JP2012167617A - Control device of multi-cylinder internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a multi-cylinder internal combustion engine which can perform the arithmetic processing of each cylinder by two CPUs at proper timing while minimizing calculation loads of the CPUs.SOLUTION: The device includes an electronic control unit 40B comprising a main CPU 41 and sub-CPU 42. The main CPU 41 executes arithmetic processing for performing cylinder discrimination and arithmetic processing for calculating a control target value of a fuel injection amount. On the basis of the result from the arithmetic processing, operation signals including a driving pulse for valve opening drive of fuel injection valves 20 and a dummy pulse with a pulse width not opening fuel injection valves 20 at the timing set in advance before the driving pulses are outputted to each fuel injection valve 20 and the sub-CPU 42, respectively. The sub CPU 42 specifies a cylinder executing fuel injection immediately thereafter based on the input of the dummy pulse, and carries out arithmetic processing for detecting fuel pressure by a pressure sensor 51 corresponding to the specific cylinder.

Description

  The present invention relates to a control device for a multi-cylinder internal combustion engine.

  In a multi-cylinder internal combustion engine, cylinders that reach the combustion stroke are identified based on the detection signals of the crank sensor and cam sensor (so-called cylinder discrimination), and the fuel injection valves of each cylinder are driven to open based on the results. It is executed at an appropriate timing.

  In a multi-cylinder internal combustion engine, the fuel pressure in the fuel supply path during fuel injection is detected, and the operating characteristics of the fuel injection valve (for example, injection amount error or valve opening delay) based on the fluctuation waveform of the fuel pressure. A device for detecting time and valve closing delay time has been proposed (see Patent Document 1). In such a device, in order to efficiently detect the operating characteristics of the fuel injection valve provided for each cylinder, the fuel injection valve in which fuel injection is performed before the start of fuel injection, that is, the cylinder that is in the combustion stroke is recognized. It is necessary to keep. In the device described in Patent Document 1, after identifying the cylinder that is in the combustion stroke based on the result of cylinder discrimination, the detection of the fuel pressure in the fuel supply path and the fluctuation waveform of the fuel pressure are determined for each cylinder. The operation characteristics of the fuel injection valve are detected.

JP 2008-144749

  The internal combustion engine is provided with an electronic control unit as its peripheral equipment. Various arithmetic processes for engine operation such as a process for driving control of the fuel injection valve and a process for cylinder discrimination are executed by a central processing unit (CPU) built in the electronic control unit. .

  In recent years, it has been proposed to provide a plurality of dedicated CPUs set for each target arithmetic processing in the same electronic control unit. If such a device is applied to the device described in Patent Document 1, a fuel pressure fluctuation waveform is detected separately from the main CPU that executes processing for drive control of the fuel injection valve. It is conceivable to provide a sub CPU.

  In this case, in addition to causing the main CPU to execute calculation processing for cylinder discrimination, the sub CPU executes the calculation processing so that the fuel injection valve opening drive and the fuel pressure detection of each cylinder are performed at appropriate timings. Will be executed. However, the calculation process for cylinder discrimination is not simply a process of capturing the detection signal of the crank sensor or cam sensor, but the rotational phase of the engine output shaft is specified based on the relationship between the detection signal of the crank sensor and the detection signal of the cam sensor. Since this is a complicated process, the calculation load tends to increase. For this reason, it is inefficient and not desirable to execute such processing for cylinder discrimination in both the main CPU and the sub CPU.

Such inconvenience in executing the cylinder discrimination similarly occurs in an apparatus including a plurality of CPUs that perform specification of a cylinder to be executed and calculation processing for the cylinder.
The present invention has been made in view of such circumstances, and an object of the present invention is to execute calculation processing for each cylinder by the central processing units at appropriate timings while suppressing the calculation load of the two central processing units to be small. An object of the present invention is to provide a control device for a multi-cylinder internal combustion engine capable of performing

In the following, means for achieving the above object and its operational effects will be described.
In the configuration described in claim 1, the multi-cylinder internal combustion engine is provided with an electronic control unit having a first central processing unit (first CPU) and a second central processing unit (second CPU). Then, the first CPU executes a calculation process for discriminating the cylinder, and based on the result, a drive pulse for opening the fuel injector is provided for any one of the fuel injectors provided for each cylinder. Output selectively. As a result, a drive pulse is output to each fuel injection valve at an appropriate timing. In addition to outputting a drive pulse from the first CPU, a dummy pulse having a pulse width that does not open the fuel injection valve at a predetermined time (a predetermined rotation phase of the engine output shaft) is output. Then, by inputting this dummy pulse to the second CPU, it becomes possible to cause the second CPU to grasp the rotational phase of the engine output shaft at this time, so that the calculation process is performed based on the grasped rotational phase. It is possible to specify a cylinder to be executed, and it is also possible to execute calculation processing for the specified cylinder. Although the dummy pulse is output to each fuel injection valve, the pulse width of the dummy pulse is set to a length that does not open the fuel injection valve. The injection valve is not driven to open unnecessarily.

  As described above, according to the above configuration, although the first CPU and the second CPU both execute the identification of the cylinder to be executed and the arithmetic processing for the cylinder, the first CPU and the second CPU execute the first discrimination based on the result of the cylinder discrimination by the first CPU. Arithmetic processing by two CPUs can be performed appropriately. Therefore, both the first CPU and the second CPU execute the arithmetic processing for each cylinder in the CPU at an appropriate timing while suppressing the arithmetic load as compared with a device that executes arithmetic processing for performing cylinder discrimination. Can do.

  The fuel pressure inside the fuel injection valve varies with the opening and closing operation of the fuel injection valve, such as decreasing as the fuel injection valve opens and then increasing as the fuel injection valve closes. Therefore, by monitoring the fluctuation waveform of the fuel pressure during fuel injection, the actual operating characteristics of the fuel injection valve (for example, when the valve opening operation is started or when the valve closing operation is started) can be accurately determined. I can grasp it well.

  According to the second aspect of the present invention, for each cylinder of the internal combustion engine, the fuel pressure at a portion between the pressure accumulating container for storing the pressurized fuel and the fuel injection valve separately connected to the pressure accumulating container is detected. A pressure sensor is provided. Then, the second central processing unit identifies a cylinder in which fuel injection is performed immediately after the input of the dummy pulse, and executes a process of detecting the fuel pressure by a pressure sensor corresponding to the cylinder.

  According to such a configuration described in claim 2, the detection of the fuel pressure at the time of executing the fuel injection can be executed for each cylinder at an appropriate timing in accordance with the valve opening drive of the fuel injection valve.

The predetermined time can be set to a time during the compression stroke of the cylinder to be executed, as in the configuration according to claim 3.
In the configuration according to claim 4, in accordance with the fact that the second central processing unit executes the process of detecting the fuel pressure by the pressure sensor corresponding to the cylinder in which the fuel injection is performed immediately thereafter, and further A process for detecting the fuel pressure is performed by a pressure sensor corresponding to the cylinder in which the fuel injection is performed. Therefore, in addition to detecting the fuel pressure at the time of executing fuel injection by inputting a dummy pulse, the fuel pressure at the time of non-execution of fuel injection, in other words, the fluctuation waveform of the fuel pressure accompanying the execution of fuel injection It is possible to detect a reference fuel pressure for monitoring. And the fluctuation waveform of the fuel pressure accompanying the opening / closing operation of the fuel injection valve can be accurately detected based on these fuel pressures.

  According to the configuration of the fifth aspect, since the pressure sensor is attached to the fuel injection valve, the fuel injection valve injection is compared with a device in which the fuel pressure at a position away from the fuel injection valve is detected by the pressure sensor. It is possible to detect the fuel pressure at a portion close to the hole, and it is possible to accurately detect a change in the fuel pressure inside the fuel injection valve accompanying the opening / closing operation of the fuel injection valve.

1 is a schematic diagram showing a schematic configuration of a control device for a multi-cylinder internal combustion engine according to an embodiment embodying the present invention. Sectional drawing which shows the cross-section of a fuel injection valve. The time chart which shows an example of the basic time waveform calculated at the time of execution of main injection. 6 is a schematic diagram showing an output path of an operation signal from the electronic control unit to the fuel injection valve. The time chart which shows an example of the relationship between a crank angle, each operation signal, and the detection execution period of a fuel pressure. The flowchart which shows the execution procedure of a main CPU process. The flowchart which shows the execution procedure of a sub CPU process.

Hereinafter, a control device for a multi-cylinder internal combustion engine according to an embodiment of the present invention will be described.
As shown in FIG. 1, an intake passage 12 is connected to the cylinder 11 of the internal combustion engine 10. Air is sucked into the cylinder 11 of the internal combustion engine 10 through the intake passage 12. As the internal combustion engine 10, a diesel engine having a plurality of (four [# 1 to # 4] in the present embodiment) cylinders 11 is employed. The internal combustion engine 10 is provided with a direct injection type fuel injection valve 20 that directly injects fuel into the cylinder 11 for each cylinder 11 (# 1 to # 4). The fuel injected by opening the fuel injection valve 20 is ignited and burned in contact with the intake air compressed and heated in the cylinder 11 of the internal combustion engine 10. In the internal combustion engine 10, the piston 13 is pushed down by the energy generated by the combustion of fuel in the cylinder 11, and the crankshaft 14 as the engine output shaft is forcibly rotated. The combustion gas combusted in the cylinder 11 of the internal combustion engine 10 is discharged as exhaust gas into the exhaust passage 15 of the internal combustion engine 10.

  Each fuel injection valve 20 is individually connected to a common rail 34 via a branch passage 31a. The common rail 34 is connected to the fuel tank 32 through a supply passage 31b. A fuel pump 33 that pumps fuel is provided in the supply passage 31b. In the present embodiment, the fuel boosted by the pumping by the fuel pump 33 is stored in the common rail 34 and supplied to each fuel injection valve 20. In this embodiment, the branch passage 31a and the supply passage 31b function as a fuel supply passage, and the common rail 34 functions as a pressure accumulating container provided in the middle of the fuel supply passage.

  A return passage 35 is connected to each fuel injection valve 20. The return passages 35 are each connected to the fuel tank 32. A part of the fuel inside the fuel injection valve 20 is returned to the fuel tank 32 through the return passage 35.

Hereinafter, the internal structure of the fuel injection valve 20 will be described.
As shown in FIG. 2, a needle valve 22 is provided inside the housing 21 of the fuel injection valve 20. The needle valve 22 is provided in a state capable of reciprocating in the housing 21 (moving up and down in the figure). Inside the housing 21 is provided a spring 24 that constantly urges the needle valve 22 toward the injection hole 23 (the lower side in the figure). In addition, a nozzle chamber 25 is formed in the housing 21 at a position on one side (lower side in the figure) with the needle valve 22 interposed therebetween, and at a position on the other side (upper side in the figure). A pressure chamber 26 is formed.

  The nozzle chamber 25 is formed with an injection hole 23 that communicates the inside with the outside of the housing 21, and fuel is supplied from the branch passage 31 a (common rail 34) through the introduction passage 27. The pressure chamber 26 is connected to the nozzle chamber 25 and the branch passage 31a (common rail 34) via a communication passage 28. The pressure chamber 26 is connected to a return passage 35 (fuel tank 32) via a discharge passage 30.

  As the fuel injection valve 20, an electrically driven type is adopted. Specifically, a piezoelectric actuator 29 in which a piezoelectric element (for example, a piezoelectric element) that expands and contracts by input of a drive signal is provided inside the housing 21 of the fuel injection valve 20. A valve body 29 a is attached to the piezoelectric actuator 29. The valve body 29 a is provided inside the pressure chamber 26. Then, through the movement of the valve element 29 a by the operation of the piezoelectric actuator 29, one of the communication path 28 (nozzle chamber 25) and the discharge path 30 (return path 35) is selectively communicated with the pressure chamber 26. It has become.

  In the fuel injection valve 20, when a valve closing signal is input to the piezoelectric actuator 29, the piezoelectric actuator 29 contracts and the valve body 29 a moves, so that the communication path 28 and the pressure chamber 26 communicate with each other. At the same time, the communication between the return passage 35 and the pressure chamber 26 is blocked. Thereby, the nozzle chamber 25 and the pressure chamber 26 are communicated with each other in a state where the discharge of the fuel in the pressure chamber 26 to the return passage 35 (fuel tank 32) is prohibited. As a result, the pressure difference between the nozzle chamber 25 and the pressure chamber 26 becomes very small, and the needle valve 22 moves to a position where it closes the injection hole 23 by the urging force of the spring 24. Is not injected (valve closed state).

  On the other hand, when a valve opening signal is input to the piezoelectric actuator 29, the piezoelectric actuator 29 extends and the valve body 29a moves, whereby the communication between the communication passage 28 and the pressure chamber 26 is blocked. The return passage 35 and the pressure chamber 26 are in communication with each other. As a result, part of the fuel in the pressure chamber 26 is returned to the fuel tank 32 via the return passage 35 in a state in which the outflow of fuel from the nozzle chamber 25 to the pressure chamber 26 is prohibited. As a result, the pressure of the fuel in the pressure chamber 26 decreases and the pressure difference between the pressure chamber 26 and the nozzle chamber 25 increases, and the needle valve 22 moves against the biasing force of the spring 24 due to the pressure difference. In order to leave the injection hole 23, the fuel injection valve 20 is in a state where the fuel is injected (opened state) at this time.

  A pressure sensor 51 that outputs a signal corresponding to the fuel pressure PQ inside the introduction passage 27 is integrally attached to the fuel injection valve 20. For this reason, for example, the fuel in a portion near the injection hole 23 of the fuel injection valve 20 as compared with a device that detects the fuel pressure at a position away from the fuel injection valve 20 such as the fuel pressure in the common rail 34 (see FIG. 1). The pressure can be detected, and the change in the fuel pressure inside the fuel injection valve 20 accompanying the opening of the fuel injection valve 20 can be detected with high accuracy. One pressure sensor 51 is provided for each fuel injection valve 20, that is, for each cylinder 11 of the internal combustion engine 10.

  As shown in FIG. 1, the internal combustion engine 10 is provided with various sensors as peripheral devices for detecting an operation state. As these sensors, in addition to the pressure sensor 51, for example, an intake air amount sensor 52 for detecting the amount of air passing through the intake passage 12 (passage air amount GA), or a pulse-like signal as the crankshaft 14 rotates. Is provided, and a cam sensor 54 is provided for outputting a pulse signal as the camshaft rotates. In addition, an accelerator sensor 55 for detecting an operation amount (accelerator operation amount ACC) of an accelerator operation member (for example, an accelerator pedal) is also provided. In the present embodiment, a signal (hereinafter referred to as a crank signal) that changes with a change in the rotational phase (crank angle) of the crankshaft 14 based on the relationship between the detection signal of the crank sensor 53 and the detection signal of the cam sensor 54 is formed. Is done. Based on the crank signal, the crank angle, the rotational speed of the crankshaft 14 (engine rotational speed NE), the cylinder 11 that performs fuel injection, and the like are specified.

  Further, as the peripheral device of the internal combustion engine 10, two electronic control units 40A and 40B configured with a central processing unit are also provided. These electronic control units 40 </ b> A and 40 </ b> B take in output signals from various sensors and perform various calculations based on these output signals to execute various controls related to the operation of the internal combustion engine 10. Note that the electronic control unit 40B executes arithmetic processing related to the operation control (fuel injection control) of the fuel injection valve 20. Further, the electronic control unit 40A mainly executes arithmetic processing related to other engine control.

  The fuel injection control is basically executed as follows. That is, first, an injection pattern is selected and various control target values for each injection of the injection pattern are calculated based on the engine operation state such as the passage air amount GA, the engine speed NE, and the accelerator operation amount ACC. Then, a drive signal is output in accordance with these control target values, and each fuel injection valve 20 is driven to open according to the input of this drive signal. As a result, an amount of fuel corresponding to the engine operating state is injected from each fuel injection valve 20 and supplied into each cylinder 11 of the internal combustion engine 10 with an injection pattern suitable for the engine operating state at that time. In addition, a rotational torque commensurate with the engine operating state is applied to the crankshaft 14.

  In the present embodiment, a plurality of injection patterns that combine main injection, pilot injection, after-injection, etc. are preset and stored in the electronic control unit 40B. One is selected. Various control target values include control target values for the fuel injection amount of each injection such as main injection, pilot injection, and after injection, and control for the fuel injection timing of various injections such as the injection timing of the main injection and the pilot interval. A target value is calculated. Furthermore, in this embodiment, the relationship between the engine operating state and each control target value suitable for the same operating state, and the relationship between the engine operating state and the injection pattern suitable for the same operating state are based on the results of experiments and simulations. It is obtained in advance and stored in the electronic control unit 40B. Then, the electronic control unit 40B sets various control target values and injection patterns separately from the above relationship based on the engine operating state at that time.

  In the present embodiment, the main injection is performed in accordance with the execution of the fuel injection based on the control target value (target main injection time) of the fuel injection amount in the main injection and the control target value (target main injection time) of the fuel injection timing. Thus, correction control for correcting the valve opening period and the fuel injection amount of the fuel injection valve 20 based on the fuel pressure PQ detected by the pressure sensor 51 is executed. Specifically, this correction control is executed as follows.

  That is, first, a basic time waveform for the fuel injection rate is calculated based on the target main injection time and the target main injection timing. In the present embodiment, the relationship between the engine operation region determined by the target main injection time and the target main injection timing and the basic time waveform suitable for the operation region is obtained in advance based on the results of experiments and simulations, and the electronic control unit 40B It is stored in a memory (not shown). Then, the electronic control unit 40B calculates a basic time waveform from the above relationship based on the engine operation region at that time.

FIG. 3 shows an example of the basic time waveform.
As shown by the solid line in FIG. 3, the basic time waveform includes a timing at which the valve opening operation of the fuel injection valve 20 is started (valve opening operation start timing Tos), and a timing at which the fuel injection rate is maximized (maximum injection rate). The trapezoidal waveform defined by the arrival time Toe), the time when the valve closing operation is started (valve closing operation start time Tcs), and the time when the valve closing operation is completed (valve closing operation completion time Tce) is set.

  On the other hand, based on the fuel pressure PQ detected by the pressure sensor 51, a time waveform (detection time waveform) of the actual fuel injection rate is formed. Specifically, first, the valve opening operation start timing Tosr, the maximum injection rate arrival timing Toer, the valve closing operation start timing Tcsr, and the valve closing operation completion timing Tcer of the fuel injection valve 20 are specified based on the transition of the fuel pressure PQ. Is done. The fuel pressure inside the fuel injection valve 20 (specifically, the nozzle chamber 25) decreases as the lift amount increases when the fuel injection valve 20 is driven to open, and then lifts when the valve is driven to close. As the amount decreases, it increases. In the present embodiment, based on the transition of the fuel pressure inside the fuel injection valve 20 (specifically, the fuel pressure PQ), the valve opening operation start timing Tosr, the maximum injection rate arrival timing Toer, and the valve closing operation start timing Tcsr. , And the valve closing operation completion timing Tcer are specified with high accuracy.

  In this embodiment, the change speed of the fuel pressure PQ (specifically, the first derivative value of the fuel pressure PQ) is calculated, and the change speed is calculated based on the valve opening operation start timing Tosr, the maximum injection rate arrival time Toer, It is used to specify the valve closing operation start timing Tcsr and the valve closing operation completion timing Tcer. As a result, the timing at which the fuel pressure PQ starts to suddenly drop with the start of the valve opening operation of the fuel injection valve 20, the timing at which the change rate of the fuel pressure PQ starts to increase after the valve opening operation starts, and the valve closing operation It is possible to easily specify the timing at which the fuel pressure PQ starts to suddenly increase with the start of time, the timing at which the change speed of the fuel pressure PQ changes from rising to falling after the start of the valve closing operation, and the like. Therefore, the operation mode of the fuel injection valve 20 based on the fuel pressure PQ is properly grasped, and the valve opening operation start timing Tosr, the maximum injection rate arrival time Toer, the valve closing operation start timing Tcsr, and the valve closing operation are completed. The time Tcer is specified with high accuracy. Then, as shown by a one-dot chain line in FIG. 3, a time waveform (detection time waveform) of the actual fuel injection rate is formed depending on the specified time.

  In the correction control of the present embodiment, the detected time waveform and the basic time waveform are compared, and a value that can suppress the difference between the detected time waveform and the basic time waveform is a correction term for the injection timing. K1 and the correction term K2 for the injection time are respectively calculated and stored in the electronic control unit 40B.

  Specifically, a value capable of compensating for the difference between the valve opening operation start timing Tos of the basic time waveform and the valve opening operation start timing Tosr of the detection time waveform is calculated as the correction term K1 and stored in the electronic control unit 40B. Is done. When executing the main injection, a value obtained by correcting the target main injection timing by the correction term K1 is set as the final target main injection timing. Further, a value capable of compensating for the difference between the area of the basic time waveform and the area of the detection time waveform is calculated as the correction term K2 and stored in the electronic control unit 40B. When executing the main injection, a value obtained by correcting the target main injection time by the correction term K2 is set as the final target main injection time.

  The correction control is performed based on the detection signal of the pressure sensor 51 provided in the cylinder 11 [# 1] of the internal combustion engine 10, for example, for each of the correction terms K1, K2 for the fuel injection valve 20 of the cylinder 11 [# 1]. The learning is executed based on the output signal of the pressure sensor 51 corresponding to each of the cylinders 11 (# 1 to # 4) of the internal combustion engine 10.

Hereinafter, the output path of the operation signal for causing the fuel injectors 20 to open and close the fuel injectors 20 from the electronic control units 40A and 40B will be described in detail.
As shown in FIG. 4, the electronic control unit 40B incorporates two central processing units (main CPU 41 and sub CPU 42). The electronic control unit 40B has a structure capable of transferring data between the main CPU 41 and the sub CPU 42 as indicated by a white arrow in the figure.

  Four signal lines SA [# 1], SA [# 2], SA [# 3], and SA [# 4] are provided between the main CPU 41 and the electronic control unit 40A. The operation signals are individually output to the fuel injection valves 20 (specifically, the electronic control unit 40A) via these signal lines SA [# 1] to SA [# 4].

  These signal lines SA [# 1] to SA [# 4] are branched on the way, and the branched signal lines SB [# 1], SB [# 2], SB [# 3], SB [# 4] are connected to the sub CPU 42, respectively. Each operation signal is individually input to the sub CPU 42 via these signal lines SB [# 1] to SB [# 4].

  Further, four signal lines SC [# 1], SC [# 2], SC [# 3], SC [# 4] are provided between the electronic control unit 40A and each fuel injection valve 20. The drive signals are individually output to the fuel injectors 20 through the signal lines SC [# 1] to SC [# 4].

  Four signal lines SD [# 1], SD [# 2], SD [# 3], SD are provided between the pressure sensor 51 provided in each fuel injection valve 20 and the sub CPU 42 of the electronic control unit 40B. [# 4] is provided. The detection signals of the pressure sensors 51 are individually input to the sub CPU 42 via these signal lines SD [# 1] to SD [# 4].

The main CPU 41 has functions described in [Function 1] to [Function 5] below.
[Function 1] Based on the relationship between the detection signal of the crank sensor 53 and the detection signal of the cam sensor 54, a crank signal that changes as the crank angle changes is formed, and the cylinder 11 that reaches the combustion stroke is identified based on the crank signal. (So-called cylinder discrimination) is performed.
[Function 2] The detection time waveform is received from the sub CPU 42 through data transfer between the main CPU 41 and the sub CPU 42, and the detection time waveform is stored for each cylinder 11.
[Function 3] Various control target values for the fuel injection control are calculated based on the engine operating state.
[Function 4] The correction control based on the detection time waveform received from the sub CPU 42 is executed.
[Function 5] Forming an operation signal including a drive pulse (a pulse defining a valve opening period of the fuel injection valve 20) for opening and closing each fuel injection valve 20 based on various control target values for the fuel injection control At the same time, these operation signals are output individually to the electronic control unit 40A via the signal paths SA [# 1] to SA [# 4].

The sub CPU 42 has functions described in [Function 6] to [Function 10] below.
[Function 6] When the fuel injection valve 20 is opened (specifically, the period from the middle of the compression stroke to the middle of the combustion stroke), the fuel pressure PQ is determined based on the detection signal of the pressure sensor 51 corresponding to the fuel injection valve 20. While detecting, the detected value is memorize | stored for every cylinder 11. FIG.
[Function 7] When the fuel injection valve 20 is closed (specifically, the period from the middle of the intake stroke to the middle of the compression stroke), the fuel pressure PQ is set based on the detection signal of the pressure sensor 51 corresponding to the fuel injection valve 20. While detecting, the detected value is memorize | stored for every cylinder 11. FIG. In the present embodiment, the average value of the fuel pressure PQ detected in this way is calculated, and the average value changes in the fuel pressure PQ accompanying the opening / closing operation of the fuel injection valve 20 when the detection time waveform is formed. It is used as a standard pressure.
[Function 8] Based on the fuel pressure PQ detected when the fuel injection valve 20 is opened and the fuel pressure PQ detected when the fuel injection valve 20 is closed, the fluctuation waveform of the fuel pressure PQ accompanying the opening / closing operation of the fuel injection valve 20 (the detection time) Waveform) and is stored for each cylinder 11.
[Function 9] The detection time waveform is output to the main CPU 41 at an appropriate timing through data transfer.
[Function 10] The operation state of the main CPU 41 is monitored by monitoring each operation signal input through the signal lines SB [# 1] to SB [# 4].

The electronic control unit 40A has a function described in [Function 11] below.
[Function 11] In response to each operation signal input from the main CPU 41 of the electronic control unit 40B, a drive signal for opening the fuel injection valve 20 (valve opening signal) and a drive signal for closing the valve (valve closing) Signal) is output at appropriate timing via the signal lines SB [# 1] to SB [# 4]. Specifically, first, the time from when the electronic control unit 40A outputs a valve opening signal to when the fuel injection valve 20 actually starts to open (the valve opening delay time TA) and the electronic control unit 40B are input. The output timing of the valve opening signal is set based on the actuated signal (specifically, the drive pulse). In addition, the time from when the valve closing signal is output from the electronic control unit 40A until the valve closing operation of the fuel injection valve 20 is actually started (valve closing delay time TB), and the operation signal input from the electronic control unit 40B Based on the above, the output timing of the valve closing signal is set. Then, the electronic control unit 40A outputs a valve opening signal or a valve closing signal to each fuel injection valve 20 at these output timings.

  Here, in this embodiment, both the main CPU 41 and the sub CPU 42 provided in the electronic control unit 40B specify the cylinder 11 in which fuel injection is performed immediately thereafter, and perform arithmetic processing (output of drive pulses, Alternatively, fuel pressure PQ is detected).

  Therefore, in the apparatus according to the present embodiment, in addition to causing the main CPU 41 to execute arithmetic processing for cylinder discrimination, the sub CPU 42 also executes the output of drive pulses from the main CPU 41 and the detection of the fuel pressure PQ by the sub CPU 42. Can be executed at appropriate timing. However, the calculation processing for determining the cylinder is not simply a process of taking in the detection signals of the crank sensor 53 and the cam sensor 54, but the crank angle is specified based on the relationship between the detection signal of the crank sensor 53 and the detection signal of the cam sensor 54. Since this involves complicated processing such as, the calculation load tends to increase. For this reason, it is inefficient and undesirable to perform the calculation processing related to cylinder discrimination in both the main CPU 41 and the sub CPU 42.

  In view of this point, in the present embodiment, prior to outputting the drive pulse from the main CPU 41, a predetermined pulse is generated at a predetermined time (BTDC 90 ° during the compression stroke) before the drive pulse. A pulse-like signal having a width (hereinafter referred to as a dummy pulse) is output. An operation signal composed of these drive pulses and dummy pulses is set for each cylinder 11. Therefore, each operation signal is individually input to the electronic control unit 40A via the signal lines SA [# 1] to SA [# 4], and in addition to the signal lines SB [# 1] to SB [# 4]. To the sub CPU 42 of the electronic control unit 40B. As the dummy pulse, a signal having a pulse width shorter than the pulse width corresponding to the invalid injection time of the fuel injection valve 20, that is, a pulse width that does not open the fuel injection valve 20 is output.

  Then, the sub CPU 42 of the electronic control unit 40B specifies the cylinder 11 in which fuel injection is performed immediately after the input of the dummy pulse. Then, the detection of the fuel pressure PQ based on the detection signal of the pressure sensor 51 corresponding to the specified cylinder 11 and the detection signal of the pressure sensor 51 corresponding to the cylinder 11 in which fuel injection is performed next to the specified cylinder 11 are performed. Based on the detection of the fuel pressure PQ.

Hereinafter, the detection mode of the fuel pressure PQ by the sub CPU 42 will be specifically described with reference to a time chart shown in FIG.
As shown in FIG. 5, at time t1, when a dummy pulse is input to the sub CPU 42 of the electronic control unit 40B via the signal line SB [# 1] corresponding to the cylinder 11 [# 1], the fuel immediately thereafter The cylinder 11 [# 1] in which the injection is performed is specified. Then, at the subsequent times t1 to t2, the detection of the fuel pressure PQ based on the detection signal of the pressure sensor 51 corresponding to the cylinder 11 [# 1] and the cylinder in which fuel injection is executed next to the cylinder 11 [# 1] The fuel pressure PQ is detected based on the detection signal of the pressure sensor 51 corresponding to 11 [# 3].

  Similarly, when a dummy pulse is input to the sub CPU 42 via the signal line SB [# 3] corresponding to the cylinder 11 [# 3] (time t2), the cylinder 11 [# 3 in which fuel injection is performed immediately afterward. ] And the detection of the fuel pressure PQ for the cylinder 11 [# 4] in which fuel injection is executed next to the cylinder 11 [# 3] (time t2 to t3). .

  In addition, when a dummy pulse is input to the sub CPU 42 via the signal line SB [# 4] corresponding to the cylinder 11 [# 4] (time t3), the cylinder 11 [# 4] in which fuel injection is performed immediately thereafter. The detection of the fuel pressure PQ for the cylinder 11 and the detection of the fuel pressure PQ for the cylinder 11 [# 2] in which fuel injection is executed next to the cylinder 11 [# 4] are executed (time t3 to t4).

  Further, when a dummy pulse is input to the sub CPU 42 via the signal line SB [# 2] corresponding to the cylinder 11 [# 2] (time t4), the cylinder 11 [# 2] in which fuel injection is performed immediately thereafter. Detection of the fuel pressure PQ for the cylinder 11 and detection of the fuel pressure PQ for the cylinder 11 [# 1] in which fuel injection is executed next to the cylinder 11 [# 2] are performed (time t4 to t5).

  Hereinafter, the operation by outputting the operation signal including the driving pulse and the dummy pulse from the main CPU 41 of the electronic control unit 40B to the sub CPU 42 and the electronic control unit 40A will be described.

  In the apparatus according to the present embodiment, the main CPU 41 executes a calculation process for determining a cylinder, and based on the result, a drive pulse for driving the fuel injection valve 20 to open is generated by the signal lines SA [# 1] to SA. Via [# 4], it is selectively output to one of the fuel injection valves 20 provided for each cylinder 11. As a result, a drive pulse (specifically, a drive signal from the electronic control unit 40A) is output to each fuel injection valve 20 at an appropriate timing.

  In addition to outputting a drive pulse from the main CPU 41, a dummy pulse is output at a predetermined time before the drive pulse, and the dummy pulse is output from the signal lines SB [# 1] to SB [# 4]. Is input to the sub CPU 42 via Therefore, the cylinder 11 corresponding to the fuel injection valve 20 that is driven to open immediately after the dummy pulse is input to the sub CPU 42 via any one of the signal lines SB [# 1] to SB [# 4]. Can be grasped by the sub CPU 42. Thereby, the detection of the fuel pressure PQ based on the detection signal of the pressure sensor 51 corresponding to the cylinder 11 in which fuel injection is performed immediately after that, and the pressure sensor corresponding to the cylinder 11 in which fuel injection is performed next to the cylinder 11 The detection of the fuel pressure PQ based on the detection signal 51 can be executed.

  As described above, in the present embodiment, both the main CPU 41 and the sub CPU 42 specify the cylinder 11 in which fuel injection is performed immediately afterward and the arithmetic processing for the cylinder 11 (output of a drive pulse or detection of the fuel pressure PQ). However, the arithmetic processing by the sub CPU 42 can be appropriately performed based on the result of the cylinder discrimination by the main CPU 41. Therefore, the calculation processing for each cylinder 11 in the main CPU 41 and the sub CPU 42 is appropriately performed while suppressing the calculation load as compared with a device that executes the calculation processing for performing cylinder determination in both the main CPU 41 and the sub CPU 42. It can be executed at the timing.

  In this embodiment, although the dummy pulse is input to the electronic control unit 40A via the signal lines SA [# 1] to SA [# 4], the pulse width of the dummy pulse opens the fuel injection valve 20. Since the length is set so as not to cause the fuel injection valve 20 to be opened unnecessarily when the dummy pulse is input.

  In the present embodiment, in order to realize the [Function 10] in which the sub CPU 42 monitors the operating state of the main CPU 41, each operating signal output from the main CPU 41 is transmitted from the signal lines SB [# 1] to SB [# 4. ] Is input to the sub CPU 42.

  In the present embodiment, the configuration for input / output of each operation signal (specifically, signal lines SB [# 1] to SB [# 4], circuits, programs, etc.) is used for cylinder discrimination. The signal (dummy pulse) is output from the main CPU 41 to the sub CPU 42.

  Therefore, as compared with a device that inputs and outputs a signal for cylinder discrimination by separately providing a dedicated configuration, it is possible to simplify the program for inputting and outputting the signal and the structure of the electronic control unit 40B. . Further, in the present embodiment, each operation signal output from the main CPU 41 for realizing the [Function 10] is input to the sub CPU 42 via the signal lines SB [# 1] to SB [# 4]. When such an apparatus is applied, since an existing configuration can be used, the addition of a new configuration can be suppressed as much as possible.

Hereinafter, a specific execution procedure of the process of outputting the dummy pulse and the process of detecting the fuel pressure PQ based on the input of the dummy pulse will be described.
First, an execution procedure of a process (main CPU process) executed by the main CPU 41 to output an operation signal including a dummy pulse will be described with reference to a flowchart shown in FIG. A series of processes shown in this flowchart is executed as an interrupt process at predetermined intervals.

  As shown in FIG. 6, in this process, when the crank angle becomes the detection reference angle (step S11: YES), the signal line (SA [# 1] to SA [SA [#] corresponding to the cylinder 11 on which fuel injection is performed immediately afterward). Dummy pulse is output via any one of # 4] (step S12). The detection reference angles include four angles (Cd [# 1], Cd [# 2], Cd [# 3], Cd [# 4]) at which any cylinder 11 becomes BTDC 90 ° during the compression stroke. It is set in advance. In the present embodiment, as the detection reference angles Cd [# 1] to Cd [# 4], four angles having a crank angle interval of 180 ° are set. Therefore, in this process, every time any cylinder 11 reaches BTDC 90 ° during the compression stroke, a dummy is transmitted via the signal line (any one of SA [# 1] to SA [# 4]) corresponding to the cylinder 11. A pulse is output.

  Further, when the crank angle becomes the injection reference angle (step S13: YES), the correction for the main injection of the cylinder 11 based on the detection time waveform in the previous combustion cycle for the cylinder 11 for which fuel injection is performed immediately thereafter. Control is executed (step S14). As the detection time waveform, a value received in advance from the sub CPU 42 and stored for each cylinder 11 is used.

  As the injection reference angle, similarly to the detection reference angle, four angles (Ci [# 1], Ci [# 2], Ci [# 3], Ci [# 4], which are 180 ° apart in crank angle, are used. ) Is preset. However, each of these injection reference angles is a drive reference pulse from the detection reference angle (specifically, BTDC 90 ° during the compression stroke of the cylinder 11 where fuel injection is performed immediately thereafter) to the fuel injection valve 20 corresponding to the cylinder 11. Is set to a predetermined angle in a range up to a crank angle at which the output of the engine may start.

  Therefore, in this process, the cylinder order in which the fuel injection is executed (cylinder 11 [# 1] → cylinder 11 [# 3] → cylinder 11 [# 4] → cylinder 11 [# 2]) is performed every 180 ° crank angle. At the timing, the correction control for any one of the cylinders 11 is selectively executed. In other words, correction control based on the detection time waveform in the previous combustion cycle is executed once for each cylinder 11 in one combustion cycle.

  Furthermore, in this process, the output timing of the drive pulse is set based on the control target value for the main injection set through the process of step S14 and the control target value for the injection other than the main injection set through a separate process. . Then, at the output timing, the drive pulse is output via a signal line (any one of SA [# 1] to SA [# 4]) corresponding to the cylinder 11 that is the output target of the drive pulse (step S15). ).

  Next, processing (sub CPU processing) executed by the sub CPU 42 to detect the fuel pressure PQ based on the input of the dummy pulse will be described with reference to the flowchart shown in FIG. A series of processes shown in this flowchart is executed as an interrupt process at predetermined intervals.

As shown in FIG. 7, in this process, first, it is determined whether or not a dummy pulse is input via any of the signal lines SB [# 1] to SB [# 4] (step S21).
If it is determined that a dummy pulse has been input (step S21: YES), immediately after based on the signal line (any one of SB [# 1] to SB [# 4]) to which the dummy pulse is input. The cylinder 11 in which the fuel injection is executed is specified, and the cylinder number of the cylinder 11 is stored as the current pulse cylinder N (step S22). For example, when a dummy pulse is input via the signal line SB [# 1], the cylinder number “1” of the cylinder 11 [# 1] is stored as the current pulse cylinder N. If no dummy pulse is input (step S21: NO), the current pulse cylinder N is not changed (the process of step S22 is jumped). In the present embodiment, when the internal combustion engine 10 is started by operating the operation switch, the initial value of the current pulse cylinder N is a predetermined value (for example, “0”) other than one of the cylinder numbers (1 to 4). Is set.

  Thereafter, it is determined whether it is time to switch the cylinder 11 that is the detection target of the fuel pressure PQ (step S23). Here, when the current pulse cylinder N and the previous pulse cylinder [N-1], which will be described later, do not match, it is determined that it is time to switch the cylinder 11 to be detected. When it is determined that it is time to switch the cylinder 11 to be detected (step S23: YES), the process of step S24 and the process of step S25, which will be described later, are executed, and then the current pulse cylinder N is set. The stored value is stored as the previous pulse cylinder [N-1] (step S26). In the present embodiment, when the internal combustion engine 10 is started by operating the operation switch, the initial value of the previous pulse cylinder [N-1] is a predetermined value other than one of the cylinder numbers (1 to 4) (for example, “0”) is set.

  For this reason, in this process, the current pulse cylinder N and the previous pulse cylinder [N-1] do not match only immediately after the dummy pulse is input and the current pulse cylinder N is updated (step S21: YES). Therefore, the process of step S24 and the process of step S25 are executed only once each time a dummy pulse is input.

  The process of step S24 is performed as follows. That is, first, based on the current pulse cylinder N, the cylinder 11 (next pulse cylinder [N + 1]) in which fuel injection is performed next to the cylinder 11 in which fuel injection is performed immediately after is specified. In this embodiment, the relationship between the current pulse cylinder N determined by the cylinder order and the next pulse cylinder [N + 1] (for example, [N + 1] = 3 if N = 1, [N + 1] = 4 if N = 3, etc.) The next pulse cylinder [N + 1] is specified from the current pulse cylinder N based on the correspondence relationship. Then, based on the pressure sensor 51 corresponding to the current pulse cylinder N, execution of processing for detecting the fuel pressure PQ (that is, fuel pressure PQ at the time of execution of fuel injection), and pressure sensor corresponding to the next pulse cylinder [N + 1] 51, the execution of the process for detecting the fuel pressure PQ (that is, the fuel pressure PQ when fuel injection is not executed) is started. The detected fuel pressure PQ is stored separately in the memory of the sub CPU 42. At this time, the detection and storage of the fuel pressure PQ by the pressure sensors 51 other than the pressure sensor 51 corresponding to the current pulse cylinder N and the next pulse cylinder [N + 1] are not executed.

  Moreover, the process of step S25 is performed as follows. Each fuel pressure PQ detected and stored immediately before it is determined that the cylinder 11 to be detected has been switched in the processing of the previous step S23, that is, when fuel injection is not performed in the cylinder 11 where fuel injection is performed immediately after. The process of forming a detection time waveform is started on the basis of the fuel pressure PQ at 1 and the fuel pressure PQ at the time of the fuel injection of the cylinder 11 in which the fuel injection was performed immediately before. When the formation of the detection time waveform is completed, the waveform is transferred to the main CPU 41 as a detection time waveform corresponding to the cylinder 11 for which fuel injection has been performed immediately before.

  As described above, in this process, every time a dummy pulse is input, the cylinder 11 that is the detection target of the fuel pressure PQ is switched, and the detection time waveform is formed based on the fuel pressure PQ detected before the switching. The waveform is transferred to the main CPU 41.

As described above, according to the present embodiment, the following effects can be obtained.
(1) The main CPU 41 executes arithmetic processing for discriminating cylinders and selectively outputs a drive pulse to any one of the fuel injection valves 20 provided for each cylinder 11 based on the result. . In addition to outputting a drive pulse from the main CPU 41, a dummy pulse is output at a predetermined time before the drive pulse, and this dummy pulse is input to the sub CPU. Therefore, both the main CPU 41 and the sub CPU 42 execute the identification of the cylinder 11 in which the fuel injection is performed immediately afterward and the arithmetic processing (output of the drive pulse or detection of the fuel pressure PQ) for the cylinder 11. Based on the result of cylinder discrimination by the main CPU 41, the arithmetic processing by the sub CPU 42 can be appropriately performed. Therefore, the calculation processing for each cylinder 11 in the main CPU 41 and the sub CPU 42 is appropriately performed while suppressing the calculation load as compared with a device that executes the calculation processing for performing cylinder determination in both the main CPU 41 and the sub CPU 42. It can be executed at the timing.

  (2) The sub CPU 42 executes a process of specifying the cylinder 11 in which fuel injection is performed immediately after the input of the dummy pulse and a process of detecting the fuel pressure PQ by the pressure sensor 51 corresponding to the cylinder 11. I did it. Therefore, the detection of the fuel pressure PQ at the time of executing the fuel injection can be executed for each cylinder 11 at an appropriate timing in accordance with the valve opening drive of the fuel injection valve 20.

  (3) Immediately after the process of detecting the fuel pressure PQ by the pressure sensor 51 corresponding to the cylinder 11 on which fuel injection is performed, the process corresponds to the cylinder 11 on which fuel injection is performed next. A process of detecting the fuel pressure PQ by the pressure sensor 51 is executed. For this reason, in addition to detecting the fuel pressure PQ when the fuel injection is performed, the fuel pressure PQ when the fuel injection is not performed, that is, the fuel injection valve when forming the detection time waveform due to the input of the dummy pulse. It is possible to detect a pressure that serves as a reference for a change in the fuel pressure PQ accompanying the opening / closing operation 20. And a detection time waveform can be accurately formed based on these fuel pressures PQ.

The above embodiment may be modified as follows.
The detection of the fuel pressure PQ is not limited to start immediately after the dummy pulse is input, but the detection of the fuel pressure PQ is started after some time has elapsed after the dummy pulse is input. Good.

  In the above embodiment, two fuel pressures PQ for different cylinders 11 among the fuel pressures PQ detected and stored for each cylinder 11 by the sub CPU 42 (specifically, fuel at the time of executing fuel injection) A detection time waveform is formed based on the pressure PQ and the fuel pressure PQ when the fuel injection is not executed. Alternatively, the detection time waveform may be formed based on the fuel pressure PQ when the fuel injection is performed for the same cylinder 11 and the fuel pressure PQ when the fuel injection is not performed.

  The fuel pressure PQ at the time of executing the fuel injection is not limited to being detected by the pressure sensor 51 corresponding to the cylinder 11 at which the fuel injection is performed next to the cylinder 11 at which the fuel injection is performed immediately thereafter. You may detect with the pressure sensor 51 corresponding to the cylinder 11 in which fuel injection is performed further (after 2 times) of the cylinder 11 in which injection is performed. Further, the fuel pressure PQ at the time of executing the fuel injection can be detected by the pressure sensor 51 corresponding to the cylinder 11 in which the fuel injection is executed after three times.

  The output timing of the dummy pulse is not limited to BTDC 90 ° during the compression stroke, but can be arbitrarily changed. Note that if the output timing of the dummy pulse is advanced, the period from when the dummy pulse is input to the sub CPU 42 to when the cylinder 11 that is the detection target of the fuel pressure PQ is switched becomes longer. In addition, the setting accuracy of the detection period of the fuel pressure PQ is likely to be reduced. If the dummy pulse output timing is too late, detection of the fuel pressure PQ cannot be started at a timing before the fuel injection valve 20 is opened. For this reason, it is desirable to set the time when both the following [Requirement 1] and [Requirement 2] are satisfied as the output timing of the dummy pulse. [Requirement 1] A crank angle at which the detection of the fuel pressure PQ can be reliably started before the opening of the fuel injection valve 20 of the cylinder 11 in which fuel injection is performed immediately after the start. [Requirement 2] For example, the cylinder 11 in which fuel injection is performed immediately after, for example, the crank angle after the crank angle range in which the fuel injection valve 20 of the cylinder 11 in which fuel injection is performed immediately before may be opened. The crank angle is not too far from the valve opening start timing of the fuel injection valve 20.

The function of monitoring the operating state of the main CPU 41 by the sub CPU 42 (the [Function 10]) may be omitted.
A dummy pulse for detecting the fuel pressure PQ when the fuel injection is performed and a dummy pulse for detecting the fuel pressure PQ when the fuel injection is not performed may be set separately.

  -The control device concerning the above-mentioned embodiment can be applied to the device which does not perform detection of fuel pressure PQ at the time of non-execution of fuel injection, after changing the composition suitably. In this case, the fuel pressure PQ detected immediately before the fuel injection valve 20 is opened is used as a reference pressure for the change of the fuel pressure PQ accompanying the opening / closing operation of the fuel injection valve 20 when the detection time waveform is formed. It may be used.

  If the pressure that is an index of the fuel pressure inside the fuel injection valve 20 (specifically, in the nozzle chamber 25), in other words, the fuel pressure that changes with the change in the fuel pressure can be properly detected. The pressure sensor 51 is not limited to being directly attached to the fuel injection valve 20, and the manner of attaching the pressure sensor 51 can be arbitrarily changed. Specifically, the pressure sensor 51 may be attached to a portion (branch passage 31 a) between the common rail 34 and the fuel injection valve 20 in the fuel supply passage, or may be attached to the common rail 34.

  -Something about the specified cylinder 11 is identified, for example, by specifying a cylinder 11 in which fuel injection is performed immediately after input of a dummy pulse and detecting a pressure at the time of fuel combustion in the cylinder 11 A calculation process other than the process of detecting the fuel pressure PQ by the pressure sensor 51 corresponding to the cylinder 11 may be executed. In the case of adopting such a configuration, the configuration for executing the correction control such as each pressure sensor 51 and a control program for executing the correction control can be omitted.

  Not only specifying the cylinder 11 in which fuel injection is performed immediately after the input of the dummy pulse, but also specifying the cylinder 11 in which fuel injection is performed next (two times after) the cylinder 11 The cylinder 11 in which fuel injection is executed after the rotation may be specified, or the arithmetic processing for the specified cylinder 11 may be executed.

  A dummy pulse is applied at a predetermined crank angle through a signal line (any one of SB [# 1] to SB [# 4]) corresponding to the cylinders 11 other than the cylinder 11 in which fuel injection is performed immediately thereafter. While outputting, the cylinder 11 may be specified as the cylinder 11 to be executed based on the input of the dummy pulse. For example, a predetermined crank angle predetermined in the middle of the compression stroke of the cylinder 11 via a signal line (any one of SB [# 1] to SB [# 4]) corresponding to the cylinder 11 on which fuel injection is performed immediately before. In addition to outputting a dummy pulse, the cylinder 11 in which fuel injection is executed immediately before can be specified based on the input of the dummy pulse.

  In place of the type of fuel injection valve 20 driven by the piezoelectric actuator 29, a type of fuel injection valve driven by an electromagnetic actuator having a solenoid coil or the like may be employed.

  The present invention can be applied not only to an internal combustion engine having four cylinders but also to an internal combustion engine having two cylinders, an internal combustion engine having three cylinders, or an internal combustion engine having five or more cylinders. .

  The present invention can be applied not only to a diesel engine but also to a gasoline engine using gasoline fuel and a natural gas engine using natural gas fuel.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Cylinder, 12 ... Intake passage, 13 ... Piston, 14 ... Crankshaft, 15 ... Exhaust passage, 20 ... Fuel injection valve, 21 ... Housing, 22 ... Needle valve, 23 ... Injection hole, 24 ... Spring, 25 ... Nozzle chamber, 26 ... Pressure chamber, 27 ... Introduction passage, 28 ... Communication passage, 29 ... Piezoelectric actuator, 29a ... Valve element, 30 ... Discharge passage, 31a ... Branch passage, 31b ... Supply passage, 32 ... Fuel Tank, 33 ... Fuel pump, 34 ... Common rail, 35 ... Return passage, 40A, 40B ... Electronic control unit, 41 ... Main CPU (first central processing unit), 42 ... Sub CPU (second central processing unit), 51 ... Pressure sensor, 52 ... Intake amount sensor, 53 ... Crank sensor, 54 ... Cam sensor, 55 ... Accelerator sensor.

Claims (5)

A control device for a multi-cylinder internal combustion engine comprising an electronic control unit having a first central processing unit and a second central processing unit,
The first central processing unit performs arithmetic processing for performing cylinder discrimination and arithmetic processing for calculating a control target value for the fuel injection amount, and opens the fuel injection valve based on the result of the arithmetic processing. A fuel injection valve provided in each cylinder of the internal combustion engine and a second operation signal including a drive pulse for driving and a dummy pulse having a pulse width that is set at a predetermined time and does not open the fuel injection valve Output to the central processing unit separately,
The control apparatus for a multi-cylinder internal combustion engine, wherein the second central processing unit specifies a cylinder to be subjected to calculation processing based on the input of the dummy pulse, and executes calculation processing for the specified cylinder. . The control apparatus for a multi-cylinder internal combustion engine according to claim 1,
The internal combustion engine has a pressure accumulating container that stores fuel in a pressurized state, and a fuel injection valve provided in each cylinder is separately connected to the pressure accumulating container, and the fuel injection is performed in each cylinder. A pressure sensor for detecting a pressure at a portion between the pressure accumulating container and an injection hole of the fuel injection valve in a fuel supply passage for supplying fuel to the valve;
The first central processing unit sets the output time of the dummy pulse to a time before the drive pulse,
The second central processing unit specifies a cylinder in which fuel injection is executed immediately after as the cylinder to be executed, and the fuel is detected by a pressure sensor corresponding to the cylinder as calculation processing for the specified cylinder. A control apparatus for a multi-cylinder internal combustion engine, characterized by executing a process for detecting pressure. The control apparatus for a multi-cylinder internal combustion engine according to claim 2,
The control apparatus for a multi-cylinder internal combustion engine, wherein the predetermined time is a time during a compression stroke of the cylinder to be executed. The control apparatus for a multi-cylinder internal combustion engine according to claim 2 or 3,
In accordance with the execution of the process of detecting the fuel pressure by the pressure sensor corresponding to the cylinder in which fuel injection is performed immediately after the second central processing unit, the fuel is next to the cylinder in which fuel injection is performed immediately after the cylinder. A control apparatus for a multi-cylinder internal combustion engine, wherein a process for detecting a fuel pressure is performed by a pressure sensor corresponding to a cylinder in which injection is performed. In the control device for a multi-cylinder internal combustion engine according to any one of claims 2 to 4,
The control apparatus for a multi-cylinder internal combustion engine, wherein the pressure sensor is attached to the fuel injection valve.

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