JP2010229903A - Abnormality decision device for supercharged internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent wrong decision while inhibiting increase of manufacturing cost in abnormality decision of an intake air change over valve. <P>SOLUTION: An abnormality decision device (100) for a supercharged internal combustion engine is mounted on a vehicle (1) equipped with an internal combustion engine (11) having two superchargers (14, 15), and includes a mode change over means (22) capable of mutually changing between a single turbo mode and a twin turbo mode, including an intake air change over valve (16) capable of mutually changing over between a first channel introducing intake air supplied to the internal combustion engine through one of the supercharges and a second channel introducing intake air through both of the two superchargers, and an abnormality decision means (21) deciding whether the intake air change over valve is abnormal or not based on abnormality decision value and a differential value between target supercharging pressure and actual supercharging pressure in mode change over from the single turbo mode to the twin turbo mode. The abnormality decision means renews abnormality decision value under a condition where a vehicle is in an acceleration state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an abnormality determination device for an internal combustion engine having two superchargers, and more particularly to a technical field of abnormality determination of an intake switching valve capable of switching an intake air flow path.

  In this type of device, for example, in order to avoid a malfunction that occurs when the single turbo mode is switched to the twin turbo mode when the intake switching valve stops operating in a closed state, the intake switching valve malfunctions. A determination is made.

  As this type of device, for example, Patent Document 1 discloses a target boost pressure determined by the rotational speed and speed ratio of an internal combustion engine and an actual boost pressure when shifting from a single turbo mode to a twin turbo mode. Based on the above, there is disclosed an apparatus provided with failure determination means for determining whether or not the intake air switching valve is in failure. Alternatively, Patent Document 2 discloses a device that diagnoses the presence or absence of a failure of an intake control valve or the like based on a differential pressure between an upstream pressure and a downstream pressure of an intake control valve as an example of an intake switching valve.

JP-A-5-98981 JP-A-6-123234

  However, in the technique disclosed in Patent Document 1, for example, when a difference occurs between the target supercharging pressure and the actual supercharging pressure due to a delay in supercharging following, for example, when the vehicle is accelerated, an erroneous determination is made. There is a technical problem that may arise. Moreover, in the technique disclosed in Patent Document 2, for example, a differential pressure sensor or the like must be provided, and there is a technical problem that the manufacturing cost may increase.

  The present invention has been made in view of the above problems, for example, and proposes an abnormality determination device for a supercharged internal combustion engine that can prevent erroneous determination while suppressing manufacturing cost. .

  In order to solve the above-described problem, an abnormality determination device for an internal combustion engine with a supercharger according to the present invention is mounted on a vehicle including an internal combustion engine having two superchargers, and one of the two superchargers. A single turbo mode in which supercharging is performed by a charger and a twin turbo mode in which supercharging is performed by both of the two superchargers can be switched to each other, and intake air supplied to the internal combustion engine is A mode having an intake air switching valve capable of switching between a first flow path leading to the internal combustion engine via a supercharger and a second flow path leading to the internal combustion engine via both of the two superchargers When the switching means and the mode switching to switch from the single turbo mode to the twin turbo mode, the intake switching valve is abnormal based on the difference value between the target boost pressure and the actual boost pressure and the abnormality determination value. Abnormal judgment to determine whether or not And a stage, the abnormality determination means, on condition that the vehicle is in the accelerating state, changes the abnormality determination value.

  According to the abnormality determination device for an internal combustion engine with a supercharger according to the present invention, a vehicle equipped with the abnormality determination device includes an internal combustion engine having two superchargers. Here, the two superchargers according to the present invention are so-called “two-way twin turbos” connected in parallel to each other.

  The mode switching means can switch between a single turbo mode in which supercharging is performed by one of the two superchargers and a twin turbo mode in which supercharging is performed by both of the two superchargers. .

  The mode switching means includes a first flow path for guiding the intake air supplied to the internal combustion engine to the internal combustion engine through one of the two superchargers, and the internal combustion engine via both the two superchargers. An intake switching valve that can switch between the second flow path leading to the engine is provided. The mode switching means further includes both a third flow path for guiding the exhaust discharged from the internal combustion engine to the outside of the vehicle via one of the two superchargers, and the two superchargers. And an exhaust switching valve that can switch between the fourth flow path that leads to the outside of the vehicle via the vehicle.

  The mode switching means switches from the third flow path to the fourth flow path while controlling the intake air switching valve so as to switch from the first flow path to the second flow path when switching from the single turbo mode to the twin turbo mode. The exhaust gas switching valve is controlled as follows. On the other hand, when switching from the twin turbo mode to the single turbo mode, the mode switching means controls the intake air switching valve so as to switch from the second flow path to the first flow path, and from the fourth flow path to the third flow path. The exhaust switch valve is controlled to switch to

  For example, the abnormality determination means including a memory, a processor, a comparator, and the like, when switching the mode from the single turbo mode to the twin turbo mode, a difference value between the target boost pressure and the actual boost pressure, an abnormality determination value, Based on the above, it is determined whether or not the intake air switching valve is abnormal. Here, the differential value between the target boost pressure and the actual boost pressure typically means a value obtained by subtracting the actual boost pressure from the target boost pressure. Therefore, the difference value increases as the target boost pressure deviates from the actual boost pressure.

  Specifically, for example, the abnormality determination unit determines that the intake switching valve is abnormal when the difference value between the target boost pressure and the actual boost pressure is larger than the abnormality determination value. On the other hand, the abnormality determining means determines that the intake switching valve is not abnormal when the difference value between the target boost pressure and the actual boost pressure is smaller than the abnormality determination value. When the difference value between the target boost pressure and the actual boost pressure and the abnormality determination value are “equal”, they may be included in either case.

  The “abnormality determination value” according to the present invention is a value that determines whether or not the intake air switching valve is abnormal, and is typically a value that is set as a variable value according to a physical quantity or some parameter. is there. Such an abnormality determination value is obtained by, for example, experimentally, empirically, or simulating the relationship between the opening degree of the intake switching valve and the difference value between the target boost pressure and the actual boost pressure based on the driving state of the vehicle. It is obtained every time, and based on the obtained relationship, it is set as a value that can be said to be certain that an abnormality has occurred in the intake air switching valve.

  According to the present invention, “when switching from the single turbo mode to the twin turbo mode” means that the intake switching valve and the exhaust switching valve are controlled from the time when control of the intake switching valve and the exhaust switching valve is started in order to shift from the single turbo mode to the twin turbo mode. Not only until the time when the control of the exhaust gas switching valve is terminated, but also when the intake air switching valve and the exhaust gas switching valve are not operated from a time point slightly later than the time when the control of the intake air switching valve and the exhaust gas switching valve is started or when a predetermined time has passed. It may mean a time point slightly later than the time point when the control ends or a time point until a predetermined time has passed.

  According to the research of the present inventor, in an apparatus that determines the abnormality of the intake switching valve based on the difference value between the target boost pressure and the actual boost pressure, the followability decreases when the vehicle is accelerated, etc. As a result, if there is a difference between the target boost pressure and the actual boost pressure, an erroneous determination may occur. On the other hand, a device for determining an abnormality of the intake switching valve based on the differential pressure between the upstream pressure and the downstream pressure of the intake switching valve has been proposed.For example, a differential pressure sensor or the like must be provided, Manufacturing costs may increase. Furthermore, it has been found that the layout of piping, for example, may become complicated due to the provision of a differential pressure sensor or the like.

  However, in the present invention, when the mode is switched from the single turbo mode to the twin turbo mode by the abnormality determination means, the intake air switching is performed based on the difference value between the target boost pressure and the actual boost pressure and the abnormality determination value. It is determined whether the valve is abnormal. In the present invention, in particular, the abnormality determination value is changed by the abnormality determination means on condition that the vehicle is in an accelerated state.

  For this reason, even if it is predicted that the follow-up performance of the supercharging pressure will be reduced, whether or not the intake switching valve is abnormal based on the abnormality determination value considering the decrease in the follow-up performance of the supercharging pressure. Therefore, erroneous determination can be prevented. In addition, in the present invention, for example, there is no need to newly provide a differential pressure sensor or the like, and therefore the manufacturing cost can be suppressed.

  Whether or not the vehicle is in an accelerated state may be determined by detecting, for example, the amount of depression of the accelerator pedal.

  In one aspect of the abnormality determination device for an internal combustion engine with a supercharger according to the present invention, the abnormality determination means determines whether or not the intake switching valve is abnormal after a predetermined period of time has elapsed since switching to the twin turbo mode. judge.

  According to this aspect, even when the supercharging pressure falls when switching from the single turbo mode to the twin turbo mode, erroneous determination can be prevented, which is very advantageous in practice.

  The “predetermined period” according to the present invention is a value that determines the timing for determining whether or not the intake air switching valve is abnormal, and is a fixed value in advance or variable according to a physical quantity or some parameter. It is a value set as a value. Such a predetermined period is, for example, between the elapsed time from the start of the switching from the single turbo mode to the twin turbo mode, and the target boost pressure and the actual boost pressure, experimentally, empirically, or by simulation. The relationship with the degree of divergence is obtained for each degree of decrease in supercharging pressure, and based on the obtained relationship, the case where the intake switching valve is abnormal and the case where the intake switching valve is normal can be distinguished It may be set as a long period. This utilizes the fact that when the intake air switching valve is normal, the degree of deviation between the target boost pressure and the actual boost pressure decreases with time.

  In another aspect of the abnormality determination device for an internal combustion engine with a supercharger according to the present invention, the abnormality determination means detects target supercharging pressure determining means for determining the target supercharging pressure, and detects the actual supercharging pressure. And a supercharging pressure detecting means.

  According to this aspect, the difference value between the target supercharging pressure and the actual supercharging pressure can be obtained relatively easily, which is very advantageous in practice.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a block diagram which shows the structure of the vehicle by which the abnormality determination apparatus which concerns on embodiment of this invention is mounted. It is a conceptual diagram which shows an example of transition of a target supercharging pressure and an actual supercharging pressure at the time of shifting from the single turbo mode to the twin turbo mode. It is a conceptual diagram which shows an example of transition of the grade of the deviation | shift of the actual supercharging pressure with respect to a target supercharging pressure at the time of shifting to the single turbo mode from the twin turbo mode. It is a flowchart which shows the abnormality determination process which the abnormality determination apparatus which concerns on embodiment of this invention performs.

  Hereinafter, an embodiment of an abnormality determination device for a supercharged internal combustion engine according to the present invention will be described with reference to FIGS. 1 to 4.

  First, a vehicle equipped with the abnormality determination device according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a vehicle on which the abnormality determination device according to this embodiment is mounted. In FIG. 1, for convenience of explanation, only members that are directly related to the present embodiment are shown, and other members are omitted. Moreover, the solid line arrow in the figure indicates the flow of intake air, and the dotted line arrow indicates the flow of exhaust gas.

  In FIG. 1, a vehicle 1 includes an internal combustion engine 11, a first supercharger 14, and a second supercharger 15. An intake passage 12 and an exhaust passage 13 are connected to the internal combustion engine 11. The intake passage 12 is provided with a compressor 14a of the first supercharger 14, a compressor 15a of the second supercharger 15, and an intake air switching valve 16. On the other hand, the exhaust passage 13 is provided with a turbine 14b of the first supercharger 14, a turbine 15b of the second supercharger 15, and an exhaust switching valve 17. The turbine 14b of the first supercharger 14 is a turbine with a variable nozzle VN.

  When the intake switching valve 16 and the exhaust switching valve 17 are closed, the air taken from the outside of the vehicle 1 is guided to the internal combustion engine 11 via the compressor 14a of the first supercharger 14, and the internal combustion engine The exhaust discharged from 11 is guided to the outside of the vehicle 1 via the turbine 14 b of the first supercharger 14. In this case, only the first supercharger 14 operates (that is, the single turbo mode).

  On the other hand, when the intake switching valve 16 and the exhaust switching valve 17 are in the open state, the air taken in from the outside of the vehicle 1 passes through the compressor 14a of the first supercharger 14 and the compressor 15a of the second supercharger 15. The exhaust discharged from the internal combustion engine 11 is guided to the outside of the vehicle 1 through the turbine 14 b of the first supercharger 14 and the turbine 15 b of the second supercharger 15. In this case, the first supercharger 14 and the second supercharger 15 operate (that is, the twin turbo mode).

  In addition, according to the present embodiment, “a flow path for guiding air to the internal combustion engine 11 via the compressor 14 a of the first supercharger 14” and “exhaust gas outside the vehicle 1 via the turbine 14 b of the first supercharger 14. The “flow path leading to” is an example of the “first flow path” and the “third flow path” according to the present invention, respectively. Further, according to the present embodiment, “a flow path for guiding air to the internal combustion engine 11 through the compressor 14a of the first supercharger 14 and the compressor 15a of the second supercharger 15” and “the exhaust gas is directed to the first supercharger 14”. The “flow path leading to the outside of the vehicle 1 via the turbine 14b of the second turbocharger 15 and the turbine 15b of the second supercharger 15” are examples of the “second flow path” and the “fourth flow path” according to the present invention, respectively. .

  The abnormality determination device 100 includes a determination unit 21, a control unit 22, and a supercharging pressure sensor 23. The control unit 22 switches the single turbo mode and the twin turbo mode to each other by closing the intake switching valve 16 and the exhaust switching valve 17 respectively. Here, the “determination unit 21”, “control unit 22”, and “supercharging pressure sensor 23” according to the present embodiment are respectively referred to as “abnormality determination unit”, “mode switching unit”, and “supercharging” according to the present invention. It is an example of “pressure detection means”.

  The determination unit 21 typically stores a map for determining the target boost pressure in advance, and is stored based on, for example, the rotational speed of the internal combustion engine 11 or a transmission gear ratio (not shown). The target boost pressure is determined from the existing map. Such a map can be determined experimentally, empirically, or by simulation, for example, the rotational speed of the internal combustion engine, the transmission gear ratio, and the boost pressure that achieves the output required for that rotational speed or gear ratio. The relationship may be determined based on the determined relationship.

  Moreover, the determination part 21 determines whether the vehicle 1 is in an acceleration state by detecting the depression amount of the accelerator pedal 24. Note that the determination unit 21 is not limited to the amount of depression of the accelerator pedal 24, and obtains, for example, a change amount (that is, acceleration) per unit time of the vehicle speed acquired via a vehicle speed sensor (not shown). Whether or not the vehicle 1 is in an accelerated state may be determined based on the acceleration.

  Next, transition of the target supercharging pressure and the actual supercharging pressure when shifting from the single turbo mode to the twin turbo mode when the vehicle 1 is in an acceleration state will be described with reference to FIG. FIG. 2 is a conceptual diagram showing an example of a transition between the target boost pressure and the actual boost pressure when shifting from the single turbo mode to the twin turbo mode.

  The upper part of FIG. 2 shows the transition of the value of “emdtb” that is a parameter indicating the state of the turbo mode. When the value of emdtb is “0”, this indicates a single turbo mode in which only the first supercharger 14 is operated. When the value of emdtb is “1”, the exhaust gas switching valve 17 is opened by a minute opening. When the value of emdtb is “2”, it indicates a twin turbo mode in which the first supercharger 14 and the second supercharger 15 operate.

  Accordingly, in FIG. 2, the exhaust gas switching valve 17 is controlled by the control unit 22 so that the exhaust gas switching valve 17 opens by a minute opening at time t1, and at time t2, the intake air switching valve 16 and the exhaust gas switching valve 17 are turned on. The intake switching valve 16 and the exhaust switching valve 17 are controlled by the control unit 22 so that the valve is opened.

  In the present embodiment, when shifting from the single turbo mode to the twin turbo mode, first, the exhaust gas switching valve 17 is opened by a minute opening degree, and the second supercharger 15 is pre-rotated. As a result, it is possible to suppress a drop in the supercharging pressure when shifting from the single turbo mode to the twin turbo mode, which is very advantageous in practice.

  The lower part of FIG. 2 shows the transition of the supercharging pressure. In the lower part of FIG. 2, the parameters “epim”, “epimtrg”, “epimdltch”, and “epimdlt” are “actual supercharging pressure”, “target supercharging pressure”, “just before turbo mode switching (for example, in FIG. 2). The difference between the target supercharging pressure and the actual supercharging pressure at time t1) and “the difference between the target supercharging pressure and the actual supercharging pressure” are shown. A broken line a indicates a value obtained by subtracting epimdltch from epimtrg.

  As shown in FIG. 2, the actual supercharging pressure is accompanied by a follow-up delay with respect to the target supercharging pressure due to the vehicle 1 being in an acceleration state. When the mode is changed from the single turbo mode to the twin turbo mode (that is, when the value of emdtb becomes “2”), the actual supercharging pressure (that is, epim) drops more or less (the intake switching valve 16 is normal). Or even abnormal).

  When the intake air switching valve 16 is normal (that is, when the intake air switching valve 16 is in an open state), the actual supercharging pressure drops once and then with the passage of time, the target supercharging pressure (that is, epimtrg). On the other hand, when the intake air switching valve 16 is abnormal (for example, when the intake air switching valve 16 does not open), the actual supercharging pressure deviates from the target supercharging pressure with the passage of time.

  Next, the transition of the actual supercharging pressure with respect to the target supercharging pressure will be described with reference to FIG. FIG. 3 is a conceptual diagram showing an example of transition of the degree of deviation of the actual supercharging pressure from the target supercharging pressure when shifting from the single turbo mode to the twin turbo mode. FIG. 3 shows the transition of the actual supercharging pressure with respect to the value obtained by subtracting the difference (epimdltch) between the target supercharging pressure and the actual supercharging pressure immediately before the turbo mode switching from the target supercharging pressure (ie, epimdtrg). Yes. Also, times t1 and t2 in FIG. 3 correspond to times t1 and t2 in FIG. 2, respectively.

  The solid lines a, b, c, and d in FIG. 3 respectively indicate “changes in the actual supercharging pressure when the supercharging pressure drop is relatively large when the intake switching valve 16 is abnormal”, “when the intake switching valve 16 is abnormal. “Changes in actual supercharging pressure when the supercharging pressure drop is relatively small”, “Changes in actual supercharging pressure when the supercharging pressure drop is relatively large when the intake switching valve 16 is normal”, and “Intake switching valve” 16 shows the transition of the actual boost pressure when the drop in the boost pressure is relatively small when normal. Further, the “period α” according to the present embodiment is an example of the “predetermined period” according to the present invention.

  Here, in FIG. 3, for example, it is assumed that it is determined whether or not the intake switching valve 16 is abnormal within the period α. Assuming the transition of the actual boost pressure when the intake switching valve 16 is abnormal as indicated by a solid line a, an abnormality determination value for determining whether or not the intake switching valve 16 is abnormal is indicated by a broken line A in FIG. If set between the broken line B and the actual boost pressure as shown by the solid line b (that is, when the drop in the boost pressure is relatively small when the intake switch valve 16 is abnormal), the intake switching valve 16 is Cannot be determined to be abnormal. On the other hand, assuming the transition of the actual boost pressure when the intake air switching valve 16 is abnormal as indicated by the solid line b and setting the abnormality determination value between the broken line C and the broken line D in FIG. When the actual supercharging pressure changes (ie, when the drop in the supercharging pressure is relatively large when the intake switching valve 16 is normal), it is determined that the intake switching valve 16 is abnormal (ie, erroneous determination). Resulting in).

  For this reason, the abnormality determination device 100 according to the present embodiment is configured to make a final determination as to whether or not the intake air switching valve 16 is abnormal after time t3, which is the time when the period α has elapsed from time t2. Has been. If comprised in this way, even if an abnormality determination value is set to the broken line D of FIG. 3, for example, it can be determined appropriately whether the intake switching valve 16 is abnormal.

  Next, the abnormality determination process performed by the abnormality determination device 100 when the vehicle 1 in which the abnormality determination device 100 configured as described above is mounted is mainly accelerated and when the vehicle is shifted from the single turbo mode to the twin turbo mode. Will be described with reference to the flowchart of FIG.

  In FIG. 4, first, the determination unit 21 detects that the value of the parameter emdtb changes from “0” to “1” (step S101), and sets the target boost pressure and the boost pressure sensor 23 at that time. The difference from the actual supercharging pressure acquired through the process is stored as a value of the parameter epidltch (step S102). Next, the control unit 22 releases the restriction on the amount of fuel injected from the fuel injection valve (not shown) in order to compensate for the drop in the supercharging pressure that occurs during the turbo mode switching (step S103).

  Next, the determination unit 21 determines whether or not the value of the parameter emdtb is “2” (step S104). When it is determined that the value of the parameter emdtb is not “2” (step S104: No), the process of step S104 is executed again. On the other hand, when it is determined that the value of the parameter emdtb is “2” (step S104: Yes), the determination unit 21 is a parameter in which a difference value between the value of the parameter epimdlt and the value of the parameter epimdltch indicates an abnormality determination value. It is determined whether or not the value is greater than a certain epimop2am value (step S105). In the present embodiment, the value of the parameter epimop2am is set to the broken line D in FIG.

  Here, as described above, the parameter epimdlt is the difference between the target supercharging pressure and the actual supercharging pressure, and the parameter epimdltch is the difference between the target supercharging pressure and the actual supercharging pressure immediately before switching to the turbo mode (in other words, The difference due to the supercharging pressure follow-up delay that exists immediately before the turbo mode switching). In addition, the determination formula in step S105 can be modified as “epimlt> epimop2am + epimltch”. Therefore, in this embodiment, the difference between the target supercharging pressure and the actual supercharging pressure is compared with the abnormality determination value that takes into account the supercharging pressure follow-up delay (that is, increased by the value of the parameter epidltch). Thus, it can be said that it is determined whether or not the intake air switching valve 16 is abnormal.

  In the process of step S105, when it is determined that the difference between the value of the parameter epimdlt and the value of the parameter epimdltch is smaller than the value of the parameter epimdrop2am (step S105: No), in this case, the intake switching valve 16 is normal. Since there is, the process is temporarily terminated. On the other hand, in the process of step S105, when it is determined that the difference value between the value of the parameter epimdlt and the value of the parameter epimdltch is greater than the value of the parameter epimlp2am (that is, it is determined that the intake air switching valve 16 is abnormal). Case) (step S105: Yes), the determination unit 21 counts up Ecfvnop2a which is a parameter indicating an elapsed time since the transition to the twin turbo mode (step S106).

  Subsequently, the determination unit 21 determines whether or not the value of the parameter Ecfvnop2a is larger than the period α (see FIG. 3) (step S107). When it is determined that the value of the parameter Ecfvnop2a is smaller than the period α (step S107: No), since the period α has not elapsed in this case, the process of step S105 is executed after the value of the parameter epimdlt is updated. .

  On the other hand, when it is determined that the value of the parameter Ecfvnop2a is greater than the period α (step S107: Yes), in this case, since it is determined that the period α has elapsed and the intake air switching valve 16 is abnormal, the intake air A final determination is made that the switching valve 16 is abnormal, and the determination unit 21 turns on the abnormal flag (step S108). Subsequently, the control unit 22 limits the injection amount so that the vehicle 1 can be operated only in the single turbo mode (step S109), and once ends the process.

  Note that the control unit 22 may notify the driver of the abnormality by turning on a warning lamp (MIL), for example, before or after the process of step S109.

  Further, in the exhaust gas switching valve 17 according to the present embodiment, when the transition from the single turbo mode to the twin turbo mode is performed, the exhaust gas switching valve 17 is opened by a small opening degree to pre-rotate the second supercharger 15. An opening sensor is provided. Therefore, it can be determined whether or not the exhaust gas switching valve 17 is abnormal based on the output signal from the opening sensor.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and is accompanied by such a change. An abnormality determination device for a supercharged internal combustion engine is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 11 ... Internal combustion engine, 14 ... 1st supercharger, 15 ... 2nd supercharger, 16 ... Intake switching valve, 17 ... Exhaust gas switching valve, 21 ... Determination part, 22 ... Control part, 23 ... Supercharger Supply pressure sensor, 100 ... abnormality determination device

Claims (3)

Mounted on a vehicle with an internal combustion engine having two superchargers,
A single turbo mode in which supercharging is performed by one of the two superchargers and a twin turbo mode in which supercharging is performed by both of the two superchargers can be switched to each other, and the internal combustion A first flow path for guiding intake air supplied to the engine to the internal combustion engine via the one supercharger, and a second flow path for guiding the intake air to the internal combustion engine via both of the two superchargers. Mode switching means having an intake switching valve that can be switched to each other;
Whether or not the intake switching valve is abnormal based on the difference value between the target boost pressure and the actual boost pressure and the abnormality determination value when the mode is switched from the single turbo mode to the twin turbo mode. An abnormality determination means for determining whether or not
The abnormality determination device for an internal combustion engine with a supercharger, wherein the abnormality determination means changes the abnormality determination value on condition that the vehicle is in an acceleration state.   2. The supercharger-equipped internal combustion engine according to claim 1, wherein the abnormality determination unit determines whether or not the intake switching valve is abnormal after a predetermined period of time has elapsed since switching to the twin turbo mode. Engine abnormality determination device. The abnormality determining means includes
Target boost pressure determining means for determining the target boost pressure;
The abnormality determination device for an internal combustion engine with a supercharger according to claim 1, further comprising: a supercharging pressure detecting unit that detects the actual supercharging pressure.

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