JP2012026373A - Control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an internal combustion engine capable of accurately detecting a rotational phase of an engine output shaft.SOLUTION: This device includes a waveform shaping circuit for outputting a pulse signal of a 10° CA interval having a reference phase, measures a pulse interval and stores a measuring result in a just near predetermined period. The device specifies the reference phase based on the relationship of these pulse intervals, and detects a crank phase based on the pulse signal and the reference phase. The device includes an automatic stopping restarting system for automatically stopping the internal combustion engine when an automatic stopping condition is established, and restarting the internal combustion engine when a restarting condition is established thereafter. The device prohibits specification of the reference phase (S102) over a specific period with the starting timing (S101: YES) of restarting of the internal combustion engine as a starting point and the timing (S103: YES) having the possibility of specifying that the measured pulse interval is the reference phase before and after starting the restarting.

Description

  The present invention relates to a control device for an internal combustion engine that includes a phase detection system that detects a rotational phase of an engine output shaft and an automatic stop / restart system that temporarily automatically stops engine operation.

  As a control device for an internal combustion engine, a rotation sensor that outputs a pulse-like signal (pulse signal) at every predetermined phase as the engine output shaft rotates is provided and the rotation of the engine output shaft is performed based on the output signal of the rotation sensor. What detects a phase and uses it for engine control, such as fuel injection control, is known. In addition, as in the device described in Patent Document 1, a part where the output interval of the pulse signal is set longer than the other part, that is, a so-called missing tooth part is set, and the rotation phase where the part is detected is set as a reference phase. Devices that perform such operations are also known. In such a device, a missing tooth portion is detected on the condition that the output interval (pulse interval) of the pulse signal is larger than the pulse interval before and after the pulse signal. Then, the number of output of the pulse signal is counted as the rotation amount of the engine output shaft, and the rotation phase of the engine output shaft is detected based on the rotation amount and the reference phase.

  The internal combustion engine is mounted on a vehicle as a drive source, and the internal combustion engine does not need to be operated such as when the vehicle is stopped at an intersection of the vehicle in order to reduce fuel consumption and emission. It is practical to execute automatic stop / restart control for temporarily stopping the operation. In this automatic stop / restart control, normally, when a predetermined automatic stop condition is satisfied, execution of the fuel injection control is stopped and the internal combustion engine is automatically stopped. After that, when the restart condition is satisfied, driving of the starter motor and fuel The execution of the injection control is started and the internal combustion engine is restarted.

JP 2009-68425 A

  By the way, when the internal combustion engine is automatically stopped through the automatic stop / restart control, the rotational speed of the engine output shaft (engine rotational speed) rapidly decreases as the fuel injection control is stopped. On the other hand, when the internal combustion engine is restarted through the automatic stop / restart control, the engine speed rapidly increases as the starter motor starts to be driven.

  For this reason, if the internal combustion engine is restarted immediately after the process of decreasing the engine speed during the automatic stop of the internal combustion engine or immediately after the engine output shaft stops rotating, the engine speed rapidly increases immediately after the engine speed rapidly decreases. Change. In this case, the output interval of the pulse signal output from the rotation sensor changes in such a manner that it temporarily expands, such as once it rapidly expands and then decreases, and then rapidly decreases. become. Such a change mode of the pulse interval is very similar to a change mode of the pulse interval before and after the missing tooth portion, that is, a change mode in which the pulse interval becomes larger than the pulse interval before and after the pulse interval. Therefore, if the missing tooth portion is detected based on the transition of the pulse interval when the internal combustion engine is restarted, the missing portion is detected in the rotational phase at which the engine rotational speed is the lowest (specifically, the rotational phase where the pulse interval is the longest). There is a possibility that the tooth portion is erroneously detected and the rotation phase is erroneously detected as the reference phase.

  In such a case, since the rotational phase of the engine output shaft is detected based on the erroneously detected reference phase, engine control such as fuel injection control is performed based on the erroneously detected rotational phase of the engine output shaft. It will be executed. Therefore, there is a possibility that the start-up performance is reduced such that the time required for restarting the internal combustion engine becomes longer.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a control device for an internal combustion engine that can accurately detect the rotational phase of the engine output shaft.

In the following, means for achieving the above object and its operational effects will be described.
According to the first aspect of the present invention, there is provided a rotation signal that generates a rotation signal comprising a pulse sequence having a predetermined phase interval corresponding to the rotation of the engine output shaft and having a reference phase having a pulse interval longer than that of other portions in the middle thereof. The reference phase based on the relationship between the generation means, the storage means for measuring the pulse interval based on the rotation signal, and storing the measurement result in the most recent predetermined period, and the pulse interval stored by the storage means. A rotation phase detection system having a specifying means for specifying, a detection means for detecting a rotation phase of the engine output shaft based on the rotation signal and the reference phase, and automatically stopping the internal combustion engine when an automatic stop condition is satisfied And control of the internal combustion engine provided with an automatic stop / restart system for restarting the internal combustion engine when a restart condition is satisfied thereafter When the start time of the restart is set as a starting point and the pulse interval measured by the storage unit before and after the start of the restart may be specified as the reference phase by the specifying unit The gist is to prohibit the specification of the reference phase by the specifying means over a specific period of time.

  According to the above configuration, the longest value among the pulse intervals measured before and after the start of the restart of the internal combustion engine, in other words, the pulse interval measured when the internal combustion engine is automatically stopped and restarted corresponds to the reference phase. It can be avoided that the value is erroneously determined to be a value. For this reason, although the pulse interval measured by the storage means is changed temporarily when the internal combustion engine is automatically stopped and restarted, the reference phase is erroneously caused by the change. It can suppress being specified. Therefore, the reference phase can be specified with high accuracy, and the rotational phase of the engine output shaft can be detected with high accuracy.

  According to a second aspect of the present invention, in the control device for an internal combustion engine according to the first aspect of the present invention, the predetermined means stores a predetermined relationship predetermined by the storage means, where N is a predetermined natural number. When the relationship between the pulse intervals is satisfied, the rotational phase when the value N times before of the plurality of pulse intervals stored in the storage unit is measured is specified as the reference phase. The gist of the invention is that the specific period is a period from when the restart is started to when the pulse interval is measured and stored only “N + 1” times.

  In the above configuration, as the predetermined relationship, a relationship capable of specifying the rotation phase when the value N times before the pulse interval stored in the storage unit is measured as the reference phase is determined in advance. Yes. Therefore, if the specification of the reference phase is not prohibited, the storage means at the timing when the value measured when the pulse interval becomes the longest when the internal combustion engine is restarted becomes the value before N times. The relationship between the stored pulse intervals may become a predetermined relationship, and the rotational phase obtained by measuring the previous N times may be erroneously specified as the reference phase. And after the pulse interval is measured “N + 2” times after the restart of the internal combustion engine, basically, it is stored in the storage means unless the pulse interval corresponding to the actual reference phase is measured. The relationship between the pulse intervals is not a relationship indicating that the pulse interval has temporarily increased rapidly. Therefore, in this case, it can be said that the relationship between the pulse intervals stored in the storage means does not satisfy a predetermined relationship.

  According to the above configuration, only after the pulse interval is measured “N + 2” times after restarting the internal combustion engine, that is, only when the possibility that the reference phase is erroneously specified becomes very low. Since the specification of the phase is permitted, the reference phase can be specified with high accuracy.

  The configuration of the invention described in claim 1 or 2 may be applied to an apparatus including a starter motor that is driven when the internal combustion engine is started to apply auxiliary torque to the engine output shaft, as in claim 3. it can.

  According to a fourth aspect of the present invention, there is provided the control device for an internal combustion engine according to the third aspect, wherein the control device uses the start time of the restart as the drive start time of the starter motor. And

  According to a fifth aspect of the present invention, in the control apparatus for an internal combustion engine according to the third aspect, the control apparatus determines the start timing of the restart based on the condition that the starter motor is driven and the engine. The gist is that it is a time when both conditions that the rotational speed of the output shaft is increasing are satisfied.

  According to the configuration of the invention described in claim 4 or 5, when the starter motor starts to be driven when the internal combustion engine is restarted and the rotational speed of the engine output shaft starts to increase, in other words, it is erroneously determined that the phase is the reference phase. It is possible to start the above-described prohibition of the reference phase at the timing immediately before (or immediately after) the pulse interval that may be specified by the measurement, and to execute the specific prohibition of the reference phase accurately. it can.

  The invention according to claim 6 is the control apparatus for an internal combustion engine according to any one of claims 3 to 5, wherein the control apparatus is configured to execute the restart condition when the restart condition is satisfied. The starter motor is driven on the condition that the rotational speed of the engine output shaft is less than a predetermined speed, and the reference phase is set on the condition that the internal combustion engine is restarted with the starter motor being driven. Its gist is that it is prohibited to specify.

  In the above configuration, when restarting the internal combustion engine with driving of the starter motor, the engine rotation speed increases rapidly and the pulse interval reduction speed is also fast. Therefore, the reference phase is erroneously changed based on the sudden change in the pulse interval. There is a risk of identification. On the other hand, when restarting the internal combustion engine without driving the starter motor, for example, restarting only by restarting fuel injection, the engine speed increase rate is relatively slow and the pulse interval reduction rate is also relatively slow. Therefore, it is very unlikely that the reference phase is erroneously specified.

  According to the above configuration, when the internal combustion engine is restarted with driving of the starter motor, that is, when there is a high possibility that the reference phase is erroneously specified, the specification is prohibited, so the reference phase is erroneously set. It is possible to accurately suppress identification. Moreover, when the internal combustion engine is restarted without driving the starter motor, that is, when the possibility that the reference phase is erroneously specified is very low, the specification is not prohibited, so that the reference phase can be specified early. become able to.

1 is a schematic diagram illustrating a schematic configuration of a control device for an internal combustion engine according to an embodiment of the present invention. The time chart which shows an example of the measurement result of the pulse interval at the time of restart of an internal combustion engine. The time chart which shows the other example of the measurement result of the pulse interval at the time of restart of an internal combustion engine. The flowchart which shows notionally the execution procedure of a specific prohibition process. The timing chart which shows an example of the execution aspect of a specific prohibition process.

A control apparatus for an internal combustion engine according to an embodiment embodying the present invention will be described below.
FIG. 1 shows a schematic configuration of a control device for an internal combustion engine according to the present embodiment. The control device according to the present embodiment is applied to an internal combustion engine mounted on a vehicle as a drive source.

  As shown in FIG. 1, a starter motor 11 is provided in the internal combustion engine. The starter motor 11 is driven when the engine is started to apply auxiliary torque to the engine output shaft 12. The control device of the present embodiment includes an electronic control unit 20 and various sensors.

  As these sensors, for example, a temperature sensor 31 for detecting the temperature of engine cooling water and a speed sensor 32 for detecting the traveling speed of the vehicle are provided. Further, a rotational phase sensor 33 for detecting the rotational phase (crank phase [° CA]) and rotational speed (engine rotational speed NE) of the engine output shaft 12 and for detecting the rotation of the cam shaft 13 of the internal combustion engine. A cylinder discrimination sensor 34 is provided. In addition, a brake switch 35 for detecting whether or not the brake pedal 14 is depressed, an idle switch 36 for detecting whether or not the accelerator pedal 15 (not shown) is depressed, and the like are also provided.

  The electronic control unit 20 captures output signals from various sensors. The electronic control unit 20 performs various calculations based on these output signals, and starts operation of the internal combustion engine such as operation control of the starter motor 11 and operation control of the fuel injection valve 16 (fuel injection control) based on the calculation results. Perform various controls.

The apparatus according to the present embodiment includes automatic stop / restart for executing control (automatic stop / restart control) for temporarily stopping the operation of the internal combustion engine when the vehicle is stopped at an intersection or the like, which is one of the various controls. The system is installed. In this automatic stop / restart control, it is determined that the automatic stop condition is satisfied when all of the following conditions [condition 1] to [condition 5] are satisfied.
[Condition 1] The internal combustion engine has been warmed up (the temperature of the cooling water is higher than the lower limit).
[Condition 2] The accelerator pedal 15 is not depressed (the idle switch 36 is “ON”).
[Condition 3] The brake pedal 14 is depressed (the brake switch 35 is “ON”).
[Condition 4] The vehicle is stopped.
[Condition 5] After all [Condition 1] to [Condition 4] are satisfied, there is no history of the automatic stop of the internal combustion engine.

  When the automatic stop condition is satisfied, for example, when the vehicle stops at an intersection, the operation of the internal combustion engine is stopped, for example, by stopping the fuel supply to the internal combustion engine. On the other hand, under the condition that the internal combustion engine is in a stopped state when the above-described automatic stop condition is satisfied, the restart condition is satisfied when any one of [Condition 1] to [Condition 4] is not satisfied. Is determined to have been established. When the restart condition is satisfied, the starter motor 11 is driven to start the cranking operation and the fuel injection control is executed to restart the internal combustion engine.

In the present embodiment, by executing such automatic stop / restart control, the fuel consumption of the internal combustion engine and the emission can be reduced.
In the device according to the present embodiment, when the internal combustion engine is restarted, the starter motor 11 is provided on condition that the engine speed NE when the restart condition is satisfied is less than a predetermined speed V1 (for example, 400 rpm). Is driven. That is, when the engine speed NE when the restart condition is satisfied is less than the predetermined speed V1, the starter motor 11 is driven to forcibly stop the internal combustion engine while automatically applying the auxiliary torque to the engine output shaft 12. When the various controls (for example, fuel injection control) are restarted, the internal combustion engine is restarted. On the other hand, when the engine speed NE at the time when the restart condition is satisfied is equal to or higher than the predetermined speed V1, the starter motor 11 is not driven. That is, in this case, the internal combustion engine is restarted only by resuming various controls that are forcibly stopped when the internal combustion engine is automatically stopped without driving the starter motor 11.

  In addition, the apparatus of the present embodiment is provided with a rotational phase detection system that detects the rotational phase (crank phase) of the engine output shaft 12 based on the detection signal of the rotational phase sensor 33 and the detection signal of the cylinder discrimination sensor 34. ing. Hereinafter, the rotational phase detection system will be described in detail.

  The electronic control unit 20 includes a waveform shaping circuit 21. The waveform shaping circuit 21 receives a detection signal from the rotational phase sensor 33 and a detection signal from the cylinder discrimination sensor 34. The rotational phase sensor 33 is provided at a position close to the pulsar 12a attached to the engine output shaft 12, and detects that the teeth on the outer periphery of the pulsar 12a have passed by a built-in pickup coil. The cylinder discrimination sensor 34 is provided at a position close to the pulsar 13a attached to the camshaft 13, and detects that the teeth on the outer periphery of the pulsar 13a have passed by a built-in pickup coil.

  The waveform shaping circuit 21 converts the output signal of the rotation phase sensor 33 into a pulse signal (pulse signal) and outputs the signal as a rotation signal (hereinafter referred to as NE10 signal). The waveform shaping circuit 21 converts the output signal of the cylinder discrimination sensor 34 into a pulse signal and outputs the signal as a rotation signal (hereinafter referred to as a Gin signal). These NE10 signal and Gin signal are input to the microcomputer 22 of the electronic control unit 20. In the present embodiment, the rotation phase sensor 33 and the waveform shaping circuit 21 function as rotation signal generation means.

  The NE10 signal is composed of a pulse train every 10 ° CA (predetermined phase interval), and a portion (hereinafter referred to as a missing tooth portion) in which two pulses are missing is provided in the middle of the pulse train. The interval between the missing tooth portions is 360 ° CA, and this missing tooth portion corresponds to “a reference phase having a longer pulse interval than other portions”.

  The apparatus according to the present embodiment detects a crank phase based on these NE10 signal and Gin signal, and performs various fuel injection control and the like based on the crank phase (specifically, a count value CA of a crank counter described later). Execute control. Specifically, in order to control the drive of various devices such as the fuel injection valve 16 based on the count value CA of the crank counter, a control command signal is output from the electronic control unit 20 to these devices.

Such crank phase detection is performed as follows.
In this detection, the electronic control unit 20 starts an interrupt process for each rising edge of the NE10 signal input from the waveform shaping circuit 21. The following processing is executed through this interrupt processing.

  In this process, the past value and the current value of the timer value TA of the internal timer for detecting the time between rising edges of the NE10 signal are updated. Specifically, the previous value TA [i−2] stored in the RAM 23 of the electronic control unit 20 is stored as a new previous value TA [i−3], and is also stored in the RAM 23. The previous value TA [i−1] is stored as the new previous value TA [i−2], and the current value TA [i] stored in the RAM 23 is the new previous value TA [i−1]. Stored as value TA [i-1]. Further, the timer value TA of the internal timer at this time is stored as the current value TA [i], and the timer value TA is reset to “0”.

  As described above, in the present embodiment, the electronic control unit 20 measures the pulse interval based on the rotation signal (NE10 signal) and at the same time the measurement result (specifically, TA [i-3]). , TA [i-2], TA [i-1], TA [i]) are stored. In the present embodiment, the electronic control unit 20 functions as a storage unit.

When detecting a missing tooth part, it is first determined whether the current value TA [i] and the previous value TA [i-1] satisfy the following [Condition A].
[Condition A] Determination value J1 (for example, 2.4) ≦ (TA [i] / TA [i−1]) <determination value J2 (for example, 6.0)
When this [Condition A] is satisfied, the phenomenon that the pulse interval, which is one of the detection conditions of the missing tooth portion, suddenly increases, and the pulse interval suddenly increases when the rotation of the engine output shaft 12 stops, It is judged that there is no. When this [Condition A] is satisfied, the temporary determination flag is turned on.

When the temporary determination flag is turned on in this way, after this processing (specifically, the past value of the timer value TA and the update of the current value described above) are executed three times, The previous value TA [i-3], the previous value TA [i-2], the previous value TA [i-1] and the current value TA [i] are as follows: It is determined whether or not all the conditions [d] are satisfied.
[Condition B] (TA [i-2] / TA [i-3]) <judgment value J3 (for example, 0.7)
[Condition C] (TA [i-1] / TA [i-2]) ≧ judgment value J4 (for example, 0.1)
[Condition D] (TA [i] / TA [i-1]) ≧ determination value J5 (for example, 0.1)
When all of these [Condition B] to [Condition D] are satisfied, it is determined that the phenomenon that the pulse interval, which is also one of the detection conditions of the missing tooth part, has occurred, and this missing tooth determination flag is turned on. Operated.

  In the apparatus according to the present embodiment, since the temporary missing flag is turned on after the temporary missing flag is turned on in this way, it is assumed that the pulse interval temporarily becomes long and the missing interval is determined. The tooth part is identified. Specifically, the crank phase when the value TA [i-3] three times before is measured is specified as the reference phase (specifically, the rotational phase of the engine output shaft 12 corresponding to the missing tooth portion). The

  Thus, in the present embodiment, each pulse interval (specifically, TA [i-3], TA [i-2], TA [i-1], TA stored in the electronic control unit 20 is described. When the relationship [i]) satisfies a predetermined relationship (specifically, [Condition A] to [Condition D]), the value TA [i− 3] is determined as the reference phase. The electronic control unit 20 has an experiment on the relationship in which the crank phase when the value TA [i-3] three times before the pulse interval stored in the RAM 23 is measured can be specified as the reference phase. Further, it is obtained in advance based on the result of the simulation and the obtained relationship is stored as the predetermined relationship. In this embodiment, the electronic control unit 20 functions as specifying means for specifying the reference phase based on the relationship between the pulse intervals stored by the storage means.

  In the apparatus according to the present embodiment, the crank phase is detected based on the reference phase specified as described above and the NE10 signal. Specifically, a crank counter is set in the electronic control unit 20. The count value CA of the crank counter is incremented by “1” every time the engine output shaft 12 rotates 30 ° CA (every time the NE10 signal is input three times). The count value CA of the crank counter is reset to the initial value (“0” or “12”) when the engine output shaft 12 rotates by 210 ° CA after the missing tooth determination flag is turned on. Specifically, when the Gin signal is on, the initial value is reset to “0”, and when the Gin signal is off, the initial value is reset to “12”.

  As a result, the count value CA of the crank counter becomes a value from “0” to “23”. Based on the count value CA, the crank phase is detected, for example, “0” is 0 ° CA, “1” is 30 ° CA, “2” is 60 ° CA, and the like. Thus, various controls related to engine control are executed. In the present embodiment, the electronic control unit 20 functions as detection means for detecting the rotational phase of the engine output shaft 12 based on the rotational signal (NE10 signal) and the reference phase.

  By the way, when the internal combustion engine is restarted immediately after the process of decreasing the engine speed NE during the automatic stop of the internal combustion engine or immediately after the engine output shaft 12 stops rotating, the pulse interval (output interval of the NE10 signal) temporarily increases. That is, it changes in a manner that closely resembles the change mode in the missing tooth region. Therefore, when the missing tooth part (reference phase) is detected based on the transition of the pulse interval when the internal combustion engine is restarted, the crank phase at which the engine speed NE is the lowest (specifically, the pulse interval becomes the longest). (Crank phase) may be erroneously detected as a missing tooth portion, and the crank phase may be erroneously detected as the reference phase. In this case, since the crank phase is detected based on the erroneously detected reference phase, engine control such as fuel injection control is executed based on the erroneously detected crank phase, There is a possibility that the start-up performance may be reduced such that the time required for restarting the internal combustion engine becomes longer.

  In view of this point, in the present embodiment, it is prohibited to specify the reference phase based on the pulse interval until the specific period elapses after the restart of the internal combustion engine is started.

  The start point of the specific period is set when the restart of the internal combustion engine is started, specifically, when the control command signal is output from the electronic control unit 20 to start driving the starter motor 11. Thereby, when the starter motor 11 starts to be driven when the internal combustion engine is restarted and the engine rotational speed NE starts to rise, in other words, a pulse interval that may be erroneously specified as the reference phase is measured. A period for prohibiting specification of the reference phase (the specified period) starts immediately before (or immediately after). Therefore, the specific prohibition of the reference phase can be accurately executed.

FIG. 2 shows an example of the measurement result of the pulse interval when the internal combustion engine is restarted.
In the example shown in FIG. 2, the pulse interval is immediately after the starter motor 11 is started due to a rapid decrease in the engine rotational speed NE accompanying the automatic stop of the internal combustion engine or the rotation stop of the engine output shaft 12. When measured (time t12), the previous value TA [i-1] and the current value TA [i] of the pulse interval stored in the electronic control unit 20 satisfy [Condition A]. Value.

  In the apparatus according to the present embodiment, even when driving of the starter motor 11 is started in such a state, the determination based on [Condition A] is prohibited along with the start of driving of the starter motor 11 (time After t11), the temporary determination flag is not turned on. Therefore, it is possible to accurately prevent the reference phase from being erroneously specified due to the rapid decrease in the engine speed NE accompanying the automatic stop of the internal combustion engine or the rotation stop of the engine output shaft 12.

  In the present embodiment, the engine speed NE at the start of restart of the internal combustion engine is less than the predetermined speed V1, in other words, the restart of the internal combustion engine accompanied by the drive of the starter motor 11. As a condition, identification of the reference phase is prohibited.

  In general, when the internal combustion engine is restarted with the starter motor 11 being driven, the engine rotational speed NE increases rapidly, and the pulse interval reduction speed is fast. Therefore, the reference phase is erroneously changed based on the sudden change in the pulse interval. There is a risk of identification. On the other hand, when restarting the internal combustion engine without driving the starter motor 11 (restarting only by restarting fuel injection or the like), the increase speed of the engine rotational speed NE is relatively slow and the reduction speed of the pulse interval is also compared. The possibility of misidentifying the reference phase is very low.

  In the apparatus of the present embodiment, when the internal combustion engine is restarted with the starter motor 11 being driven, that is, when there is a high possibility that the reference phase is erroneously specified, the specification is prohibited. Can be accurately suppressed from being erroneously specified. In addition, when the internal combustion engine is restarted without driving the starter motor 11, that is, when the possibility that the reference phase is erroneously specified is very low, the specification is not prohibited, so that the reference phase is specified early. Will be able to.

  On the other hand, as the end point of the specific period, the pulse interval measured and stored before and after the start of the restart of the internal combustion engine may be specified as the reference phase, specifically, the internal combustion engine The timing at which the number of measurements and the number of storages of the pulse interval (NE10 signal output interval) after the start of the restart is four is set.

FIG. 3 shows an example of the measurement result of the pulse interval when the internal combustion engine is restarted.
In the present embodiment, as described above, the predetermined relationship ([Condition A] to [Condition D]) is stored in the pulse interval (TA [i-3], TA [i-2] stored in the electronic control unit 20. ], TA [i-1], TA [i]) are satisfied, and the crank phase (time t21 to t23 in FIG. 3) when the value TA [i-3] three times before is measured is a reference. Identified as phase.

  Therefore, if the specification of the reference phase is not prohibited, the timing at which the number of measurement of the pulse interval after the restart of the internal combustion engine becomes four times (time t24), that is, the pulse interval at the restart of the internal combustion engine. There is a possibility that the relationship between the pulse intervals stored in the electronic control unit 20 becomes the predetermined relationship at the timing when the value measured when becomes the longest becomes the value TA [i-3] three times before. There is. In such a case, the crank phase obtained by measuring the value TA [i-3] three times before is erroneously specified as the reference phase.

  On the other hand, when the number of measurement of the pulse interval after the restart of the internal combustion engine becomes five times or more, the value measured when the pulse interval becomes the longest when the internal combustion engine is restarted is the value TA [ i-3] Since the value is measured before the electronic control unit 20, the electronic control unit 20 is not stored. Therefore, after the pulse interval is measured five times after restarting the internal combustion engine, basically, the electronic control unit 20 stores the pulse interval unless the pulse interval corresponding to the actual missing tooth part (reference phase) is measured. The relationship between the pulse intervals is not a relationship indicating that the pulse interval has temporarily increased rapidly. Therefore, in this case, it is very unlikely that the relationship between the pulse intervals stored in the electronic control unit 20 erroneously satisfies the predetermined relationship, and the possibility that the reference phase is erroneously specified is very low. .

  In this regard, in the apparatus of the present embodiment, when the internal combustion engine is restarted, only after the pulse interval is measured five times after the restart (after time t25), that is, the reference phase is specified incorrectly. Since the specification of the reference phase is permitted only when the possibility becomes very low, the reference phase can be specified with high accuracy.

  Thus, according to the present embodiment, the longest value among the pulse intervals measured before and after the start of the restart of the internal combustion engine, in other words, the pulse intervals measured when the internal combustion engine is automatically stopped and restarted. Can be erroneously determined to be a value corresponding to the reference phase. Specifically, the pulse intervals measured and stored when the internal combustion engine is automatically stopped and restarted (specifically, TA [i-3], TA [i-2], TA [i-1], TA Although the change mode of [i]) is a change mode that temporarily expands, it is possible to prevent the reference phase from being erroneously specified based on the change mode. Therefore, the reference phase can be specified with high accuracy, and the crank phase can be detected with high accuracy based on the reference phase.

Hereinafter, a specific execution mode of the process for prohibiting the specification of the reference phase (specific prohibition process) will be described with reference to the float shown in FIG. 4 and the timing chart shown in FIG.
Note that the series of processing shown in the flowchart of FIG. 4 conceptually shows the execution procedure of the specific prohibition processing, and the actual processing is executed by the electronic control unit 20 as interrupt processing for each predetermined time period. . Further, the timing chart shown in FIG. 5 shows an example of an execution mode of the specific prohibition process.

  As shown in FIG. 4, in this process, first, it is determined whether or not driving of the starter motor 11 is started with the establishment of the restart condition (step S101). If it is determined that the starter motor 11 is not being driven (step S101: NO), this processing is temporarily terminated without executing the following processing (steps S102 to S104). In this case (before time t31 in FIG. 5), specification of the reference phase based on the relationship between the pulse intervals stored in the electronic control unit 20 is not prohibited.

  On the other hand, when it is determined that the start of the starter motor 11 has been started by repeating this process (step S101: YES in FIG. 4), the specific prohibition flag is turned on (step S102). When the specific prohibition flag is turned on (time t31 in FIG. 5), the specification of the reference phase based on the relationship between the pulse intervals stored in the electronic control unit 20 is prohibited thereafter.

  As described above, in the present embodiment, when the starter motor 11 is driven to restart the internal combustion engine when the engine rotational speed NE is decreasing due to the automatic stop of the internal combustion engine, measurement is performed before and after that. Since the reference phase may be erroneously specified based on the set pulse interval, the specification prohibition flag is turned on and the specification of the reference phase is prohibited.

  Then, after the starter motor 11 is started to be driven, the specific prohibition flag is set until the number of measurement of the output interval (pulse interval) of the NE10 signal becomes five (step S103: NO in FIG. 4). It remains in the on-operated state. Then, while the specific prohibition flag is turned on (time t31 to t32 in FIG. 5), the specification of the reference phase based on the relationship between the pulse intervals stored in the electronic control unit 20 is prohibited.

  Incidentally, in the example shown in FIG. 5, if the reference phase is specified without being prohibited, the missing tooth determination flag is erroneously turned on as shown by the one-dot chain line in FIG. The phase is specified incorrectly. In the present embodiment, even in such a case, since the specification of the reference phase is prohibited, it is avoided that the reference phase is specified incorrectly.

  Thereafter, when the number of pulse interval measurements after the starter motor 11 starts to be driven reaches five (step S103: YES in FIG. 4), the specific prohibition flag is turned off (step S104). As a result, the specification of the reference phase based on the relationship between the pulse intervals stored in the electronic control unit 20 is permitted thereafter (after time t32 in FIG. 5). As described above, in the apparatus according to the present embodiment, when the internal combustion engine is restarted, only after the pulse interval is measured five times after the restart, that is, the possibility that the reference phase is erroneously specified is very low. Since the specification of the reference phase is allowed only when the reference phase is reached, the reference phase is specified with high accuracy.

  Thus, according to the present embodiment, the longest value among the pulse intervals measured before and after the start of the restart of the internal combustion engine, in other words, the pulse intervals measured when the internal combustion engine is automatically stopped and restarted. Can be erroneously determined to be a value corresponding to the reference phase. Therefore, the reference phase can be specified with high accuracy, and the crank phase can be detected with high accuracy based on the reference phase.

As described above, according to the present embodiment, the effects described below can be obtained.
(1) Over a specific period starting from the restart timing of the internal combustion engine and having a timing at which the pulse interval measured before and after the start of the restart may be specified as the reference phase, The specification of the reference phase is prohibited. Therefore, the reference phase can be specified with high accuracy, and the crank phase can be detected with high accuracy based on the reference phase.

  (2) As the end point of the specific period, the time when the number of measurement and storage of the pulse interval after the start of restart of the internal combustion engine is set to four is set. Therefore, when the internal combustion engine is restarted, only after the pulse interval is measured five times after the restart, that is, only when the possibility that the reference phase is erroneously specified becomes very low. And the reference phase can be specified with high accuracy.

  (3) As a starting point of the specific period, a time when a control command signal is output from the electronic control unit 20 to start driving the starter motor 11 is set. Thereby, when the starter motor 11 starts to be driven when the internal combustion engine is restarted and the engine rotational speed NE starts to rise, in other words, a pulse interval that may be erroneously specified as the reference phase is measured. The specific prohibition of the reference phase can be started at the timing immediately before or after, and the specific prohibition of the reference phase can be accurately executed.

  (4) The specification of the reference phase is prohibited on the condition that the internal combustion engine is restarted with the starter motor 11 being driven. For this reason, when the internal combustion engine is restarted with the starter motor 11 being driven, that is, when there is a high possibility that the reference phase is erroneously specified, the specification is prohibited, so the reference phase is erroneously specified. This can be suppressed accurately. In addition, when the internal combustion engine is restarted without driving the starter motor 11, that is, when the possibility that the reference phase is erroneously specified is very low, the specification is not prohibited, so that the reference phase is specified early. Can do.

The embodiment described above may be modified as follows.
The apparatus according to the above embodiment can be applied to an apparatus in which the starter motor 11 is always driven when the internal combustion engine is restarted.

  The start point of the specific period is not limited to the time when the drive of the starter motor 11 is started, but can be arbitrarily changed as long as it is a time corresponding to the restart time of the internal combustion engine. As the starting point of such a specific period, a time when both the condition that the starter motor 11 is driven and the condition that the engine speed NE is increasing can be adopted. According to such a configuration, the specific prohibition of the reference phase is erroneously specified when the rotation speed of the engine output shaft starts to increase due to the restart of the internal combustion engine accompanied by the drive of the starter motor, that is, the reference phase. It is possible to start accurately at the timing immediately before or after the measurement of the pulse interval with which there is a fear. In addition, as the starting point of the specific period, it is possible to adopt the time when the restart condition is satisfied.

  The specification of the reference phase may be prohibited even when the internal combustion engine is restarted without driving the starter motor 11. According to this configuration, the reference phase can be accurately specified in an apparatus in which the reference phase may be erroneously specified when the pulse interval temporarily increases when the internal combustion engine is restarted. The crank phase can be accurately detected based on the reference phase. In the above-described configuration, the timing at which various controls that are forcibly stopped when the internal combustion engine is automatically stopped, the timing at which the restart condition is satisfied, or the like may be set as the starting point of the specific period.

  As long as the reference phase is specified on the condition that the pulse interval is longer than the preceding and succeeding pulse intervals, the execution mode of the processing for specifying the reference phase can be arbitrarily changed. Specifically, the predetermined phase for specifying the reference phase by changing the number of measurement results of the pulse interval stored in the electronic control unit 20 or comparing with the relationship of the pulse interval stored in the electronic control unit 20. You may change the relationship.

  Note that, as such a predetermined relationship, it is possible to specify the crank phase when the value before N (where N is a natural number) times of the pulse intervals stored in the electronic control unit 20 is measured as the reference phase. When the above relationship is set, the specific period may be a period from when the restart of the internal combustion engine is started until the pulse interval is measured and stored only “N + 1” times.

  In this configuration, after the pulse interval is measured “N + 2” times after the restart of the internal combustion engine, basically, the electronic control unit 20 stores the pulse interval unless the pulse interval corresponding to the actual reference phase is measured. The relationship between the pulse intervals is not a relationship indicating that the pulse interval has temporarily increased rapidly. Therefore, in this case, it can be said that the relationship between the pulse intervals stored in the electronic control unit 20 does not satisfy the predetermined relationship. According to the above configuration, only after the pulse interval is measured “N + 2” times after restarting the internal combustion engine, that is, only when the possibility that the reference phase is erroneously specified becomes very low. Since the specification of the phase is permitted, the reference phase can be specified with high accuracy.

  The apparatus according to the above embodiment is applied not only to a vehicle that temporarily stops the operation of the internal combustion engine when the vehicle stops at an intersection or the like, but also to a hybrid vehicle that includes an internal combustion engine and an electric motor as a vehicle drive source. be able to.

  DESCRIPTION OF SYMBOLS 11 ... Starter motor, 12 ... Engine output shaft, 12a ... Pulsar, 13 ... Cam shaft, 13a ... Pulsar, 14 ... Brake pedal, 15 ... Accelerator pedal, 16 ... Fuel injection valve, 20 ... Electronic control unit, 21 ... Waveform shaping Circuit, 22 ... Microcomputer, 23 ... RAM, 31 ... Temperature sensor, 32 ... Speed sensor, 33 ... Rotation phase sensor, 34 ... Cylinder discrimination sensor, 35 ... Brake switch, 36 ... Idle switch.

Claims (6)

A rotation signal generating means for generating a rotation signal comprising a pulse sequence of a predetermined phase interval corresponding to the rotation of the engine output shaft and having a reference phase having a pulse interval longer than that of other portions in the middle thereof; and based on the rotation signal Storage means for measuring the pulse interval and storing a measurement result in the most recent predetermined period; a specifying means for specifying the reference phase based on the relationship between the pulse intervals stored by the storage means; and the rotation signal And a rotation phase detection system having a detection means for detecting the rotation phase of the engine output shaft based on the reference phase, and the internal combustion engine is automatically stopped when the automatic stop condition is satisfied and the restart condition is satisfied thereafter. In a control device for an internal combustion engine comprising an automatic stop / restart system for restarting the internal combustion engine,
The start time of the restart is a start point, and the end point is a time when the pulse interval measured before and after the start of the restart by the storage unit may be specified as the reference phase by the specifying unit. An internal combustion engine control apparatus that prohibits specification of the reference phase by the specifying means over a specified period. The control apparatus for an internal combustion engine according to claim 1,
When the predetermined natural number is N, the specifying unit stores a plurality of the storage units stored in the storage unit when the relationship between the pulse intervals stored in the storage unit satisfies a predetermined relationship. The rotation phase when the value N times before the pulse interval is measured is specified as the reference phase,
The control apparatus according to claim 1, wherein the specific period is a period from when the restart is started to when the pulse interval is measured and stored only "N + 1" times. . The control apparatus for an internal combustion engine according to claim 1, further comprising a starter motor that is driven when starting the internal combustion engine and applies an auxiliary torque to the engine output shaft. The control apparatus for an internal combustion engine according to claim 3,
The control device for an internal combustion engine, wherein the start time of the restart is set as a drive start time of the starter motor. The control apparatus for an internal combustion engine according to claim 3,
In the control device, the restart timing is set to a timing when both the condition that the starter motor is driven and the condition that the rotation speed of the engine output shaft is increased are satisfied. An internal combustion engine control apparatus comprising: The control apparatus for an internal combustion engine according to any one of claims 3 to 5,
The control device drives the starter motor on the condition that the rotational speed of the engine output shaft is less than a predetermined speed when the restart condition is satisfied when the internal combustion engine is restarted. The control apparatus for an internal combustion engine is characterized by prohibiting specification of the reference phase on the condition that the internal combustion engine is restarted with the drive of the engine.

Images