JP2005320900A - Fuel injection control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection control device for an internal combustion engine capable of correcting fuel injection time to inject fuel of appropriate quantity even if pressure in an intake pipe changes during fuel injection operation. <P>SOLUTION: In the fuel injection control device for the internal combustion engine provided with an injector 3 controlling fuel pressure constant in relation to atmospheric pressure, an injector control part driving the injector to inject fuel from the injector 3 during injection time determined in relation to various control conditions, the injector control part is constructed to monitor pressure in the intake pipe after the injector 3 starts fuel injection operation, and to calculate correction quantity of injection time in relation to pressure difference between atmospheric pressure and newly detected pressure in the intake pipe to correct injection time by calculated correction quantity when variation exceeding a set value is detected in monitored pressure in the intake pipe. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection control device that controls an injector (fuel injection valve) of a fuel injection device for an internal combustion engine.

  In a fuel injection device for an internal combustion engine, the amount of fuel injected from the injector is determined by the pressure of the fuel applied to the injector and the time (injection time) for injecting the fuel. In general, since the pressure (fuel pressure) of fuel applied to the injector is kept constant by a pressure regulator, the amount of fuel injected from the injector is managed by the injection time.

  In the fuel injection control device for an internal combustion engine, when estimating the intake air amount from the rotation speed and the intake pipe pressure, the atmospheric pressure is a standard pressure based on the rotation speed and the intake pipe pressure using a map created by experiment etc. By calculating the intake air amount when the intake air temperature is equal to a certain value (a constant value) equal to the atmospheric pressure, and converting this intake air amount into the intake air amount at the actual atmospheric pressure and intake air temperature, Calculate the intake air amount in the state. A basic injection amount Qp [cc] is calculated from the intake air amount and the target air-fuel ratio. Then, the basic injection amount Qp is added to the post-startup increase correction coefficient, the warm-up increase correction coefficient, the acceleration / deceleration correction coefficient, etc. obtained based on various control conditions such as the elapsed time from the start, the coolant temperature, and the throttle opening. By multiplying these various correction coefficients, the injection amount corresponding to the state of the engine is calculated as the reference injection amount QA. Thereafter, this reference injection amount QA, and an injector constant kinj (injection amount / valve opening time), which is a conversion constant between the injection amount and the valve opening time when fuel is injected into the atmosphere at a constant fuel pressure with respect to atmospheric pressure, From this, the reference injection time TA (= QA / kinj) when the pressure in the intake pipe at the time of injection is equal to the atmospheric pressure is obtained.

  In the above description, the basic injection amount is calculated by multiplying the basic injection amount by various correction factors, and the reference injection time is calculated from the reference injection amount and the constant of the injector. In some cases, the basic injection time is obtained from the constants of the injector and the injector, and the basic injection time is calculated by multiplying the basic injection time by various correction coefficients.

  As a pressure regulator that keeps the fuel pressure given to the injector constant, when the fuel pressure given to the injector exceeds the adjustment value, a part of the fuel given to the injector is returned from the fuel tank to the injector through the fuel pump. Many things are used. The reference injection time is calculated from the injector constant (injection amount / valve opening time) assuming that the fuel pressure is constant. When the pressure regulator as described above is used, the fuel injection amount is actually determined. The pressure is not a fuel pressure but a differential pressure between the fuel pressure and the intake pipe pressure. Therefore, it is necessary to correct the reference injection time TA calculated by the reference injection amount and the injector constant with respect to the pressure difference between the atmospheric pressure and the intake pipe pressure.

  When the injector is driven, the reference injection time TA is invalid for the effective injection time obtained by correcting the pressure difference between the atmospheric pressure and the intake pipe pressure and the difference between the reference value of the atmospheric pressure and the actual atmospheric pressure. The time obtained by adding the injection time (the time from when the injector driving is started until the injector valve is actually opened) is set as the injector driving time, and an injection pulse having a pulse width equal to the driving time is given to the injector driving circuit. The injector driving circuit applies a driving voltage to the solenoid of the injector while an injection pulse is applied, thereby causing a driving current to flow through the solenoid to perform an injection operation.

Fuel injection for controlling a fuel injection device using a pressure regulator that returns a part of the fuel supplied to the injector from the fuel tank through the fuel pump when the fuel pressure applied to the injector exceeds the adjustment value The control device is described in Patent Document 1, for example.
JP 2001-107776 A

  As described above, in the fuel injection control device for an internal combustion engine, the injection time is corrected for the differential pressure between the atmospheric pressure and the intake pipe pressure. However, in the conventional fuel injection control device, various control conditions are satisfied. On the other hand, after calculating the injection time, the fuel is injected for the calculated injection time on the assumption that the pressure in the intake pipe does not change until the fuel injection start timing. When the intake pipe pressure fluctuates immediately before the injection start timing or during the injection operation, the fluctuation cannot be dealt with and the correct amount of fuel may not be injected.

  FIG. 12 shows the fuel injection control operation of the single cylinder internal combustion engine. FIG. 4A shows the intake pipe pressure Py, and FIGS. 2B and 2C show the injection pulse Vj and the throttle opening θth applied to the injector drive circuit. The time t [sec] is taken on the horizontal axis of FIGS. In FIG. 12A, Pa represents atmospheric pressure.

  As shown by the solid line in FIG. 12C, when the throttle opening θth is kept constant, the intake pipe pressure Py is shown by the solid line in FIG. To change. Assuming that the proper injector drive time in the state where the intake pipe pressure Py changes in this way is Tj1 shown in the figure, the injector drive circuit is given an injection pulse Vj having a pulse width equal to the drive time Tj1. The drive circuit applies a drive voltage to the solenoid of the injector while the injection pulse Vj is being applied, causes a drive current to flow through the solenoid, and injects fuel from the injector.

  Here, as indicated by the wavy line in FIG. 12 (C), the throttle opening momentarily changed, and the intake pipe pressure increased (intake air amount increased) as indicated by the wavy line in FIG. 12 (A). And At this time, in order to maintain the air-fuel ratio at a correct value, it is necessary to widen the pulse width of the injection pulse Vj as indicated by the wavy line in FIG. 12B and set the injector drive time to Tj2 (> Tj1). However, in the prior art, the operation of the internal combustion engine may become unstable because the injection time cannot be corrected when the intake pipe pressure changes during the injection operation.

  An object of the present invention is to provide a fuel injection control device for an internal combustion engine that can stably operate an engine by injecting a correct amount of fuel even when the pressure in the intake pipe changes during the injection operation. is there.

  The present invention relates to an injector that injects fuel into a fuel injection space of an internal combustion engine, a fuel pump that supplies fuel from a fuel tank to the injector, and a pressure adjustment that controls the fuel pressure applied from the fuel pump to the injector to be constant with respect to atmospheric pressure. A difference between the atmospheric pressure detected by the atmospheric pressure detection means and the pressure in the intake pipe detected by the pressure sensor, the atmospheric pressure detection means for detecting the atmospheric pressure, the pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, A fuel injection control device for an internal combustion engine, comprising: an injector control unit that drives the injector so that fuel is injected from the injector during an injection time determined for various control conditions including the pressure difference set to target.

  In the present invention, the pressure in the intake pipe is monitored even after the injector starts the fuel injection operation, and when a fluctuation exceeding the set value is detected in the intake pipe pressure, the atmospheric pressure is newly detected in the intake pipe. The injector control unit is configured to calculate a correction amount of the injection time with respect to the pressure difference from the pressure, and to correct the injection time by the calculated correction amount.

  When the injector control unit is configured as described above, the fuel injection time is set to an appropriate length even when the pressure in the intake pipe shows an instantaneous change immediately before the injector starts fuel injection or after the injection starts. Since the correct amount of fuel can be injected to compensate for the intake air amount, the engine can be operated stably even when the pressure in the intake pipe fluctuates immediately before fuel injection starts or during the injection operation. be able to.

In a preferred aspect of the present invention, the injector control unit is configured by the following elements.
(1a) Injection start timing detection means for detecting injection start timing.
(1b) Reference injection time calculation means for calculating the fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(1c) When the injection start timing is detected, the provisional drive time is defined as the provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. Injection start time processing means for setting the injection timer so as to cause the injection timer to start and to start the time measuring operation of the injection timer.
(1d) Injection pulse generating means for generating an injection pulse while the injection timer is performing a time measuring operation.
(1e) An injector driving circuit that drives the injector while the injection pulse is generated.
(1f) Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when an injection pulse is generated.
(1g) When the intake pipe pressure newly sampled by the intake pipe pressure sampling means shows an increase of a set value or more with respect to the previously sampled intake pipe pressure, the atmospheric pressure and the newly sampled intake pipe An injection that calculates a corrected injection time that is added to a time that is already measured by the injection timer to correct the injector drive time with respect to the pressure difference from the pressure, and resets the corrected injection time in the injection timer. Correction processing means during operation.

In another preferred aspect of the present invention, the injector control unit includes the following elements.
(2a) injection start timing detection means for detecting injection start timing;
(2b) Reference injection time calculation means for calculating the fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(2c) The provisional driving time is defined as a provisional driving time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference when the injection start timing is detected. Injection start time processing means for setting the injection timer so as to be measured by the injection timer and starting measurement of the provisional driving time and generating an injection pulse.
(2d) An injector driving circuit that drives the injector while the injection pulse is generated.
(2e) Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when an injection pulse is generated.
(2f) When the intake pipe pressure newly sampled by the intake pipe pressure sampling means shows an increase of the set value or more with respect to the previously sampled intake pipe pressure, the atmospheric pressure and the newly sampled intake pipe Calculate the corrected injection time that is added to the time already measured by the injection timer to correct the injector drive time for the pressure difference from the pressure, and the newly calculated corrected injection time is calculated last time. An injection operation time correction processing means for resetting the injection timer so as to extend the time to be measured by the injection timer when the set time is longer than the provisional injection time or the corrected injection time by the corrected injection time.

In still another preferred aspect of the present invention, the injector control unit includes the following elements.
(3a) Injection start timing detection means for detecting injection start timing.
(3b) A reference injection time calculation means for calculating a fuel injection time when the pressure in the intake pipe is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(3c) When the injection start timing is detected, the provisional drive time is set to the provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse.
(3d) An injector driving circuit that drives the injector while the injection pulse is generated.
(3e) Intake pipe internal pressure sampling means for sampling the intake pipe internal pressure at regular time intervals when an injection pulse is generated.
(3f) A correction injection time to be added to the time already measured by the injection timer in order to correct the drive time of the injector for the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. The time calculated by the injection timer when it is determined that the newly calculated corrected injection time is longer than the preset calculated temporary injection time or the corrected injection time by a set value or more is extended by the corrected injection time. Injecting operation correction processing means for resetting the injection timer as described above.

In still another preferred aspect of the present invention, the injector control unit is configured by the following elements.
(4a) Injection start timing detection means for detecting injection start timing.
(4b) Reference injection time calculation means for calculating the fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(4c) When the injection start timing is detected, the provisional drive time is set to the provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse.
(4d) An injector driving circuit that drives the injector while the injection pulse is generated.
(4e) Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when an injection pulse is generated.
(4f) A correction injection time to be added to the time already measured by the injection timer to correct the drive time of the injector with respect to the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. The time calculated by the injection timer when it is determined that the newly calculated corrected injection time is longer than the preset calculated temporary injection time or the corrected injection time by a set value or more is extended by the corrected injection time. Injecting operation correction processing means for resetting the injection timer as described above.
(4g) When the intake pipe pressure newly sampled by the intake pipe pressure sampling means does not show an increase beyond the preset value with respect to the previously sampled intake pipe pressure, or when the newly calculated corrected injection time is the previous time An end-of-injection processing means that extinguishes the injection pulse when the calculated provisional injection time or the corrected injection time is not longer than a set value.

In still another preferred aspect of the present invention, the injector control unit is configured by the following elements.
(5a) Injection start timing detection means for detecting injection start timing.
(5b) Reference injection time calculation means for calculating the fuel injection time when the pressure in the intake pipe is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(5c) When the injection start timing is detected, the provisional drive time is defined as the provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse.
(5d) An injector driving circuit that drives the injector while the injection pulse is generated.
(5e) Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when an injection pulse is generated.
(5f) A correction injection time to be added to the time already measured by the injection timer in order to correct the drive time of the injector for the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. When the calculated corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the injection timer is restarted to extend the time to be measured by the injection timer by the corrected injection time. Correction processing means for injection operation to be set.
(5g) An end-of-injection processing means for extinguishing the injection pulse when the newly calculated corrected injection time is not longer than the preset calculated temporary injection time or corrected injection time by a set value or more.

In still another preferred aspect of the present invention, the injector control unit is configured by the following elements.
(6a) Injection start timing detection means for detecting injection start timing.
(6b) Reference injection time calculation means for calculating the fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(6c) When the injection start timing is detected, the provisional drive time is defined as the provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer so as to cause the measurement to be started and starting the measurement of the provisional drive time and generating an injection pulse.
(6d) An injector driving circuit that drives the injector while the injection pulse is generated.
(6e) Intake pipe internal pressure sampling means for sampling the intake pipe internal pressure when the injection timer completes the timing operation.
(6f) When the intake pipe pressure newly sampled by the intake pipe pressure sampling means shows an increase over the preset value with respect to the previously sampled intake pipe pressure, the atmospheric pressure and the newly sampled intake pipe In order to correct the injector driving time with respect to the pressure difference from the pressure, the correction injection time added to the time already measured by the injection timer is calculated, and the time to be measured by the injection timer is extended by the correction injection time. Injecting operation correction processing means for resetting the injection timer.
(6g) When the intake pipe pressure newly sampled by the intake pipe pressure sampling means does not indicate an increase over the preset value with respect to the previously sampled intake pipe pressure, or when the newly calculated corrected injection time is the previous time An end-of-injection processing unit that extinguishes the injection pulse when the calculated provisional injection time or the corrected injection time is not longer than a set value.

In still another preferred aspect of the present invention, the injector control unit is configured by the following elements.
(7a) Injection start timing detection means for detecting injection start timing.
(7b) Reference injection time calculation means for calculating the fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(7c) When the injection start timing is detected, the provisional drive time is injected by setting the provisional injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer so as to be measured by the timer and starting the measurement of the provisional drive time and generating an injection pulse.
(7d) An injector driving circuit that drives the injector while the injection pulse is generated.
(7e) Intake pipe pressure sampling means for sampling the intake pipe pressure when the injection timer completes the timing operation.
(7f) A correction injection time to be added to the time already measured by the injection timer in order to correct the drive time of the injector with respect to the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. When the newly calculated corrected injection time is longer than the previously calculated provisional injection time or the corrected injection time by a set value or more, the time to be measured by the injection timer is extended by the corrected injection time. Correction processing means at the time of injection operation for resetting the timer.

In still another preferred aspect of the present invention, the injector control unit is configured by the following elements.
(8a) Injection start timing detection means for detecting injection start timing.
(8b) Reference injection time calculation means for calculating the fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference.
(8c) When the injection start timing is detected, the provisional drive time is injected with the provisional drive time defined as a time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer so as to be measured by the timer and starting the measurement of the provisional drive time and generating an injection pulse.
(8d) An injector driving circuit that drives the injector while the injection pulse is generated.
(8e) First intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when an injection pulse is generated.
(8f) Second intake pipe pressure sampling means for sampling the intake pipe pressure when the injection timer completes the timing operation.
(8g) The intake pipe pressure newly sampled when the intake pipe pressure newly sampled by the first intake pipe pressure sampling means shows a rise above the set value with respect to the previously sampled intake pipe pressure. In order to correct the injector drive time with respect to the pressure difference between the pressure and the atmospheric pressure, the correction injection time added to the time already measured by the injection timer is calculated, and the newly calculated correction injection time is calculated last time. Injecting operation correction processing means for resetting the injection timer so as to extend the time to be measured by the injection timer by the corrected injection time when it is determined that the set time is longer than the provisional injection time or the corrected injection time.
(8h) The second intake pipe pressure sampling when the intake pipe pressure newly sampled by the second intake pipe pressure sampling means shows an increase over the set value with respect to the previously sampled intake pipe pressure. Calculating a correction injection time to be added to the time already measured by the injection timer in order to correct the drive time of the injector with respect to the pressure difference between the intake pipe pressure newly sampled by the means and the atmospheric pressure. The injection time so that the time that the injection timer measures is extended by the correction injection time when it is determined that the correction injection time calculated in (i) is longer than the previously calculated provisional injection time or correction injection time by a set value or more. The timer is reset, and the intake pipe pressure newly sampled by the second intake pipe pressure sampling means is When there is no increase over the set value with respect to the pulled intake pipe pressure, or when the newly calculated corrected injection time is not longer than the set value by more than the previously calculated provisional injection time or corrected injection time An end-of-injection processing means for extinguishing the injection pulse.

  As described above, according to the present invention, after the injector starts the fuel injection operation, the intake pipe pressure is monitored, and when a fluctuation exceeding the set value is detected in the monitored intake pipe pressure, The injection time correction amount is calculated for the pressure difference between the atmospheric pressure and the monitored intake pipe pressure, and the injection time is corrected by the calculated correction amount, so the injector starts fuel injection. Even if the pressure in the intake pipe shows an instantaneous change after this, the fuel injection time is corrected to an appropriate length and an appropriate amount of fuel is injected that matches the amount of intake air. Can be made.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
First Embodiment FIG. 1 is a configuration diagram showing a configuration example of an internal combustion engine control device in which a fuel injection control device according to the present invention is incorporated. The illustrated internal combustion engine 1 is a single-cylinder four-cycle engine, and includes a cylinder 1a, a piston 1b, a crankshaft 1c connected to the piston 1b via a connecting rod, a cylinder head 1f having an intake port 1d and an exhaust port 1e. The intake valve 1g and the exhaust valve 1h for opening and closing the intake port and the exhaust port, the cam shaft 1i driven by the crankshaft 1c, and the valves for driving the intake valve 1g and the exhaust valve 1h as the cam shaft 1i rotates. A drive mechanism 1j and an intake pipe 1k connected to the intake port 1d are provided, and a throttle valve 1m is provided in the intake pipe 1k. A spark plug 2 is attached to the cylinder head of the internal combustion engine 1, and the spark plug 2 is connected to a secondary coil of the ignition coil IG through a high-voltage cord.

  An injector (electromagnetic injector) 3 is attached to an intake pipe 1k of the internal combustion engine. The illustrated injector 3 has an injector body having a fuel injection port at the front end and a fuel supply port near the rear end, a position (open position) for opening the fuel injection port, and a position (closed position) for opening the fuel injection port in the injector body. ), A valve member such as a needle provided so as to be displaceable, a biasing means for biasing the valve member to the normally closed position side, and a solenoid for driving the valve member to the open position side. The fuel injection port is opened while a drive current is applied to the solenoid, and fuel is injected into the intake pipe of the internal combustion engine.

  4 is a fuel tank that stores fuel to be supplied to the engine, 5 is an electric fuel pump that supplies the fuel in the fuel tank 4 to the injector 3, and 6 is a pressure regulator connected to a pipe connected to the fuel supply port of the injector 3. It is a vessel. The pressure regulator 6 is adjusted so as to keep the fuel pressure substantially at the set value by returning a part of the fuel supplied from the fuel pump 5 to the fuel tank 4 when the fuel pressure applied to the injector 3 exceeds the set value. To do.

  Thus, since the fuel pressure applied to the injector 3 is kept substantially constant, the amount of fuel injected from the injector 3 (fuel injection amount) is the time during which the injection port of the injector 3 is open (valve opening time). It depends on. The valve opening time of the injector 3 is almost determined by the time during which the drive current is applied to the injector. Therefore, when controlling the fuel injection amount, the fuel injection amount required by the engine is calculated according to various control conditions, the injection time required to obtain the injection amount is obtained, and the predetermined injection timing is determined. During the injection time calculated when detected, a drive current is applied to the injector to cause fuel injection.

  Reference numeral 7 denotes a magnet generator driven by an engine crankshaft 1c. The illustrated magnet generator includes a magnet rotor 7a attached to the crankshaft 1c and a stator 7b fixed to an engine case or the like. ing. The illustrated magnet rotor 7a is a well-known flywheel magnet rotor including a cup-shaped flywheel 7c attached to the crankshaft 1c and a plurality of permanent magnets 7d attached to the inner periphery of the flywheel. It has become. In the illustrated example, six permanent magnets 7d are attached to the inner periphery of the flywheel, and these permanent magnets are magnetized to 12 poles.

  The stator 7b includes a multipolar star-shaped iron core in which a large number of teeth are radially formed and a large number of power generation coils wound around the numerous teeth of the iron core. The magnetic pole part at the tip of each tooth part of the multipolar star-shaped core to be configured is opposed to the magnetic pole part of the magnet rotor 7a via a predetermined gap.

  8 is an ECU that controls the fuel injection amount from the injector and the ignition timing of the engine, and 9 is a battery that is charged through the regulator 10 by the output voltage Vb of the battery charging generator coil provided in the stator of the magnet generator 7. The output voltage of the battery 9 is applied to the power supply terminal of the electric fuel pump 5 and the power supply terminal of the ECU 8. A power supply circuit for adjusting the battery voltage to a constant voltage suitable for driving the microcomputer is provided in the ECU 8, and the power supply voltage is applied from the power supply circuit to the power supply terminal of the microcomputer.

  The ECU 8 receives outputs from various sensors that detect a control condition for controlling the amount of fuel injected from the injector 3 and a control condition for controlling the ignition timing of the engine. In the illustrated example, a pressure sensor 12 that detects the pressure in the intake pipe 1k as an intake pipe pressure, an intake temperature sensor 13 that detects the intake temperature of the engine, a water temperature sensor 14 that detects the temperature of cooling water in the engine, An atmospheric pressure detecting means 15 for detecting the atmospheric pressure and a throttle sensor 16 for detecting the opening degree of the throttle valve 1m are provided, and outputs of these sensors are inputted to an A / D input port of the ECU 8.

  Further, a pulser 17 that generates a pulse at a specific rotational angle position of the crankshaft is provided, and the output of this pulser is input to the ECU 8. The pulsar 17 generates a pulse by detecting the edge of the reluctator 7e formed of a protrusion or a recess formed on the outer periphery of the flywheel 7c. The permanent magnet is magnetically coupled to the iron core and a signal coil wound around the iron core.

  The pulser 17 generates a pair of pulses having different polarities when detecting the front end edge of the reluctator 7e in the rotation direction and detecting the rear end edge of the reluctator 7e in the rotation direction. The pulsar 17 constitutes a reference signal generator, and one of a pair of pulses generated by the pulsar is used as a reference signal. Here, it is assumed that a negative pulse Vp1 and a positive pulse Vp2 are generated when the pulser 17 detects the front edge and the rear edge of the reluctator 7e, respectively. Either of these pulses Vp1 and Vp2 may be used as a reference signal, but here, a negative-polarity pulse Vp1 generated earlier is used as a reference signal, and the generation position of the pulse Vp1 (pulse Vp1 is used as a threshold value). (Position to reach) is set as a reference rotation angle position.

  When the ECU 8 recognizes that the reference signal Vp1 has been generated, the ECU 8 detects that the rotation angle position of the crankshaft of the engine matches the reference rotation angle position. Since the illustrated internal combustion engine is a four-cycle engine, the reference signal Vp1 is generated twice per combustion cycle.

  In the ECU 8, an injector driving circuit and a primary current control circuit for controlling the primary current of the ignition coil IG are provided. The injector 3 and the ignition are respectively connected to the output terminal of the injector driving circuit and the output terminal of the primary current control circuit. A primary coil of the coil IG is connected.

  The ECU 8 causes the microcomputer to execute a predetermined program, thereby constituting various function realizing means necessary for controlling the primary current of the injector 3 and the ignition coil IG, the pressure sensor 12, the intake air temperature sensor 13, Together with the water temperature sensor 14, the atmospheric pressure detection means 15, the throttle sensor 16, and the pulser 17, various function realizing means constituting the fuel injection control device are configured.

  FIG. 2 is a block diagram showing the configuration of the main part of the hardware of the system shown in FIG. 1 and the configuration of various function realizing means configured by a microcomputer in the ECU 8 and a program executed by the microcomputer. It is shown.

  2, parts that are the same as the parts shown in FIG. 1 are given the same reference numerals as those shown in FIG. A portion not shown in FIG. 1 will be described. 801 is an injector drive circuit provided as a hardware circuit in the ECU 8, and a power supply voltage Vcc is applied to a power supply terminal of the injector drive circuit from a power supply circuit (not shown). Yes. The injector drive circuit 801 includes a switch element capable of on / off control interposed between the power supply terminal and the solenoid of the injector, and the injector is turned on while the injection pulse Vj is applied. The power supply voltage Vcc is applied to the solenoid 3 as a drive voltage. As a result, a drive current flows through the solenoid of the injector 3, and when the drive current reaches a predetermined level, the injector valve is opened and fuel injection is started. The drive current is switched to a low value (hold current) necessary to keep the valve open after the injector valve is open.

  Although not shown, the ECU 8 is provided with a primary current control circuit for controlling the primary current of the ignition coil IG, and the primary current control circuit and the ignition coil IG constitute an ignition circuit. In FIG. 2, each function realization means constituting the parts excluding various sensors and other hardware and the primary current control circuit and the injector drive circuit 801 is configured by causing a microcomputer to execute a predetermined program. .

  Explaining the function realization means constituted by a microcomputer, reference numeral 802 denotes a rotational speed detection means for detecting the rotational speed of the engine. The interrupt pulse executed when the pulser 17 generates the pulse Vp1 generates the previous pulse Vp1. The time Tm from when the current pulse Vp1 is generated (the time required for one rotation of the crankshaft) is taken from the timer, and the engine speed is calculated from this time Tm.

  Reference numeral 803 denotes an injection start timing detecting means for detecting timing for starting fuel injection. This means calculates the time required for the crankshaft to rotate in the section from the position where the pulser 17 generates the reference signal Vp1 to the crank angle position where fuel injection is started, as injection start timing timing data, When the reference signal Vp1 is generated, the injection start timing timing data calculated in the timer in the microcomputer is set to start the measurement, and the timing when the timer completes the measurement of the injection start timing timing data is started. Detect as timing.

  Reference numeral 804 denotes an invalid injection time detection unit that detects a time from when a drive voltage is applied to the injector 3 to when the valve of the injector is opened as an invalid injection time. Since the invalid injection time is determined by the magnitude of the drive voltage applied to the injector, the invalid injection time detection unit 806 used in the present embodiment performs map calculation of the invalid injection time of the injector from the power supply voltage applied to the injector 801. It is configured to detect an invalid injection time.

  Reference numeral 805 denotes reference injection time calculation means for calculating the fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as the reference injection time. This means first uses the map created by experiment etc., and the intake air when the atmospheric pressure is equal to the standard atmospheric pressure and the intake air temperature is equal to a certain value (constant value) from the rotational speed and the intake pipe pressure. The intake air amount in the actual state is calculated by calculating the amount and converting the intake air amount into the intake air amount at the actual atmospheric pressure and intake air temperature. A basic injection amount Qp [cc] is calculated from the intake air amount and the target air-fuel ratio. Then, the basic injection amount Qp is added to the post-startup increase correction coefficient, the warm-up increase correction coefficient, the acceleration / deceleration correction coefficient, etc. obtained based on various control conditions such as the elapsed time from the start, the coolant temperature, and the throttle opening. By multiplying these various correction coefficients, the injection amount corresponding to the state of the engine is calculated as the reference injection amount QA. Thereafter, this reference injection amount QA, and an injector constant kinj (injection amount / valve opening time), which is a conversion constant between the injection amount and the valve opening time when fuel is injected into the atmosphere at a constant fuel pressure with respect to atmospheric pressure, From this, the reference injection time TA (= QA / kinj) when the pressure in the intake pipe at the time of injection is equal to the atmospheric pressure is obtained.

  The method for obtaining the reference injection time TA is not limited to the above example. First, the basic injection time Tp is obtained from the basic injection amount Qp and the constants of the injector, and various correction coefficients are set for the basic injection time Tp. The reference injection time TA may be calculated by multiplication.

  The reference injection time TA is given to the temporary injection time calculation means 806. The provisional injection time calculation means 806 detects the current atmospheric pressure value (current atmospheric pressure detected by the atmospheric pressure detection means 15) and the pressure sensor 12 when the injection start timing is detected by the injection start timing detection means 803. The temporary injection time Ty is obtained by correcting the reference injection time TA with respect to the difference from the intake pipe pressure at the start timing of injection, and the time obtained by adding the invalid injection time To to the temporary injection time Ty1 is provisionally driven. Calculation is performed as time Tj1 (= Ty1 + To). This provisional driving time Tj1 is given to the injection timer setting means 808. The injection timer setting means 808 sets the provisional driving time calculated by the provisional driving time calculating means 807 in the injection timer 809, and causes the injection timer to start measuring the provisional driving time. The injection pulse generation means 810 generates the injection pulse Vj during the time measuring operation for measuring the driving time when the injection timer 809 is set. This injection pulse is given to the injector drive circuit 3, and a drive voltage is given from the injector drive circuit 3 to the injector 3 while the injection pulse Vj is generated.

  In the present invention, the injection time calculated by correcting the reference injection time TA at the injection start timing is corrected as needed along with the change in the intake pipe pressure during the injection operation. Therefore, the injection time calculated at the injection start timing is called “temporary injection time” in the sense that it is a temporary injection time that may be corrected later. In the same sense, the drive time at which the injection timer starts measuring at the injection start timing is referred to as “provisional drive time”.

  When correcting the reference injection time TA, the difference between the current value of the atmospheric pressure and the intake pipe pressure at the injection start timing detected by the pressure sensor 12 (current atmospheric pressure−intake pipe pressure) is used as the pressure difference ΔP. Asking. After obtaining the pressure difference ΔP, the correction coefficient when the pressure in the intake pipe is atmospheric pressure (when the pressure difference is 0) is defined as a first correction coefficient kx, and between the intake pipe pressure and atmospheric pressure. The correction coefficient when there is a pressure difference ΔP is set as the second correction coefficient ky, and the actual injection time is calculated by performing the calculation for correcting the reference correction time TA using these correction coefficients. An arithmetic expression used in the correction calculation is obtained as follows.

It is known that when the difference between the fuel pressure applied to the injector and the external pressure (pressure difference) is ΔP, the injection amount Q from the injector is proportional to (ΔP) ^1/2 and the injection time t. That is, the injection amount Q is given by the following equation.
Q = C · (ΔP) ^1/2 · t (1)
Here, when the injection times for injecting the same amount of fuel with different pressure differences ΔP1 and ΔP2 are t1 and t2, respectively,
C · (ΔP1) ^1/2 · t1 = C · (ΔP2) ^1/2 · t2 (2)
From equation (2)
t2 = t1 (ΔP1) ^1/2 / (ΔP2) ^1/2 (3)
It becomes. That is, when the injection time t1 is obtained for the pressure difference ΔP1, the injection time t2 for the newly obtained pressure difference P2 can be obtained from the equation (3).

In the present invention, when the injection amount Q [cc] is converted into the injection time, the fuel of the constant pressure (control pressure) Pf adjusted by the pressure regulator is reduced below the reference pressure (= atmospheric pressure) Pa of the pressure regulator. Is determined as a reference injection time TA. The control pressure Pf of the pressure regulator is Pf + a when the fuel pressure applied to the injector is Pf + a.
Pf = Pf + a-Pa (4)
It is given by and shows a substantially constant value.
At this time, the reference injection time TA is
TA = Q · {1 / C · (Pf) ^1/2 } (5)
Given in. Here, when the injector constant is kinj = C · (Pf) ^1/2 , the reference injection time TA is
TA = Q / kinj (6)
Given in.

When the injection time (reference injection time) TA when the pressure difference is 0 is obtained, the injection time Ty when the pressure difference is ΔP is t1 = TA, ΔP1 = Pf, As ΔP2 = Pf + ΔP and t2 = Ty,
Ty = TA · {C (Pf) ^1/2 } / C (Pf + ΔP) ^1/2 (7)
Is required. Substituting equation (5) into TA in equation (7)
Ty = Q · {1 / C (Pf + ΔP) ^1/2 } (8)
In the equation (7),
C · (Pf) ^1/2 = kx (9)
C · (Pf + ΔP) ^1/2 = ky (10)
far. In the present invention, the above kx and ky are referred to as a first correction coefficient and a second correction coefficient, respectively. Using these correction coefficients and the reference injection time TA, the injection time Ty when the pressure difference between the atmospheric pressure and the intake pipe pressure is ΔP2 is calculated by the following equation.
Ty = TA × (kx / ky) (11)

  The first correction coefficient kx is a correction coefficient when there is no difference between the intake pipe pressure and the atmospheric pressure (when the intake pipe pressure is equal to the atmospheric pressure), and the second correction coefficient ky is the intake pipe pressure. Is a correction coefficient when there is a pressure difference ΔP1 between the atmospheric pressure and the atmospheric pressure. There is a relationship like the curve shown in FIG. 13 between the second correction coefficient ky and the pressure difference ΔP.

  Since the control pressure Pf is constant, the first correction coefficient kx may be stored as a constant. The second correction coefficient ky may be calculated by the equation (10). However, in order to perform the calculation quickly, the relationship of the ΔP-ky curve shown in FIG. 13 is stored in the form of a table (map). In this case, it is preferable to obtain ky by searching the table for ΔP and performing an interpolation operation.

  In the present invention, at the start of fuel injection, a second correction coefficient ky is obtained for the detected pressure difference ΔP1 between the intake pipe pressure and the atmospheric pressure, and this correction coefficient ky is stored as a first constant. From the correction coefficient kx and the reference injection time TA, the injection time Ty is calculated by the equation (11), and this injection time Ty is set as the temporary injection time.

  In this example, when the injection start timing is detected by the temporary injection time calculation means 806, the temporary drive time calculation means 807, the injection timer setting means 808, and the injection timer 809, the atmospheric pressure and the intake pipe pressure The injection timer is set to cause the injection timer to measure the provisional drive time as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. The injection start time processing means 811 is configured to start the timing operation of the injection timer.

  In the present invention, after the injection operation is started, the intake pipe pressure is monitored, and when it is detected that the pressure difference between the current value of the atmospheric pressure and the intake pipe pressure has increased, the drive time of the injector is extended. Correct as follows. Therefore, in the example shown in FIG. 2, intake pipe pressure sampling means 812, intake pipe pressure change determining means 813, and injection operation correction processing means 814 are provided.

  The intake pipe pressure sampling means 812 shown in FIG. 2 is means for sampling the intake pipe pressure Py at a constant minute time interval (1 msec interval in this embodiment) when the injection pulse Vj is generated. This means includes, for example, means for reading the output of the pressure sensor 12 every time a clock pulse is generated while the injection pulse Vj is being generated. The sampling of the intake pipe pressure is also performed when the injection start timing is detected.

  The intake pipe pressure change determining means 813 is a means for determining at any time whether or not a change in the intake pipe pressure requiring correction of the injection time (extension of the corrected injection time) has occurred, and is newly added by the intake pipe pressure sampling means 812. Whether a change in intake pipe pressure that requires correction of the injection time has occurred by determining whether the sampled intake pipe pressure has risen above the set value with respect to the previously sampled intake pipe pressure Determine whether.

  The injection operation correction processing means 814 monitors the change in the intake pipe pressure during the injection operation, and corrects the effective injection time during the injection operation to be extended when the change in the intake pipe pressure is shown. It is an injection operation time correction processing means. This injection operation correction processing means can take various configurations, but in this embodiment, if the newly sampled intake pipe internal pressure shows a rise above the set value with respect to the previously sampled intake pipe internal pressure, The time that the injection timer has already measured to correct the drive time of the injector with respect to the pressure difference between the atmospheric pressure and the newly sampled intake pipe pressure, as determined by the in-pipe pressure change determination means 813 The corrected injection time to be added to is calculated, and this corrected injection time is reset in the injection timer.

  For example, as shown in FIG. 4, the injection operation correction processing means 814 that performs the function as described above increases the newly sampled intake pipe pressure more than a preset value with respect to the previously sampled intake pipe pressure. Is determined by the intake pipe pressure change determining means 813, the injection timer has already measured the pressure difference between the atmospheric pressure and the newly sampled intake pipe pressure to correct the injector drive time. Corrected injection time calculating means 814A for calculating a corrected injection time to be added to the time being set, and resetting the corrected injection time to the injection timer so as to extend the time already measured by the injection timer 809 by the corrected injection time And injection timer resetting means 814B.

  FIG. 14 shows how the drive time of the injector is corrected after the injection operation is started and the timing for performing the correction calculation. When the intake pipe pressure Py changes as indicated by a curve a shown by a solid line in FIG. 14A (when the throttle opening does not change), the temporary drive time of the injector calculated at the injection start timing is Tj. Suppose that at the injection start timing tj1, the provisional drive time Tj is set in the injection timer 808 and the measurement is started. When the throttle opening does not change and the intake pipe pressure Py changes along the curve a (the intake pipe pressure newly sampled during the injection operation rises above the set value with respect to the previously sampled intake pipe pressure In the case where the injection time is not indicated, the drive time is not corrected, and the injection pulse Vj is extinguished when the injection timer 808 completes the measurement of the drive time Tj at the injection end timing tj2.

  On the other hand, when it is detected that the intake pipe pressure Py has increased (the throttle opening has increased) at the time tx after the start of the injection operation, as indicated by a curved line b shown in FIG. The injection amount is increased by correcting the drive time as Tj ′ and delaying the injection end timing to tj3.

  Ts shown in FIG. 14C is a period in which the intake pipe pressure is sampled and the injector drive time correction calculation can be performed when the intake pipe pressure Py changes as shown by the curve a in FIG. (Period in which the invalid injection time is removed from the period in which the drive voltage is applied to the injector), and Ts ′ in the figure is when the intake pipe pressure Py changes as shown by the curve b in FIG. The period during which the intake pipe pressure is sampled to correct the injector drive time is shown. A series of pulses shown in FIG. 14C shows clock pulses generated at intervals of 1 msec, and the intake pipe pressure is sampled when each clock pulse is generated in a state where the injection pulse Vj is generated. .

Here, with reference to FIG. 15, the calculation operation of the injector drive time and the correction operation of the effective injection time performed by the fuel injection control device according to the present invention will be described in order.
FIG. 15A shows the change in the intake pipe pressure Py, and FIG. 15B shows the injection pulse Vj. (C) and (D) show the injection start timing t1 and the injection end timing t4, respectively, and (E) shows the sample timing of the intake pipe pressure that arrives at 1 msec intervals. In the present embodiment, the effective injection time is corrected using the intake pipe pressure sampled at timings t2, t3 and t4 that arrive while the injection pulse is generated in the series of sample timings of FIG. Do. In FIG. 15, Py1 to Py4 indicate intake pipe pressures sampled at timings t1 to t4, respectively, and Ty1 indicates a provisional injection time calculated at injection start timing t1. Ty2 and Ty3 indicate the corrected injection time calculated using the correction coefficient obtained from the intake pipe pressure and the atmospheric pressure sampled at the sample timings t2 and t3, respectively, T1 is the time between timings t1 and t2, and Ts is Sample interval is shown.

  In the control device according to the present invention, the injection start process is performed when the injection start timing t1 is detected, and when the sample timing t2 arrives after the start of the injection operation and when the sample timing t3 arrives, Perform correction processing. In the example shown in the drawing, since the intake pipe pressure Py4 newly sampled at the sample timing did not increase more than the set value with respect to the previously sampled intake pipe pressure Py3, the injection time is corrected at the sample timing t4. Instead, the injection pulse is extinguished when the injection timer finishes measuring the timing data set at the sample timing t3 at timing t5. Hereinafter, these processes will be described in order.

Processing at Injection Start Timing t1 When the injection start timing t1 is detected, the intake pipe pressure Py1 is first sampled, and the second correction coefficient ky1 is calculated using the difference ΔP1 between the newly sampled intake pipe pressure P1 and the atmospheric pressure. Calculate. Then, the second correction coefficient, the first correction coefficient kx that is a correction coefficient when the intake pipe pressure is equal to the atmospheric pressure, and the pressure difference ΔP1 between the newly sampled intake pipe pressure P1 and the atmospheric pressure are obtained. And the provisional injection time Ty1 = TA (kx / ky1) by performing the calculation of the equation (11) for correcting the reference injection time TA, which is the injection time when the intake pipe pressure is equal to the atmospheric pressure, with respect to the pressure difference ΔP1. ) The temporary drive time Tj1 is calculated by adding the invalid injection time To to the temporary injection time Ty1. The provisional drive time Tj1 is set in the injection timer to start the measurement, and the injection pulse Vj is generated while the injection timer performs the time measuring operation. After the injection pulse Vj is generated, the intake pipe pressure is sampled at the sample timings t2 and t3, and the intake pipe pressure is set as necessary with respect to the previously sampled intake pipe pressure each time the intake pipe pressure is sampled. When the increase is greater than the value), the injection time is corrected.

Processing at Sample Timings t2 and t3 At the sample timing tn (in this example, n = 2 or 3) after the injection operation is started, the intake pipe pressure Pn and the atmospheric pressure newly sampled at each sample timing are used. Thus, the pressure difference ΔP is obtained, and the correction coefficient kyn is obtained from this pressure difference. Then, this correction coefficient kyn, the correction coefficient kyn-1 obtained for the difference between the intake pipe pressure and the atmospheric pressure at the previous sample timing, the injection time Tyn-1 calculated at the previous sample timing, The corrected injection time Tyn is calculated using the time Tn from the time when the injection timer is set to the current time and the constant α, and the injection time already measured by the injection timer is further extended by this corrected injection time Tyn. In this manner, the corrected injection time Tyn is reset in the injection timer 809 and the time counting operation is continued.

FIGS. 16A and 16B are diagrams for explaining how to calculate the temporary injection time and the corrected injection time. FIG. 16A shows the intake pipe pressure Py, and FIG. 16B shows the injection pulse Vj. FIG. 16C shows a pulse Vs that gives the sample timing of the intake pipe pressure.
In FIG. 16, To represents the invalid injection time of the injector, and Ts represents the sample interval of the intake pipe pressure. Further, t1 indicates the injection start timing, and t2 and t3 indicate the first sample timing after the start of injection and the second sample timing after the start of injection, respectively. Further, Py1 to Py3 indicate intake pipe pressures sampled at times t1 to t3, respectively, and Ty1 indicates a temporary injection time calculated at time t1. Ty2 and Ty3 indicate corrected injection times calculated at times t2 and t3, respectively. Furthermore, T1 indicates the time that has elapsed between the timing at which the intake pipe pressure was sampled last time and the current sampling timing.

At the injection start timing t1, the provisional injection time Ty1 = (kx / ky1) · TA is obtained using the equation (11). At time t2, the injection time is corrected for the increase in the intake pipe pressure at that time. In this correction calculation, first, how the injection time after time t2 is to be corrected is determined based on the change in the intake pipe pressure from Py1 to Py2.
Of the injection time Ty1 calculated for the intake pipe pressure Py1 at time t1, the remaining injection time remaining after time t2 is Ty1- (T1-To). The remaining injection time Ty1−T1 obtained for the intake pipe pressure Ty1 is calculated as the corrected remaining injection time by the following equation to determine the length of the newly sampled intake pipe pressure Py2. .
Corrected remaining injection time = (ky1 / ky2) · {Ty1− (T1−To)} (12)

Next, the injection time T1-To that has already passed is corrected for the increase in the intake pipe pressure. The injection time T1-To when the intake pipe pressure is Py1 is (ky1 / ky2) · (T1-To) if the intake pipe pressure is Py2. However, since the intake pipe pressure from time t1 to t2 is not constant, the average of T1-To and (ky1 / ky2) (T1-To) is necessary when the intake pipe pressure is Py2. The injection time is {(T1-To) + (ky1 / ky2) (T1-To)} / 2. Since the time T1-To has already elapsed from the injection start timing, the shortage of the injection time is obtained as shown in the following equation.
Insufficient injection time = [{(T1−To) + (ky1 / ky2) (T1−To)} / 2] − (T1−To)
= (T1-To) · {(ky1 / ky2) -1} / 2 (13)

  In addition, originally, the intake pipe pressure Py1 ′ at the time when the effective injection is started should be used instead of Py1, but it is troublesome to sample the intake pipe pressure when the invalid injection time has elapsed. Therefore, for the sake of simplicity, the intake pipe pressure Py1 at the start of injection is used.

The corrected injection time Ty2, which is the injection time after the first sample timing t2 after the start of injection, is obtained by adding the corrected remaining injection time according to the equation (12) and the insufficient injection time according to the equation (13) by the following equation. .
Ty2 = (ky1 / ky2). {Ty1- (T1-To) + (T1-To). {(Ky1 / ky2) -1} / 2 (14)
At the first sample timing t2 after the start of injection, the corrected injection time Ty2 obtained by the equation (14) is set in the injection timer and the measurement is performed. As a result, the effective injection time is corrected from Ty1 to (T1−To) + Ty2.

The corrected injection time Tyn at the second and subsequent sample timings tn after the start of injection (n ≧ 3, only n = 3 in the example shown in FIG. 16) is the sample timing tn−1 immediately before each sample timing tn (FIG. In the example of 16, the elapsed time up to t2) is Tn, the second correction coefficient calculated for the intake pipe pressure sampled at each sample timing is kyn, and the intake pipe sampled at the previous sample timing When the second correction coefficient calculated for the pressure is kyn-1, it is given by the following equation.
Tyn = (kyn−1 / kyn) (Tyn−1−Tn) + Tn · {(kyn−1 / kyn) −1} / 2 (15) In equation (15), Tn is shown in FIG. Equal to the sampling interval Ts (1 msec in this embodiment).

At the sample timing t3, the correction coefficient ky3 calculated for the pressure difference ΔP3 obtained from the intake pipe pressure Py3 newly sampled at this timing and the atmospheric pressure, and the intake pipe pressure Py2 sampled at the previous sample timing t2 Using the correction coefficient ky2 obtained for the pressure difference ΔP2 from the atmospheric pressure, the injection time Ty2 calculated at the previous sample timing, and the time T3 from the time when the previous injection timer was set to the current time, The corrected injection time Ty3 is obtained by the following equation.
Ty3 = (Ty2−T3) (ky2 / ky3) + T3 · {(ky2 / ky3) −1} / 2 (16)

  The time measurement data to be measured by the injection timer is reset so that the corrected injection time Ty3 is added to the injection time, and the time measurement operation of the injection timer is continued. At this time, the effective injection time is corrected to (T2−To) + T3 + Ty3.

In the present embodiment, since the intake pipe pressure Py4 sampled at the sample timing t4 did not increase more than the set value with respect to the previously sampled intake pipe pressure Py3, the injection time is not corrected at the sample timing t4. The injection pulse is extinguished when the measurement of the timing data Ty3 in which the injection timer is set is completed at timing t5.
In this example, the timing t5 at which the measurement of the timing data for which the injection timing has been set ends is the injection end timing.

Second Embodiment In the above embodiment, when the newly sampled intake pipe pressure does not show an increase over the set value with respect to the previously sampled intake pipe pressure, the correction of the injection time is stopped, The injection operation is ended when the injection timer ends the time measuring operation. In the second embodiment of the present invention, the injection operation time correction processing means 814 is newly sampled by the intake pipe pressure sampling means. When the intake pipe pressure shows a rise above the set value with respect to the previously sampled intake pipe pressure, the injector drive time is set to the pressure difference between the atmospheric pressure and the newly sampled intake pipe pressure. The correction injection time added to the time already measured by the injection timer 809 for correction is calculated, and the newly calculated correction injection time is calculated last time. When the calculated provisional injection time or the corrected injection time is longer than the set value, the injection timer is reset so that the time to be measured by the injection timer is extended by the corrected injection time.

  FIG. 5 shows the configuration of the main part of the second embodiment of the present invention. In this embodiment, the corrected injection time newly calculated by the corrected injection time calculation means 814A is the provisional calculation previously calculated. A correction injection time determination unit 814C that determines whether or not the injection time or the correction injection time is longer than a set value is provided in the correction processing unit 814 during the injection operation. In this embodiment, the injection is performed only when it is determined by the corrected injection time determining means 814C that the newly calculated corrected injection time is longer than the preset calculated temporary injection time or the corrected injection time by a set value or more. The correction injection time is set in the injection timer 809 by the timer setting means 814B so that the injection time is corrected. The other points are the same as in the first embodiment.

Third Embodiment FIG. 6 shows the configuration of the main part of the third embodiment of the present invention. In this embodiment, the intake pipe pressure change determining means 813 is omitted, and an injection pulse is generated. When the intake pipe pressure is sampled by the intake pipe pressure sampling means 812, the corrected injection time is always calculated, and the newly calculated corrected injection time is set to a value that is greater than the previously calculated provisional injection time or corrected injection time. When it is determined that the time is longer, the injection time is corrected. When it is determined that the newly calculated corrected injection time is not longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the corrected injection time is not calculated and the injection timer is reset. Since it is not performed, the injection pulse disappears when the measurement of the injection time for which the injection timer is set is completed.

  That is, in this embodiment, the injection timer 809 has already measured the time to correct the injector driving time with respect to the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means 812 and the atmospheric pressure. The corrected injection time to be added is calculated, and when it is determined that the newly calculated corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the corrected injection time is set in the injection timer. By performing the resetting, the injection operation correction processing means 814 is configured to extend the time measured by the injection timer by the corrected injection time.

Fourth Embodiment In each of the above-described embodiments, the fuel injection operation is terminated by extinguishing the injection pulse when the time measurement of the time measurement data in which the injection timer 808 is set is completed. As shown in FIG. In addition, an end-of-injection processing means 815 is provided for performing processing for extinguishing the injection pulse when a predetermined condition is satisfied, and the injection end-time processing means 815 performs injection when the condition for ending the fuel injection is satisfied. The injection operation may be stopped by resetting the timer.

  FIG. 7 shows a fourth embodiment of the present invention in which an injection end time processing means 815 is provided so that an injection pulse is extinguished by resetting an injection timer 809 when a condition for ending fuel injection is satisfied. The structure of the principal part is shown. The intake pipe pressure sampling means 812 and the intake pipe pressure change determining means 813 shown in FIG. 7 are the same as those shown in FIG. 4, and the intake pipe pressure sampling means 812 is used when the injection pulse is generated. Intake pipe pressure is sampled at regular sample intervals. Further, the intake pipe pressure change determining means 813 determines whether or not the newly sampled intake pipe internal pressure shows an increase of a set value or more with respect to the previously sampled intake pipe internal pressure.

  In this example, the injection end time processing means 815 is constituted by an injection timer resetting means 815A. The injection timer resetting means 815A detects when the intake pipe pressure change determining means 813 determines that the newly sampled intake pipe pressure did not increase more than the set value with respect to the previously sampled intake pipe pressure, and newly The injection timer 809 is reset when it is determined by the corrected injection time determination means 814C that the corrected injection time calculated in (i) is not longer than the set value or the provisional injection time or corrected injection time calculated last time. The injection timer reset means 815A is configured to extinguish the injection pulse (forcibly completing the counting operation of the injection timer).

  That is, in the embodiment shown in FIG. 7, the injection timer has already measured to correct the drive time of the injector with respect to the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means 812 and the atmospheric pressure. The corrected injection time to be added to the calculated time is calculated, and when it is determined that the newly calculated corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the corrected injection time is set. The injection operation correction processing means 814 is configured to extend the time that the injection timer measures by the correction injection time by resetting to the injection timer.

  Further, when the intake pipe pressure newly sampled by the intake pipe pressure sampling means 812 does not show an increase over the preset value with respect to the previously sampled intake pipe pressure, or when the newly calculated corrected injection time is the previous time The injection end time processing means 815 is configured to extinguish the injection pulse when it is not longer than the calculated provisional injection time or the corrected injection time by a set value or more.

  As described above, when it is determined by the intake pipe pressure change determining means 813 that the newly sampled intake pipe pressure did not show an increase over the set value with respect to the previously sampled intake pipe pressure, and the corrected injection time When the determination unit 814C determines that the newly calculated corrected injection time is not longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the injection pulse is extinguished. When the fuel injection operation is stopped, the fuel injection amount may be excessive because the throttle valve is closed immediately after the injection time is corrected (extended) because the throttle valve is once opened. In such a case, the fuel injection can be stopped immediately, so that the air-fuel ratio becomes rich and the engine output decreases or does not move. It can be prevented from becoming unstable.

Fifth Embodiment FIG. 8 shows a main part of a fifth embodiment of the present invention. In this example, the intake pipe pressure change determining means 812 provided in the embodiment of FIG. 7 is omitted, and the corrected injection time newly calculated by the corrected injection time calculating means 814A is the previously calculated provisional injection time or When the determination that the correction injection time is not longer than the set value is made by the correction injection time determination means 814C, the injection timer 809 is reset to extinguish the injection pulse.

Sixth Embodiment In each of the above embodiments, the intake pipe pressure sampling means 812 is configured to sample the intake pipe pressure at regular time intervals when an injection pulse is generated. In this embodiment, the intake pipe internal pressure sampling means is configured to sample the intake pipe internal pressure every time the measurement of the timing data in which the injection timer is set is completed.

  FIG. 9 shows the configuration of the main part of the sixth embodiment of the present invention. In this embodiment, the intake pipe pressure is sampled when the measurement of the time measurement data set by the injection timer 809 is completed. The intake pipe internal pressure sampling means 812 'is configured. Other configurations are the same as those of the embodiment shown in FIG.

  In the embodiment shown in FIG. 9, the intake pipe pressure is sampled when the measurement of the time measurement data (provisional injection time or corrected injection time) in which the injection timer 809 is set is completed. Then, when the intake pipe pressure change determining means 813 determines that the newly sampled intake pipe pressure shows an increase over a preset value with respect to the previously sampled intake pipe pressure, the corrected injection time calculating means By 814A, the corrected injection time is calculated for the pressure difference between the atmospheric pressure and the newly sampled intake pipe pressure. When the corrected injection time determination unit 814C determines that the newly calculated corrected injection time is longer than the previously calculated provisional injection time or the corrected injection time by a set value or more, the injection timer setting unit 814B performs the injection. The corrected injection time calculated this time is set in the timer 809, and the measurement is started. The injection timer 809 generates an injection pulse while measuring the set correction injection time.

  FIG. 17 shows an example of the intake pipe pressure sampling operation and the injection time correction operation in this embodiment. In the example shown in FIG. 17, the provisional drive time Tj1 is set in the injection timer at time t1 to generate the injection pulse Vj, and the intake pipe pressure is sampled when the injection timer completes the time measuring operation at time t2. ing. In the example shown in the drawing, the intake pipe pressure determining means 813 determines that the intake pipe pressure sampled at time t2 has risen above the set value with respect to the previously sampled intake pipe pressure (at time t1). The corrected injection time Ty1 is calculated by the injection time calculation means 814A. Since it is determined by the corrected injection time determining means 814C that the newly calculated corrected injection time Ty1 is longer than the set value by the previously calculated provisional injection time, the injection timer resetting means 814B performs the injection timer 809. Then, the correction injection time Ty1 is set to start measurement of the correction injection time, and the injection pulse Vj is continued.

  When the measurement of the corrected injection time Ty1 in which the injection timer is set is completed at time t3, the intake pipe pressure sampling means 812 'samples the intake pipe pressure. In the example shown in the figure, since it is determined that the newly sampled intake pipe pressure at this time has increased by more than a set value with respect to the intake pipe pressure sampled at time t2, the corrected injection time calculation means 814A And the corrected injection time Ty2 is calculated for the pressure difference between the newly sampled intake pipe pressure. Since it is determined by the corrected injection time determining means 814C that the newly calculated corrected injection time Ty2 is longer than the set value by the previously calculated corrected injection time Ty1, the injection timer setting means 814B Ty2 is set in the injection timer 809 to start the measurement, and the injection pulse Vj is continued. Since the injection timer has completed the measurement of the corrected injection time Ty2 at time t4, the intake pipe pressure is sampled at time t4. The intake pipe pressure sampled at time t4 does not show an increase over the set value with respect to the previously sampled intake pipe pressure, or shows an increase over the set value with respect to the previously sampled intake pipe pressure. However, since the newly calculated corrected injection time has been determined by the corrected injection time determination means to be longer than the preset calculated temporary injection time or the corrected injection time by the corrected injection time determination means, the injection timer is reset. Means 815A resets the injection timer 809 to stop the injection operation.

  That is, in the embodiment shown in FIG. 9, when the intake pipe pressure newly sampled by the intake pipe pressure sampling means 812 is higher than a preset value with respect to the previously sampled intake pipe pressure, a large amount is obtained. In order to correct the injector drive time for the pressure difference between the atmospheric pressure and the newly sampled intake pipe pressure, the correction injection time added to the time already measured by the injection timer is calculated, and the corrected injection time is injected. The injection operation correction processing means is configured to extend the time to be measured by the injection timer by the correction injection time by resetting the timer.

  In addition, when the intake pipe pressure newly sampled by the intake pipe pressure sampling means does not show an increase over the preset value with respect to the previously sampled intake pipe pressure, or the newly calculated corrected injection time is calculated last time. The injection end time processing means 815 is configured to extinguish the injection pulse when it is not longer than the preset injection time or the corrected injection time by a set value or more.

Seventh Embodiment FIG. 10 shows the configuration of the main part of the seventh embodiment of the present invention. In this embodiment, the intake pipe pressure change determining means 813 is omitted, and the injection timer 809 is set. Each time the intake pipe pressure sampling means 812 'samples the intake pipe pressure after completing the measurement of the injection time, the corrected injection time is calculated for the pressure difference between the newly sampled intake pipe pressure and the atmospheric pressure. . When the corrected injection time determining means determines that the newly calculated corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the injection timer setting means 814B The correction injection time is set in the injection timer 809, the injection pulse is continued, and it is determined that the newly calculated correction injection time is not longer than the set value by the provisional injection time or the correction injection time previously calculated. When this is done, the injection pulse is extinguished without resetting the injection timer 809.

  In the embodiment shown in FIG. 10, the injection timer has already measured the time for correcting the drive time of the injector with respect to the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. The corrected injection time to be added is calculated, and when the newly calculated corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the corrected injection time is reset in the injection timer. Thus, the injection operation correction processing means 814 is configured to extend the time to be measured by the injection timer by the corrected injection time.

Eighth Embodiment FIG. 11 shows the main part of an eighth embodiment of the present invention. In this example, the intake pipe pressure is sampled at regular time intervals when an injection pulse is generated. The first intake pipe pressure sampling means 812a, the second intake pipe pressure sampling means 812b for sampling the intake pipe pressure when the injection timer 809 completes the timing operation, and the first intake pipe pressure sampling means 812a A first intake pipe pressure change determining means 813a for determining whether or not the intake pipe pressure sampled in the period of time indicates an increase over a preset value with respect to the previously sampled intake pipe pressure, and a second intake pipe pressure The intake pipe pressure newly sampled by the sampling means 812a is set with respect to the previously sampled intake pipe pressure. There is provided second intake pipe pressure change determining means 813b for determining whether or not the increase is greater than the value.

  Further, in this embodiment, when it is determined that the intake pipe pressure newly sampled by the first intake pipe pressure sampling means 812a shows an increase over the set value with respect to the previously sampled intake pipe pressure. Correction injection time calculation means 814A for calculating a correction injection time to be added to the time already measured by the injection timer in order to correct the drive time of the injector with respect to the newly sampled pressure difference between the intake pipe pressure and the atmospheric pressure; A newly calculated corrected injection time 814C for determining whether the corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more, and the newly calculated corrected injection time When the injection timer is to be measured when it is determined that it is longer than the preset value by the preliminarily calculated provisional injection time or corrected injection time The corrected injection time only by re-setting the injection timer and injection timer resetting means 814B is provided so as to extend, these by time injection operation correction unit 814B is configured to.

  In the embodiment shown in FIG. 11, the intake pipe pressure newly sampled by the second intake pipe pressure sampling means 812b is higher than the set value with respect to the previously sampled intake pipe pressure. When it is judged by the second intake pipe pressure change judging means 813b, the drive time of the injector is corrected with respect to the pressure difference between the intake pipe pressure newly sampled by the second intake pipe pressure sampling means and the atmospheric pressure. Therefore, the correction injection time calculation means 815B for calculating the correction injection time to be added to the time already measured by the injection timer, and the correction injection time newly calculated by this calculation means, the provisional injection time or the correction injection time previously calculated Correction injection time determination means 815C for determining whether or not the set value is longer than the set value, and newly calculated correction injection An injection timer that resets the injection timer so that the time that the injection timer 809 measures is extended by the corrected injection time when it is determined that the time is longer than the set value by the provisional injection time or the corrected injection time calculated last time If the intake pipe pressure newly sampled by the resetting means 815D and the second intake pipe pressure sampling means 812b does not show a rise higher than the preset value with respect to the previously sampled intake pipe pressure, the second intake pipe internal pressure When it is determined by the pressure change determination means 813b, and when the newly calculated corrected injection time is not longer than the preset calculated temporary injection time or corrected injection time by the set value or more, the second corrected injection time determination means 815C. Injection timer reset that resets the injection timer 809 and eliminates the injection pulse when judged by And the stage 815A is provided, the injection end processing unit 815 is composed of these.

  In each of the above embodiments, the function realizing means such as the intake pipe pressure sampling means 812, the intake pipe pressure change determining means 813, and the injection operation correction processing means 814 causes a microcomputer provided in the ECU to execute a predetermined program. It is constituted by. Hereinafter, the algorithm of the task executed by the microcomputer of the ECU will be described with reference to the flowcharts shown in FIGS. 18 to 22, taking the eighth embodiment shown in FIG. 11 as an example.

  FIG. 18 shows the algorithm of the main routine. In this main routine, after initializing each part, in step 1, the engine speed, the intake pipe pressure, the coolant temperature, the intake air temperature, the throttle opening, etc. On the other hand, the reference injection amount QA when the atmospheric pressure is equal to the reference value (reference pressure) is calculated. In step 2, the reference when the intake pipe pressure is equal to the atmospheric pressure is calculated from the reference injection amount QA and the injector constant kinj. The injection time TA (= QA / kinj) is calculated. Next, in step 3, the output (Pa) of the atmospheric pressure detecting means is read, and in step 4, the crank angle position (injection start position) at which injection is started is calculated. Next, in step 5, the invalid injection time To of the injector is calculated from the power supply voltage of the injector drive circuit. In step 6, other necessary processing such as calculation of ignition timing is performed, and then the process returns to step 1.

  FIG. 19 shows an interrupt process executed when the pulser 17 generates the reference signal (pulse) Vp1. In this interrupt process, first, in step 1, the time from the previous execution time of the interrupt process to the current time ( The time required for one revolution of the crankshaft is calculated, and the engine speed is calculated from this time in step 2. Next, at step 3, the time required for the crankshaft to rotate from the reference position (crank angle position where the reference signal Vp1 is generated) to the injection start position at the current rotation speed is calculated as injection start timing time measurement data. Thereafter, in step 4, the injection start timing timing data is set in the timer to start the measurement, and the process returns to the main routine.

  When the timer completes the measurement of the injection start timing timing data, the injection start timing interruption process of FIG. 20 is executed. In this interruption process, after the intake pipe pressure Py is read in step 1, the pressure difference ΔP is calculated in step 2 by subtracting the intake pipe pressure Py from the atmospheric pressure Pa read in the main routine. Next, in step 3, the second correction coefficient ky is calculated from the pressure difference ΔP and the control pressure Pf of the pressure regulator, and in step 4, the reference injection time TA is corrected with respect to the atmospheric pressure difference and the pressure difference to make provisional injection. An operation Ty = TA × (ky / ky) for obtaining the time Ty is performed. Next, at step 5, the invalid injection time To is added to the provisional injection time Ty to calculate a provisional drive time (time from the injection start timing to the provisional injection end timing) Tj, and this provisional injection time is set in the injection timer. Start the measurement. The injection pulse Vj is generated simultaneously with the start of measurement by the injection timer. Thereafter, in step 6, the flag indicating that the invalid injection time To should be taken into consideration is set to 1, and this interruption process is terminated.

  Each time sample timing arrives at a minute time interval (1 msec interval in this embodiment), the sample timing interrupt processing shown in FIG. 21 is performed. In this interruption process, it is first determined in step 1 whether or not an injection operation is being performed. This determination can be made, for example, by confirming whether or not the injection pulse Vj is generated. As a result, when it is determined that the injection operation is not being performed, the interruption process is immediately terminated and the process returns to the main routine. When it is determined in step 1 that the injection operation is being performed, the routine proceeds to step 2 where the intake pipe pressure Py is read. In step 3, the intake pipe pressure newly read from the atmospheric pressure Pa detected in the main routine is read. An operation of subtracting Py is performed to obtain a pressure difference ΔP. Next, in step 4, a calculation is made to subtract the previously detected intake pipe pressure Py 'from the intake pipe pressure Py read (detected) this time to obtain a change ΔPy in the intake pipe pressure, and this change ΔP is a set value. Is determined (whether the newly sampled intake pipe pressure indicates an increase over the set value with respect to the previously sampled intake pipe pressure). As a result, when the change ΔPy is less than or equal to the set value (when the newly sampled intake pipe pressure does not show an increase above the set value with respect to the previously sampled intake pipe pressure), the process proceeds to step 5. Then, the intake pipe pressure Py detected last time is set to the intake pipe pressure Py detected this time, and this interruption process is terminated.

  When it is determined in step 4 that the change ΔPy in the intake pipe pressure is equal to or less than the set value (the newly sampled intake pipe pressure indicates an increase over the set value with respect to the previously sampled intake pipe pressure) Is determined), the process proceeds to step 6 and the correction coefficient ky calculated for the pressure difference ΔPy when the interruption process was executed last time is set as the correction coefficient ky ′. A new correction coefficient ky is calculated for the new pressure difference ΔP. Next, in step 8, the time Tn from the time when the previous injection timer was set (the time when the injection operation was started or the effective injection time was corrected) to the present time is calculated. Then, in step 9, it is determined whether or not the flag is 1 (whether or not the invalid injection time should be taken into account). If the flag is 1, the process proceeds to step 10 and the invalid injection time To from Tn. Tn is obtained by subtracting. Next, in step 11, whether or not Tn is greater than 0 (whether or not time Tn exists), that is, whether or not the injection operation was performed between the time when the previous injection timer was set and the current time. Determine whether or not. When it is determined in step 9 that the flag is not 1 (ineffective injection time need not be considered), the process proceeds to step 11 without passing through step 10 and the time from the previous injection timer setting to the current time is set. It is determined whether or not an injection operation has been performed in the meantime.

  If it is determined in step 11 that the injection operation has not been performed between the time when the previous injection timer was set and the current time, the routine proceeds to step 5 where the previously detected intake pipe pressure Py is detected this time. The interruption process is terminated as the intake pipe pressure Py. When it is determined in step 11 that the injection operation has been performed between the time when the previous injection timer was set and the current time, the routine proceeds to step 12 where the corrected injection time Ty is calculated by equation (15). . In the flowchart, kyn-1 and kyn in equation (15) are ky 'and ky, respectively, and Tny-1 and Tny are Ty' and Ty, respectively.

  After calculating the corrected injection time Ty in step 12, the difference Ty−Ty ′ between the corrected injection time Ty calculated this time and the corrected injection time Ty ′ calculated at the previous execution of this interrupt process is calculated. Whether or not the absolute value of this difference is greater than or equal to the set value (the newly calculated corrected injection time is the previously calculated corrected injection time (at the first sampling after the start of injection, it is longer than the set value by the provisional injection time) As a result, when it is determined that the absolute value of the difference Ty−Ty ′ is greater than or equal to the set value, the routine proceeds to step 14 where the corrected injection time Ty is reset to the injection timer. In step 15, the flag is set to 0, and this interruption routine is terminated, when it is determined in step 13 that the absolute value of the difference Ty−Ty ′ in the corrected injection time is less than the set value. And the interrupt processing ends as an intake pipe pressure Py detected current intake pipe pressure Py which previously detected the routine proceeds to step 5.

  When the measurement of the time for which the injection timer is set is completed, the injection end interruption process shown in FIG. 22 is performed. In this interruption process, first, the intake pipe pressure Py is read in step 1, and in step 2, the pressure difference ΔP is obtained by subtracting the newly read intake pipe pressure Py from the atmospheric pressure Pa detected in the main routine. . Next, a calculation is performed to subtract the previously detected intake pipe pressure Py ′ from the intake pipe pressure Py read (detected) this time to obtain a change ΔPy in the intake pipe pressure. In step 3, this change ΔPy is set to a set value. It is determined whether or not it exceeds. As a result, when the change ΔPy is less than or equal to the set value, the routine proceeds to step 4 where the injection pulse is extinguished and this interruption process is terminated.

  When it is determined in step 3 that the change ΔPy in the intake pipe pressure is equal to or less than the set value, the process proceeds to step 5 to correct the correction count ky calculated for the pressure difference ΔPy when this interrupt process was executed last time. In step 6, a new correction coefficient ky is calculated for the new pressure difference ΔP calculated in step 2. Next, in step 7, the time Tn from the time when the previous injection timer was set (the time when the injection operation was started or the effective injection time was corrected) to the present time is calculated. Then, in step 8, it is determined whether or not the flag is 1 (whether or not the invalid injection time should be taken into account). If the flag is 1, the process proceeds to step 9 and the invalid injection time To from Tn. Tn is obtained by subtracting. Next, in step 10, whether or not Tn is greater than 0 (whether or not time Tn exists), that is, whether or not the injection operation was performed from the time when the previous injection timer was set to the current time. Determine whether or not. If it is determined in step 8 that the flag is not 1 (ineffective injection time need not be considered), the process proceeds to step 10 without passing through step 9 and from the time when the previous injection timer was set to the current time. It is determined whether or not an injection operation has been performed during the period.

  When it is determined in step 10 that the injection operation has not been performed between the time when the previous injection timer was set and the current time, the routine proceeds to step 4 where the injection pulse is extinguished. If it is determined in step 10 that the injection operation has been performed between the time when the previous injection timer was set and the current time, the routine proceeds to step 11 where the corrected injection time Ty is calculated. Next, a difference Ty−Ty ′ between the corrected injection time Ty calculated this time and the corrected injection time Ty ′ calculated at the previous execution of the interrupt process is calculated, and in step 12, the absolute value of the difference between the corrected injection times is set. It is determined whether or not the value is greater than or equal to. As a result, when it is determined that the absolute value of the difference Ty−Ty ′ in the corrected injection time is greater than or equal to the set value, the process proceeds to step 13 where the corrected injection time Ty is reset in the injection timer and this interrupt process is terminated. When it is determined in step 12 that the absolute value of the corrected injection time difference Ty−Ty ′ is less than the set value, the routine proceeds to step 4 where the injection pulse is extinguished and this interruption process is terminated.

  In the case of the algorithm shown in FIGS. 18 to 22, the rotation speed detecting means 802 is constituted by the interrupt processing steps 1 and 2 in FIG. 19, and the injection start timing detecting means is constituted by the interrupt processing steps 3 and 4 in FIG. 803 is configured. Further, the invalid injection time detecting means 804 is constituted by step 5 of the main routine of FIG. 18, and the reference injection time calculating means 805 is constituted by steps 1 and 2 of the main routine of FIG. Further, the provisional injection time calculating means 806 is configured by steps 2 to 4 of the interrupt processing of FIG. 20, and the provisional driving time calculating means 807, the injection timer setting means 808 and the injection pulse generating means 810 are configured by step 5 of the interrupt processing. The Further, the first intake pipe pressure sampling means 812a is configured by step 2 of the interrupt process in FIG. 21, and the second intake pipe pressure sampling means 812b is configured by step 2 of the interrupt process in FIG. Further, the correction processing means 814 during the injection operation is configured by step 2 and subsequent steps of the interrupt processing in FIG. Further, the first intake pipe pressure change determining means 813a is configured by step 4 in FIG. 21, and the second intake pipe pressure change determining means 813b is configured by step 3 of the interrupt process in FIG. Further, the injection end time processing means 815 is constituted by step 3 and subsequent steps of the interrupt processing of FIG.

  The provisional injection time calculation means 806, the provisional drive time calculation means 807, the injection timer setting means 808, and the injection timer 809 constitute an injection start time processing means 811. This injection start time processing means and rotation speed Detection means 802, injection start timing detection means 803, invalid injection time detection means 804, reference injection time calculation means 805, intake pipe pressure sampling means 812a and 812b, intake pipe pressure change determination means 813a and 813b, The injection operation time correction processing means 814 and the injection end time processing means 815 constitute an injector control unit.

  As described above, after the injector 3 starts the fuel injection operation, the pressure in the intake pipe is monitored, and when an increase exceeding the set value is detected in the monitored intake pipe pressure, it is newly detected. If the injection time is corrected by calculating the corrected injection time with respect to the intake pipe internal pressure and resetting the calculated corrected injection time to the injection timer, the intake pipe internal pressure is set after the injector starts fuel injection. Even if the fuel pressure changes, the fuel injection time can be corrected to an appropriate length to inject an appropriate amount of fuel commensurate with the amount of intake air, and the air-fuel ratio can be kept in an appropriate range. The internal combustion engine can always be operated stably.

It is the block diagram which showed the structural example of the internal combustion engine control apparatus with which the fuel-injection control apparatus concerning this invention is integrated. FIG. 2 is a block diagram showing an example of the configuration of the main parts of the hardware of the system shown in FIG. 1 and the configuration of various function realizing means configured by a microcomputer in the ECU and a program executed by the microcomputer. . FIG. 2 is a block diagram showing another example of the configuration of the main parts of the hardware of the system shown in FIG. 1 and the configuration of various function realizing means configured by a microcomputer in the ECU and a program executed by the microcomputer. It is. It is the block diagram which showed the structure of the principal part of the 1st Embodiment of this invention. It is the block diagram which showed the structure of the principal part of the 2nd Embodiment of this invention. It is the block diagram which showed the structure of the principal part of the 3rd Embodiment of this invention. It is the block diagram which showed the structure of the principal part of the 4th Embodiment of this invention. It is the block diagram which showed the structure of the principal part of the 5th Embodiment of this invention. It is the block diagram which showed the structure of the principal part of the 6th Embodiment of this invention. It is the block diagram which showed the structure of the principal part of the 7th Embodiment of this invention. It is the block diagram which showed the structure of the principal part of the 8th Embodiment of this invention. 3 is a time chart for explaining a fuel injection control operation of a single cylinder internal combustion engine. It is the graph which showed an example of the relationship between the correction coefficient k used in order to correct | amend the injection time with respect to the pressure difference (DELTA) P concerning an injector, and a pressure difference. It is a graph for demonstrating a mode that the drive time of an injector is correct | amended after an injector starts injection operation | movement, and the timing which performs the correction | amendment calculation. It is a time chart for demonstrating the correction | amendment operation | movement of the injection time by this invention. It is a graph used when demonstrating how to obtain | require correction | amendment injection time. It is a time chart for demonstrating the other correction | amendment operation | movement of the injection time by this invention. It is the flowchart which showed an example of the principal part of the algorithm of the main routine of the program which the microcomputer of ECU performs in embodiment of this invention. It is the flowchart which showed an example of the algorithm of the reference signal interruption process of the program which the microcomputer of ECU in the embodiment of this invention performs. It is the flowchart which showed an example of the algorithm of the injection start timing interruption process of the program which the microcomputer of ECU performs in embodiment of this invention. It is the flowchart which showed an example of the algorithm of the sample timing interruption process of the program which the microcomputer of ECU in the embodiment of this invention performs. It is the flowchart which showed an example of the algorithm of the interruption process at the time of completion | finish of the injection of the program which the microcomputer of ECU in the embodiment of this invention performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 3 Injector 4 Fuel tank 5 Fuel pump 6 Pressure regulator 8 ECU
17 Pulser 801 Injector drive circuit 802 Rotational speed detection means 803 Injection start timing detection means 804 Invalid injection time detection means 805 Reference injection time calculation means 806 Temporary injection time calculation means 807 Temporary drive time calculation means 808 Injection timer 809 Injection pulse generation means 810 Injection start time processing means 811 Intake pipe pressure sampling means 812 Injection operation time correction processing means 813 Injection end time processing means

Claims (9)

An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector control unit monitors the pressure in the intake pipe even after the injector starts the fuel injection operation, and when a fluctuation exceeding the set value is detected in the intake pipe pressure during the injection operation, The internal combustion engine is configured to calculate an injection time correction amount with respect to a newly detected pressure difference from the intake pipe pressure, and to correct the injection time by the calculated correction amount. Fuel injection control device. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. Injection start time processing means for setting the injection timer so as to cause the injection timer to start and to start the timing operation of the injection timer;
Injection pulse generating means for generating an injection pulse while the injection timer is measuring time;
An injector driving circuit for driving the injector while the injection pulse is generated;
Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when the injection pulse is generated;
When the intake pipe pressure newly sampled by the intake pipe pressure sampling means shows an increase over a preset value with respect to the previously sampled intake pipe pressure, the atmospheric pressure and the newly sampled intake pipe pressure In order to correct the injector driving time, a correction injection time to be added to the time already measured by the injection timer is calculated, and the correction injection time is reset in the injection timer. Injection processing correction processing means;
A fuel injection control device for an internal combustion engine. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse;
An injector driving circuit for driving the injector while the injection pulse is generated;
Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when the injection pulse is generated;
When the intake pipe pressure newly sampled by the intake pipe pressure sampling means shows an increase over a preset value with respect to the previously sampled intake pipe pressure, the atmospheric pressure and the newly sampled intake pipe pressure In order to correct the drive time of the injector, a corrected injection time to be added to the time already measured by the injection timer is calculated, and the newly calculated corrected injection time is calculated last time. Injection operation correction processing means for resetting the injection timer so as to extend the time to be measured by the injection timer when the set time is longer than the provisional injection time or the corrected injection time by the correction injection time;
A fuel injection control device for an internal combustion engine. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse;
An injector driving circuit for driving the injector while the injection pulse is generated;
Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when the injection pulse is generated;
A correction injection time to be added to the time already measured by the injection timer in order to correct the drive time of the injector with respect to the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. The time calculated by the injection timer when it is determined that the newly calculated corrected injection time is longer than the preset calculated temporary injection time or the corrected injection time by a set value or more is extended by the corrected injection time. Injection operation correction processing means for resetting the injection timer so as to
A fuel injection control device for an internal combustion engine. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse;
An injector driving circuit for driving the injector while the injection pulse is generated;
Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when the injection pulse is generated;
A correction injection time to be added to the time already measured by the injection timer in order to correct the drive time of the injector with respect to the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. The time calculated by the injection timer when it is determined that the newly calculated corrected injection time is longer than the preset calculated temporary injection time or the corrected injection time by a set value or more is extended by the corrected injection time. Injection operation correction processing means for resetting the injection timer so as to
When the intake pipe pressure newly sampled by the intake pipe pressure sampling means does not show an increase over the preset value with respect to the previously sampled intake pipe pressure, or the newly calculated corrected injection time is calculated last time. An end-of-injection processing means for extinguishing the injection pulse when it is not longer than a set value or more than the provisional injection time or the corrected injection time;
A fuel injection control device for an internal combustion engine. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse;
An injector driving circuit for driving the injector while the injection pulse is generated;
Intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when the injection pulse is generated;
Calculates a correction injection time to be added to the time already measured by the injection timer to correct the drive time of the injector against the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. Then, when the calculated corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more, the injection timer is restarted so as to extend the time to be measured by the injection timer by the corrected injection time. Injection processing correction processing means to be set;
An injection end time processing means for extinguishing the injection pulse when the newly calculated corrected injection time is not longer than the preset calculated temporary injection time or the corrected injection time by a set value or more,
A fuel injection control device for an internal combustion engine. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse;
An injector driving circuit for driving the injector while the injection pulse is generated;
Intake pipe pressure sampling means for sampling the intake pipe pressure when the injection timer completes the timekeeping operation;
When the intake pipe pressure newly sampled by the intake pipe pressure sampling means shows an increase over a preset value with respect to the previously sampled intake pipe pressure, the atmospheric pressure and the newly sampled intake pipe pressure The correction injection time to be added to the time already measured by the injection timer to correct the injector drive time for the pressure difference is calculated, and the time to be measured by the injection timer is extended by the correction injection time. Injection processing correction processing means for resetting the injection timer,
When the intake pipe pressure newly sampled by the intake pipe pressure sampling means does not show an increase over the preset value with respect to the previously sampled intake pipe pressure, or the newly calculated corrected injection time is calculated last time. An end-of-injection processing means for extinguishing the injection pulse when it is not longer than a set value or more than the provisional injection time or the corrected injection time;
A fuel injection control device for an internal combustion engine. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse;
An injector driving circuit for driving the injector while the injection pulse is generated;
Intake pipe pressure sampling means for sampling the intake pipe pressure when the injection timer completes the timekeeping operation;
Calculates a correction injection time to be added to the time already measured by the injection timer to correct the drive time of the injector against the pressure difference between the intake pipe pressure newly sampled by the intake pipe pressure sampling means and the atmospheric pressure. An injection timer so as to extend the time to be measured by the injection timer when the newly calculated corrected injection time is longer than the previously calculated provisional injection time or corrected injection time by a set value or more. Correction processing means at the time of injection operation for resetting,
A fuel injection control device for an internal combustion engine. An injector for injecting fuel into an intake pipe of an internal combustion engine, a fuel pump for supplying fuel from a fuel tank to the injector, and a pressure regulator for controlling a fuel pressure applied from the fuel pump to the injector to be equal to atmospheric pressure; An atmospheric pressure detecting means for detecting atmospheric pressure, a pressure sensor for detecting the pressure in the intake pipe of the internal combustion engine, and a difference between the atmospheric pressure detected by the atmospheric pressure detecting means and the pressure in the intake pipe detected by the pressure sensor A fuel injection control for an internal combustion engine comprising: an injector control unit that drives the injector to inject fuel from the injector during an injection time determined for various control conditions including the pressure difference In the device
The injector controller is
Injection start timing detection means for detecting injection start timing;
A reference injection time calculation means for calculating a fuel injection time when the intake pipe pressure is equal to the atmospheric pressure as a reference injection time for control conditions other than the pressure difference;
When the injection start timing is detected, the provisional drive time is defined as a provisional drive time obtained by adding the invalid injection time to the provisional injection time obtained by correcting the reference injection time with respect to the pressure difference. An injection start time processing means for setting the injection timer to start measurement and starting measurement of the provisional drive time and generating an injection pulse;
An injector driving circuit for driving the injector while the injection pulse is generated;
First intake pipe pressure sampling means for sampling the intake pipe pressure at regular time intervals when the injection pulse is generated;
Second intake pipe internal pressure sampling means for sampling the intake pipe internal pressure when the injection timer completes the timing operation;
When the intake pipe pressure newly sampled by the first intake pipe pressure sampling means shows a rise of a set value or more with respect to the previously sampled intake pipe pressure, the first intake pipe pressure sampling means Calculate a corrected injection time that is added to the time already measured by the injection timer to correct the injector drive time for the newly sampled pressure difference between the intake pipe pressure and the atmospheric pressure. The injection timer so as to extend the time to be measured by the injection timer by the correction injection time when it is determined that the set correction injection time is longer than the provisional injection time or the correction injection time previously calculated by a set value or more. Injection processing correction processing means for resetting;
When the intake pipe pressure newly sampled by the second intake pipe pressure sampling means shows an increase of a preset value or more with respect to the previously sampled intake pipe pressure, the second intake pipe pressure sampling means Calculate a corrected injection time that is added to the time already measured by the injection timer to correct the injector drive time for the newly sampled pressure difference between the intake pipe pressure and the atmospheric pressure. The injection timer so as to extend the time to be measured by the injection timer by the correction injection time when it is determined that the set correction injection time is longer than the provisional injection time or the correction injection time previously calculated by a set value or more. The intake pipe pressure newly sampled by the second intake pipe pressure sampling means When there is no increase over the set value with respect to the ring intake pipe pressure, or when the newly calculated corrected injection time is not longer than the set value by more than the previously calculated provisional injection time or corrected injection time An end-of-injection processing means for extinguishing the injection pulse;
A fuel injection control device for an internal combustion engine.

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