JP6311588B2 - Electronic control unit - Google Patents

Description

  The present invention relates to an electronic control device for controlling an internal combustion engine provided with a supercharger.

  Conventionally, in an engine equipped with a turbocharger, when the difference between the supercharging pressure and the atmospheric pressure is greater than or equal to a predetermined value, a valve opening command is output to the air bypass valve, and based on the subsequent change in supercharging pressure A technique for determining whether or not an abnormality has occurred in an air bypass valve is known (see, for example, Patent Document 1).

JP 2007-77897 A

  However, in the technique described in Patent Document 1, abnormality determination of the air bypass valve may be performed in a situation where the supercharging pressure increases as abnormality occurs in the engine. For this reason, even if an abnormality of the air bypass valve is detected when the supercharging pressure becomes so high that an abnormality occurs in the engine, it is difficult to avoid the occurrence of the abnormality of the engine due to the abnormality of the air bypass valve. There was a risk of becoming.

  The present invention has been made in view of these problems, and an object thereof is to suppress the occurrence of a situation in which a failure occurs in an internal combustion engine due to an abnormality of an air bypass valve.

An electronic control device of the present invention made to achieve the above object includes start determination means, valve opening means, diagnostic operation means, and abnormality determination means.
The start determination means indicates that the supercharging pressure that is the pressure of the intake air compressed by the supercharger having the turbine provided in the exhaust passage of the internal combustion engine and the compressor provided in the intake passage of the internal combustion engine is low. It is determined whether a preset diagnosis start condition is satisfied.

  The valve opening means opens the intake bypass passage for the air bypass valve that opens and closes the intake bypass passage that bypasses the compressor when the start determination means determines that the diagnosis start condition is satisfied.

  When the start determination means determines that the diagnosis start condition is satisfied, the diagnosis operation means is configured such that the air bypass valve closes the intake bypass passage relative to the waste gate valve that opens and closes the exhaust bypass passage that bypasses the turbine. When it is assumed that the boost pressure is increased, the abnormality diagnosis operation is set in advance so that the supercharging pressure increases.

  The abnormality determination means is configured so that after the waste gate valve is operated for abnormality diagnosis, a preset normal determination condition indicating a supercharging pressure when the air bypass valve opens the intake bypass passage is not established. In some cases, it is determined that an abnormality has occurred in the air bypass valve.

  In the electronic control device of the present invention configured as described above, when the supercharging pressure rises by operating both the air bypass valve and the waste gate valve when the supercharging pressure is low, an abnormality occurs in the air bypass valve. It can be determined that it occurred.

  As described above, the electronic control device of the present invention can diagnose whether or not an abnormality has occurred in the air bypass valve even when the supercharging pressure is low. Therefore, the electronic control device of the present invention can detect an abnormality of the air bypass valve before the supercharging pressure becomes so high that a failure occurs in the internal combustion engine. Thus, the electronic control device of the present invention can suppress the occurrence of a situation in which a failure occurs in the internal combustion engine due to an abnormality of the air bypass valve.

1 is a diagram showing a configuration of an engine control system 1. FIG. It is a flowchart which shows an abnormality diagnosis process. It is a flowchart which shows a WGV abnormality diagnosis process. It is a flowchart which shows the first half part of an ABV initial diagnosis process. It is a flowchart which shows the latter half part of an ABV initial diagnosis process. It is a flowchart which shows an ABV periodical diagnosis process. It is a timing chart which shows operation of ABV171 and WGV181 in ABV first diagnosis processing. It is a timing chart which shows operation of ABV171 and WGV181 in ABV periodic diagnosis processing. It is a graph which shows the relationship between an engine speed and a request torque, and a supercharging area | region. It is a graph which shows the relationship between an engine speed, a WGV opening degree, and a supercharging area | region.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the engine control system 1 includes an engine 100 and an electronic control unit (Electronic Control Unit) 2 (hereinafter referred to as an engine ECU 2) that controls the engine 100.

  The engine 100 is an internal combustion engine mounted on a vehicle, and a cylinder 101, a piston 102, and a cylinder head 103 form a combustion chamber 104 for each of a plurality of cylinders. A spark plug 105 for igniting the fuel is attached in the combustion chamber 104.

An intake pipe 120 is connected to the combustion chamber 104 of the engine 100 via an intake valve 106, and an exhaust pipe 140 is connected via an exhaust valve 107.
The intake pipe 120 is provided with a throttle valve 130 that adjusts the amount of air supplied to the engine 100. The intake pipe 120 is connected to each cylinder of the engine 100 via an intake manifold 121, and the air whose amount is adjusted by the throttle valve 130 through the intake pipe 120 passes through the intake manifold 121 and passes through the engine. Distribution is supplied to each of the 100 cylinders.

  The intake manifold 121 is provided with an injector 122 for each cylinder of the engine 100. The fuel injected from the injector 122 is mixed with air from the intake pipe 120 and supplied to each cylinder of the engine 100.

  Further, in each cylinder of the engine 100, the air-fuel mixture is introduced into the combustion chamber 104 as the intake valve 106 is opened and closed, and the introduced air-fuel mixture is combusted by ignition of the ignition plug 105, whereby the piston 102 is pushed down. Torque is applied to the crankshaft 108 of the engine 100. The exhaust gas after combustion is discharged to the outside through the exhaust pipe 140 as the exhaust valve 107 is opened and closed.

The engine 100 is provided with a crank angle sensor 110, a throttle opening sensor 124, and the like as sensors for detecting the operating state.
Crank angle sensor 110 detects the rotation angle of crankshaft 108 of engine 100. Specifically, the crank angle sensor 110 outputs a crank angle signal that causes an edge at every predetermined angle (for example, every 10 ° CA) in accordance with the rotation of the crankshaft 108 of the engine 100. The throttle opening sensor 124 detects the opening of the throttle valve 130 (hereinafter referred to as the throttle opening).

  The engine 100 is provided with a turbocharger 160. The turbocharger 160 includes a turbine 161, a compressor 162, and a rotating shaft 163 that connects the turbine 161 and the compressor 162.

  The turbine 161 is provided in the exhaust pipe 140. The turbine 161 is configured to rotate around the rotation shaft 163 when the exhaust gas discharged from the engine 100 flows through the exhaust pipe 140.

  The compressor 162 is provided in the intake pipe 120 upstream of the throttle valve 130. The compressor 162 is configured to rotate around the rotation shaft 163 by the driving force transmitted from the turbine 161 via the rotation shaft 163. The compressor 162 compresses the air in the intake pipe 120 by its rotation and sends it out to the engine 100.

  The intake pipe 120 is provided with an intake bypass passage 170 that bypasses the compressor 162 and distributes the air in the intake pipe 120. The intake bypass passage 170 is provided with an air bypass valve 171 (hereinafter referred to as ABV 171) that opens and closes the intake bypass passage 170.

  The exhaust pipe 140 is provided with an exhaust bypass passage 180 that bypasses the turbine 161 and distributes the exhaust gas in the exhaust pipe 140. The exhaust bypass passage 180 is provided with a waste gate valve 181 (hereinafter referred to as WGV 181) that opens and closes the exhaust bypass passage 180.

The WGV 181 is provided with a WGV opening sensor 182 that detects the opening of the WGV 181 (hereinafter referred to as the WGV opening).
The engine control system 1 also includes a supercharging pressure sensor 135 that detects the pressure in the intake pipe 120 (that is, the supercharging pressure by the turbocharger 160), and an atmospheric pressure sensor 137 that detects atmospheric pressure. The supercharging pressure sensor 135 is installed in the intake pipe 120 at a position upstream of the throttle valve 130 and downstream of the compressor 162.

  The engine ECU 2 includes a microcomputer 3 that executes processing for controlling the engine 100, a drive circuit 4 that operates various actuators according to control signals from the microcomputer 3, and an input circuit that inputs various signals to the microcomputer 3. And 5.

The microcomputer includes a CPU 11, a ROM 12, and a RAM 13.
The CPU 11 executes various processes for controlling the engine 100 based on a program stored in the ROM 12. The ROM 12 is a non-volatile memory, and stores a program executed by the CPU 11 and data referred to when the program is executed. The RAM 13 is a volatile memory, and temporarily stores calculation results of the CPU 11 and the like.

  A signal from the crank angle sensor 110, a signal from the throttle opening sensor 124, a signal from the boost pressure sensor 135, and the like are input to the microcomputer 3 via the input circuit 5. The input circuit 5 is a general one, and can be processed by the microcomputer 3 by performing predetermined signal processing such as analog / digital conversion, noise removal, waveform shaping, etc., on a signal such as a sensor signal. Convert input signal to signal.

  The microcomputer 3 detects the state of the engine 100 based on the above signals input via the input circuit 5 and outputs a control signal to the drive circuit 4 based on the detection result. Thereby, the microcomputer 3 controls the ignition plug 105, the intake valve 106, the exhaust valve 107, the injector 122, the throttle valve 130, the ABV 171 and the WGV 181 to operate the engine 100.

  For example, the microcomputer 3 calculates the target boost pressure based on the throttle opening, the engine speed, and the like. The microcomputer 3 calculates the target WGV opening based on the difference between the calculated target supercharging pressure and the supercharging pressure detected by the supercharging pressure sensor 135, and the WGV opening sensor 182 detects the target WGV opening. Control to make the WGV opening coincide with the target WGV opening is performed.

Further, the microcomputer 3 outputs a control signal for opening the ABV 171 when the boost pressure detected by the boost pressure sensor 135 is equal to or higher than a preset ABV release determination value.
In the engine control system 1 configured as described above, the CPU 11 of the microcomputer 3 executes an abnormality diagnosis process for diagnosing the abnormality of the ABV 171.

  First, the procedure of abnormality diagnosis processing will be described. The abnormality diagnosis process is a process that is repeatedly executed at every preset execution cycle (for example, 5 ms in the present embodiment) during the operation of the microcomputer 3.

  When the abnormality diagnosis process is executed, the CPU 11 of the microcomputer 3 first determines whether or not the WGV diagnosis result is “not detected” in S10 as shown in FIG. Specifically, it is determined whether or not a value indicating “not detected” is stored in the WGV diagnosis result information provided in the RAM 13 for storing the WGV diagnosis result. If a value indicating “not detected” is stored in the WGV diagnosis result information, it is determined that the WGV diagnosis result is “not detected”. The initial value of the WGV diagnosis result information is a value indicating “not detected”.

  If the WGV diagnosis result is “not detected” (S10: YES), a WGV abnormality diagnosis process described later is executed in S20, and the process proceeds to S30. On the other hand, when the WGV diagnosis result is not “not detected” (S10: NO), the process proceeds to S30.

  In S30, it is determined whether or not the WGV diagnosis result is “normal”. Specifically, it is determined whether or not a value indicating “normal” is stored in the WGV diagnosis result information. When the value indicating “normal” is stored in the WGV diagnosis result information, it is determined that the WGV diagnosis result is “normal”.

  When the WGV diagnosis result is not “normal” (S30: NO), the process proceeds to S80. On the other hand, if the WGV diagnosis result is “normal” (S30: YES), it is determined in S40 whether the ABV diagnosis result is “not detected”. Specifically, it is determined whether or not a value indicating “not detected” is stored in the ABV diagnosis result information provided in the RAM 13 for storing the ABV diagnosis result. When the value indicating “not detected” is stored in the ABV diagnosis result information, it is determined that the ABV diagnosis result is “not detected”. The initial value of the ABV diagnosis result information is a value indicating “not detected”.

  If the ABV diagnosis result is “not detected” (S40: YES), an ABV initial diagnosis process described later is executed in S50, and the process proceeds to S70. On the other hand, if the ABV diagnosis result is not “not detected” (S40: NO), an ABV periodic diagnosis process described later is executed in S60, and the process proceeds to S70.

  In S70, it is determined whether the ABV diagnosis result is “abnormal”. Specifically, it is determined whether or not a value indicating “abnormal” is stored in the ABV diagnosis result information. If a value indicating “abnormal” is stored in the ABV diagnosis result information, it is determined that the ABV diagnosis result is “abnormal”.

If the ABV diagnosis result is “abnormal” (S70: YES), the process proceeds to S80. Then, when the process proceeds to S80, the supercharging pressure limit is executed, and the abnormality diagnosis process is temporarily ended.
On the other hand, if the ABV diagnosis result is not “abnormal” (S70: NO), the supercharging pressure restriction is canceled in S90, and the abnormality diagnosis process is temporarily terminated.

Next, the procedure of the WGV abnormality diagnosis process executed in S20 will be described.
When the WGV abnormality diagnosis process is executed, as shown in FIG. 3, the CPU 11 of the microcomputer 3 firstly, at S110, the WGV opening detected by the WGV opening sensor 182 (hereinafter referred to as the current WGV opening). ) To calculate the WGV diagnosis lower limit value and the WGV diagnosis upper limit value. Specifically, a value obtained by subtracting a preset diagnostic margin from the current WGV opening is calculated as the WGV diagnosis lower limit, and a value obtained by adding the current WGV opening and the diagnostic margin is used as the WGV diagnosis upper limit. calculate.

  In S120, it is determined whether or not the target WGV opening is not less than the WGV diagnosis lower limit value and not more than the WGV diagnosis upper limit value. If the target WGV opening is less than the WGV diagnosis lower limit value or exceeds the WGV diagnosis upper limit value (S120: NO), the WGV abnormality determination counter provided in the RAM 13 is incremented (1) in S130. Further, the WGV normality determination counter provided in the RAM 13 is reset (set to 0).

  Thereafter, in S140, whether or not the value of the WGV abnormality determination counter (hereinafter referred to as the WGV abnormality determination counter value) is greater than or equal to a preset WGV abnormality determination value (in this embodiment, for example, a value corresponding to 1 second). Judging. Here, when the WGV abnormality determination counter value is less than the WGV abnormality determination value (S140: NO), the WGV abnormality diagnosis process is terminated. On the other hand, if the WGV abnormality determination counter value is greater than or equal to the WGV abnormality determination value (S140: YES), the WGV diagnosis result is set to “abnormal” in S150. Specifically, a value indicating “abnormal” is stored in the WGV diagnosis result information. Then, after setting the WGV diagnosis result to “abnormal”, the WGV abnormality diagnosis process is terminated.

  If the target WGV opening is not less than the WGV diagnosis lower limit value and not more than the WGV diagnosis upper limit value in S120 (S120: YES), the WGV normality determination counter is incremented in S160, and the WGV abnormality is further detected. Reset the judgment counter.

  Thereafter, in S170, whether or not the value of the WGV normality determination counter (hereinafter referred to as the WGV normality determination counter value) is greater than or equal to a preset WGV normality determination value (in this embodiment, for example, a value corresponding to 1 second). Judging. Here, when the WGV normality determination counter value is less than the WGV normality determination value (S170: NO), the WGV initial diagnosis process is terminated. On the other hand, if the WGV normality determination counter value is greater than or equal to the WGV normality determination value (S170: YES), the WGV diagnosis result is set to “normal” in S180. Specifically, a value indicating “normal” is stored in the WGV diagnosis result information. Then, after setting the WGV diagnosis result to “normal”, the WGV abnormality diagnosis process is terminated.

Next, the procedure of the ABV initial diagnosis process executed in S50 will be described.
When the ABV initial diagnosis process is executed, the CPU 11 of the microcomputer 3 first determines whether or not the initial diagnosis start flag provided in the RAM 13 is set in S310 as shown in FIGS. . If the initial diagnosis start flag is not set (S310: NO), it is determined in S320 whether the target boost pressure is equal to or lower than the atmospheric pressure detected by the atmospheric pressure sensor 137.

  Here, when the target supercharging pressure exceeds the atmospheric pressure (S320: NO), a control signal for instructing closing of the ABV 171 is output in S330. As a result, the ABV 171 closes the intake bypass passage 170.

  Further, at S340, the ABV abnormality determination counter provided in the RAM 13 is reset. In S350, the ABV normality determination counter provided in the RAM 13 is reset. In step S360, the ABV diagnosis result is set to “not detected”. Specifically, a value indicating “not detected” is stored in the ABV diagnosis result information. Then, after setting the ABV diagnosis result to “not detected”, the ABV initial diagnosis process is terminated.

  If the target boost pressure is equal to or lower than the atmospheric pressure at S320 (S320: YES), it is determined at S370 whether the boost pressure sensor 135 is normal. If the supercharging pressure sensor 135 is not normal (S370: NO), the process proceeds to S330 and the above-described process is executed. On the other hand, when the supercharging pressure sensor 135 is normal (S370: YES), the supercharging pressure detected by the supercharging pressure sensor 135 at the present time (hereinafter referred to as the current supercharging pressure) is preliminarily determined in S380. It is determined whether it is equal to or greater than the set ABV diagnosis lower limit value and equal to or less than the preset ABV diagnosis upper limit value. In the present embodiment, the ABV diagnosis lower limit value is a value obtained by subtracting a preset diagnostic margin from the target boost pressure. The ABV diagnosis upper limit value is a value obtained by adding the target boost pressure and the diagnostic margin.

  Here, when the supercharging pressure is less than the ABV diagnosis lower limit value or exceeds the ABV diagnosis upper limit value (S380: NO), the process proceeds to S330 and the above-described processing is executed. On the other hand, if the current supercharging pressure is not less than the ABV diagnosis lower limit value and not more than the ABV diagnosis upper limit value (S380: YES), an undiagnosed elapsed counter provided in the RAM 13 is incremented in S390.

  Then, in S400, whether or not the value of the undiagnosed progress counter (hereinafter referred to as the undiagnosed progress counter value) is less than a preset diagnosis stop determination value (in this embodiment, for example, a value corresponding to 5 seconds). Judging. If the undiagnosed elapsed counter value is greater than or equal to the diagnosis stop determination value (S400: NO), the ABV diagnosis result is set to “timeout” in S410. Specifically, a value indicating “timeout” is stored in the ABV diagnosis result information. Then, after setting the ABV diagnosis result to “timeout”, the process proceeds to S610.

  On the other hand, if the undiagnosed elapsed counter value is less than the diagnosis stop determination value (S400: YES), a control signal instructing opening of the ABV 171 is output in S420. As a result, the ABV 171 opens the intake bypass passage 170. Further, in S430, an initial diagnosis start flag is set, and the ABV initial diagnosis process is terminated.

  If the initial diagnosis start flag is set in S310 (S310: YES), it is determined in S440 whether or not the WGV closing start flag provided in the RAM 13 is set. If the WGV closing start flag is not set (S440: NO), the ABV release counter provided in the RAM 13 is incremented in S450.

  In S460, it is determined whether or not the value of the ABV opening counter (hereinafter referred to as the ABV opening counter value) is equal to or greater than a preset WGV closing determination value (in this embodiment, for example, a value corresponding to 5 milliseconds). to decide. Here, when the ABV opening counter value is less than the WGV closing determination value (S460: NO), the ABV initial diagnosis process is terminated.

  On the other hand, if the ABV opening counter value is greater than or equal to the WGV closing determination value (S460: YES), the target WGV opening is set to the opening indicating the fully closed state (hereinafter referred to as WGV fully closing opening) in S470. Set. As a result, the WGV 181 closes the exhaust bypass passage 180. In S480, a WGV closing start flag is set. In S490, the ABV release counter is reset, and the ABV initial diagnosis process is terminated.

  If the WGV closing start flag is set in S440 (S440: YES), the WGV closing counter provided in the RAM 13 is incremented in S500.

  In S510, it is determined whether or not the value of the WGV closing counter (hereinafter referred to as the WGV closing counter value) is equal to or greater than a preset closing release determination value (in this embodiment, for example, a value corresponding to 1 second). To do. Here, when the WGV closing counter value is less than the closing cancellation determination value (S510: NO), the process proceeds to S540.

  On the other hand, when the WGV closing counter value is equal to or larger than the closing cancellation determination value (S510: YES), the state where the target WGV opening is set to the WGV fully closing opening is released in S520. Thereby, WGV181 operates so that the opening degree may correspond to the target WGV opening degree calculated sequentially. Further, in S530, the WGV closing counter is reset, and the process proceeds to S540.

  In S540, it is determined whether or not the current supercharging pressure is not less than the ABV diagnosis lower limit value and not more than the ABV diagnosis upper limit value. If the current supercharging pressure is less than the ABV diagnosis lower limit value or exceeds the ABV diagnosis upper limit value (S540: NO), the ABV abnormality determination counter provided in the RAM 13 is incremented in S550, Further, the ABV normality determination counter provided in the RAM 13 is reset.

  Thereafter, in S560, the value of the ABV abnormality determination counter (hereinafter referred to as the ABV abnormality determination counter value) is equal to or greater than a preset ABV abnormality determination value (in this embodiment, for example, a value corresponding to 0.1 second). Judge whether or not. Here, if the ABV abnormality determination counter value is less than the ABV abnormality determination value (S560: NO), the ABV initial diagnosis process is terminated. On the other hand, if the ABV abnormality determination counter value is greater than or equal to the ABV abnormality determination value (S560: YES), the ABV diagnosis result is set to “abnormal” in S570. Specifically, a value indicating “abnormal” is stored in the ABV diagnosis result information. Then, after setting the ABV diagnosis result to “abnormal”, the process proceeds to S610.

  If the current supercharging pressure is not less than the ABV diagnosis lower limit value and not more than the ABV diagnosis upper limit value in S540 (S540: YES), the ABV normality determination counter is incremented in S580, and an ABV abnormality is detected. Reset the judgment counter.

  Thereafter, in S590, whether or not the value of the ABV normality determination counter (hereinafter referred to as the ABV normality determination counter value) is equal to or greater than a preset ABV normality determination value (in this embodiment, for example, a value corresponding to 1 second). Judging. Here, if the ABV normality determination counter value is less than the ABV normality determination value (S590: NO), the ABV initial diagnosis process is terminated. On the other hand, if the ABV normality determination counter value is greater than or equal to the ABV normality determination value (S590: YES), the ABV diagnosis result is set to “normal” in S600. Specifically, a value indicating “normal” is stored in the ABV diagnosis result information. Then, after setting the ABV diagnosis result to “normal”, the process proceeds to S610.

  When the process proceeds to S610, a control signal for instructing closing of the ABV 171 is output. As a result, the ABV 171 closes the intake bypass passage 170. In S620, the initial diagnosis start flag and the WGV closing start flag are cleared, and the ABV initial diagnosis process is terminated.

Next, the procedure of the ABV periodic diagnosis process executed in S60 will be described.
When the ABV periodic diagnosis process is executed, the CPU 11 of the microcomputer 3 first decrements (subtracts 1) the diagnosis interval counter provided in the RAM 13 in S710 as shown in FIG. In the diagnosis interval counter, an execution cycle determination value (a value corresponding to, for example, 1 minute in the present embodiment) set in advance to indicate the execution cycle of the ABV periodic diagnosis process is set as an initial value.

  In S720, it is determined whether or not the value of the diagnostic interval counter (hereinafter referred to as diagnostic interval counter value) is zero. If the diagnosis interval counter value is not 0 (S720: NO), the ABV abnormality determination counter and the ABV normality determination counter are reset in S730, and the ABV periodic diagnosis process is terminated.

  On the other hand, if the diagnosis interval counter value is 0 (S720: YES), it is determined in S740 whether a preset periodic diagnosis start condition is satisfied. The periodical diagnosis start condition of the present embodiment is that all of the following first period start condition, second period start condition, third period start condition, and fourth period start condition are satisfied.

The first periodic start condition is that the throttle opening is equal to or less than a first start determination value set in advance so as to be a low opening.
The second regular start condition is that the control is performed to open the WGV 181 in order to suppress the increase in supercharging pressure. Specifically, based on a plurality of the most recently calculated target WGV opening degrees, when the target WGV opening degree gradually increases with time, it is determined that the control is performed to open the WGV 181. .

  The third periodic start condition is that the current supercharging pressure is less than a pressure at which supercharging can be turned off by controlling only the WGV 181 (hereinafter referred to as WGV supercharging off pressure). The WGV supercharging off pressure is determined with reference to a three-dimensional map in which the value of the WGV supercharging off pressure is set in advance using the engine rotation, the charging efficiency to the cylinder 101, and the current WGV opening as parameters. The

The fourth periodic start condition is that the supercharging pressure sensor 135 is normal.
Here, when the periodical diagnosis start condition is not satisfied (S740: NO), the process proceeds to S730 and the above-described process is executed. On the other hand, if the periodic diagnosis start condition is satisfied (S740: YES), a control signal instructing opening of the ABV 171 is output in S750, and the target WGV opening is set to the steady target value at the current throttle opening. Set to. The steady target value is a target WGV opening calculated in a steady state where the current throttle opening is maintained.

  Thereafter, in S760, it is determined whether or not the current supercharging pressure is not less than the ABV diagnosis lower limit value and not more than the ABV diagnosis upper limit value. Here, when the current supercharging pressure is less than the ABV diagnosis lower limit value or exceeds the ABV diagnosis upper limit value (S760: NO), the ABV abnormality determination counter is incremented in S770, and further, the ABV normality determination is performed. Reset the counter.

  Thereafter, in S780, it is determined whether or not the ABV abnormality determination counter value is equal to or larger than the ABV abnormality determination value. Here, if the ABV abnormality determination counter value is less than the ABV abnormality determination value (S780: NO), the ABV periodic diagnosis process is terminated. On the other hand, when the ABV abnormality determination counter value is equal to or larger than the ABV abnormality determination value (S780: YES), the ABV diagnosis result is set to “abnormal” in S790, and the process proceeds to S830.

  If the current supercharging pressure is not less than the ABV diagnosis lower limit value and not more than the ABV diagnosis upper limit value in S760 (S760: YES), the ABV normality determination counter is incremented in S800, and the ABV abnormality is detected. Reset the judgment counter.

  Thereafter, in S810, it is determined whether or not the ABV normality determination counter value is greater than or equal to the ABV normality determination value. Here, when the ABV normality determination counter value is less than the ABV normality determination value (S810: NO), the ABV periodic diagnosis process is terminated. On the other hand, if the ABV normality determination counter value is greater than or equal to the ABV normality determination value (S810: YES), the ABV diagnosis result is set to “normal” in S820, and the process proceeds to S830.

  In S830, a control signal for instructing closing of the ABV 171 is output and the state where the target WGV opening is set to the steady target value is canceled. As a result, the ABV 171 closes the intake bypass passage 170. Further, the WGV 181 operates so that the opening degree coincides with the sequentially calculated target WGV opening degree.

  In step S840, the diagnosis interval counter is initialized. Specifically, the value of the diagnosis interval counter is set to the above execution cycle determination value. Then, when the initialization of the diagnostic interval counter is finished, the ABV periodic diagnostic process is finished.

Next, operations of ABV 171 and WGV 181 in the ABV initial diagnosis process will be described.
As shown in FIG. 7, immediately after the engine 100 is started (see the throttle opening TP), the ABV initial diagnosis process is executed, and the microcomputer 3 first instructs the opening of the ABV 171 (see time t1). Then, after the time corresponding to the WGV closing determination value has elapsed, the microcomputer 3 closes the WGV 181 (see time t2). Furthermore, after the time corresponding to the closing cancellation determination value has elapsed, the microcomputer 3 opens the WGV 181 (see time t3).

  When the ABV 171 is opened by instructing the opening of the ABV 171, the current supercharging pressure does not change even if the WGV 181 is closed (see the supercharging pressure BP1). On the other hand, if the ABV 171 remains closed due to the abnormality of the ABV 171 even though the opening of the ABV 171 is instructed, the current supercharging pressure increases (see the supercharging pressure BP2).

The microcomputer 3 determines whether the ABV 171 is normal or abnormal based on the current supercharging pressure, and then instructs the ABV 171 to be closed (see time t4).
Thus, the ABV initial diagnosis process can diagnose an abnormality of the ABV 171 in a situation where there is no supercharging request. In a situation where there is no supercharging request, the target supercharging pressure is set to atmospheric pressure. For this reason, when ABV 171 is normal, the abnormality of ABV 171 can be diagnosed without fluctuation of the supercharging pressure.

Next, operations of ABV 171 and WGV 181 in the ABV periodic diagnosis process will be described.
As shown in FIG. 8, when the throttle opening becomes equal to or less than the first start determination value, the microcomputer 3 first instructs the opening of the ABV 171 and sets the target WGV opening to the steady target value TG11 at the current throttle opening. Set (see time t11). The microcomputer 3 controls the WGV 181 so that the target WGV opening becomes transiently larger than the steady target value TG11 when the throttle opening decreases when the ABV periodic diagnosis process is not executed (see the WGV opening WP11). ).

  When the ABV 171 is opened by instructing the opening of the ABV 171, the current supercharging pressure does not change even if the opening degree of the WGV 181 is fixed at the steady target value TG11 (see the supercharging pressure BP11). On the other hand, when the ABV 171 remains closed due to the abnormality of the ABV 171 even though the opening of the ABV 171 is instructed, the current supercharging pressure increases (see the supercharging pressure BP12).

  Then, the microcomputer 3 determines whether the ABV 171 is normal or abnormal based on the current supercharging pressure, and then instructs the ABV 171 to close (see time t12). The microcomputer 3 cancels the state where the target WGV opening is set to the steady target value. Thereby, the WGV 181 is the target WGV opening whose opening is sequentially calculated (see the target WGV opening TG12). Works to match.

  Thus, in the ABV periodic diagnosis process, the WGV 181 is operated so that the supercharging pressure increases in a situation where the supercharging pressure is decreased by the WGV 181 at normal times. Since the throttle opening is small, the abnormality of ABV 171 can be diagnosed in a situation where the supercharging pressure is low. For this reason, even when the supercharging pressure changes due to the abnormality diagnosis of ABV171, the influence on the behavior of the vehicle is small.

The engine ECU 2 configured in this manner determines whether or not a preset diagnosis start condition indicating that the supercharging pressure is low is satisfied (S320, S380, S740).
The diagnosis start condition is that the first start condition or the second start condition is satisfied.

  The first start condition includes that the target supercharging pressure is equal to or lower than atmospheric pressure (S320), and that the current supercharging pressure is equal to or higher than the ABV diagnosis lower limit value and equal to or lower than the ABV diagnosis upper limit value (S380). Thus, the first start condition can be satisfied when the engine 100 is idling.

The second start condition includes that the throttle opening is equal to or less than the first start determination value (S740). Accordingly, the second start condition can be satisfied when the supercharging pressure is low.
When the diagnosis start condition is satisfied, the engine ECU 2 opens the intake bypass passage 170 to the ABV 171 that opens and closes the intake bypass passage 170 that bypasses the compressor 162 (S420, S750).

  Further, the engine ECU 2 is set in advance so that the boost pressure rises when it is assumed that the ABV 171 closes the intake bypass passage 170 with respect to the WGV 181 that opens and closes the exhaust bypass passage 180 that bypasses the turbine 161. The operation is performed for abnormality diagnosis (S470, S750). Specifically, when the first start condition is satisfied, engine ECU 2 causes WGV 181 to close exhaust bypass passage 180 as an abnormality diagnosis operation (S470). Further, when the second start condition is satisfied, the engine ECU 2 sets the target WGV opening to a steady target value at the current throttle opening as an operation for abnormality diagnosis (S750).

  When the engine ECU 2 operates the WGV 181 with the abnormality diagnosis operation, the preset normal determination condition indicating the supercharging pressure when the ABV 171 opens the intake bypass passage 170 is not established. It is determined that an abnormality has occurred in ABV 171 (S540 to S570, S760 to S790).

  The engine ECU 2 configured as described above can determine that an abnormality has occurred in the ABV 171 when the supercharging pressure is increased by operating both the ABV 171 and the WGV 181 when the supercharging pressure is low.

Thus, the engine ECU 2 can diagnose whether or not an abnormality has occurred in the ABV 171 even when the supercharging pressure is low.
As shown in FIG. 9, supercharging is performed when the required torque exceeds the output limit torque Tl due to natural intake regardless of the engine speed (see supercharging regions RB1, RB2). In FIG. 9, among the supercharging region RB1 and the supercharging region RB2, the supercharging region RB1 indicates a region where the ABV 171 needs to be operated in order to suppress an increase in the supercharging pressure.

  As shown in FIG. 10, the engine ECU 2 does not need to operate the ABV 171 to suppress the increase in the supercharging pressure (that is, when the situation corresponds to the supercharging region RB2). Abnormal diagnosis of ABV 171 can be performed by operating both ABV 171 and WGV 181. In FIG. 10, the region above the diagnostic operation boundary line Lw indicates a region where ABV 171 abnormality diagnosis can be performed.

  For this reason, the engine ECU 2 can detect an abnormality in the ABV 171 before the supercharging pressure becomes so high that a failure occurs in the engine 100. Thereby, engine ECU2 can suppress generation | occurrence | production of the situation where a failure generate | occur | produces in engine 100 resulting from abnormality of ABV171.

  Further, the engine ECU 2 performs abnormality diagnosis of the ABV 171 when the supercharging pressure is low. For this reason, even if the supercharging pressure rises due to the abnormality of ABV 171 at the time of abnormality diagnosis of ABV 171, this pressure change is small. Thereby, the engine ECU 2 can suppress the influence of the change in the supercharging pressure due to the abnormality diagnosis of the ABV 171 on the behavior of the vehicle (for example, fluctuations in the engine speed) to the minimum necessary. In addition, when the behavior of the vehicle changes due to a change in supercharging pressure in the abnormality diagnosis of ABV171, the driver of the vehicle who senses this behavior change may recognize that an abnormality may have occurred in ABV171. it can.

  Further, the occurrence frequency of the situation where the supercharging pressure is low is higher than the occurrence frequency of the situation where the supercharging pressure is high. And since engine ECU2 performs abnormality diagnosis of ABV171 when supercharging pressure is low, it can increase the frequency | count of abnormality diagnosis of ABV171.

  Further, the first start condition is that the target boost pressure is equal to or lower than the atmospheric pressure (S320), and the current boost pressure is equal to or higher than the ABV diagnosis lower limit value and equal to or lower than the ABV diagnosis upper limit value (S380). This includes that the undiagnosed elapsed counter value is greater than or equal to the diagnosis stop determination value (S400). As a result, the engine ECU 2 can execute the ABV initial diagnosis process when the engine 100 is started and when the engine 100 is idling. Since the vehicle is stopped when the engine 100 is started, the engine ECU 2 determines that the behavior change is detected even when the behavior of the vehicle changes due to a change in the supercharging pressure in the abnormality diagnosis of the ABV 171. It is possible to avoid obstructing the driving of the vehicle due to.

  Further, when the undiagnosed elapsed counter value is equal to or greater than the diagnosis stop determination value (S400: NO), the abnormality diagnosis operation (that is, the ABV initial diagnosis process) due to the establishment of the first start condition is prohibited.

  Thus, after the diagnosis stop determination time corresponding to the diagnosis stop determination value has elapsed, not only both the ABV initial diagnosis process and the ABV periodic diagnosis process, but only the ABV periodic diagnosis process is executed. The load can be reduced.

  In the embodiment described above, the engine ECU 2 is the electronic control unit according to the present invention, the processes at S320, S380, and S740 are the start determining means according to the present invention, the processes at S420 and S750 are the valve opening means according to the present invention, and the processes at S470 and S750. Is an operation means for diagnosis in the present invention, the processes in S540 to S570 and S760 to S790 are abnormality determination means in the present invention, and the process in S400 is prohibition means in the present invention.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, As long as it belongs to the technical scope of this invention, a various form can be taken.
(Modification 1)
For example, in the above embodiment, the execution of the ABV initial diagnosis process is limited to the time when the diagnosis stop determination time corresponding to the diagnosis stop determination value elapses. However, even after the diagnosis stop determination time has elapsed, when the first start condition is satisfied, the ABV initial diagnosis process may be executed.

  In addition, the functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Moreover, you may abbreviate | omit a part of structure of the said embodiment. Further, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified only by the wording described in the claim are embodiment of this invention.

  2 ... Engine ECU, 3 ... Microcomputer, 100 ... Engine, 120 ... Intake pipe, 140 ... Exhaust pipe, 160 ... Turbocharger, 161 ... Turbine, 162 ... Compressor, 170 ... Intake bypass passage, 171 ... ABV, 180 ... Exhaust bypass Aisle, 181 ... WGV

Claims (5)

Compressed by a supercharger (160) having a turbine (161) provided in the exhaust passage (140) of the internal combustion engine (100) and a compressor (162) provided in the intake passage (120) of the internal combustion engine. Start determination means (S320, S380, S740) for determining whether or not a preset diagnosis start condition indicating that the supercharging pressure that is the pressure of the intake air is low is satisfied;
A valve that opens the intake bypass passage with respect to the air bypass valve (171) that opens and closes the intake bypass passage (170) that bypasses the compressor when the start determination means determines that the diagnosis start condition is satisfied. Opening means (S420, S750);
When the start determination unit determines that the diagnosis start condition is satisfied, the air bypass valve is connected to the intake bypass valve with respect to the waste gate valve (181) that opens and closes the exhaust bypass passage (180) that bypasses the turbine. Diagnostic operation means (S470, S750) for operating in an abnormality diagnosis operation set in advance so that the supercharging pressure increases when it is assumed that the passage is closed;
After the waste gate valve is operated in the abnormality diagnosis operation, a preset normal determination condition indicating the supercharging pressure when the air bypass valve opens the intake bypass passage is not established. An electronic control device (2) comprising: an abnormality determining means (S540 to S570, S760 to S790) for determining that an abnormality has occurred in the air bypass valve in some cases. The diagnosis start condition is that the internal combustion engine is idling.
The electronic control apparatus according to claim 1, wherein the abnormality diagnosis operation is closing the exhaust bypass passage. The diagnosis start condition is that an opening degree of a throttle valve provided in the intake passage is equal to or less than a preset start determination value indicating that the throttle opening degree is small,
The electronic control device according to claim 1, wherein the abnormality diagnosis operation is to make the opening degree of the waste gate valve smaller than a case where the diagnosis start condition is not satisfied. The electronic control unit according to claim 2, wherein the diagnosis start condition is when the internal combustion engine is started and the internal combustion engine is in the idle operation. The diagnosis start condition is a first start condition indicating that the internal combustion engine is idling, or a throttle valve opening provided in the intake passage is preset to indicate that the throttle opening is small. The second start condition indicating that it is less than or equal to the start determination value,
The abnormality diagnosis operation is to close the exhaust bypass passage when the first start condition is satisfied, and to open the waste gate valve when the second start condition is satisfied. , Making it smaller than when the second start condition is not satisfied,
And a prohibiting means (S400) for prohibiting the abnormality diagnosis operation caused by the establishment of the first start condition when a preset diagnosis stop determination time elapses after the internal combustion engine is started. The electronic control device according to claim 1.