JP2016020634A - Abnormality determination device of waist gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abnormality determination device of a waist gate valve which can accurately perform abnormality determination.SOLUTION: An engine system comprises an exhaust drive type supercharger, a communication passage which makes an exhaust upstream side and an exhaust downstream side of the supercharger in an exhaust passage of an internal combustion engine communicate with each other, and a waist gate valve which opens and closes the communication passage. An abnormality determination device performs the abnormality determination of the waist gate valve on the basis of boost pressure in the engine system. The abnormality determination device calculates a dispersion value V of a suction air amount GA of the internal combustion engine in a prescribed period. When the dispersion value V is not larger than a prescribed value Jg (S21: YES), the abnormality determination device on-operates an execution flag (S22). By this constitution, the execution of the detection of the boost pressure as a determination parameter of the abnormality determination is permitted.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an abnormality determination device for a waste gate valve provided in an exhaust passage of an internal combustion engine with a supercharger.

  It is often used to provide an exhaust-driven supercharger in an engine system centering on an internal combustion engine. This supercharger includes an exhaust turbine provided in an exhaust passage of the internal combustion engine and a compressor provided in an intake passage of the internal combustion engine.

  In addition, as in Patent Document 1, it is often used to provide a communication passage that connects an exhaust upstream side and an exhaust downstream side of an exhaust turbine in an exhaust passage, and a waste gate valve that opens and closes the communication passage. By opening the waste gate valve, the exhaust gas of the internal combustion engine flows around the exhaust turbine. Therefore, an unnecessary increase in the back pressure of the internal combustion engine can be suppressed by opening the waste gate valve during low load operation, and an excessive increase in the rotational speed of the exhaust turbine can be achieved by opening the waste gate valve during high load operation. It can be suppressed.

JP 2014-20252 A

  Here, if the waste gate valve becomes abnormal, such as when the waste gate valve is stuck at a predetermined opening, the amount of exhaust passing through the exhaust turbine becomes different from the expected amount, and accordingly the supercharging pressure is normal. The pressure will be different. For this reason, it is possible to perform abnormality determination of the waste gate valve based on the supercharging pressure.

  However, in an engine system equipped with an exhaust-driven supercharger, there is a response delay (so-called supercharging delay) of a change in supercharging pressure with respect to a change in intake air amount. Therefore, if the abnormality determination of the waste gate valve is executed simply based on the supercharging pressure during the transient operation of the internal combustion engine in which such a supercharging delay occurs, the determination accuracy becomes low.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a waste gate valve abnormality determination device capable of accurately performing abnormality determination.

  An exhaust gate supercharger comprising a compressor provided in an intake passage of an internal combustion engine and an exhaust turbine provided in an exhaust passage of the internal combustion engine, to achieve an abnormality determination device for a waste gate valve for achieving the above-described problem, In addition, the present invention is applied to an engine system that includes a communication passage that connects the exhaust upstream side and the exhaust downstream side of the supercharger in the exhaust passage, and a waste gate valve that opens and closes the communication passage. The abnormality determination device performs abnormality determination of the waste gate valve based on a supercharging pressure, and calculates a dispersion value of the intake air amount of the internal combustion engine in a predetermined period, and the calculated dispersion value An execution unit that executes detection of the supercharging pressure as a determination parameter for the abnormality determination.

  Since the supercharging delay is a response delay of the change in the supercharging pressure with respect to the change in the intake air amount, the fact that the supercharging delay has ended and the change in the supercharging pressure has converged is that the intake air amount has been reduced in the immediately preceding predetermined period. Judgment can be made with the convergence of changes. However, since the change rate of the intake air amount becomes extremely low at the end of the supercharging delay, it is difficult to determine that the change has converged simply by the decrease of the change rate of the intake air amount.

  On the other hand, the dispersion value of the intake air amount in the predetermined period is a mean square value of the difference between the average value and the absolute value of the intake air amount in the predetermined period, and thus the change rate of the absolute value of the intake air amount is low. Even at times, it tends to be large. Therefore, such a small dispersion value makes it possible to accurately determine that the change in the intake air amount has converged even when the change rate of the intake air amount is extremely slow.

  According to the above apparatus, it is possible to determine that the change in the intake air amount has converged when the dispersion value of the intake air amount in the predetermined period is equal to or less than the determination value. It can be detected as a supercharging pressure at the end of the delay. Then, by using the detected supercharging pressure as a determination parameter for the abnormality determination, it is possible to accurately determine the abnormality of the waste gate valve.

In the abnormality determination device, the intake air amount of the internal combustion engine can be detected at a constant period, and a dispersion value for the intake air amount detected within the predetermined period can be calculated.
In the abnormality determination device, the engine operation region is determined by the execution unit according to the amount of intake air, and when the waste gate valve is normal, the valve is opened and the boost pressure is unlikely to increase. It is preferable that the supercharging pressure and the intake air amount as the determination parameters are detected in the first region and the second region, respectively. In such an abnormality determination device, the supercharging pressure detected in the first region is set to “P1”, the intake air amount detected in the first region is set to “GA1”, and the supercharging detected in the second region is set. When the pressure is “P2”, the intake air amount detected in the second region is “GA2”, and the increase rate of the detected supercharging pressure accompanying the increase in the detected intake air amount is “ΔP” It is preferable to determine that the waste gate valve is abnormal when the increase speed ΔP determined by the relational expression [ΔP = (P2−P1) / (GA2−GA1)] is equal to or higher than a determination value.

  In the above apparatus, when the waste gate valve is normal, the valve is opened so that it is difficult for both the supercharging pressure in the first region and the supercharging pressure in the second region to rise. ΔP is lowered. Therefore, it can be determined that the waste gate valve is opened when the increase speed ΔP is low.

  On the other hand, when an abnormality occurs in which the waste gate valve cannot be opened sufficiently, the opening of the valve is reduced and the supercharger is operated, thereby supercharging the first region and the second region. Pressure may rise unnecessarily. In this case, the supercharging pressure increases unnecessarily as the intake air amount increases, so the increase rate ΔP of the supercharging pressure determined by the above relational expression increases. Therefore, it is possible to determine that an abnormality that the waste gate valve is not sufficiently opened occurs due to the increase rate ΔP being high.

  Therefore, according to the above apparatus, it is possible to determine that an abnormality has occurred in which the waste gate valve is not sufficiently opened by comparing the increase speed ΔP with the determination value.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows schematic structure of the engine system with which the abnormality determination apparatus of the waste gate valve of one Embodiment is applied. The graph which shows the outline | summary of an abnormality determination process. The flowchart which shows the execution procedure of an abnormality determination process. The flowchart which shows the execution procedure of flag operation processing. The flowchart which shows the execution procedure of a variance value calculation process. Explanatory drawing for demonstrating the calculation aspect of a dispersion value. The timing chart which shows an example of transition of (a) operation mode of execution flag (b) intake air amount (c) dispersion value (d) supercharging pressure during execution of each process.

Hereinafter, an embodiment of a waste gate valve abnormality determination device will be described.
As shown in FIG. 1, a throttle valve 12 and a fuel injection valve 13 are provided in the intake passage 11 of the internal combustion engine 10. The internal combustion engine 10 is provided with a spark plug 14. In this engine system, the amount of air taken into the combustion chamber 15 of the internal combustion engine 10 is adjusted through the opening degree control of the throttle valve 12. An ignition plug 14 ignites an air-fuel mixture composed of air sucked into the combustion chamber 15 through the intake passage 11 and fuel injected from the fuel injection valve 13, thereby burning the air-fuel mixture. Thus, the internal combustion engine 10 is operated. The air-fuel mixture burned in the combustion chamber 15 of the internal combustion engine 10 is discharged into the exhaust passage 16 as exhaust.

  The engine system is provided with an exhaust-driven supercharger 20. The supercharger 20 includes an exhaust turbine 21 provided in the exhaust passage 16 and a compressor 22 provided upstream of the throttle valve 12 in the intake passage 11. A turbine wheel 21 </ b> A inside the exhaust turbine 21 and a compressor impeller 22 </ b> A inside the compressor 22 are connected via a shaft 23 so as to be integrally rotatable. When the exhaust gas is blown onto the turbine wheel 21A during the operation of the internal combustion engine 10, the turbine wheel 21A rotates together with the compressor impeller 22A. Is sent to.

  The exhaust passage 16 of the internal combustion engine 10 is provided with a communication passage 24 that communicates a portion upstream of the exhaust turbine 21 and a portion downstream of the exhaust turbine 21 so as to bypass the exhaust turbine 21. The communication passage 24 is provided with a waste gate valve 25 for opening and closing the communication passage 24.

  The engine system is provided with various sensors for detecting the operating state of the internal combustion engine 10. As various sensors, for example, the rotational speed sensor 31 for detecting the rotational speed of the output shaft 17 of the internal combustion engine 10 (engine rotational speed NE) or the amount of air sucked into the internal combustion engine 10 (intake air amount GA) is used. An intake air amount sensor 32 for detection is provided. In addition, the throttle sensor 33 for detecting the opening of the throttle valve 12 (throttle opening TA), and the pressure of the intake air (supercharging pressure P) in the portion of the intake passage 11 between the compressor and the throttle valve 12 are set. A supercharging pressure sensor 34 and the like for detection are also provided.

  Further, the engine system is provided with an electronic control unit 30 configured with, for example, a microcomputer. The electronic control unit 30 takes in the output signals of various sensors and performs various calculations based on the output signals, and the fuel injection valve 13, the throttle valve 12, the spark plug 14, and the waste gate according to the calculation results. Various controls related to the operation of the internal combustion engine 10 such as operation control of various devices such as the valve 25 are executed. In the present embodiment, the electronic control device 30 corresponds to a calculation unit and an execution unit.

  In the operation control of the waste gate valve 25 of the present embodiment, the waste gate valve 25 is opened in a low rotation / low load region where the engine rotational speed NE is low and the engine load KL is small. The engine load KL is the amount of air taken into the combustion chamber 15 per cycle of the internal combustion engine 10, and is calculated based on the intake air amount GA and the engine rotational speed NE.

  In the present embodiment, a process (abnormality determination process) is performed to determine the occurrence of an abnormality (open valve abnormality) that cannot sufficiently open the waste gate valve 25 in the low rotation and low load region of the internal combustion engine 10. Hereinafter, an execution procedure of the abnormality determination process will be described.

  As shown in FIG. 2, in the present embodiment, two execution regions that are determined by the intake air amount GA are used as execution regions in which detection parameters for abnormality determination (specifically, the supercharging pressure P and the intake air amount GA) are detected. An engine operation region (first region and second region) is set. In both the first region and the second region, when the waste gate valve 25 is normal, the valve 25 is opened and the supercharging pressure P does not increase (specifically, the supercharging pressure P is almost at atmospheric pressure). Engine operating range) is set. An engine operation region that does not overlap the first region and the second region is set, and an engine operation region that has a smaller intake air amount GA than the second region is set in the first region.

FIG. 3 shows an execution procedure of the abnormality determination process. Note that a series of processes shown in the flowchart of FIG. 3 is executed by the electronic control unit 30 as an interrupt process at predetermined intervals.
As shown in FIG. 3, in this process, when the execution flag is turned on (step S11: YES), if the engine operating region (specifically, intake air amount GA) is the first region (step S11). S12: YES), the supercharging pressure P at this time is stored as the first region supercharging pressure P1, and the intake air amount GA is stored as the first region intake amount GA1 (step S13).

  On the other hand, when the execution flag is turned on (step S11: YES), if the engine operation region is the second region (step S12: NO and step S14: YES), the supercharging pressure P at this time is While being stored as the second region boost pressure P2, the intake air amount GA at this time is stored as the second region intake amount GA2 (step S15).

  When the first region boost pressure P1 and the first region intake air amount GA1 are stored (step S13), or when the second region boost pressure P2 and the second region intake air amount GA2 are stored (step S13). S15) An increase rate ΔP of the supercharging pressure accompanying an increase in the intake air amount is calculated based on the following relational expression (step S16).

Thereafter, it is determined whether or not the increase speed ΔP is equal to or higher than a determination value Jp (step S17). When the increase speed ΔP is equal to or higher than the determination value Jp (step S17: YES), it is determined that a valve opening abnormality has occurred in the waste gate valve 25 (step S18). On the other hand, when the increase speed ΔP is less than the determination value Jp (step S17: NO), it is not determined that the valve opening abnormality has occurred (the process of step S18 is jumped).

  When the execution flag is turned off (step S11: NO), or when the engine operation region is neither the first region nor the second region (step S12: NO and step S14: NO), The process of step S13 and the processes of steps S15 to S18 are not executed.

  Here, as shown by the solid line in FIG. 2, when the waste gate valve 25 is operating normally, the valve 25 is opened and the first region boost pressure P1 and the second region boost pressure P2 are both set. Since the pressure becomes substantially atmospheric pressure without increasing, the increase rate ΔP of the supercharging pressure determined by the above relational expression becomes low. Therefore, it can be determined that the waste gate valve 25 is sufficiently opened by the low increase speed ΔP, that is, that the valve opening abnormality has not occurred.

  On the other hand, as shown by the one-dot chain line in FIG. 2, when the valve opening abnormality occurs in the waste gate valve 25, the opening degree of the valve 25 is reduced and the supercharger 20 is operated. The first region supercharging pressure P1 and the second region supercharging pressure P2 may increase unnecessarily. In this case, since the supercharger 20 operates, the supercharging pressure P increases unnecessarily as the intake air amount GA increases, and the increase rate ΔP of the supercharging pressure determined by the above relational expression increases. Therefore, when the increase speed ΔP is high, it can be determined that a valve opening abnormality has occurred in the waste gate valve 25.

In view of this point, in the abnormality determination process, it is determined whether or not there is an abnormality in the opening of the waste gate valve 25 by comparing the increase speed ΔP with the determination value Jg.
By the way, since the turbocharger 20 is mounted in the engine system, there is a response delay (so-called supercharging delay) of the supercharging pressure P with respect to a change in the intake air amount GA. Therefore, in the above-described abnormality determination process, if the abnormality determination of the waste gate valve 25 is simply executed based on the supercharging pressure P or the intake air amount GA during the transient operation of the internal combustion engine 10 in which the supercharging delay occurs, the determination accuracy is increased. Will be lower.

  Therefore, in the present embodiment, the dispersion value V of the intake air amount GA in the immediately preceding predetermined period (for example, several tens of milliseconds) is calculated, and the determination in the abnormality determination process is performed when the dispersion value V is equal to or less than the determination value Jg. Detection of parameters (first region boost pressure P1, second region boost pressure P2, first region intake air amount GA1, and second region intake air amount GA2) is executed. Specifically, the execution flag referred to in the abnormality determination process (FIG. 3) is turned on on condition that the variance value V is equal to or less than the determination value Jg.

  FIG. 4 shows an execution procedure of a process for operating an execution flag (flag operation process). Note that the series of processing shown in the flowchart of FIG. 4 is executed by the electronic control unit 30 as interrupt processing at predetermined intervals.

As shown in FIG. 4, in this process, it is first determined whether or not all of the following (Condition A), (Condition B), and (Condition C) are satisfied (Step S21).
(Condition A) The engine load KL is in a stable state with little change.

(Condition b) The throttle opening TA is in a stable state with little change.
(Condition C) The dispersion value V of the intake air amount GA in a predetermined period is equal to or less than the determination value Jg.
When all of (Condition A) to (Condition C) are satisfied (Step S21: YES), the execution flag is turned on (Step S22). On the other hand, if any one of (Condition A) to (Condition B) is not satisfied (Step S21: NO), the execution flag is turned off (Step S23).

  FIG. 5 shows an execution procedure of the process for calculating the variance value V (variance value calculation process). The series of processes shown in the flowchart of FIG. 5 is executed by the electronic control unit 30 as an interrupt process every predetermined cycle (for example, several milliseconds).

  As shown in FIG. 5, in this process, first, the number of times the detection and storage of the intake air amount GA used to calculate the dispersion value V is repeated (the number of repetitions) is a predetermined number of times (for example, several tens of times). ) Is determined (step S31).

  If the number of repetitions is less than the predetermined number (step S31: NO), all stored values [M (0), M (1)...] Are executed once before this processing. It is stored as the value stored at times (step S32). In this process, for example, the stored value M (1) at the previous execution of this process is stored as the stored value M (2) at the previous execution of this process, and the stored value M (0) at the current execution of this process is stored. ) Is stored as the stored value M (1) at the previous execution of this process.

  Thereafter, the intake air amount GA at this time is stored as a stored value M (0) at the time of the current execution of this processing (step S33), and “1” is added to the number of repetitions (step S34). This process is temporarily terminated. Then, until the number of repetitions reaches a predetermined number (step S31: NO), the processing of step S32 to step S34 is repeatedly executed.

  Thereafter, this process is repeatedly executed, and when the number of repetitions reaches a predetermined number (step S31: YES), an average value Mave of all stored values M (0) to M (n) is calculated (step S35). ). Based on the average value Mave and the stored values M (0) to M (n), the dispersion value V of the intake air amount GA in a predetermined period is calculated from the following relational expression (step S36).

Thereafter, after the number of repetitions is reset to “0” (step S37), this process is temporarily terminated.

  In the present embodiment, it is determined whether or not (condition c) in the flag operation process (FIG. 4) is satisfied using the variance value V calculated by the variance value calculation process described above. As a result, on the condition that the variance value V is equal to or less than the determination value Jg, the execution flag is turned on, and the supercharging pressure (the first region supercharging pressure P1, the second region supercharging) as the determination parameter of the abnormality determination process The supply pressure P2) and the intake air amount (first region intake air amount GA1, second region intake air amount GA2) are detected.

Hereinafter, an operation by executing such flag operation processing and variance value calculation processing will be described.
Since the supercharging delay is a response delay of the change in the supercharging pressure P with respect to the change in the intake air amount GA, the fact that the supercharging delay has ended and the change in the supercharging pressure P has converged in the predetermined period immediately before the intake. It can be determined by the fact that the change in the air amount GA has converged. However, since the change rate of the intake air amount GA becomes extremely low at the end of the supercharging delay, it is determined that the change has converged simply by the decrease of the change rate of the intake air amount GA. difficult.

  On the other hand, as shown in an example in FIG. 6, the variance value V of the intake air amount GA in a predetermined period is an average value Mave and an absolute value [each stored value M (0) ˜ M (n)] is a mean square value of the difference (value indicated by an arrow in the figure), and therefore tends to be large even when the rate of change of the absolute value of the intake air amount GA is low. Therefore, even when the change speed of the intake air amount GA is extremely slow, it is possible to accurately determine that the change of the intake air amount GA has converged with such a small dispersion value V. In the present embodiment, the predetermined period is a period until the number of repetitions reaches a predetermined number in the above-described variance value calculation process (FIG. 5). As this predetermined period, a period during which the end of the supercharging delay can be accurately determined based on the results of various experiments and simulations is obtained in advance and stored in the electronic control unit 30.

  In the present embodiment, when the variance value V calculated through the variance value calculation process is equal to or less than the determination value Jg, it is possible to accurately determine that the change in the intake air amount GA during the immediately preceding predetermined period has converged. it can. Then, the supercharging pressure P and the intake air amount GA at that time are used as the supercharging pressure (first region supercharging pressure P1, second region supercharging pressure P2) and the intake air amount (first region) at the end of the supercharging delay. It can be detected and stored as a region intake air amount GA1, a second region intake air amount GA2). Accordingly, the values thus detected and stored (the first region boost pressure P1, the second region boost pressure P2, the first region intake air amount GA1, and the second region intake air amount GA2) are subjected to abnormality determination processing (FIG. By using it as the determination parameter in 3), it is possible to accurately determine the valve opening abnormality of the waste gate valve 25 while suppressing adverse effects due to the delay in supercharging.

FIG. 7 shows an example of an execution mode of each process of the present embodiment.
During the transient operation of the internal combustion engine 10, since the intake air amount GA repeatedly increases and decreases, the supercharging pressure P also repeatedly increases and decreases. In the example shown in FIG. 7, after the intake air amount GA [FIG. 7 (b)] reaches an increase peak at time t11, the boost pressure P [FIG. 7 (d)] reaches an increase peak at time t12. However, the supercharging pressure P at time t12 does not increase to the supercharging pressure corresponding to the intake air amount GA at time t11, and the change is not stable. In the present embodiment, during such transient operation of the internal combustion engine 10, the variance value V [FIG. 7 (c)] temporarily decreases when the increase / decrease in the intake air amount GA is switched, but the variance value V is much smaller. Therefore, the execution flag [FIG. 7A] is not turned on, and the supercharging pressure P and the intake air amount GA are not detected. Therefore, it is avoided that the supercharging pressure P and the intake air amount GA before the supercharging delay ends are detected and stored as the determination parameters of the abnormality determination process.

  On the other hand, when the supercharging pressure P is stabilized after the supercharging delay (time t13 to t14) ends (after time t14), the dispersion value V in a predetermined period immediately before the supercharging delay ends becomes small. When the flag is turned on, the detection and storage of the supercharging pressure P and the intake air amount GA as determination parameters for the abnormality determination process are executed. In the example shown in FIG. 7, at time t14, the supercharging pressure P is detected and stored as the supercharging pressure corresponding to the second region (second region supercharging pressure P2), and the intake air amount GA is detected. Is stored as the intake air amount corresponding to the second region (second region intake amount GA2). As a result, the supercharging pressure P and the intake air amount GA after the end of the supercharging delay are accurately detected as determination parameters for the determination process.

As described above, according to the present embodiment, the following effects can be obtained.
(1) The dispersion value V of the intake air amount GA of the internal combustion engine 10 in a predetermined period is calculated, and when the dispersion value V is equal to or less than the determination value Jg, the supercharging pressure P and intake air as determination parameters for abnormality determination The detection and storage of the quantity GA is performed. Therefore, the supercharging pressure (first region supercharging pressure P1, second region supercharging pressure P2) and intake air amount (first region intake air amount GA1, second region intake air amount GA2) at the end of the supercharging delay are detected. And memorize it. Therefore, by using the value detected and stored in this way as a determination parameter in the abnormality determination process, it is possible to accurately determine the valve opening abnormality of the waste gate valve 25.

  (2) Supercharging pressure detected in the first region (first region supercharging pressure P1), intake air amount detected in the first region (first region intake amount GA1), supercharging pressure detected in the second region ( From the relational expression [ΔP = (P2−P1) / (GA2−GA1)] based on the second region boost pressure P2) and the intake air amount detected in the second region (second region intake air amount GA2), The increase rate ΔP was calculated. When the increase speed ΔP is equal to or higher than the determination value Jp, it is determined that the waste gate valve 25 is abnormal. Thus, by comparing the increase speed ΔP and the determination value Jp, it can be determined that an abnormality has occurred in which the waste gate valve 25 is not sufficiently opened.

The above embodiment may be modified as follows.
As the first region and the second region, an engine operation region where the supercharging pressure P is slightly higher than the atmospheric pressure when the waste gate valve 25 is normal may be set. As the first region and the second region, it is possible to set an engine operation region in which the supercharging pressure P hardly increases when the waste gate valve 25 is normal.

  Instead of calculating the dispersion value V each time the number of repetitions reaches a predetermined number, it is stored at this time each time detection and storage of the intake air amount GA used to calculate the dispersion value V is executed. The variance value V may be calculated based on the stored value [stored value M (0)] and previously stored values [stored values M (1) to M (n)].

  The occurrence of a valve opening abnormality in the waste gate valve 25 may be determined based on whether the first region boost pressure P1 is equal to or higher than a predetermined determination value (P1 ≧ determination value). In this case, the determination value can be set based on the first region intake air amount GA1, such that the determination value is increased as the intake air amount GA increases. Furthermore, in this case, the process of detecting and storing the second region supercharging pressure P2 and the second region intake air amount GA2 can be omitted.

  When the boost pressure P increases, the integrated value of the intake air amount GA (intake amount integrated value) until the boost pressure P reaches the peak value is obtained, and the intake value integrated value and the peak value of the boost pressure P On the basis of the relationship, the abnormality determination process for determining whether a valve closing abnormality (such as sticking at a minute opening degree) at which the waste gate valve 25 is not sufficiently closed occurs. . In this abnormality determination process, the determination value is calculated based on the peak value such that the larger the peak value of the boost pressure P is, the larger the determination value is calculated, and the integrated intake air amount is larger than the determination value. Sometimes, it can be determined that the valve closing abnormality of the waste gate valve 25 has occurred.

  Here, if the opening degree of the waste gate valve 25 becomes unnecessarily large, the amount of exhaust gas that flows around the exhaust turbine 21 increases, and therefore the intake air amount GA required to raise the supercharging pressure P to a predetermined pressure. (= The displacement of the internal combustion engine 10) increases. For this reason, it can be said that when the valve closing abnormality occurs in the waste gate valve 25, the intake air amount integrated value increases. In the abnormality determination process, it is possible to determine the occurrence of the valve closing abnormality of the waste gate valve 25 when the integrated value of the intake air amount is larger than the determination value.

  The period for calculating the intake air amount integrated value is the boost pressure P from the start of acceleration (for example, when the accelerator pedal is depressed, when the throttle opening TA starts increasing, or when the waste gate valve 25 is closed). Or a period from when supercharging starts (specifically, when supercharging pressure P starts to increase) to when supercharging pressure P reaches a peak value can be employed.

  Further, in the abnormality determination process, as a process for determining that the boost pressure P has reached the peak value, a process of determining that the variance value V of the intake air amount GA during the predetermined period is equal to or less than the determination value. Can be adopted.

  According to such an apparatus, the supercharging pressure P at the end of the supercharging delay can be detected as the peak value of the supercharging pressure P. Therefore, by using this peak value as a determination parameter for abnormality determination, it is possible to accurately determine whether the waste gate valve 25 is closed abnormally while suppressing the influence of supercharging delay.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Intake passage, 12 ... Throttle valve, 13 ... Fuel injection valve 13 ... Spark plug 14 ... Combustion chamber, 16 ... Exhaust passage, 17 ... Output shaft, 20 ... Supercharger, 21 ... Exhaust turbine, 21A ... Turbine wheel, 22 ... Compressor, 22A ... Compressor impeller, 23 ... Shaft, 24 ... Communication path, 25 ... Waste gate valve, 30 ... Electronic control device, 31 ... Rotational speed sensor, 32 ... Intake amount sensor, 33 ... Throttle Sensor, 34 ... supercharging pressure sensor.

Claims (3)

An exhaust-driven supercharger having a compressor provided in an intake passage of an internal combustion engine and an exhaust turbine provided in an exhaust passage of the internal combustion engine, and an exhaust upstream side of the supercharger and exhaust in the exhaust passage Abnormality of the waste gate valve that is applied to an engine system having a communication passage communicating with the downstream side and a waste gate valve that opens and closes the communication passage, and performs abnormality determination of the waste gate valve based on supercharging pressure In the judgment device,
A calculation unit for calculating a dispersion value of the intake air amount of the internal combustion engine in a predetermined period;
An abnormality determination device for a waste gate valve, comprising: an execution unit that detects the supercharging pressure as a determination parameter for the abnormality determination when the calculated variance value is equal to or less than a determination value. In the waste gate valve abnormality determination device according to claim 1,
The abnormality determination device detects the intake air amount at a constant period,
The waste gate valve abnormality determination device, wherein the calculation unit calculates a dispersion value of the intake air amount detected within the predetermined period. In the waste gate valve abnormality determination device according to claim 1 or 2,
The execution unit is two engine operation regions determined by the intake air amount, and a first region in which the valve is opened when the waste gate valve is normal and the supercharging pressure does not easily increase. And in the second region, the supercharging pressure and the intake air amount are detected as the determination parameters, respectively.
The abnormality determination device sets the boost pressure detected in the first region to “P1”, the intake air amount detected in the first region to “GA1”, and the boost pressure detected in the second region to “ P2 ”, the intake air amount detected in the second region is“ GA2 ”, and the increase rate of the detected supercharging pressure accompanying the increase in the detected intake air amount is“ ΔP ”, the relational expression [ΔP = The waste gate valve is characterized in that the waste gate valve is determined to be abnormal when the increase speed ΔP determined by (P2-P1) / (GA2-GA1)] is equal to or greater than a determination value. Abnormality judgment device.