JP2013011231A - Engine control system, fuel injection apparatus and injection driving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control unit in an engine control system, which is reduced in cost and improved in development efficiency.SOLUTION: The engine control system 10 sends a drive start timing of an actuator 25 to open an injection port, and an injection command value to indicate a drive continuous time, to each injector IJ1 to IJ4, from an engine ECU 11. Each injector IJ1 to IJ4 is provided with a sensor 27 detecting a fuel pressure (inlet pressure), and also is provided with a microcomputer 51, an AD converter 55, and a drive circuit 57. The microcomputer 51 AD converts a signal from the sensor 27 for every constant time interval, and detects actual injection characteristics, and by correcting the injection command value from an engine ECU 11 and by the corrected injection command value after the correction is calculated based on the detected value of the injection characteristics, then the actuator 25 is driven. As a result, regarding the need of the correction control processing through the injection characteristics detection value, the engine ECU 11 is used in common.

Description

  The present invention relates to an engine control system that controls fuel injection to an engine (internal combustion engine).

  For example, in the field of control of a diesel engine mounted on a vehicle, a predetermined fuel path from a fuel outlet of a common rail, which is a pressure accumulating container that stores high-pressure fuel pumped by a fuel pump, to an injection port of a fuel injection device (so-called injector). A fuel pressure sensor is provided at the position, and the voltage value of the sensor signal output from the fuel pressure sensor is AD converted and read at regular intervals, so that the fuel pressure that fluctuates with the fuel injection from the injection port is sequentially detected. It is considered that the actual injection characteristic of the fuel injection device is detected from the detection result, and the detection result of the injection characteristic is fed back to the fuel injection control and used (for example, Patent Document 1). 2).

  For example, the injection characteristics to be detected include the fuel injection start time, the injection end time, the injection amount, and the like. The electronic control unit that controls the engine drives the fuel injection device based on the detected injection characteristics (details). Corrects the timing for starting the driving of the actuator for opening the injection port of the fuel injection device and the driving duration. Further, in order to detect the injection characteristic of a cylinder, the sensor signal from the fuel pressure sensor (hereinafter also referred to as a fuel pressure signal) is traced in a waveform during a period including the fuel injection period of the cylinder. AD conversion is performed at a very short fixed time interval (for example, every several tens of μs).

Here, FIG. 12 shows a configuration example of an engine control system to which the above technical idea is applied.
The engine control system illustrated in FIG. 12 includes an engine control unit (hereinafter also referred to as an engine ECU) 1 that is an electronic control unit that performs processing for controlling the engine, and a fuel injection device provided for each cylinder of the engine. Injector IJn (n is any one of 1 to 4). In this example, the number of cylinders of the engine is four.

  Each injector IJn detects a fuel pressure in the fuel passage and outputs a fuel pressure signal having a voltage corresponding to the fuel pressure. Thus, an actuator An (n is any one of 1 to 4) that opens the injection port of the injector IJn is provided.

  Further, the engine ECU 1 includes a microcomputer 2, an AD converter 3 that AD converts a fuel pressure signal from the fuel pressure sensor Sn of each injector IJn, and each injector IJn according to a drive signal from the microcomputer 2. And a drive circuit 4 for driving the actuator An.

  Then, the microcomputer 2 of the engine ECU 1 detects the operating state of the engine, such as the engine speed and the amount of operation of the accelerator pedal, based on signals from various sensors (not shown), and based on the detected operating state. A process of calculating an injection command value indicating the drive start timing and drive duration of the actuator An of each injector IJn, and a fuel pressure signal from each injector IJn is AD-converted at regular intervals, A process for detecting an injection characteristic of each injector IJn from the AD conversion value and the time series AD conversion value and the operating state of the engine, and a correction value for correcting the injection command value for each injector IJn. Processing based on the detected injection characteristics for each injector IJn A process of correcting all the injection command values according to the correction value calculated for the injector IJn, and a process of causing the drive circuit 4 to drive the actuator An of each injector IJn based on the injection command value corrected by the process ,I do.

JP 2008-144749 JP 2009-57928 A

  In order to perform the process of detecting the injection characteristic, correcting the injection command value, and driving the actuator of the injector (hereinafter referred to as the correction control process using the injection characteristic detection value), for example, every very short period of time such as several tens of μs. In addition, since it is necessary to perform AD processing on the fuel pressure signal and to sequentially acquire each AD conversion value and perform an arithmetic process, a high-performance microcomputer is required. In particular, in the engine ECU 1 in the above conventional engine control system, the microcomputer 2 needs to have a higher performance in order to perform the correction control process based on the injection characteristic detection value for the injectors IJn of each of the plurality of cylinders. In general, a high-performance microcomputer is expensive.

In addition, as an engine control system, there are a system that performs correction control processing based on an injection characteristic detection value and a system that does not perform correction control depending on the type of engine to be controlled.
For this reason, the engine ECU is manufactured separately using microcomputers having different performances depending on the presence or absence of correction control processing based on the detected injection characteristic value. For example, even if correction control processing based on the injection characteristic detection value is unnecessary, a high-performance microcomputer capable of performing the processing is used for the engine ECU, and a function of correction control processing based on the injection characteristic detection value is incorporated. It is possible to aim to reduce costs by sharing parts and configurations by disabling it, but it is because the wasteful cost due to excessive performance becomes larger than the cost reduction effect by sharing it. .

  For this reason, in the conventional engine control system, the engine ECU cannot be shared with respect to the presence or absence of the correction control process based on the detected injection characteristic value, and there is a limit to the cost reduction of the engine ECU. Also, the development efficiency of the engine ECU was poor.

  Accordingly, an object of the present invention is to reduce the cost of an engine control unit and improve the development efficiency.

  The engine control system according to claim 1 is a fuel injection device to which the fuel is supplied from a pressure accumulating vessel that stores fuel pumped by a fuel pump, and an injection port that injects the fuel into a cylinder of the engine when opened. A fuel injection device having an actuator that opens the injection port when driven, and provided at a predetermined position in a fuel passage from a fuel outlet of the pressure accumulating container to an injection port of the fuel injection device. A fuel pressure detecting means for detecting a fuel pressure in the fuel passage that fluctuates with fuel injection from the engine and outputting a sensor signal having a voltage corresponding to the fuel pressure; and driving of the actuator based on the operating state of the engine Command calculation means for calculating injection command information for instructing start timing and drive duration, and reading the voltage value of the sensor signal at regular intervals, From the sampling result, based on the injection characteristic detection means for detecting the injection characteristic of the fuel injection device and the injection characteristic detected by the injection characteristic detection means, a correction value for correcting the injection command information is calculated. Correction value calculating means, correction means for correcting the injection command information calculated by the command calculating means in accordance with the correction value calculated by the correction value calculating means, and injection command information corrected by the correcting means Drive means for driving the actuator on the basis thereof.

  In particular, in this engine control system, the injection characteristic detecting means, the correction value calculating means, the correcting means, and the driving means are provided in a separate device from the engine control unit including the command calculating means. The injection command information is supplied from the engine control unit to the separate device.

  That is, the part (injection characteristic detection means, correction value calculation means, correction means, and drive means) that performs correction control processing based on the injection characteristic detection value is provided in a separate device from the engine control unit that includes the command calculation means. The separate device corrects the injection command information calculated by the command calculation means of the engine control unit in accordance with the correction value based on the detected injection characteristic, and drives the actuator of the fuel injection device. It has become.

  Therefore, according to the engine control system of the first aspect, the engine control unit may output the injection command information with the same logic regardless of the presence or absence of the correction control process based on the detected injection characteristic value. When applied to a system that does not perform the correction control process based on the injection characteristic detection value, the correction control process based on the injection characteristic detection value is not performed as the separate device. The injection command information is used without driving the actuator based on the injection command information without correction, or the injection command information from the engine control unit is corrected with a fixed correction value. Based on the above, what drives the actuator may be used.

  Therefore, the engine control unit can be made common with respect to the presence or absence of the correction control processing based on the injection characteristic detection value, and the cost reduction of the engine control unit can be achieved by making the parts and configuration common. Become. In particular, the engine control unit does not need to perform the correction control process based on the injection characteristic detection value, so that it can be configured using a low-performance and inexpensive microcomputer. Furthermore, since the engine control unit can be developed independently of the content of the correction control process based on the detected injection characteristic value, the development efficiency of the engine control unit can be improved.

  Next, an engine control system according to claim 2 is characterized in that, in the engine control system according to claim 1, the separate device is the fuel injection device. That is, the fuel injection device is provided with injection characteristic detection means, correction value calculation means, correction means, and drive means.

According to this structure, compared with the conventional engine control system, a system can be comprised using a microcomputer with low performance and low price.
As described above, in a conventional engine control system, a microcomputer provided in an engine control unit (engine ECU) performs a correction control process based on an injection characteristic detection value for a fuel injection device (injector) of each of a plurality of cylinders. Therefore, a high-performance microcomputer was necessary. In particular, when the injection periods of two cylinders overlap, the injection characteristics of the fuel injection devices corresponding to the two cylinders must be detected simultaneously.

  On the other hand, according to the configuration of claim 2, each of the fuel injection devices only needs to perform the correction control process based on the detected injection characteristic value, so that the injection periods of a plurality of cylinders may not overlap. However, the processing load in each fuel injection device is a processing load for one cylinder and does not change. Therefore, the injection characteristic detecting means, the correction value calculating means, the correcting means, and the driving means can be realized by using a microcomputer having lower performance and lower cost than conventional ones.

  Further, in the conventional system in which the engine control unit performs correction control processing based on the injection characteristic detection value for the fuel injection device of each cylinder, the detection result of the injection characteristic is obtained for each cylinder after the next injection cycle (after 720 ° CA). However, according to the configuration of claim 2, the response until the detection result of the injection characteristic is reflected in the correction of the injection command information is increased. Can do. For example, in the case of multi-stage injection in which multiple fuel injections are performed during the same injection cycle, the injection characteristic detected at the time of previous fuel injection is used to correct the injection command information for the next fuel injection. It can be configured. Note that “CA” is an abbreviation for crank angle.

Next, in an engine control system according to a third aspect, in the engine control system according to the second aspect, the fuel injection device further includes the fuel pressure detecting means.
According to this configuration, the fuel pressure detecting means and the injection characteristic detecting means are provided in the same apparatus. For this reason, it can suppress that noise gets on the sensor signal from a fuel pressure detection means to an injection characteristic detection means, and it becomes possible to detect an injection characteristic accurately by extension.

  In the conventional engine control system, the sensor signal from the fuel pressure sensor corresponding to the fuel pressure detecting means is transmitted to the engine control unit via the signal line (analog signal line) in the vehicle. The noise was easy to ride. In particular, in order to detect the injection characteristic with high accuracy, the sensitivity of the sensor signal (that is, the ratio of the voltage fluctuation of the sensor signal to the fluctuation of the fuel pressure) is increased. When noise is added to the signal, the detection error of the fuel pressure becomes large, and as a result, the detection accuracy of the injection characteristic is deteriorated. However, according to the configuration of the third aspect, the problem of the influence of noise can be solved.

On the other hand, in the engine control system according to claim 1, the separate device may be a device different from the fuel injection device as described in claim 4.
Moreover, according to the fuel injection device of claim 5, it can be used as a fuel injection device in the engine control system of claim 3.

  Moreover, according to the injection drive device of claim 6, it can be used as the separate device in the engine control system of claim 4.

It is a block diagram showing the engine control system of 1st Embodiment with the engine of a control object. It is a block diagram showing the engine control system of 1st Embodiment. It is a flowchart showing the driving | running state detection process and injection command value transmission process which the microcomputer of engine ECU of 1st Embodiment performs. It is a flowchart showing the injection command value reception process which the microcomputer of each injector of 1st Embodiment performs. It is a flowchart showing the injection control process which the microcomputer of each injector of 1st Embodiment performs. It is a flowchart showing the injection characteristic detection process which the microcomputer of each injector of 1st Embodiment performs. It is a flowchart showing the correction value calculation process which the microcomputer of each injector of 1st Embodiment performs. It is a block diagram showing the engine control system of 2nd Embodiment. It is a flowchart showing the pressure value transmission process which the microcomputer of each injector of 2nd Embodiment performs. It is a flowchart showing the pressure value reception process which the microcomputer of engine ECU of 2nd Embodiment performs. It is a block diagram showing the engine control system of 3rd Embodiment. It is explanatory drawing explaining the conventional engine control system.

  Hereinafter, an engine control system according to an embodiment to which the present invention is applied will be described. In addition, the engine control system of this embodiment controls the fuel injection to the diesel engine of a motor vehicle.

[First Embodiment]
As shown in FIG. 1, the engine control system 10 of 1st Embodiment is injector IJ1 as a fuel-injection apparatus provided in each cylinder (4 cylinders in this embodiment) # 1- # 4 of the vehicle-mounted diesel engine 13. As shown in FIG. To IJ4 and an engine ECU (engine control unit) 11 for controlling fuel injection to the engine 13 by controlling the injectors IJ1 to IJ4.

  Each of the injectors IJ1 to IJ4 is connected to a fuel supply pipe (fuel passage) 17 extending from the fuel outlet of the common rail 15 which is a fuel pressure storage container. The fuel stored in the fuel tank 19 of the vehicle is pumped to the common rail 15 by a fuel pump 21. The injectors IJ1 to IJ4 are supplied with high-pressure fuel stored in the common rail 15 via the fuel supply pipe 17.

  Each of the injectors IJ1 to IJ4 includes an injection port 23 that injects the supplied fuel to a cylinder of the engine 13 and an actuator 25 that opens the injection port 23 when driven. Therefore, in each of the injectors IJ1 to IJ4, when the actuator 25 is driven, the injection port 23 is opened, and fuel is injected from the injection port 23 into the cylinders # 1 to # 4.

  In the present embodiment, the fuel pump 21 is, for example, an engine-driven high-pressure pump that is driven by the rotation of the crankshaft of the engine 13 and performs a pump operation. The actuators 25 of the injectors IJ1 to IJ4 are, for example, electromagnetic solenoids that open the ejection port 23 by energizing the coils, but may be piezoelectric actuators.

  Further, in each of the injectors IJ1 to IJ4, the fuel pressure (so-called inlet pressure) at that position is detected at the connecting portion with the fuel supply pipe 17 (that is, the fuel intake port of the injectors IJ1 to IJ4). A fuel pressure sensor 27 is provided for outputting a sensor signal having a voltage corresponding to the pressure (hereinafter referred to as a fuel pressure signal). For this reason, the fuel pressure detected by the fuel pressure sensor 27 varies depending on the fuel injection operation of the injectors IJ1 to IJ4 provided with the fuel pressure sensor 27. In the following description, the fuel pressure means the fuel pressure detected by the fuel pressure sensor 27 unless otherwise specified, and the fuel pressure at the fuel intake ports of the injectors IJ1 to IJ4.

And each injector IJ1-IJ4 is connected so that communication with ECU11 is possible via the separate communication line L1-L4.
On the other hand, signals from various sensors for detecting the operating state of the engine 13 are also input to the engine ECU 11. As the operation state detection sensor, for example, a known crank angle sensor 29, an intake air amount sensor for detecting the intake air amount to the engine 13, a water temperature sensor for detecting the cooling water temperature of the engine 13, or an accelerator depression amount sensor There are a common rail pressure sensor that detects a common rail pressure that is a fuel pressure in the common rail 15, a fuel temperature sensor that detects a fuel temperature in the common rail 15, and the like.

  And engine ECU11 is provided with the microcomputer 31 which performs the process for injecting fuel to the injectors IJ1-IJ4, and the communication circuit 33 for the microcomputer 31 to communicate with the injectors IJ1-IJ4.

Next, a more detailed configuration of the engine ECU 11 and the injectors IJ1 to IJ4 will be described with reference to FIG.
As shown in FIG. 2, the microcomputer 31 of the engine ECU 11 includes a CPU 41 that executes a program, a ROM 42 that stores a program executed by the CPU 41, and a RAM 43 that stores a calculation result and the like by the CPU 41. And the function of the driving | running state detection part 45 and the injection command value calculation part 47 is implement | achieved because CPU41 runs the program in ROM42.

  Here, the operation state detection unit 45 reads a signal from the above-described operation state detection sensor, and the engine speed, intake air amount, cooling water temperature, accelerator depression amount, common rail pressure, fuel temperature, etc. The operating state of the engine 13 is detected. These operating states are control parameters for fuel injection control.

  The injection command value calculation unit 47 calculates an injection command value indicating the drive start timing and drive duration of the actuator 25 of each injector IJ1 to IJ4 based on the operation state detected by the operation state detection unit 45. The calculated injection command value for each of the injectors IJ1 to IJ4 is transmitted from the communication circuit 33 to the injector corresponding to the injection command value together with a part or all of the operation state detected by the operation state detection unit 45. The

  On the other hand, each of the injectors IJ1 to IJ4 includes a microcomputer 51 that performs a process for driving the actuator 25 based on an injection command value from the engine ECU 11 in addition to the actuator 25 and the fuel pressure sensor 27 described above, and the microcomputer 51 includes the engine ECU 11. A communication circuit 53 for communicating with the fuel pressure sensor 27, an AD converter 55 for AD-converting the fuel pressure signal from the fuel pressure sensor 27, and a drive circuit 57 for driving the actuator 25 in response to a drive signal from the microcomputer 51. ing.

  The microcomputer 51 includes a CPU 61 that executes a program, a ROM 62 that stores a program executed by the CPU 61, a RAM 63 that stores a calculation result and the like by the CPU 61, and a non-volatile memory (for example, a flash memory) that can rewrite data. Memory or EEPROM) 64. Then, the CPU 61 executes the program in the ROM 62, thereby realizing the functions of the injection characteristic detection unit 65, the correction value calculation unit 66, and the injection command value correction unit 67.

  Here, the injection characteristic detection unit 65 causes the AD converter 55 to AD-convert the fuel pressure signal every very short fixed time Ta (for example, 10 μs in this embodiment) that traces the waveform, and each AD The conversion value is read, and the injection characteristic of the injector is detected on the basis of the time-series AD conversion value (that is, the detected value of the fuel pressure) in consideration of the operation state received from the engine ECU 11.

  The correction value calculation unit 66 calculates a correction value for correcting the injection command value transmitted from the engine ECU 11 to the injector based on the injection characteristic detected by the injection characteristic detection unit 65, and calculates the correction value. The correction value is stored in the nonvolatile memory 64.

  The injection command value correction unit 67 corrects the injection command value for the injector received from the engine ECU 11 according to the correction value calculated by the correction value calculation unit 66, and based on the corrected injection command value, the drive circuit 57, the actuator 25 is driven.

Next, processing performed by the microcomputer 31 of the engine ECU 11 and the microcomputer 51 of the injectors IJ1 to IJ4 will be described in more detail with reference to FIGS.
First, FIG. 3 is a flowchart showing a process performed by the microcomputer 31 of the engine ECU 11. FIG. 3A shows an operation state detection process for realizing the function of the operation state detection unit 45, and FIG. 3B shows an injection command value calculation. The injection command value transmission process which implement | achieves the function of the part 47 is represented. In addition, the driving | running state detection process of FIG. 3 (A) is performed for every fixed time, for example. Further, the injection command value transmission process of FIG. 3B is a process executed for each cylinder, for example, before the stroke (intake stroke or compression stroke) for performing fuel injection to the corresponding cylinder. It is executed at the timing of a predetermined crank angle.

  As shown in FIG. 3A, when the microcomputer 31 of the engine ECU 11 starts the operation state detection process, first, in S110, as described above, the signal from the operation state detection sensor is read and the engine 13 The operating state (for example, engine speed, intake air amount, cooling water temperature, accelerator depression amount, common rail pressure, fuel temperature, etc.) is detected.

In the subsequent S120, the operation state detected in S110 is stored (saved) in the operation state storage area of the RAM 43, and then the operation state detection process is terminated.
Further, as shown in FIG. 3B, when the microcomputer 31 of the engine ECU 11 starts the injection command value transmission process for a certain cylinder (here, #n: n is any one of 1 to 4), At S150, the currently detected operating state of engine 13 is read from the operating state storage area of RAM 43.

In the next S160, the injection state of the cylinder #n is set by applying the operation state read in S150 to a map or mathematical formula stored in the ROM 42.
The injection pattern is determined by parameters such as the number of injection stages (number of injections), the injection start timing, the injection continuation time from the injection start timing (corresponding to the injection amount), and the injection interval (injection interval in the case of multistage injection). is there. Further, for example, the injection continuation time is obtained by converting the target injection amount determined based on the engine speed, the accelerator depression amount, and the like into time according to a predetermined conversion rule based on the common rail pressure, the fuel temperature, and the like.

In subsequent S170, based on the injection pattern set in S160, an injection command value suitable for the injection pattern is calculated.
This injection command value is information indicating to the injector IJn the drive start timing (drive start time in the present embodiment) of the actuator 25 provided in the injector IJn of the cylinder #n and the drive continuation time from the drive start timing. is there. For example, among the parameters of the injection pattern set in S160, the injection start timing is set as the drive start timing in the information indicated by the injection command value, and the injection duration is the information indicated by the injection command value. It is set as the drive duration. In the case of multi-stage injection, information indicating the injection instruction value for which stage of injection the injection command value may be added.

  In the next S180, the injection command value calculated in S170 is transmitted to the injector IJn of the cylinder #n via the communication circuit 33. In the case of multi-stage injection, the injection command value for each stage is transmitted. Further, in S180, part or all of the operation state stored in the operation state storage area of the RAM 43 in S120 is also transmitted to the injector IJn. For example, in this embodiment, at least the fuel temperature is transmitted. Then, when the transmission process in S180 ends, the injection command value transmission process ends.

  Next, FIG. 4 is a flowchart showing an injection command value reception process performed by the microcomputer 51 of each injector IJ1 to IJ4. This injection command value reception process is executed, for example, at regular intervals.

  As shown in FIG. 4, when the microcomputer 51 of each injector IJ1 to IJ4 (here, IJn: n is any one of 1 to 4) starts the injection command value acquisition process, first, in S210, the engine It is determined whether or not the injection command value from the ECU 11 to the injector IJn is received by the communication circuit 53. If the injection command value is not received, the injection command value acquisition process is terminated as it is. On the other hand, if the injection command value is received, the process proceeds to S220.

  In S220, the received injection command value is stored (saved) in the injection command value storage area of the RAM 63, and the operation state sent from the engine ECU 11 together with the injection command value is stored in the operation state storage area of the RAM 63. Remember (save). Then, the injection command value receiving process is terminated. If the operation state is sent from the engine ECU 11 separately from the injection command value, the reception confirmation and storage process of the operation state may be performed separately from the injection command value reception process.

  Next, FIG. 5 is a flowchart showing an injection control process performed by the microcomputer 51 of each injector IJ1 to IJ4. In addition, this injection control process is a process which implement | achieves the function of the injection command value correction | amendment part 67, for example, is performed for every fixed time.

  As shown in FIG. 5, the microcomputer 51 of each of the injectors IJ1 to IJ4 (here, IJn is also assumed: n is any one of 1 to 4) starts the injection control process. It is determined whether or not there is an unprocessed injection command value (that is, an injection command value that has not yet been read and used for fuel injection) in the injection command value storage area. If there is no unprocessed injection command value, the injection control process is terminated as it is. If there is an unprocessed injection command value, the process proceeds to S320, and the unprocessed injection command value is read.

  Next, in S330, the correction value for the injection command value is read from the nonvolatile memory 64. In subsequent S340, the injection command value read in S320 is corrected according to the correction value read in S330.

  The correction value in the nonvolatile memory 64 read in S330 is sequentially calculated and updated by a correction value calculation process in FIG. Further, the correction value is a correction value for each of the drive start timing and the drive continuation time indicated by the injection command value, specifically, a timing correction value indicating how much the drive start timing is shifted forward and backward, And a time correction value indicating how much the drive duration time is increased or decreased. For this reason, the injection command value corrected in S340 indicates the timing at which the drive start timing indicated by the injection command value before correction is shifted by the timing correction value as the drive start timing, and is corrected as the drive continuation time. This indicates the time when the drive duration indicated by the previous injection command value is increased or decreased by the time correction value.

  In step S350, the actuator 25 is driven by the drive circuit 57 based on the injection command value corrected in step S340. Specifically, the actuator 25 is driven by the drive circuit 57 from the drive start timing indicated by the corrected injection command value until the drive duration indicated by the corrected injection command value elapses. Then, the injection control process ends.

  Next, FIG. 6 is a flowchart showing an injection characteristic detection process performed by the microcomputer 51 of each injector IJ1 to IJ4. In addition, this injection characteristic detection process is a process which implement | achieves the function of the injection characteristic detection part 65, and is performed for every above-mentioned fixed time Ta (for example, 10 microseconds).

  As shown in FIG. 6, the microcomputer 51 of each injector IJ1 to IJ4 (here, IJn is also assumed: n is any one of 1 to 4) starts the injection characteristic detection process. It is determined whether or not an execution condition is satisfied. If the execution condition is not satisfied, the injection characteristic detection process is terminated as it is. If the execution condition is satisfied, the process proceeds to S420. The execution condition determined in S410 can be arbitrarily set, for example, that the fuel pressure sensor 27 is normal.

  In S420, the fuel pressure is detected. Specifically, the fuel pressure signal from the fuel pressure sensor 27 is AD-converted by the AD converter 55, and the AD conversion value (that is, the voltage value of the fuel pressure signal) by the AD converter 55 is converted into the fuel pressure detection value. And stored (saved) in the fuel pressure storage area of the RAM 63. Instead of starting the AD converter 55 every time in S420, it is set so that the AD converter 55 performs AD conversion every predetermined time Ta. The latest AD conversion value may be read.

  Next, in S430, based on the time-series fuel pressure detection values stored in the fuel pressure storage area of the RAM 63 in the current and past S420, the operation characteristics received from the engine ECU 11 are also taken into account, and the injection characteristics of the injector IJn are determined. Perform detection processing. If the injection characteristic is detected, the detected injection characteristic is the injection command value corresponding to the injection characteristic (that is, the injection command value from which the injection characteristic is obtained, and the current fuel injection (actuator In association with the injection command value used for the driving of 25), it is stored (saved) in the injection characteristic storage area of the RAM 63. And after this S430, the said injection characteristic detection process is complete | finished.

  For example, the types of injection characteristics (detection target injection characteristics) detected in S430 include fuel injection start time, injection end time, and injection amount. The injection start time can be detected as the time when the fuel pressure detection value falls below the predetermined injection start threshold, and the injection end time is detected as the time when the fuel pressure detection value exceeds the predetermined injection end threshold. be able to. Further, a fuel pressure detection value (for example, a fuel pressure detection value at the injection start time) when fuel is not injected is set as a reference pressure value, and the reference pressure value and each fuel pressure from the injection start time to the injection end time The difference from the detected value is integrated, and the injection amount can be detected (estimated) from the integrated value and the fuel temperature received from the engine ECU 11.

  Next, FIG. 7 is a flowchart showing a correction value calculation process performed by the microcomputer 51 of each injector IJ1 to IJ4. The correction value calculation process is a process for realizing the function of the correction value calculation unit 66, and is executed, for example, every time the injection characteristic detection process in FIG. 6 is completed.

  As shown in FIG. 7, when the microcomputer 51 of each of the injectors IJ1 to IJ4 (here, IJn: n is any one of 1 to 4) starts the correction value calculation process, first, in S510, a predetermined value is set. It is determined whether or not an execution condition is satisfied. If the execution condition is not satisfied, the correction value calculation process is terminated as it is. If the execution condition is satisfied, the process proceeds to S520. The execution condition determined in S510 is, for example, that the detection of all types of injection characteristics to be detected for one fuel injection is completed by the injection characteristic detection process of FIG. Can also be set arbitrarily.

In S520, the injection characteristic detected by the injection characteristic detection process and the injection command value corresponding to the injection characteristic are read from the injection characteristic storage area of the RAM 63.
Next, in S530, using the injection characteristic and the injection command value read out in S520, a correction value for correcting the injection command value supplied from the engine ECU 11 through communication is calculated, and the calculated correction value is stored in a nonvolatile manner. Stored (saved) in the memory 64. Then, the correction value calculation process ends.

  For example, among the injection characteristics read in S520, the injection start time is “ts”, the injection end time is “te”, the injection amount is “Q”, and the information indicated by the injection command value read in S520 Of these, assuming that the drive start timing is “Ts” and the drive continuation time is “Tq”, in S530, the difference between ts and Ts (ts−Ts) is calculated as the timing correction value of the correction values. Further, in S530, based on the common rail pressure, fuel temperature, etc. received from the engine ECU 11, Tq is converted into an injection quantity q according to a rule reverse to the conversion rule used on the engine ECU 11 side, and the conversion is further performed. A value obtained by converting the difference (q−Q) between the injection amounts q and Q into time according to the conversion rule is calculated as a time correction value among the correction values. For this reason, in S340 in the injection control process of FIG. 5 described above, among the information indicated by the injection command value read in S320, the drive start timing is corrected to be advanced by the timing correction value, and the drive duration time is set. Then, correction for adding the time correction value is performed.

  In the engine control system 10 of the first embodiment as described above, the injector characteristic detection processing of FIG. 6, the correction value calculation processing of FIG. 7, and the injection control of FIG. A microcomputer 51 that performs processing, an AD converter 55, and a drive circuit 57 are provided, and the injection command values before being corrected based on the injection characteristics are transmitted from the engine ECU 11 to the injectors IJ1 to IJ4 via the communication lines L1 to L4. It comes to be supplied through. That is, the injectors IJ1 to IJ4 are provided with a portion for performing correction control processing (processing for detecting the injection characteristics to correct the injection command value and driving the actuator 25) based on the injection characteristic detection values.

  According to the engine control system 10 as described above, the engine ECU 11 may output the injection command value with the same logic regardless of the presence or absence of the correction control process based on the injection characteristic detection value. For example, when applied to a system that does not perform the correction control process using the injection characteristic detection value, the injectors IJ1 to IJ4 do not perform the correction control process using the injection characteristic detection value, but rather the injection command information value from the engine ECU 11 The actuator 25 is driven based on the injection command value without correcting, or the injection command value from the engine ECU 11 is corrected with a fixed correction value stored in advance in the ROM 62 or the nonvolatile memory 64, What drives the actuator 25 based on the corrected injection command value may be used.

  Therefore, the engine ECU 11 can be made common with respect to the presence or absence of the correction control processing based on the injection characteristic detection value, and the cost of the engine ECU 11 can be reduced due to the common parts and configuration. In particular, the engine ECU 11 does not need to perform the correction control process based on the detected injection characteristic value, so that a microcomputer with low performance and low cost can be used as the microcomputer 31. Furthermore, since the engine ECU 11 can be developed independently of the content of the correction control process based on the detected injection characteristic value, the development efficiency of the engine ECU 11 can also be improved.

  Also, the entire system can be configured using an inexpensive microcomputer with low performance. This is because each of the injectors IJ1 to IJ4 only needs to perform correction control processing based on the detected injection characteristic value for itself. This is because the processing load for one cylinder does not change. Therefore, an engine control system can be configured using a microcomputer having lower performance and lower cost than conventional ones.

  Further, according to the present embodiment, since the correction control processing based on the injection characteristic detection value is performed on the side of each of the injectors IJ1 to IJ4, the responsiveness until the detection result of the injection characteristic is reflected in the correction of the injection command value is increased. Can do. For this reason, in this embodiment, even in the case of multi-stage injection, the correction value based on the injection characteristic detected at the time of the previous stage fuel injection can be used to correct the injection command value for the next stage fuel injection. I am doing so. Of course, in the case of multi-stage injection, a correction value dedicated to each stage is calculated from the injection characteristics detected for each stage, and the correction value for each stage is corrected to the injection command value for the same stage in the next injection cycle. You may make it use for.

  Furthermore, in this embodiment, since the fuel pressure sensor 27 is also provided in the injectors IJ1 to IJ4, it is possible to suppress noise from being added to the fuel pressure signal (sensor signal) from the fuel pressure sensor 27 to the AD converter 55. As a result, the injection characteristic can be detected with high accuracy.

  For example, in the conventional engine control system illustrated in FIG. 12, the fuel pressure signal is sequentially AD converted on the injectors IJ1 to IJ4 side, and each AD conversion value is transmitted to the engine ECU 1 by communication, thereby affecting the influence of noise. In such a configuration, for example, if the number of bits of the AD conversion value is 10 bits, high-speed communication such as “10 bits / 10 μs” is required. However, according to the present embodiment, such high-speed communication every 10 μs is unnecessary.

  On the other hand, in the present embodiment, the fuel pressure sensor 27 corresponds to the fuel pressure detecting means. In addition, the injection command values transmitted from the engine ECU 11 as the engine control unit to the injectors IJ1 to IJ4 correspond to the injection command information, and the injectors IJ1 to IJ4 correspond to devices separate from the engine control unit. Yes.

  And in engine ECU11, the function as a command calculation means is implement | achieved by the injection command value transmission process of FIG.3 (B). Further, in the injectors IJ1 to IJ4, the function as the injection characteristic detection means is realized by the AD converter 55 and the injection characteristic detection process of FIG. 6, and as the correction value calculation means by the correction value calculation process of FIG. The function as the correcting means is realized by the processes of S310 to S340 in the injection control process of FIG. And the function as a drive means is implement | achieved by the process of S350 and the drive circuit 57 in the injection control process of FIG.

[Second Embodiment]
In the engine control system 10 of the first embodiment, the microcomputer 31 of the engine ECU 11 calculates the common rail pressure based on a signal from a common rail pressure sensor (not shown) as one piece of information (operating state) for calculating the injection command value. The injection command value was calculated based on the detected common rail pressure. This is because the relationship between the injection duration (drive duration) and the injection amount changes depending on the common rail pressure (pressure of fuel supplied to the injectors IJ1 to IJ4).

Here, when there is no common rail pressure sensor, it can be configured as in the second embodiment described below.
As shown in FIG. 8, the engine control system 70 of the second embodiment has no common rail pressure sensor as compared with the first embodiment, and therefore the engine is controlled from at least one of the injectors IJ1 to IJ4 (here, IJ1). A fuel pressure detection value (AD converted value of the fuel pressure signal) is transmitted to the ECU 11.

  More specifically, the microcomputer 51 of the injector IJ1 is in the non-injection time when the actuator 25 is not driven (for example, when the time when the fuel pressure to be detected is stabilized after the fuel injection ends). The pressure value transmission process of FIG. 9 is performed.

  In the pressure value transmission process, first, in S610, the AD converter 55 is caused to AD-convert the fuel pressure signal, and the AD conversion value is read as a fuel pressure detection value. If the fuel pressure at the time of non-injection is detected in S420 of FIG. 6, the detected fuel pressure value may be read from the RAM 63.

In the next S620, the fuel pressure detection value acquired in S610 is transmitted to the engine ECU 11, and then the pressure value transmission process is terminated.
On the other hand, the microcomputer 31 of the engine ECU 11 executes the pressure value receiving process shown in FIG. 10 at regular time intervals, for example.

  As shown in FIG. 10, when the microcomputer 31 of the engine ECU 11 starts the pressure value receiving process, first, in S710, it is determined whether or not the fuel pressure detection value from the injector IJ1 is received by the communication circuit 33. If the fuel pressure detection value is not received, the pressure value reception processing is terminated as it is. If the fuel pressure detection value is received, the process proceeds to S720. In S720, the fuel pressure detection value received this time is stored (saved) in the operation state storage area of the RAM 43, and then the pressure value receiving process is terminated.

  Then, the microcomputer 31 of the engine ECU 11 calculates the injection command value using the fuel pressure detection value received from the injector IJ1 in the injection command value transmission process of FIG. That is, instead of the common rail pressure, the injection command value is calculated using the inlet pressure of the injector IJ1 when fuel injection is not performed.

According to such 2nd Embodiment, there exists an advantage that a common rail pressure sensor becomes unnecessary.
Further, in the second embodiment, the fuel pressure detection value transmitted from the injector IJ1 to the engine ECU 11 is not used for detecting the injection characteristics but is used instead of the common rail pressure. The communication with the engine ECU 11 may be, for example, a communication at a speed such as “10 bits / 1 ms”, and the high-speed communication such as “10 bits / 10 μs” described above is of course necessary.

[Third Embodiment]
The engine control system 72 of the third embodiment shown in FIG. 11 differs from the first embodiment in the following points.

First, the injectors IJ1 to IJ4 are not provided with the microcomputer 51, the communication circuit 53, the AD converter 55, and the drive circuit 57.
Then, between the engine ECU 11 and the injectors IJ1 to IJ4, the actuators 25 of the injectors IJ1 to IJ4 are driven based on the injection command value for each cylinder from the engine ECU 11 to inject fuel into the injectors IJ1 to IJ4. An electronic drive unit (hereinafter referred to as EDU) 75 as an ejection drive device is provided.

  The EDU 75 includes a microcomputer 81, a communication circuit 83 for the microcomputer 81 to communicate with the engine ECU 11, an AD converter 85 for AD-converting the fuel pressure signal from the fuel pressure sensor 27 of each injector IJ 1 to IJ 4, and the microcomputer 81. And a drive circuit 87 for driving the actuators 25 of the injectors IJ1 to IJ4 in accordance with the drive signal from.

  The microcomputer 81 includes a CPU 91 that executes a program, a ROM 92 that stores a program executed by the CPU 91, a RAM 93 that stores a calculation result by the CPU 91, and a non-volatile memory that can rewrite data (for example, a flash memory). Memory or EEPROM) 94.

  In the engine control system 72, the same information is transmitted to the injectors IJ1 to IJ4 from the engine ECU 11 of the first embodiment, and the injection command value for each cylinder (for each injector IJ1 to IJ4) and the engine 13 are the same. Are transmitted from the engine ECU 11 to the EDU 75.

  And the microcomputer 81 of EDU75 performs the same process as the process which the microcomputer 51 performs in the injectors IJ1-IJ4 of 1st Embodiment about each injector IJ1-IJ4. More specifically, the injection command value reception process of FIG. 4 among the processes of FIGS. 4 to 7 described above is performed in common for each of the injectors IJ1 to IJ4, but the injection control process of FIG. 5 and the injection of FIG. The characteristic detection process and the correction value calculation process of FIG. 7 are performed for each of the injectors IJ1 to IJ4.

  That is, in the engine control system 72 of the third embodiment, the EDU 75 that is a device separate from the engine ECU 11 is provided with a portion that performs correction control processing based on the detected injection characteristic value for each of the injectors IJ1 to IJ4.

  For this reason, as in the other embodiments described above, the engine ECU 11 can be shared with respect to the presence / absence of the correction control process based on the detected injection characteristic value, and the cost of the engine ECU 11 can be reduced due to the common parts and configuration. Since the engine ECU 11 can be developed independently of the content of the correction control process based on the detected injection characteristic value, the development efficiency of the engine ECU 11 can also be improved. .

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to such Embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect. .

  For example, information indicating an injection angle (a crank angle at which injection should be started) and an injection amount are transmitted as an injection command value (injection command information) from the engine ECU 11 to each of the injectors IJ1 to IJ4 or EDU75. The information may be converted into the drive start timing and the drive duration time of the actuator 25 by the IJ4 or EDU75, and the above-described processing may be performed. That is, any injection command value (injection command information) transmitted from the engine ECU 11 may be used as long as it can instruct the transmission start timing and driving duration of the actuator 25 to the transmission counterpart. Either the form to perform or the form to instruct indirectly may be sufficient.

  On the other hand, the position where the fuel pressure sensor 27 is provided is not limited to the fuel intake ports of the injectors IJ1 to IJ4, but is injected from the fuel outlet of the common rail 15 (the end on the common rail 15 side of the fuel supply pipe 17). It may be at any position in the fuel passage to the mouth.

  The target of fuel injection control may be a gasoline engine. Further, the number of cylinders of the engine may be other than four.

DESCRIPTION OF SYMBOLS 10,70,72 ... Engine control system 11 ... Engine ECU (engine control unit), L1-L4 ... Communication line 13 ... Engine (vehicle-mounted diesel engine), 15 ... Common rail 17 ... Pipe for fuel supply, 19 ... Fuel tank, 21 ... fuel pumps IJ1 to IJ4 ... injectors (fuel injection devices), 23 ... injection ports 25 ... actuators, 27 ... fuel pressure sensors, 29 ... crank angle sensors 31, 51, 81 ... microcomputers, 33, 53, 83 ... communication circuits 41 61, 91 ... CPU, 42, 62, 92 ... ROM
43, 63, 93 ... RAM, 45 ... operating state detection unit, 47 ... injection command value calculation unit 55,85 ... AD converter, 57,87 ... drive circuit, 64,94 ... nonvolatile memory 65 ... injection characteristic detection unit , 66 ... Correction value calculation unit, 67 ... Injection command value correction unit

Claims (6)

An injection port for injecting the fuel into a cylinder of the engine by being opened while the fuel is supplied from a pressure accumulating container for storing fuel pumped by a fuel pump; and an actuator for opening the injection port by being driven; A fuel injection device having
A fuel pressure in the fuel passage, which is provided at a predetermined position in a fuel passage from the fuel outlet of the pressure accumulating container to the injection outlet of the fuel injection device, fluctuates with fuel injection from the injection opening, is detected, and the fuel pressure Fuel pressure detecting means for outputting a sensor signal having a voltage corresponding to
Command calculation means for calculating injection command information for instructing the drive start timing and drive duration of the actuator based on the operating state of the engine;
An injection characteristic detecting means for reading the voltage value of the sensor signal at regular intervals and detecting the injection characteristic of the fuel injection device from the read result;
Correction value calculating means for calculating a correction value for correcting the injection command information based on the injection characteristics detected by the injection characteristic detecting means;
Correction means for correcting the injection command information calculated by the command calculation means according to the correction value calculated by the correction value calculation means;
Drive means for driving the actuator based on the injection command information corrected by the correction means;
In an engine control system with
The injection characteristic detection means, the correction value calculation means, the correction means, and the drive means are provided in a separate device from the engine control unit that includes the command calculation means. The injection command information is supplied from the engine control unit;
An engine control system characterized by The engine control system according to claim 1,
The separate device is the fuel injection device;
An engine control system characterized by The engine control system according to claim 2,
The fuel injection device comprises the fuel pressure detection means;
An engine control system characterized by The engine control system according to claim 1,
The separate device is:
The fuel injection device is another device;
An engine control system characterized by An injection port for injecting the fuel into a cylinder of the engine by being opened while the fuel is supplied from a pressure accumulating container for storing fuel pumped by a fuel pump; and an actuator for opening the injection port by being driven; A fuel injection device having
A fuel pressure in the fuel passage, which is provided at a predetermined position in a fuel passage from the fuel outlet of the pressure accumulating container to the injection outlet of the fuel injection device, fluctuates with fuel injection from the injection opening, is detected, and the fuel pressure Fuel pressure detecting means for outputting a sensor signal having a voltage corresponding to
Command calculation means for calculating injection command information for instructing the drive start timing and drive duration of the actuator based on the operating state of the engine;
An injection characteristic detecting means for reading the voltage value of the sensor signal at regular intervals and detecting the injection characteristic of the fuel injection device from the read result;
Correction value calculating means for calculating a correction value for correcting the injection command information based on the injection characteristics detected by the injection characteristic detecting means;
Correction means for correcting the injection command information calculated by the command calculation means according to the correction value calculated by the correction value calculation means;
Drive means for driving the actuator based on the injection command information corrected by the correction means;
The fuel injection device in an engine control system comprising:
The fuel pressure detection means, the injection characteristic detection means, the correction value calculation means, the correction means and the drive means,
The injection command information is supplied from an engine control unit including the command calculation means;
A fuel injection device characterized by the above. An injection port for injecting the fuel into a cylinder of the engine by being opened while the fuel is supplied from a pressure accumulating container for storing fuel pumped by a fuel pump; and an actuator for opening the injection port by being driven; A fuel injection device having
A fuel pressure in the fuel passage, which is provided at a predetermined position in a fuel passage from the fuel outlet of the pressure accumulating container to the injection outlet of the fuel injection device, fluctuates with fuel injection from the injection opening, is detected, and the fuel pressure Fuel pressure detecting means for outputting a sensor signal having a voltage corresponding to
Command calculation means for calculating injection command information for instructing the drive start timing and drive duration of the actuator based on the operating state of the engine;
An injection characteristic detecting means for reading the voltage value of the sensor signal at regular intervals and detecting the injection characteristic of the fuel injection device from the read result;
Correction value calculating means for calculating a correction value for correcting the injection command information based on the injection characteristics detected by the injection characteristic detecting means;
Correction means for correcting the injection command information calculated by the command calculation means according to the correction value calculated by the correction value calculation means;
Drive means for driving the actuator based on the injection command information corrected by the correction means;
An injection drive device that causes the fuel injection device to inject the fuel by driving the actuator of the fuel injection device, comprising:
The injection characteristic detection means, the correction value calculation means, the correction means and the drive means,
The injection command information is supplied from an engine control unit including the command calculation means;
An injection driving device characterized by the above.

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