JP3640085B2 - Control method and control apparatus for fuel injection device for internal combustion engine - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a control method for controlling a fuel injection device for an internal combustion engine, and a control device used for carrying out the control method.
[0002]
[Prior art]
As a device for supplying fuel to the internal combustion engine, an electronically controlled fuel injection device (EFI) is used.
[0003]
An electronically controlled fuel injection device includes an injector attached to an intake manifold or the like of an engine, an injector drive circuit that conducts while an injection command pulse is applied and supplies a drive current from a power source to a drive coil of the injector, and an injector A fuel pump that supplies fuel, a pressure regulator that controls the pressure of the fuel supplied from the fuel pump to the injector, and a CPU, the engine speed [rpm], the throttle valve opening (throttle opening) And an electronic control unit that controls the fuel injection time with respect to various control conditions such as intake air temperature (cooling water and crankcase temperature) and engine acceleration.
[0004]
The injector includes, for example, a valve that opens and closes a fuel injection port and an electromagnet that drives the valve. A drive coil of the electromagnet is connected to a power supply for driving the injector via an injector drive circuit. The injector drive circuit is composed of a switch such as a transistor that can be turned on / off, and the switch is turned on to excite the drive coil of the injector only while an injection command pulse is applied. The injector opens the valve and injects fuel only while the drive coil is energized. Since the fuel pressure applied to the injector is controlled to be constant, the fuel injection amount is determined by the pulse width of the injection command pulse.
[0005]
The electronic control unit is equipped with a ROM that stores a map that gives the relationship between various control conditions and fuel injection time. By using values read from the map for various detected control conditions, an interpolation method is used. An injection time is calculated, and an injection command pulse having a pulse width corresponding to the calculated injection time is given to the injector drive circuit in order to inject fuel from the injector during the calculated injection time.
[0006]
In the internal combustion engine, the fuel supply amount is set in consideration of the engine output, the fuel consumption rate, the exhaust gas component amount, etc., and the air-fuel ratio A is set so that the set amount of fuel is sufficiently burned. / F (air weight / fuel weight) is controlled. Since the air weight in the same volume decreases as the atmospheric pressure is lower, the weight of fresh air retained in the cylinder after the end of the intake process decreases when the atmospheric pressure decreases. Therefore, when the atmospheric pressure becomes low, the air-fuel ratio becomes small, the amount of oxygen necessary for combustion becomes insufficient, and the engine output decreases.
[0007]
As described above, since the output of an internal combustion engine using EFI is affected by atmospheric pressure, the atmospheric pressure is detected, and the fuel injection amount from the injector is corrected in accordance with the detected value ( Atmospheric pressure correction). In this atmospheric pressure correction, the correction coefficient Kp for the detected atmospheric pressure is calculated using the atmospheric pressure correction coefficient calculation map that gives the relationship between the atmospheric pressure P and the injection time correction coefficient Kp, and the throttle opening degree, etc. Using the injection time calculated for control conditions other than atmospheric pressure as the basic injection time, the corrected actual injection time is obtained by multiplying the basic injection time by the correction coefficient Kp. The electronic control unit gives an injection command pulse having a pulse width corresponding to the corrected actual injection time to the injector drive circuit.
[0008]
FIG. 2 shows the relationship between the correction coefficient Kp and the atmospheric pressure P [Kpa] given by the atmospheric pressure correction coefficient calculation map used when performing atmospheric pressure correction in the conventional electronic fuel injection device. In this map, the correction coefficient Kp is linearly increased in proportion to the atmospheric pressure P. By performing such correction, the air-fuel ratio can be kept almost constant both when the engine is operated in a low altitude with high atmospheric pressure and when the engine is operated in a high altitude with low atmospheric pressure, resulting in oxygen shortage. The fuel can be burned without causing it.
[0009]
[Problems to be solved by the invention]
When the atmospheric pressure correction is performed as described above and the air-fuel ratio A / F is controlled to be substantially constant regardless of the atmospheric pressure, if the throttle opening is constant, combustion is performed when the atmospheric pressure is low. Since the weight of the fuel decreases, the output of the engine decreases. When the atmospheric pressure is high, the weight of the burning fuel increases and the output of the engine increases.
[0010]
As described above, even when the atmospheric pressure correction is performed to control the air-fuel ratio to be constant, the engine output at each throttle opening is affected by the atmospheric pressure. Since the throttle opening is adjusted so as to obtain a predetermined output, the engine operation is not hindered.
[0011]
However, when paying attention to the engine during idling, the throttle opening during idling is uniquely determined by the position of the stopper of the throttle valve and cannot be adjusted, so the atmospheric pressure is low and the weight of the burning fuel decreases. In this case, when the engine output decreases and the idle speed decreases, the atmospheric pressure increases, and the amount of fuel to burn increases, the engine output increases and the idle speed increases.
[0012]
Accordingly, when the atmospheric pressure correction is applied to the fuel injection amount, the idling speed increases at high altitudes where the atmospheric pressure is high, and the idling speed decreases at high altitudes where the atmospheric pressure is low. Therefore, if the engine adjusted so that the idling speed is appropriate in the lowland is operated in the highland, the idling speed becomes too low and the engine stalls or the engine becomes difficult to start. In addition, when an engine whose idle speed is adjusted so that the idle speed is appropriate at high altitudes is operated at low altitude, problems such as an increase in idle speed and noise increase occur.
[0013]
In particular, in vehicles such as snowmobiles that travel from low to high altitudes, if an automatic clutch that automatically connects the clutch when the engine speed exceeds a certain value is used, adjust to the high altitude. If the idling speed is adjusted, the engine may be started at the time of driving in the lowland, and at the same time, the automatic clutch may be engaged and started against the driver's intention, which may cause a personal injury.
[0014]
In order to solve the above problem, as shown in FIG. 3, the relationship between the correction coefficient Kp and the atmospheric pressure P when the atmospheric pressure correction is performed is made non-linear, and the correction coefficient increases as the atmospheric pressure P increases. It is conceivable to increase the rate of increase of Kp (ΔKp / ΔP).
[0015]
In this way, if the relationship between the correction coefficient and the atmospheric pressure is made non-linear and adjusted so that an appropriate idle speed can be obtained at high altitude, the fuel injection amount increases when the atmospheric pressure rises and mixing is performed. Since the concentration of the air increases and the combustion efficiency decreases, the idling speed in the lowland can be kept low.
[0016]
However, if the relationship between the correction coefficient and the atmospheric pressure is made non-linear as described above and the air-fuel ratio A / F is adjusted to fall within an appropriate range during idle operation and steady operation at high altitudes, Since the air-fuel ratio becomes smaller and the air-fuel mixture becomes rich during steady operation (the fuel concentration increases), the combustion efficiency during steady operation decreases and the engine output decreases, and the fuel consumption rate decreases. It is inevitable that the exhaust gas components deteriorate.
[0017]
An object of the present invention is to provide a fuel for an internal combustion engine that can maintain an air-fuel ratio A / F during a steady operation within an appropriate range and obtain a substantially constant idle speed regardless of the atmospheric pressure. An object of the present invention is to provide a control method for an injection device and a control device used for carrying out the control method.
[0018]
[Means for Solving the Problems]
The present invention detects at least a throttle opening and an atmospheric pressure as control conditions, calculates a fuel injection time for a control condition other than the atmospheric pressure as a basic injection time, a correction coefficient for the atmospheric pressure and the injection time, The process for calculating the correction coefficient for the atmospheric pressure detected using the map for calculating the atmospheric pressure correction coefficient that gives the relationship is calculated, and the process for calculating the actual injection time by multiplying the basic injection time by the correction coefficient. The present invention relates to a control method for a fuel injection device for an internal combustion engine that drives the injector so that fuel is injected from the injector during the actual injection time.
[0019]
In the present invention, the change range of the throttle opening is divided into at least an idle operation range and a steady operation range, and an atmospheric pressure correction coefficient calculation map and an idle operation correction coefficient calculation map and a normal operation correction are used. A coefficient calculation map is prepared, and when it is detected that the throttle opening is in the range during idle operation, the correction coefficient is calculated using the correction coefficient calculation map during idle operation. When it is detected that it is in the range during steady operation, the correction coefficient is computed using the steady operation correction coefficient computation map.
[0020]
The idle operation correction coefficient calculation map is created, for example, so that the increase rate of the correction coefficient increases as the atmospheric pressure increases, and the steady operation correction coefficient calculation map is substantially proportional to the atmospheric pressure. The correction coefficient is created so as to change linearly.
[0021]
In the present invention, the range of the throttle opening during steady operation can be further divided into a plurality of ranges. When the range of the throttle opening at the time of steady operation is divided into a plurality of ranges, a map for calculating a correction coefficient at the time of steady operation in which the change rate of the correction coefficient with respect to the atmospheric pressure differs for each of the plurality of ranges is prepared.
[0022]
The control device used to carry out the above method detects at least the throttle opening and the atmospheric pressure as control conditions, and calculates a fuel injection time for a control condition other than atmospheric pressure as a basic injection time. Means, a throttle opening range detecting means for detecting whether the throttle opening is in a range during idle operation or a range during steady operation, and it is detected that the throttle opening is in a range during idle operation Sometimes the correction coefficient for the injection time is calculated using the map for calculating the correction coefficient during idle operation, and when it is detected that the throttle opening is in the range for the normal operation, the map for calculating the correction coefficient during normal operation is used for injection. Correction coefficient calculation means for calculating a time correction coefficient, and actual injection time calculation means for calculating the actual injection time by multiplying the basic injection time by the correction coefficient Composed of the injection command pulse generating means for generating a pulse width being equal as the injection command pulse to the actual injection time.
[0023]
The map for calculating the correction coefficient during idle operation is created, for example, so as to increase the rate of increase of the correction coefficient as the atmospheric pressure increases, and the map for calculating the correction coefficient during steady operation is substantially proportional to the atmospheric pressure, for example. The correction coefficient is created so as to change linearly.
[0024]
[Action]
As described above, the range of change in throttle opening is divided into at least the range during idle operation and the range during steady operation, and when it is detected that the throttle opening is within the range during idle operation, correction during idle operation is performed. If the correction coefficient is calculated using the coefficient calculation map, and it is detected that the throttle opening is in the range during steady operation, the correction coefficient is calculated using the correction coefficient calculation map during steady operation. By properly creating each map, the air-fuel ratio during idle operation and steady operation can be maintained in an appropriate range regardless of the atmospheric pressure. However, the idling speed can be kept substantially constant without causing a decrease in output during steady operation.
[0025]
【Example】
FIG. 1 shows the hardware configuration of an apparatus for carrying out the control method of the present invention. In FIG. 1, reference numeral 1 denotes a CPU constituting an electronic control unit. The CPU includes a memory such as a ROM and a RAM, a first timer for ignition control, a second timer for injection control, a comparator, and the like, but these are not shown.
[0026]
Reference numeral 2 denotes a signal generator that rotates in synchronization with the internal combustion engine and generates a signal at a predetermined rotational angular position of the engine. The signal generator shown in the figure is composed of a rotor 2a having a reluctator 2a1 and a signal generator 2b. . The signal generator 2b includes a signal coil Ls wound around an iron core having a magnetic pole portion facing the rotor 2a having the rotor 2a1, and a permanent magnet for flowing a magnetic flux through the iron core around which the signal coil Ls is wound. As shown in FIG. 9 (A), the signal coil Ls has a magnetic flux change caused when the reluctator 2a1 starts to face the magnetic pole portion of the iron core around which the signal coil Ls is wound and ends the facing. Inductive pulsed signals Vs1 and Vs2 are induced. Since the signals Vs1 and Vs2 are generated at fixed rotational angle positions, information on the rotational angle position of the engine can be obtained from these signals. Further, the engine speed N depends on the generation interval of a specific signal, for example, the time from the generation of the signal Vs1 to the generation of the signal Vs2, or the time from the generation of the signal VS1 to the generation of the next signal Vs1. [Rpm] can be detected. The signals Vs1 and Vs2 obtained from the signal coil Ls are converted into waveforms that can be recognized by the CPU via the waveform shaping circuits 3 and 4 and input to the input ports A1 and A2 of the CPU1.
[0027]
In this example, a throttle sensor 5 that detects the opening of a throttle valve that adjusts the intake air amount of the internal combustion engine, and a temperature sensor 6 that detects the temperature of the cooling water of the internal combustion engine or the temperature of the crankcase (engine temperature); The atmospheric pressure sensor 7 for detecting the atmospheric pressure is provided, and the outputs of the throttle sensor 5, the temperature sensor 6 and the atmospheric pressure sensor 7 are input to the CPU input ports A3, A4 and A5, respectively.
[0028]
When other control conditions other than the throttle opening, engine temperature, and atmospheric pressure are used, a sensor for detecting another control condition is provided, and the output of the sensor is input to the CPU.
[0029]
An injector 8 is attached to the intake manifold of the internal combustion engine. The injector 8 includes, for example, a needle valve and an electromagnet that drives the needle valve, and fuel is given to the injector by a fuel pump. The fuel pressure applied to the injector is kept constant by a pressure regulator. One end of the drive coil 8a for driving the electromagnet of the injector 8 is connected to the non-grounded output terminal (positive terminal) of the DC power supply circuit 10 that uses the power generation coil 9 in the magnet generator attached to the internal combustion engine as a power source. The other end of the drive coil 8a is connected to the collector of an NPN transistor Tr1 whose emitter is grounded. The transistor Tr1 constitutes switch means for turning on and off the drive current of the drive coil 8A. The base of the transistor Tr1 is connected to the injection command pulse output port B1 of the CPU 1 through the resistor R1, and from the port B1 through the resistor R1. An injection command pulse Sj is given to the base of the transistor Tr1. In this example, an injector drive circuit 11 is constituted by a transistor Tr1 and a resistor R1.
[0030]
The DC power supply circuit 10 includes, for example, a power supply capacitor that is charged by the rectified output of the power generation coil 9 in the magnet generator, and a control circuit that controls charging of the capacitor so as to keep the voltage across the power supply capacitor at a constant value. The power supply voltage (injector drive voltage) Vj is applied from the DC power supply circuit 10 to the drive coil 8a of the injector. A constant voltage Vc stepped down from the DC power supply circuit 10 through the regulator 12 is supplied to the power supply terminal of the CPU 1 as the power supply voltage Vc.
[0031]
The ROM of the CPU 1 has a basic injection time calculation map for calculating the fuel injection time as a basic injection time Tib for control conditions other than atmospheric pressure, such as throttle opening and engine temperature, and the atmospheric pressure. A map for calculating the correction coefficient during idle operation and a map for calculating the correction coefficient during steady operation used for calculating the correction coefficient Kp during steady operation with respect to atmospheric pressure Is stored.
[0032]
In the present embodiment, the CPU 1 controls the timing (ignition timing) at which the internal combustion engine ignition device IGU performs the ignition operation. Therefore, the CPU 1 has an ignition trigger signal output port B2, and an ignition trigger signal Sf is supplied from the port B2 to the internal combustion engine ignition device IGU. The ignition device IGU generates a high voltage for ignition when the ignition trigger signal Sf is given, and applies the high voltage to a spark plug attached to a cylinder of the engine to perform an ignition operation. In order to perform the calculation of the ignition timing, a map for calculating the ignition timing is stored in the ROM of the CPU 1.
[0033]
In the control method of the present invention, the change range of the throttle opening is divided into at least an idle operation range and a steady operation range, and when it is detected that the throttle opening is in the idle operation range, the idle operation is performed. The correction coefficient is calculated using the time correction coefficient calculation map, and when it is detected that the throttle opening is in the range during steady operation, the correction coefficient is calculated using the normal operation correction coefficient calculation map. .
[0034]
The idle operation correction coefficient calculation map used in this embodiment is created so as to increase the increase rate (ΔKp / ΔP) of the correction coefficient Kp as the atmospheric pressure P increases, as shown in FIG. The correction coefficient calculation map for steady operation is created so that the correction coefficient Kp changes linearly in proportion to the atmospheric pressure P.
[0035]
The CPU 1 executes a predetermined program stored in the ROM to control the fuel injection time and injection timing and the ignition timing of the internal combustion engine. FIGS. 4 to 8 are flowcharts showing the control algorithm. FIG. 4 shows a main routine. FIG. 5 shows an interrupt routine executed every time the output of the atmospheric pressure sensor 7 is read. FIG. 6 shows a crank angle interruption routine executed every time the signal generator 2 generates a specific signal Vs1 at a predetermined crank angle. FIG. 7 shows each time the first timer for ignition control finishes counting. A first timer interrupt routine to be executed is shown. FIG. 8 shows a second timer interruption routine that is executed every time the second timer for injection control finishes counting. The operation in the case of following these flowcharts is as follows.
[0036]
When the power source of the CPU 1 is established, as shown in FIG. 4, first, each part is initialized (initialized), and first, the engine speed is calculated from the output signal generation interval of the signal generator 2. Next, various control conditions (outputs of the sensors 5 to 7) are sequentially read, and when the output of the pressure sensor 7 is read, the interruption routine of FIG. 5 is executed. In this interrupt routine, first, it is determined whether the throttle opening α already read is larger than the opening αo during idle operation, so that the throttle opening is within the range during idle operation or steady state. Detect if it is within the driving range.
[0037]
As a result, when it is detected that α ≦ αo and the opening during idle operation, the correction coefficient Kp is calculated using the idle operation correction coefficient calculation map, and α> αo, When it is detected that the opening degree is in the steady operation, the correction coefficient Kp is calculated using the steady operation correction coefficient calculation map.
[0038]
The map for calculating the correction coefficient is a table including jump values P1, P2,... Of the atmospheric pressure P and correction coefficients Kp1, Kp2,. When calculating the correction coefficient, the correction coefficient corresponding to the value close to the detected value of the atmospheric pressure P is read from the map, and the correction coefficient Kp corresponding to the actual atmospheric pressure is calculated by the interpolation method. After calculating the correction coefficient Kp, the process returns to the main routine of FIG.
[0039]
In the main routine, a basic injection time Tib for a control condition other than atmospheric pressure is calculated using a basic injection time calculation map, and an actual injection time Ti is calculated by multiplying the basic injection time by a correction coefficient Kp. The CPU also calculates the fuel injection timing (time to start fuel injection) at the already calculated rotation speed. This injection timing is calculated in the form of the time required for the engine to rotate from the position where the signal generator 2 generates the specific signal Vs1 to the fuel injection start position (the count value Tit of the second timer for injection control). Is done.
[0040]
The main routine calculates the ignition timing at each engine speed. This ignition timing is performed using an ignition timing calculation map that gives the relationship between the rotational speed and the ignition timing. The ignition timing is determined by the engine rotating from the position where the signal generator 2 generates the specific signal Vs1 to the ignition timing. Is calculated in the form of the time required for ignition (count value Tft of the first timer for ignition control).
[0041]
When the signal generator 2 generates a signal at a specific crank angle, the interrupt routine of FIG. 6 is executed. In this embodiment, as shown in FIG. 9A, when the signal generator 2 generates a specific signal Vs1 (when the signal Vs1 reaches a predetermined threshold level Vt), the waveform shaping circuit 3 A pulse signal Vp1 as shown in FIG. 9B is applied to the CPU input port A1, and when this pulse signal Vp1 is applied, the crank angle interruption routine of FIG. 6 is executed.
[0042]
In the interrupt routine of FIG. 6, first, a count value (ignition timing count value) Tft for measuring the ignition timing is set in the first timer, and counting (countdown) of the count value Tft is started. Next, a count value (injection timing count value) Tit for measuring the injection timing is set in the second timer, the second timer is started to count down the count value Tit, and the process returns to the main routine.
[0043]
When the countdown of the count value set by the first timer is completed, the interrupt routine of FIG. 7 is executed. In this interrupt routine, first, it is determined whether or not the ignition end flag is ON (whether or not the flag is set). When the first timer finishes counting down the ignition timing count value Tft, the ignition end flag is OFF (the flag is not set). At this time, the ignition trigger signal count value Tf is set in the first timer, and the ignition trigger signal output port B2 provided in the CPU is turned ON (the ignition trigger signal Sf is generated by increasing the potential of the port). At the same time, the first timer is started to count down the count value Tf. Next, the ignition end flag is turned ON and the process returns to the main routine. When the first timer finishes counting down the count value Tf during execution of the main routine, the interrupt routine of FIG. 7 is started again. At this time, since the ignition end flag is in the ON state, the ignition trigger signal output port B2 is set in the OFF state (the potential of the port is set to zero and the ignition trigger signal Sf is extinguished), and the ignition end flag is set in the OFF state.
[0044]
Further, after the interruption routine of FIG. 6 is executed, when the second timer finishes counting down the injection timing count value Tit during the execution of the main routine, the interruption routine of FIG. 8 is executed. In this interrupt routine, it is first determined whether or not the injection end flag is in an ON state. When the second timer finishes counting down the injection timing count value Tit, the injection end flag is OFF. At this time, the count value Ti of the injection time Ti is set in the second timer, the injection command pulse output port B1 provided in the CPU is turned ON, and at the same time, the second timer is started to count down the count value Ti. . Next, the injection end flag is turned ON and the process returns to the main routine. When the second timer finishes counting down the count value Ti during execution of the main routine, the interrupt routine of FIG. 8 is started again. At this time, since the injection end flag is in the ON state, the injection command pulse output port B1 is turned off and the injection end flag is turned off.
[0045]
Therefore, in this embodiment, as shown in FIG. 9A, the signal generator generates the signal Vs1 at a specific crank angle, and as shown in FIG. 9B, the pulse signal Vp1 is sent to the CPU1. When a time corresponding to the ignition timing count value Tft has elapsed, an ignition trigger signal Sf is applied to the internal combustion engine ignition device IGU as shown in FIG. When the time has elapsed, the ignition trigger signal Sf is extinguished. Further, when the injection timing count value Tit has elapsed after the pulse signal Vp1 is given to the CPU 1, the injection command pulse Sj is given to the injector drive circuit 11 as shown in FIG. 9D, and then the predetermined time Tj is given. When the time has elapsed, the injection command pulse Sj is extinguished.
[0046]
In the above embodiment, at least the throttle opening and the atmospheric pressure are detected as the control conditions by the process of calculating the basic injection time Tib of the main routine of FIG. 4, and the fuel injection time for the control conditions other than the atmospheric pressure is determined. Basic injection time calculation means for calculating the basic injection time is realized.
[0047]
Further, the throttle opening range for detecting whether the throttle opening is in the range of the idling operation or the steady operation by the process of determining the magnitude of the throttle opening α and αo in the interruption routine of FIG. The detection means is realized, and the correction coefficient calculation means is realized by the process of calculating the correction coefficient Kp using the steady operation correction coefficient calculation map or the idle operation correction coefficient calculation map according to the detection result.
[0048]
Further, in the main routine of FIG. 4, the actual injection time calculation means is realized by the process of calculating the actual injection time Ti by multiplying the basic injection time Tib by the correction coefficient Kp.
[0049]
Further, in the interrupt routine of FIG. 6, the injection timing count value is set in the second timer and the count value is started to be counted down, and the interrupt routine of FIG. 8 is used to inject pulses having the same pulse width as the actual injection time. An injection command pulse generating means for generating the command pulse is realized.
[0050]
Further, in the above embodiment, the ignition timing calculation means is realized by the process of calculating the ignition timing of the main routine shown in FIG. 4, and the ignition timing count value is set in the first timer in the interrupt routine of FIG. An ignition trigger signal generation means for generating an ignition trigger signal is realized by the process of starting the countdown of the count value and the interrupt routine of FIG.
[0051]
In the above embodiment, only one normal operation correction coefficient calculation map is prepared. However, when only one normal operation correction coefficient calculation map is used, depending on how the map is designed, idle operation may be performed. When the engine is shifted to the steady operation from the state where the engine is running, the correction coefficient changes suddenly, the fuel supply amount changes suddenly, the engine output fluctuates greatly, and the driver feels uncomfortable. There is a fear. In order to prevent this, the change range of the throttle opening during the steady operation may be divided into a plurality, and different steady operation correction coefficient calculation maps may be prepared for each of the plurality of ranges. By preparing a plurality of maps for calculating the correction coefficient during steady operation in this way, it is possible to prevent the correction coefficient from changing significantly during the transition from idle operation to steady operation. It is possible to prevent engine output fluctuations from occurring during the transition.
[0052]
In the above embodiment, the injector 8 and the CPU 1 are operated using the power generation coil 9 provided in the magnet generator attached to the internal combustion engine as a power source. The invention can be applied.
[0053]
In the above embodiment, both the injector and the internal combustion engine ignition device are controlled by the CPU 1, but the internal combustion engine ignition device is controlled by a CPU different from the CPU that controls the injector. You can also.
[0054]
【The invention's effect】
As described above, according to the present invention, it is detected that the throttle opening is in the range during idle operation by dividing the change range of the throttle opening into at least the range during idle operation and the range during steady operation. If the throttle opening is detected to be in the range for steady operation, the correction factor is calculated using the map for calculating the correction coefficient during steady operation. Therefore, by properly creating each map, the air-fuel ratio during idle operation and steady operation can be maintained within an appropriate range regardless of the atmospheric pressure. In any case, there is an advantage that the idling speed can be kept substantially constant without causing a decrease in output during steady operation regardless of the atmospheric pressure.
[0055]
In particular, according to the third aspect of the invention, the range of change in the throttle opening during steady operation is divided into a plurality of ranges, and different steady operation correction coefficient calculation maps are provided for each of the plurality of ranges. Since it is prepared, there is an advantage that it is possible to prevent the correction coefficient from changing greatly when shifting from the idle operation to the steady operation, and to prevent the engine output fluctuation.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically illustrating a hardware configuration according to an embodiment of the present invention.
FIG. 2 is a diagram showing a relationship between a correction coefficient obtained by a map for calculating a correction coefficient during steady operation used in an embodiment of the present invention and atmospheric pressure.
FIG. 3 is a diagram showing a relationship between a correction coefficient obtained by an idle operation correction coefficient calculation map used in an embodiment of the present invention and atmospheric pressure.
FIG. 4 is a flowchart showing a main routine of a program used for operating the CPU in the embodiment of the present invention.
FIG. 5 is a flowchart showing an interrupt routine executed when calculating a correction coefficient in the embodiment.
FIG. 6 is a flowchart showing an interrupt routine that is executed when the signal generator generates a specific signal in the embodiment;
FIG. 7 is a flowchart showing an interrupt routine that is executed every time the first timer finishes counting in the embodiment;
FIG. 8 is a flowchart showing an interrupt routine that is executed each time the second timer finishes counting in the embodiment;
FIG. 9 is a waveform diagram showing signal waveforms at various parts in the same example.
[Explanation of symbols]
1 CPU
2 signal generator
5 Throttle sensor
6 Temperature sensor
7 Barometric pressure sensor
8 Injector
9 Power generation coil in magnet generator
11 Injector drive circuit

Claims (2)

At least throttle opening and atmospheric pressure are detected as control conditions, and the relationship between the process of calculating the fuel injection time for control conditions other than atmospheric pressure as the basic injection time and the correction factor for atmospheric pressure and injection time is given. The process of calculating the correction coefficient for the atmospheric pressure detected using the atmospheric pressure correction coefficient calculation map and the process of calculating the actual injection time by multiplying the basic injection time by the correction coefficient are performed. In a control method of a fuel injection device for an internal combustion engine that drives an injector so that fuel is injected from the injector during an injection time,
  Divide the range of change in throttle opening into at least idle operation range and steady operation range,
  As the atmospheric pressure correction coefficient calculation map, as the atmospheric pressure rises, the correction coefficient
A map for calculating the correction coefficient during idling created so as to increase the increase rate of
A correction coefficient calculation map for steady operation prepared so as to change the correction coefficient linearly in proportion to the atmospheric pressure is prepared,
  When it is detected that the throttle opening is in the range during idle operation, the correction coefficient is calculated using the map for calculating the correction coefficient during idle operation, and the throttle opening is in the range during steady operation. Calculating the correction coefficient using the map for calculating the correction coefficient during steady operation,
A control method for a fuel injection device for an internal combustion engine. An internal combustion engine fuel injection apparatus comprising: an injector that injects fuel while a drive current of a predetermined magnitude is applied; and an injector drive circuit that supplies drive current to the injector while an injection command pulse is applied A control device,
  Basic injection time calculating means for detecting at least the throttle opening and the atmospheric pressure as control conditions and calculating the fuel injection time for the control conditions other than atmospheric pressure as the basic injection time;
  Throttle opening range detection means for detecting whether the throttle opening is in the range during idle operation or the range during steady operation;
  When it is detected that the throttle opening is in the range during idle operation, the correction coefficient for injection time is calculated using the map for calculating the correction coefficient during idle operation, and the throttle opening may be in the range during steady operation. Correction coefficient calculation means for calculating a correction coefficient for injection time using a map for calculating correction coefficient during steady operation when detected,
  Actual injection time calculating means for calculating the actual injection time by multiplying the basic injection time by a correction coefficient;
  Injection command pulse generating means for generating, as the injection command pulse, a pulse having a pulse width equal to the actual injection time,
  The map for calculating the correction coefficient during idle operation is created so as to increase the rate of increase of the correction coefficient as the atmospheric pressure increases, and the map for calculating the correction coefficient during steady operation is substantially proportional to the atmospheric pressure. A control apparatus for a fuel injection device for an internal combustion engine, characterized in that the correction coefficient is linearly changed.

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