according to the injection time; a control unit (10) that causes the fuel injection device (8) to perform at least one fuel injection during one cycle of the internal combustion engine; and at least the engine speed A fuel injection control device having an injection amount calculation unit (50) for calculating an injection amount of the fuel injection based on information on a throttle valve opening;
The injection amount calculation unit (50) calculates the injection amount every predetermined time,
The fuel injection control device, wherein the control unit (10) corrects the calculated injection amount with a newly calculated injection amount during fuel injection by the fuel injection device (8). The target value for stopping the fuel injection is predetermined as the blow end angle (R1, R2) with reference to the crank angle,
The fuel injection control device according to claim 1, wherein the control unit (10) starts fuel injection at a timing when the calculated injection amount finishes injection at the blow end angle (R1, R2). . The control unit (10) performs basic injection and additional injection to supplement the basic injection during one cycle of the internal combustion engine,
3. The fuel injection control device according to claim 1, wherein the additional injection is executed by an amount obtained by subtracting an injected amount by the basic injection from an injection amount calculated every predetermined time.   The fuel injection control device according to claim 3, wherein a prohibition section (C) for the additional injection is provided immediately after completion of the basic injection.   When the injection amount calculated during the execution of the basic injection increases from the start of the basic injection, the control unit (10) performs the injection even after the blow end angle (R1) of the basic injection has passed. 5. The fuel injection control device according to 3 or 4, wherein the fuel injection control device is continued. The blow end angle (R1) of the basic injection is set to a first predetermined angle in the vicinity of the explosion bottom dead center (BDC1) of the internal combustion engine,
The blow end angle (R2) of the additional injection is set to a second predetermined angle after the exhaust top dead center (TDC2) of the internal combustion engine,
6. The fuel injection control device according to claim 5, wherein the fuel injection is forcibly terminated at a blow end angle (R2) of the additional injection.

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