JP2010106811A - Abnormality diagnostic device for supercharging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality diagnostic device for a supercharging device diagnosing which one of an intake-side mechanism and an exhaust-side mechanism causes abnormality of supercharging pressure, based on output of a sensor monitoring the supercharging pressure and the output of a sensor provided to the exhaust-side mechanism. <P>SOLUTION: This abnormality diagnostic device for the supercharging device 40 diagnoses abnormality of the supercharging device 40 provided with the supercharging pressure sensor 51, a discharge regulating valve 46 of the exhaust-side mechanism, and the like, when there is the abnormality of the supercharging pressure with the actual supercharging pressure excessively deviated from a target supercharging pressure. In a first determination process, it is determined whether or not there is the abnormality of the supercharging pressure, and in a second determination process, it is determined whether or not there is the abnormality in the exhaust-side mechanism based on the output of the discharge regulating valve 46 or the like. When it is determined in the first and second determination processes that there is the abnormality of the supercharging pressure and there is no abnormality in the exhaust-side mechanism, the fact that the abnormality of the supercharging pressure is caused by the intake-side mechanism is set as a result of abnormal diagnosis. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes an exhaust side mechanism belonging to the engine exhaust system and an intake side mechanism belonging to the engine intake system, and includes a supercharging pressure sensor that monitors the supercharging pressure and an exhaust side sensor that monitors the state of the exhaust side mechanism. The present invention relates to an abnormality diagnosis device for a supercharging device that performs an abnormality diagnosis for the supercharging device.

  The engine equipped with the supercharging device rotates the turbine at high speed using the energy of the exhaust from the combustion chamber, and compresses air by the rotation of a compressor coaxially connected to the turbine and sends it to the combustion chamber. The engine output is improved. However, when an abnormality occurs in the supercharging device, the actual supercharging pressure greatly deviates from the target supercharging pressure, and the output is improved when the actual supercharging pressure is significantly below the target supercharging pressure. It becomes difficult.

  For example, in an engine that switches two turbochargers between single mode and twin mode, if the switching valve is locked in single mode, supercharging is not performed in twin mode, so the driver's request The output cannot be improved as expected.

As a method for detecting such an abnormal operation of the control valve, for example, in Patent Document 1, a differential pressure sensor for detecting a differential pressure upstream and downstream of a predetermined control valve is arranged, and the control is performed based on the differential pressure. A method for determining whether a valve is abnormal is described.
Japanese Patent Laid-Open No. 06-346744

  According to the abnormality diagnosis device of Patent Document 1 described above, it is possible to determine whether or not a supercharging pressure abnormality has occurred due to the abnormality of the control valve, but an abnormality has occurred in the control valve. When there is not, it is impossible to diagnose whether the supercharging pressure abnormality is caused by the exhaust side mechanism belonging to the engine exhaust system or the intake side mechanism belonging to the engine intake system in the supercharging device.

  Therefore, based on the outputs of the sensors provided in the exhaust side mechanism and the intake side mechanism when a supercharging pressure abnormality occurs, it is determined which of these mechanisms is causing the supercharging pressure abnormality. Is also possible. However, this diagnostic method cannot be applied to a supercharging device in which a sensor is provided only in the exhaust side mechanism as a sensor different from the sensor that monitors the supercharging pressure.

  The present invention has been made in view of such circumstances, and the purpose thereof is based on the output of a sensor for monitoring the boost pressure and the output of the sensor in the exhaust side mechanism, and the cause of the boost pressure abnormality is the intake side. It is an object of the present invention to provide an abnormality diagnosis device for a supercharging device capable of diagnosing whether a mechanism or an exhaust side mechanism is present.

In the following, means for achieving the above object and its effects are described.
(1) The invention according to claim 1 is composed of an exhaust side mechanism belonging to the engine exhaust system and an intake side mechanism belonging to the engine intake system, and a state of the supercharging pressure sensor for monitoring the supercharging pressure and the state of the exhaust side mechanism. For a supercharging device having an exhaust side sensor to be monitored, a supercharging device that performs abnormality diagnosis for the supercharging device when an actual supercharging pressure deviates excessively from a target supercharging pressure occurs. In the abnormality diagnosis device, a first determination process for determining whether or not the supercharging pressure abnormality has occurred based on the output of the supercharging pressure sensor, and an abnormality in the exhaust side mechanism based on the output of the exhaust side sensor And a second determination process for determining whether or not the engine has occurred. As a result of the first determination process and the second determination process, the determination result that the supercharging pressure abnormality has occurred, and the exhaust side mechanism A judgment result indicating that no abnormality has occurred is obtained. Sometimes, the abnormality diagnosis is set as a result of the abnormality diagnosis that the abnormality in the supercharging pressure is caused by the intake side mechanism, and the abnormality in the supercharging pressure occurs as a result of the first determination process and the second determination process. When the determination result indicating that there is an abnormality in the exhaust side mechanism and the determination result indicating that the abnormality is occurring in the exhaust side mechanism is set as a result of the abnormality diagnosis that the boost pressure abnormality is caused by the exhaust side mechanism The gist is to provide a diagnostic means.

  According to this invention, it is possible to determine whether the cause of the boost pressure abnormality is in the exhaust side mechanism or the intake side mechanism based on the determination results of the first determination process and the second determination process. That is, based on the output of the sensor that monitors the boost pressure and the output of the sensor in the exhaust side mechanism, it is possible to diagnose whether the cause of the boost pressure abnormality is in the intake side mechanism or the exhaust side mechanism. It becomes like this.

  (2) The invention according to claim 2 is the abnormality diagnosis device for the supercharging device according to claim 1, wherein the exhaust-side mechanism includes an exhaust adjustment mechanism for adjusting a flow rate of the exhaust, The side sensor monitors the opening degree of the exhaust adjustment mechanism as the state of the exhaust side mechanism, and the diagnosis means determines the actual opening degree of the exhaust adjustment mechanism based on the output of the exhaust side sensor. The gist is that it is determined whether or not the difference from the target opening is larger than a determination value, and it is determined that an abnormality has occurred in the exhaust adjustment mechanism based on the determination result indicating that the difference is larger. Yes.

  According to this configuration, since the diagnosis unit makes a determination based on the difference between the actual opening of the exhaust adjustment mechanism and the target opening, whether or not an abnormality has occurred in the exhaust adjustment mechanism. A stable determination result can be obtained.

  (3) The invention according to claim 3 is the abnormality diagnosis device for the supercharging device according to claim 2, wherein the exhaust side mechanism is connected to a turbine of two turbochargers and to an upstream side of the turbocharger. An upstream exhaust pipe, a downstream exhaust pipe connected to the downstream side of the turbocharger, and a twin mode that is provided in the upstream exhaust pipe and allows exhaust from the internal combustion engine to flow into one turbocharger when in single mode In this case, an exhaust amount adjusting valve as an exhaust adjusting mechanism for causing the exhaust from the internal combustion engine to flow into both turbochargers, and an adjusting valve sensor as an exhaust side sensor for monitoring the opening of the exhaust amount adjusting valve, The intake side mechanism includes two turbocharger compressors, an upstream intake pipe connected to the upstream side of the turbocharger, and the turbocharger. A downstream intake pipe connected to the downstream side, a branch communication pipe for returning a part of the intake air of the downstream intake pipe to the upstream intake pipe, and a first provided in the branch communication pipe and closed in the twin mode. The gist of the invention is that it includes an on-off valve and a second on-off valve provided in the downstream intake pipe and closed in the single mode.

  In this configuration, the exhaust side mechanism and the intake side mechanism include two turbochargers. Further, in the second determination process, it is determined whether an abnormality has occurred in the exhaust side mechanism based on the output of the exhaust side sensor for the exhaust amount adjustment valve as the exhaust adjustment mechanism.

  (4) According to a fourth aspect of the present invention, in the abnormality diagnosis device for a supercharging device according to the third aspect, the turbocharger is of a variable capacity type, and an exhaust adjustment for controlling an air flow rate of the exhaust to the turbine. The gist of the invention is that it has a vane mechanism as a mechanism and a nozzle sensor as an exhaust side sensor for monitoring the opening degree of the vane mechanism.

  In this configuration, the turbocharger is a variable displacement type and includes a vane mechanism as an exhaust adjustment mechanism. Further, in the second determination process, it is determined whether an abnormality has occurred in the exhaust side mechanism based on the output of the nozzle sensor for the vane mechanism as the exhaust adjustment mechanism.

(First embodiment)
A first embodiment in which the abnormality diagnosis device for a supercharging device of the present invention is embodied as an abnormality diagnosis device for a supercharging device of an in-line 8-cylinder diesel engine will be described with reference to FIGS.

  In a diesel engine (hereinafter referred to as “engine 1”), an engine body 10 that burns an air-fuel mixture, an intake device 20 that supplies intake air to the engine body 10, and an exhaust device 30 that sends exhaust from the engine body 10 to the outside. And a supercharging device 40 that performs supercharging using the energy of the exhaust. In addition to these devices, an electronic control device 50 that controls the engine 1 in an integrated manner is provided.

  The intake device 20 includes an intake pipe 21 that circulates air taken from the outside toward the engine body 10, an intake manifold 26 that distributes the intake air flowing through the intake pipe 21 in each cylinder of the engine body 10, and an intake air An air cleaner 27 that removes foreign matter from the air and an intake throttle 28 that adjusts the flow rate of intake air are provided.

  The exhaust device 30 includes an exhaust manifold 34 that collects exhaust gas sent from the combustion chambers of the engine body 10, an exhaust pipe 31 that distributes the exhaust gas collected by the exhaust manifold 34 to the outside, and an intermediate portion of the exhaust pipe 31. An exhaust gas purifying device 35 for purifying exhaust gas is provided in the section.

  The supercharger 40 includes two variable capacity turbochargers, that is, a first turbocharger 41 and a second turbocharger 42, and an operation mode (hereinafter referred to as “single mode”) for driving only the first turbocharger 41; Supercharging is performed by switching the operation mode (hereinafter referred to as “twin mode”) for driving the first turbocharger 41 and the second turbocharger 42.

  Each turbocharger 41, 42 is provided with a vane mechanism that adjusts the flow velocity of the exhaust blown to the respective turbine wheels 41A, 42A. This vane mechanism has a plurality of nozzle vanes, and changes the flow rate of the exhaust gas blown to the turbine wheels 41A and 42A by changing the interval between adjacent nozzle vanes by an actuator. As a result, the rotational speed of the turbine wheels 41A and 42A and the magnitude of the supercharging pressure also change. That is, each turbocharger 41, 42 adjusts the magnitude of the supercharging pressure by changing the interval between adjacent nozzle vanes.

  Here, the supercharger 40 is configured to further include a plurality of elements different from the turbochargers 41 and 42 described above, and the constituent elements of the supercharger 40 are the engine 1 as described below. The intake side mechanism and the exhaust side mechanism of the supercharger 40 belong to either the engine intake system or the engine exhaust system.

First, the configuration of the supercharging device 40 in the intake device 20 will be described.
The intake pipe 21 includes an upstream intake pipe 22 between the air cleaner 27 and the compressor wheels 41B and 42B of the turbochargers 41 and 42, and between the compressor wheels 41B and 42B of the turbochargers 41 and 42 and the intake manifold 26. And the downstream intake pipe 23.

  The upstream intake pipe 22 includes a first upstream branch pipe 22A connected to the inlet of the first turbocharger 41, a second upstream branch pipe 22B connected to the inlet of the second turbocharger 42, and inlets of these branch pipes. The upstream collecting pipe 22C is connected.

  The downstream intake pipe 23 includes a first downstream branch pipe 23A connected to the compressor wheel 41B of the first turbocharger 41, a second downstream branch pipe 23B connected to the compressor wheel 42B of the second turbocharger 42, and these branches. The downstream collecting pipe 23C is connected to the outlet of the pipe.

  As for the upstream intake pipe 22 and the downstream intake pipe 23, the first upstream branch pipe 22A and the second downstream branch pipe 23B are connected by a branch communication pipe 24. The branch communication pipe 24 is provided with a first on-off valve 43 that adjusts the flow rate of intake air between the first upstream branch pipe 22A and the second downstream branch pipe 23B.

  For the second downstream branch pipe 23B, a second flow rate adjusting the flow rate of the intake air in the second downstream branch pipe 23B between the part where the branch communication pipe 24 is connected and the part where the first downstream branch pipe 23A merges. An on-off valve 44 is provided. A downstream bypass pipe 25 that bypasses the second on-off valve 44 and distributes the intake air is provided. The downstream bypass pipe 25 is provided with a reed valve 45 that opens when the pressure in the upstream portion in the second downstream branch pipe 23B rises excessively.

Next, the configuration of the supercharging device 40 in the exhaust device 30 will be described.
The exhaust pipe 31 is located on the downstream side of the upstream exhaust pipe 32 between the exhaust manifold 34 and the turbine wheels 41A, 42A of the turbochargers 41, 42, and the turbine wheels 41A, 42A of the turbochargers 41, 42. The downstream exhaust pipe 33 is configured.

  The upstream exhaust pipe 32 includes a first upstream branch pipe 32A connected to the turbine wheel 41A of the first turbocharger 41, a second upstream branch pipe 32B connected to the turbine wheel 42A of the second turbocharger 42, and these branches. And an upstream collecting pipe 32C connected to the inlet of the pipe. The second upstream branch pipe 32B is provided with an exhaust amount adjusting valve 46 for adjusting the flow rate of the exhaust.

  The downstream intake pipe 23 includes a first downstream branch pipe 33A connected to the turbine wheel 41A of the first turbocharger 41, a second downstream branch pipe 33B connected to the turbine wheel 42A of the second turbocharger 42, and these branches. The downstream collecting pipe 33C is connected to the outlet of the pipe.

  Among the elements described above, the upstream intake pipe 22, the downstream intake pipe 23, the branch communication pipe 24, the downstream bypass pipe 25, the first on-off valve 43, the second on-off valve 44, the reed valve 45, and each compressor wheel 41B and 42B belong to the intake system of the engine 1 and constitute an intake side mechanism 40A of the supercharging device 40. Further, the upstream exhaust pipe 32, the downstream exhaust pipe 33, the exhaust amount adjustment valve 46, and the turbine wheels 41 </ b> A and 42 </ b> A belong to the engine exhaust system of the engine 1 and constitute an exhaust side mechanism 40 </ b> B of the supercharger 40. .

  The electronic control unit 50 determines the engine operating state, the vehicle traveling state, and the driver based on the outputs of various sensors including the supercharging pressure sensor 51, the first nozzle sensor 52, the second nozzle sensor 53, and the regulating valve sensor 54. For example, the following control is performed after grasping the request. That is, intake air amount control for adjusting the flow rate of the intake air in the intake pipe 21 by controlling the opening of the intake throttle 28, and supercharging pressure control for adjusting the magnitude of the supercharging pressure by controlling the nozzle vanes of the turbochargers 41 and 42. Then, abnormality diagnosis control for determining whether or not an abnormality has occurred in the supercharging device 40 is performed.

  The supercharging pressure sensor 51 is provided in the vicinity of the intake manifold 26 of the intake pipe 21 and outputs a signal corresponding to the pressure of the intake air in the pipe (hereinafter referred to as “supercharging pressure PT”). The first nozzle sensor 52 is provided in the vicinity of the first nozzle vane of the first turbocharger 41, and is a signal corresponding to the interval between the adjacent first nozzle vanes (hereinafter, “first nozzle opening NA1”). Is output. The second nozzle sensor 53 is provided in the vicinity of the second nozzle vane of the second turbocharger 42, and is a signal corresponding to the interval between the adjacent second nozzle vanes (hereinafter, “second nozzle opening NA2”). Is output. The adjustment valve sensor 54 is provided in the vicinity of the exhaust amount adjustment valve 46 and outputs a signal corresponding to the opening of the valve (hereinafter referred to as “valve opening VA”).

Next, the operation mode of the supercharging device 40 will be described.
When the supercharger 40 is in the single mode, both the first on-off valve 43 and the second on-off valve 44 are maintained in the closed state. In addition, when the pressure in the upstream portion of the second downstream branch pipe 23B is in a normal pressure state in which the pressure does not increase excessively, the reed valve 45 is maintained in a closed state. Further, the exhaust amount adjusting valve 46 is maintained in a closed state.

  Thereby, since the branch communication pipe 24 is closed, the flow of the intake air between the first upstream branch pipe 22A and the second downstream branch pipe 23B is blocked. Further, since the second downstream branch pipe 23B is closed and the downstream bypass pipe 25 is also closed, the flow of intake air from the second downstream branch pipe 23B to the downstream collecting pipe 23C is also blocked. Further, since the second upstream branch pipe 32B of the upstream exhaust pipe 32 is closed, the flow of exhaust from the engine body 10 to the second turbocharger 42 is also blocked.

  The passages of the supercharging device 40 are maintained in such a state, whereby the exhaust from the engine body 10 is supplied only to the first turbocharger 41, and the turbocharger 41 performs supercharging. The intake air compressed by the first turbocharger 41 flows into the downstream collecting pipe 23C via the first downstream branch pipe 23A.

  When the supercharger 40 is in the twin mode, the first on-off valve 43 and the second on-off valve 44 are both kept open. In addition, when the pressure in the upstream portion of the second downstream branch pipe 23B is in a normal pressure state in which the pressure does not increase excessively, the reed valve 45 is maintained in a closed state. Further, the exhaust amount adjustment valve 46 is maintained in the valve open state.

  Thereby, since the branch communication pipe 24 is opened, the flow of intake air between the first upstream branch pipe 22A and the second downstream branch pipe 23B is allowed. Further, since the second downstream branch pipe 23B is opened, the intake air flow from the second downstream branch pipe 23B to the downstream collecting pipe 23C is allowed. Further, since the second upstream branch pipe 32B of the upstream exhaust pipe 32 is opened, the exhaust flow from the engine body 10 to the second turbocharger 42 is also allowed.

  And each passage of the supercharging device 40 is maintained in such a state, so that the exhaust from the engine body 10 is supplied to both the first turbocharger 41 and the second turbocharger 42, and these turbochargers 41, 42. Supercharging is performed. The intake air compressed by the first turbocharger 41 flows into the downstream collecting pipe 23C via the first downstream branch pipe 23A. The intake air compressed by the second turbocharger 42 flows into the downstream collecting pipe 23C through the second downstream branch pipe 23B. At this time, the degree of supercharging by the turbocharger 42 can be changed by adjusting the flow rate of the exhaust gas to the second turbocharger 42 by controlling the opening of the exhaust amount adjusting valve 46.

Next, abnormality diagnosis control by the electronic control unit 50 will be described.
When the supercharging pressure sensor 51 determines that the supercharging pressure is abnormal in the single mode, the electronic control unit 50 determines the first nozzle vane and the exhaust amount based on the monitor values of the first nozzle sensor 52 and the regulating valve sensor 54. The operation abnormality of the regulating valve 46 is determined. Further, when the electronic control unit 50 determines that neither the first nozzle vane nor the exhaust amount adjustment valve 46 is abnormal, the electronic control unit 50 determines that the second on-off valve 44 has an abnormal operation, and the supercharging pressure abnormality has occurred. The fact that it is caused by the intake side mechanism 40A is set as a result of the abnormality diagnosis. On the other hand, when it is determined that there is an abnormality in either the first nozzle vane or the exhaust amount adjustment valve 46, the electronic control unit 50 performs an abnormality diagnosis that the supercharging pressure abnormality is caused by the exhaust side mechanism 40B. Set as a result.

  When the electronic control unit 50 determines that the supercharging pressure is abnormal by the supercharging pressure sensor 51 in the twin mode, the monitor values of the first nozzle sensor 52, the second nozzle sensor 53, and the regulating valve sensor 54 are displayed. Based on the above, the abnormal operation of the first nozzle vane, the second nozzle vane and the exhaust amount adjusting valve 46 is determined. Further, when the electronic control unit 50 determines that all of the first nozzle vane, the second nozzle vane, and the exhaust amount adjustment valve 46 are not abnormal, the second on-off valve 44 or the first on-off valve 43 has an operation abnormality. And the fact that the supercharging pressure abnormality is caused by the intake side mechanism 40A is set as a result of the abnormality diagnosis. On the other hand, when it is determined that any of the first nozzle vane, the second nozzle vane, and the exhaust amount adjustment valve 46 is abnormal, the electronic control unit 50 indicates that the abnormality in the supercharging pressure is caused by the exhaust side mechanism 40B. Is set as the result of abnormality diagnosis.

  The determination of the supercharging pressure abnormality in the electronic control unit 50 is performed by comparing the supercharging pressure detected by the supercharging pressure sensor 51 with a target value set according to conditions such as the amount of fluctuation of the intake throttle 28. It is determined whether the supply pressure is abnormal. For example, when the ratio between the supercharging pressure and the target value is not within a predetermined range, it is determined that the supercharging pressure is abnormal.

  In addition, the electronic control device 50 determines whether the first nozzle vane, the second nozzle vane, and the exhaust amount adjustment valve 46 are operating abnormally based on the actual opening calculated from the monitor values of the various sensors and the target opening. This is done based on the difference. Specifically, the operation abnormality of the first nozzle vane is determined by obtaining a difference from the opening degree of the first nozzle vane calculated from the monitor value of the first nozzle sensor 52 and the target opening degree, and the absolute value of the difference is obtained. This is done by determining whether it is below a predetermined value. When the absolute value of the difference exceeds a predetermined value, it is determined that the first nozzle vane is malfunctioning.

Next, an abnormality diagnosis mode setting process performed by the electronic control device 50 when an abnormal drop in the supercharging pressure occurs will be described with reference to FIGS.
As shown in FIG. 2, the electronic control unit 50 determines whether or not the operating state of the supercharging device 40 is a single mode in step S1. If the determination is YES, that is, if the mode is the single mode, the process proceeds to step S2 to perform a single abnormality diagnosis process. On the other hand, when determination is NO, it transfers to step S3 and performs a twin abnormality diagnosis process.

  As shown in FIG. 3, in the single abnormality diagnosis process, as a first determination process, in step S10, the boost pressure by the boost pressure sensor 51 is compared with the target value, so that the boost pressure is higher than the target value. Whether it is low is determined. When the determination is NO, that is, when the supercharging pressure is not low, the flow ends. On the other hand, if the determination is YES, that is, if the supercharging pressure has become lower than the margin for the target value, the process proceeds to step S11 in order to perform the second determination process.

  In step S11, it is determined whether or not the absolute value of the difference between the opening amount of the exhaust amount adjusting valve 46 calculated based on the monitor value detected by the adjusting valve sensor 54 and the target opening amount is a predetermined value or less.

  If the determination is NO, it is determined that there is an abnormality in the exhaust amount adjustment valve 46, the fact that the abnormal supercharging pressure is caused by the exhaust side mechanism 40B is set as a result of the abnormality diagnosis, and the flow is terminated. That is, at this time, the opening degree of the exhaust amount adjustment valve 46 is abnormally opened more than the target opening degree. Therefore, a part of the exhaust gas leaks to the second turbocharger 42 side, and the rotation of the turbine of the first turbocharger 41 decreases, resulting in a decrease in supercharging pressure. On the other hand, if the determination is YES, that is, if it is determined that there is no abnormal operation in the exhaust amount adjustment valve 46, the process proceeds to step S12.

  In step S12, it is determined whether the absolute value of the difference between the first nozzle opening NA1 calculated based on the monitor value detected by the first nozzle sensor 52 and the target opening is equal to or less than a predetermined value.

  When the determination is NO, it is determined that there is an abnormality in the first nozzle vane for the nozzle vanes of the first turbocharger 41, and the fact that the abnormality in the supercharging pressure is caused by the exhaust side mechanism 40B is set as a result of the abnormality diagnosis. To end the flow. That is, at this time, the opening degree of the first nozzle vane is abnormally large. For this reason, the exhaust gas flow rate does not increase, so that the compression rate of the supply air pressure by the compressor does not increase, and the supercharging pressure is reduced.

  On the other hand, if the determination is YES, that is, if it is determined that there is no abnormal operation in the first nozzle vane, it is determined that there is an abnormality in the second on-off valve 44, and the supercharging pressure abnormality is caused by the intake side mechanism 40A. Is set as a result of the abnormality diagnosis, and the flow ends.

  That is, when the supercharging device 40 is operating in the single mode, if there is no abnormal operation of the first nozzle vane and the exhaust amount adjustment valve 46, the exhaust side mechanism 40B does not cause a decrease in the supercharging pressure. . Further, since the first on-off valve 43 is on the upstream side of the second on-off valve 44, the influence on the supercharging pressure in the single mode is small, so it is determined that there is no abnormal operation in the exhaust side mechanism 40B in the single mode. When it is, it can be determined that the second on-off valve 44 is abnormal. That is, the cause of the decrease in the supercharging pressure is that the second on-off valve 44 is opened beyond the allowable range of the target opening, so that it is determined that the air is leaking, and an abnormal supercharging pressure is caused in the intake side mechanism 40A. The cause is set as a result of the abnormality diagnosis.

As shown in FIG. 4, in the twin abnormality diagnosis process, the processes in step S20 and step S21 are the same as those in step S10 and step S11 in FIG.
If the determination in step S21 is YES, that is, if it is determined that there is no abnormal operation in the exhaust amount adjustment valve 46, the process proceeds to step S22.

  In step S22, it is determined whether or not the absolute value of the difference between the first nozzle opening NA1 calculated based on the monitor value detected by the first nozzle sensor 52 and the target opening is equal to or less than a predetermined value. When the determination is NO, it is determined that there is an abnormality in the first nozzle vane for the nozzle vanes of the first turbocharger 41, and the fact that the abnormality in the supercharging pressure is caused by the exhaust side mechanism 40B is set as a result of the abnormality diagnosis. To end the flow. On the other hand, if the determination is YES, that is, if it is determined that there is no abnormal operation in the first nozzle vane, the process proceeds to step S23.

  In step S23, it is determined whether the absolute value of the difference between the second nozzle opening NA2 calculated based on the monitor value detected by the second nozzle sensor 53 and the target opening is equal to or less than a predetermined value. If the determination is NO, it is determined that there is an abnormality in the second nozzle vane for the nozzle vanes of the second turbocharger 42, and the abnormality diagnosis is set as a result of the abnormality diagnosis that the supercharging pressure abnormality is caused by the exhaust side mechanism 40B. To end the flow. On the other hand, when the determination is YES, that is, when it is determined that there is no abnormal operation in the second nozzle vane, it is determined that either the second on-off valve 44 or the first on-off valve 43 is abnormal, and the supercharging pressure abnormality is inhaled. The fact that it is caused by the side mechanism 40A is set as a result of the abnormality diagnosis, and the flow ends. That is, it is determined that the cause of the decrease in the supercharging pressure is that the second on-off valve 44 or the first on-off valve 43 is open beyond the allowable range of the target opening degree, so that air is leaking. The

  That is, when the supercharging device 40 is operating in the twin mode, if there is no abnormal operation of the first nozzle vane, the second nozzle vane, and the exhaust amount adjusting valve 46, the exhaust pressure mechanism 40B is the cause of the supercharging pressure abnormality. It will not be. Accordingly, it is determined that either the second on-off valve 44 or the first on-off valve 43 is abnormal, and the fact that the supercharging pressure abnormality is caused by the intake side mechanism is set as a result of the abnormality diagnosis.

Note that the above flow is a flow in the case of an abnormal decrease in the supercharging pressure, but the same is true in the case of an abnormal increase in the supercharging pressure, and thus the description thereof is omitted.
[Effect of the embodiment]
As described above in detail, according to the abnormality diagnosis device for the supercharging device 40 of the present embodiment, the following effects can be obtained.

  (1) In the present embodiment, it can be determined whether the cause of the supercharging pressure is in the exhaust side mechanism 40B or the intake side mechanism 40A based on the determination results of the first determination process and the second determination process. . That is, based on the output of the sensor for monitoring the supercharging pressure and the output of the sensor in the exhaust side mechanism 40B, it is diagnosed whether the cause of the supercharging pressure abnormality is in the intake side mechanism 40A or the exhaust side mechanism 40B. be able to.

  (2) In the present embodiment, the exhaust side mechanism 40B is provided with the adjustment valve sensor 54 that monitors the opening of the exhaust amount adjustment valve 46, and the electronic control unit 50 is based on the output of the adjustment valve sensor 54. It is determined whether or not the difference between the actual opening of the exhaust amount adjustment valve 46 and the target opening is larger than a determination value.

  That is, since the electronic control means makes a determination based on the difference between the actual opening of the exhaust adjustment mechanism and the target opening, it is stable as to whether or not an abnormality has occurred in the exhaust amount adjustment valve 46. A judgment result can be obtained.

  (3) In this embodiment, the turbochargers 41 and 42 are variable displacement types having a vane mechanism, and have nozzle sensors 52 and 53 as exhaust side sensors for monitoring the opening of the vane mechanism. It is configured. That is, the turbochargers 41 and 42 are variable displacement types and include a vane mechanism as an exhaust adjustment mechanism, but the exhaust side mechanism is based on the output of the nozzle sensors 52 and 53 for the vane mechanism by the second determination process. It is determined whether or not an abnormality has occurred in 40B.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG.
A second embodiment in which the abnormality diagnosis device for the supercharging device 140 of this embodiment is embodied as an abnormality diagnosis device for the supercharging device 140 of an in-line 8-cylinder diesel engine will be described.

  The abnormality diagnosis device for the supercharging device 140 of the present embodiment shows that the intake side mechanism 40A and the exhaust side mechanism 40B are one system. The abnormality diagnosis device for the supercharging device 140 according to the present embodiment has substantially the same configuration as the abnormality diagnosis device for the supercharging device 40 according to the first embodiment, except for the points described below. As shown, the same reference numerals as those in the embodiment are used except for different configurations.

  In the present embodiment, in the intake device 20, the first intake pipe 124 is connected between the upstream intake pipe 22 and the downstream intake pipe 23. The first communication pipe 124 is provided with an on-off valve 143 that adjusts the flow rate of intake air between the upstream intake pipe 22 and the downstream intake pipe 23.

  Further, in the exhaust device 30, a second communication pipe 136 is provided between the upstream exhaust pipe 32 and the downstream exhaust pipe 33, and an exhaust amount adjustment valve 146 is provided in the second communication pipe 136. The exhaust amount adjustment valve 146 adjusts the exhaust amount when the supercharging pressure becomes high.

Next, the operation mode of the supercharging device 140 will be described.
When the supercharging device 140 is in a normal pressure state in which the pressure in the downstream intake pipe 23 is not excessively increased, the exhaust amount adjustment valve 146 and the on-off valve 143 are maintained in the closed state. On the other hand, when the pressure in the downstream intake pipe 23 increases excessively and is in an abnormal pressure state, the on-off valve 143 or the exhaust amount adjustment valve 146 is opened. When the on-off valve 143 is opened, part of the intake air in the upstream intake pipe 22 flows to the downstream intake pipe 23 without passing through the turbocharger 41. When the exhaust amount adjustment valve 146 is opened, the exhaust from the upstream exhaust pipe 32 flows to the downstream exhaust pipe 33 without passing through the turbine wheel 41A. Thereby, the compression of the intake air by the turbocharger 41 is adjusted.

Next, abnormality diagnosis control by the electronic control unit 50 will be described.
When the electronic control unit 50 determines in the first determination process that the boost pressure sensor 51 is abnormal in the boost pressure, the second determination process is based on the monitor values of the nozzle sensor 52 and the adjustment valve sensor 154. The abnormal operation of the nozzle vane and the exhaust amount adjustment valve 146 is determined. Further, when the electronic control unit 50 determines that there is an abnormality in either the nozzle vane or the exhaust amount adjustment valve 146, the abnormality diagnosis indicates that the abnormality in the supercharging pressure is caused by the exhaust side mechanism 40B. Set. On the other hand, when the electronic control unit 50 determines that all of the nozzle vanes and the exhaust amount adjustment valve 146 are not abnormal, it determines that the on-off valve 143 has an abnormal operation, and a supercharging pressure abnormality has occurred in the intake side mechanism 40A. The cause is set as a result of the abnormality diagnosis. Here, the regulating valve sensor 154 is provided in the vicinity of the exhaust amount regulating valve 146 and outputs a signal corresponding to the opening degree of the valve.

[Effect of the embodiment]
As described above in detail, according to the abnormality diagnosis device for the supercharging device of the embodiment, the effects (1) to (3) shown in the first embodiment can be obtained.

(Other embodiments)
In the first embodiment, the supercharger 40 includes two variable capacity turbochargers, but the configuration of the supercharger 40 is not limited to this. The present invention is also applied to, for example, the supercharger 40 that includes a normal turbocharger.

  In the above embodiment, the electronic control unit 50 performs abnormality diagnosis for the supercharging device 40 in each of the single mode and the twin mode, but the supercharging device is only in either the single mode or the twin mode. An abnormality diagnosis for 40 may be performed.

The block diagram which shows typically the whole structure of the engine carrying the apparatus about 1st Embodiment which actualized the abnormality diagnosis apparatus of the supercharging apparatus of this invention. 7 is a flowchart showing a processing procedure of “abnormality diagnosis mode setting processing” executed by the electronic control device in the embodiment. The flowchart which shows the process sequence about the "single mode abnormality diagnosis process" performed by the electronic controller in the same embodiment. The flowchart which shows the process sequence about the "twin mode abnormality diagnosis process" performed by the electronic controller in the same embodiment. The block diagram which shows typically the whole structure of the engine carrying the apparatus about 2nd Embodiment which actualized the abnormality diagnosis apparatus of the supercharging apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 10 ... Engine main body, 20 ... Intake device, 21 ... Intake pipe, 22 ... Upstream intake pipe, 22A, 32A ... First upstream branch pipe, 22B, 32B ... Second upstream branch pipe, 22C, 32C ... Upstream Collecting pipe, 23 ... downstream intake pipe, 23A, 33B ... first downstream branch pipe, 23B, 33B ... second downstream branch pipe, 23C, 33C ... downstream collecting pipe, 24 ... branch communication pipe, 124 ... first communication pipe, 136: Second communication pipe, 25 ... Downstream bypass pipe, 26 ... Intake manifold, 27 ... Air cleaner, 28 ... Intake throttle, 30 ... Exhaust device, 31 ... Exhaust pipe, 32 ... Upstream exhaust pipe, 33 ... Downstream exhaust pipe, 34 ... exhaust manifold, 35 ... exhaust gas purification device, 40,140 ... supercharging device, 40A ... intake side mechanism, 40B ... exhaust side mechanism, 41 ... first turbocharger, 41A, 42A ... tar , 41B, 42B ... compressor wheel, 42 ... second turbocharger, 43 ... first on-off valve, 44 ... second on-off valve, 143 ... on-off valve, 45 ... reed valve, 143 ... on-off valve, 46, 146 ... Exhaust amount adjusting valve (exhaust adjusting mechanism), 50... Electronic control device (diagnostic means), 51... Supercharging pressure sensor, 52 ... first nozzle sensor, 53 ... second nozzle sensor, 54, 154.

Claims (4)

About a supercharging device comprising an exhaust side mechanism belonging to an engine exhaust system and an intake side mechanism belonging to an engine intake system, and comprising a supercharging pressure sensor for monitoring the supercharging pressure and an exhaust side sensor for monitoring the state of the exhaust side mechanism In the abnormality diagnosis device of the supercharging device that performs abnormality diagnosis on the same device when a supercharging pressure abnormality occurs where the actual supercharging pressure deviates excessively from the target supercharging pressure,
A first determination process for determining whether or not the supercharging pressure abnormality has occurred based on the output of the supercharging pressure sensor, and whether or not an abnormality has occurred in the exhaust side mechanism based on the output of the exhaust side sensor And a second determination process for determining whether
As a result of the first determination process and the second determination process, when a determination result that a supercharging pressure abnormality has occurred and a determination result that an abnormality has not occurred in the exhaust side mechanism are obtained, the supercharging is performed. As a result of abnormality diagnosis that the pressure abnormality is caused by the intake side mechanism,
As a result of the first determination process and the second determination process, when a determination result that a boost pressure abnormality has occurred and a determination result that an abnormality has occurred in the exhaust side mechanism are obtained, An abnormality diagnosing device for a supercharging device, comprising: a diagnosis unit configured to set, as a result of an abnormality diagnosis, that a supply pressure abnormality is caused by the exhaust side mechanism. The abnormality diagnosis device for a supercharging device according to claim 1,
The exhaust side mechanism includes an exhaust adjustment mechanism that adjusts the flow rate of exhaust,
The exhaust side sensor monitors the opening of the exhaust adjustment mechanism as the state of the exhaust side mechanism,
The diagnosis means determines whether or not the difference between the actual opening of the exhaust adjustment mechanism and its target opening is larger than a determination value based on the output of the exhaust side sensor, and determines that it is large An abnormality diagnosis device for a supercharging device, which determines that an abnormality has occurred in the exhaust adjustment mechanism based on a result. The abnormality diagnosis device for a supercharging device according to claim 2,
The exhaust side mechanism includes two turbocharger turbines, an upstream exhaust pipe connected to the upstream side of the turbocharger, a downstream exhaust pipe connected to the downstream side of the turbocharger, and the upstream exhaust pipe. An exhaust amount adjustment valve as an exhaust adjustment mechanism that allows exhaust from the internal combustion engine to flow into one turbocharger when in single mode and that causes exhaust from the internal combustion engine to flow into both turbochargers in twin mode; An adjustment valve sensor as an exhaust side sensor for monitoring the opening of the exhaust amount adjustment valve,
The intake side mechanism includes a compressor of two turbochargers, an upstream intake pipe connected to the upstream side of the turbocharger, a downstream intake pipe connected to the downstream side of the turbocharger, and a downstream intake pipe A branch communication pipe that recirculates a portion of the intake air to the upstream intake pipe, a first on-off valve that is provided in the branch communication pipe and is closed in a twin mode, and a single communication mode provided in the downstream intake pipe. An abnormality diagnosis device for a supercharging device, comprising: a second on-off valve that is closed. The abnormality diagnosis device for a supercharging device according to claim 3,
The turbocharger is a variable displacement type, and has a vane mechanism as an exhaust adjustment mechanism for controlling an air flow rate of exhaust gas to a turbine, and a nozzle sensor as an exhaust side sensor for monitoring an opening degree of the vane mechanism. An abnormality diagnosis device for a supercharging device, characterized in that:

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