JP2011236857A - Failure determining device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a failure of an internal combustion engine, while reducing a variation in output torque of the internal combustion engine, in a failure determining device of the internal combustion engine.SOLUTION: The failure determining device (20) of the internal combustion engine determines a failure of a compression ignition type internal combustion engine (1) having supercharging devices (6 and 6a) superchargeable to an intake system. The failure determining device of the internal combustion engine includes: movable members (6n, 14 and 70) for changing supercharging pressure by changing the flow passage area of the supercharging devices or an angle of a diffuser straightening blade by changing a position; fuel supply means (30, 31 and 32) for supplying fuel to the internal combustion engine; a supercharging pressure measuring means (7s) for measuring the supercharging pressure; and a failure determining means (20) for determining a failure of the movable members based on a change in the supercharging pressure caused by a change in the position of the movable members, by changing the position of the movable members for determining the failure, by controlling the fuel supply means so as to fix a supply quantity of the fuel to a predetermined quantity based on the supercharging pressure before starting determination of the failure, when the measured supercharging pressure exceeds a predetermined value.

Description

  The present invention relates to a technical field of an abnormality determination device for a compression ignition type internal combustion engine such as a diesel engine.

  As an abnormality determination device for this type of internal combustion engine, for example, in Patent Document 1 or the like, a failure of an air flow meter is determined based on a detected value of the air flow meter resulting from a change in the opening of a variable nozzle vane provided in a supercharger. An apparatus is disclosed.

  Alternatively, as an abnormality determination device of this type of internal combustion engine, for example, in Patent Document 2 or the like, after the fuel supply is stopped, the movable member of the supercharger is driven, and according to the change in the supercharging parameter at this time, An apparatus for determining an abnormality of a movable member is disclosed.

  Alternatively, as an abnormality determination device of this type of internal combustion engine, for example, Patent Document 3 discloses a device that suppresses torque shock by CVT gear ratio control when the operating state of the engine changes.

JP 2004-100517 A JP 2008-223711 A Japanese Patent Laid-Open No. 10-037791

  However, according to Patent Document 1 and the like described above, when the opening of the variable nozzle vane included in the supercharger is changed, the supercharging pressure changes. The fuel injection amount is changed in accordance with the changed supercharging pressure, and there is a high possibility that the fluctuation of torque output from the engine will increase. As a result, the driver's driving comfort, so-called drivability There is a technical problem that there is a high possibility that it will deteriorate.

  The present invention has been made in view of, for example, the above-described problems, and provides an abnormality determination device for an internal combustion engine that can determine abnormality of the internal combustion engine while reducing fluctuations in the output torque of the internal combustion engine. Is an issue.

  In order to solve the above-described problem, an abnormality determination device for a first internal combustion engine according to the present invention is an abnormality of an internal combustion engine that performs abnormality determination of a compression ignition internal combustion engine having a supercharging device capable of supercharging an intake system. A determination device that changes a flow area of the supercharging device or an angle of a diffuser rectifying blade by changing a position, a movable member capable of changing a supercharging pressure, and a fuel that supplies fuel to the internal combustion engine Supply means, supercharging pressure measuring means for measuring the supercharging pressure, and when the measured supercharging pressure exceeds a predetermined value, the fuel supply amount is set to the supercharging pressure before the start of the abnormality determination. Controlling the fuel supply means to be fixed to a predetermined amount based on the change of the position of the movable member for the abnormality determination, based on the change of the supercharging pressure accompanying the change of the position of the movable member, An abnormality determining means for determining an abnormality of the movable member.

  An abnormality determination device for a first internal combustion engine according to the present invention performs abnormality determination of a compression ignition type internal combustion engine such as a diesel engine having a supercharging device capable of supercharging an intake system. Here, the supercharging device according to the present invention is typically a turbocharger, an exhaust gas circulation device, a so-called EGR device, or a supercharging pressure of an intake system such as an intake passage provided with a throttle valve. Means an apparatus configured as described above. The supercharging pressure according to the present invention typically means the pressure in the intake system of a compression ignition type internal combustion engine.

  According to the abnormality determination device for a first internal combustion engine according to the present invention, the movable member can change the flow passage area of the supercharging device by changing the position of the movable member, and can change the supercharging pressure. . Alternatively, the movable member can change the supercharging pressure by changing the angle of the diffuser rectifying blade by changing the position of the movable member, changing the so-called nozzle area through which the intake air flows. Here, the diffuser rectifying blade according to the present invention is provided in the flow path of intake air, and the gap (so-called nozzle area) through which intake air flows can be changed by changing the angle of the rectifying blade with respect to the direction of intake air flow. It means a streamlined member that can rectify intake air. The diffuser rectifying blade more typically means a movable wing provided at the outlet of the compressor of the supercharger. The movable member is typically a movable member capable of changing a supercharging pressure, such as a variable nozzle vane provided in a turbocharger, an EGR valve provided in an EGR device, a diesel throttle valve provided in an intake passage, or the like. It is the meaning including. The fuel supply means supplies fuel to the internal combustion engine. For example, the supercharging pressure is measured by a supercharging pressure measuring means such as a pressure sensor.

  For example, the abnormality determination unit that can be configured by a memory, a processor, or the like, fixes the fuel supply amount to a predetermined amount based on the boost pressure before the start of the abnormality determination when the measured supercharging pressure exceeds a predetermined value. The fuel supply means is controlled. Here, the predetermined value according to the present invention is typically a value that reduces fluctuations in torque output by an engine such as 150 (KPa: Kilo Pascal), and is experimental, empirical, and theoretical. Alternatively, it can be specifically defined by simulation or the like. This predetermined value may be a value that reduces the emission of harmful exhaust gas in addition to a value that reduces the fluctuation of the torque, and may be individually specified by experiment, empirical, theoretical, or simulation. Can be defined.

  Simultaneously or in succession with fixing the fuel supply amount to a predetermined amount, the above-described abnormality determination means changes the position of the movable member for abnormality determination, and the supercharging pressure accompanying the change of the position of the movable member Based on this change, the abnormality determination of the movable member is performed.

  As described above, according to the present invention, the abnormality determination is performed when the supercharging pressure of the intake system exceeds a predetermined value, and the fuel supply amount is fixed to the predetermined amount at the time of the abnormality determination. As a result, it is possible to execute abnormality determination processing in the supercharging device while effectively reducing fluctuations in torque output from the internal combustion engine.

  In particular, according to the present invention, abnormality determination is performed under a state where the supercharging pressure of the intake system exceeds the predetermined value described above, and fluctuations in torque output from the internal combustion engine can be reduced and harmful. Since exhaust gas emissions can be reduced, it is beneficial in practice. This is very useful in practice when the internal combustion engine is a diesel engine because the effect of reducing fluctuations in the output torque of the engine is remarkably high. In addition, according to the present invention, the abnormality determination can be performed while injecting fuel into the internal combustion engine, in other words, during the driving of the internal combustion engine that is not in the so-called F / C (Fuel Cut) state. It is very useful in practice because it can be used frequently.

  One aspect of the abnormality determination device for an internal combustion engine according to the present invention further includes a position measurement unit that measures a position of the movable member, and the abnormality determination unit includes the boost pressure according to a change in the position of the movable member. Is changed, the abnormality of the position measuring means is determined as the abnormality determination, and when the supercharging pressure does not change with the change of the position of the movable member, the fixing abnormality of the movable member is determined as the abnormality determination. To do.

  According to this aspect, the position of the movable member is measured by the position measuring unit. The abnormality determining means determines an abnormality of the position measuring means as the abnormality determination when the supercharging pressure changes with the change of the position of the movable member. Here, “abnormality of the position measuring means” according to the present invention typically means that the measured position of the movable member is different from the actual position of the movable member. In addition, “when the supercharging pressure changes” according to the present invention typically means that the supercharging pressure is in a binary state where the supercharging pressure changes and a state where the supercharging pressure does not change. Means one of the changed states. Alternatively, “when the supercharging pressure changes” according to the present invention typically means a state where the degree of change in the supercharging pressure exceeds a predetermined level, and the degree of change in the supercharging pressure reaches a predetermined level. It means that the degree of change in the supercharging pressure exceeds a predetermined level in two types of states that do not exceed. The predetermined level typically means a degree larger than the measurement error level and equivalent to a substantial change in the supercharging pressure.

  On the other hand, when the supercharging pressure does not change with the change of the position of the movable member, the abnormality determination means determines the sticking abnormality of the movable member as the abnormality determination. Here, the “fixing abnormality” according to the present invention typically means an abnormal state where the movable member is fixed to a certain position and stops moving. In addition, the “case where the supercharging pressure does not change” according to the present invention typically means the supercharging in the binary state where the supercharging pressure changes and the supercharging pressure does not change. It means that the pressure is in the other state where it does not change. Or, “when the supercharging pressure does not change” according to the present invention typically means that the above-described degree of change in the supercharging pressure exceeds a predetermined level and the degree of change in the supercharging pressure. It means that the degree of change in the supercharging pressure does not exceed the predetermined level in two types of states that do not exceed the predetermined level.

  As a result, it is possible to appropriately determine whether the position measuring means is abnormal or the movable member is stuck abnormally based on the change in the supercharging pressure accompanying the change in the position of the movable member.

  In another aspect of the abnormality determination device for an internal combustion engine according to the present invention, the abnormality determination means controls the fuel supply means so as to fix the predetermined amount to the amount supplied immediately before the start of the abnormality determination.

  According to this aspect, since the fuel supply amount is substantially equal before and after starting the abnormality determination, it is possible to perform the abnormality determination while effectively reducing fluctuations in the torque output from the internal combustion engine.

  Another aspect of the abnormality determination device for an internal combustion engine according to the present invention further includes a supercharging pressure estimation means for estimating a supercharging pressure after the start of the abnormality determination, and the abnormality determination means uses the estimation as the predetermined amount. The fuel supply means is controlled so as to be fixed to an amount based on the boost pressure and the accelerator opening of the intake system.

  According to this aspect, since the fuel is supplied in response to the operating state of the internal combustion engine after the start of the abnormality determination, the abnormality determination is performed while more effectively reducing fluctuations in torque output from the engine. Can be done.

  In order to solve the above-described problem, the abnormality determination device for a second internal combustion engine according to the present invention is an abnormality of the internal combustion engine that performs abnormality determination of a compression ignition internal combustion engine having a supercharging device capable of supercharging the intake system. A determination device that changes a flow path area of the supercharging device by changing a position thereof, a movable member capable of changing a supercharging pressure, a supercharging pressure measuring unit that measures the supercharging pressure, and When the measured supercharging pressure exceeds a predetermined value, the position of the movable member is changed for the abnormality determination, and the movable pressure is changed based on the change in the supercharging pressure accompanying the change in the position of the movable member. An abnormality determining means for determining an abnormality of the member, a continuously variable transmission means capable of changing the output state of the internal combustion engine in a stepless manner, and the change of the output torque of the internal combustion engine at the time of the abnormality determination; Control means for controlling the continuously variable transmission means.

  According to the abnormality determination device for a second internal combustion engine according to the present invention, the movable member can change the flow passage area of the supercharging device by changing the position, and can change the supercharging pressure. For example, the supercharging pressure is measured by a supercharging pressure measuring means such as a pressure sensor.

  For example, the abnormality determination means that can be configured by a memory, a processor, etc., changes the position of the movable member for abnormality determination when the measured supercharging pressure exceeds a predetermined value, Based on the change of the supply pressure, the abnormality determination of the movable member is performed.

  For example, continuously variable transmission means such as CVT (Continuous Variable Transmission) can change the output state of the internal combustion engine steplessly. Here, the “output state of the internal combustion engine” according to the present invention typically means a drive state of the internal combustion engine such as an output torque of the internal combustion engine or a rotation speed of the internal combustion engine.

  For example, the control means that can be configured by a memory, a processor, or the like controls the continuously variable transmission means so as to reduce a change in the output torque of the internal combustion engine when determining abnormality. Typically, under the control of the control means, the transmission control of the continuously variable transmission means is performed so that the gear ratio of the continuously variable transmission means becomes smaller than the gear ratio before performing the abnormality determination. The continuously variable transmission means absorbs fluctuations in the output torque of the internal combustion engine.

  Thereby, it is possible to perform abnormality determination while more effectively reducing fluctuations in torque output from the internal combustion engine.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

It is the schematic diagram which showed typically the basic composition of the vehicle carrying the abnormality determination apparatus of the internal combustion engine which concerns on 1st Embodiment. 3 is a flowchart showing an operation flow in the abnormality determination device for the internal combustion engine according to the first embodiment. It is the flowchart which showed the flow of operation | movement in the abnormality determination apparatus of the internal combustion engine which concerns on 2nd Embodiment. It is the flowchart which showed the flow of operation | movement in the abnormality determination apparatus of the internal combustion engine which concerns on 3rd Embodiment. It is the schematic diagram which showed typically the basic composition of the vehicle carrying the abnormality determination apparatus of the internal combustion engine which concerns on 4th Embodiment. It is the schematic diagram which showed typically the basic composition of the vehicle carrying the abnormality determination apparatus of the internal combustion engine which concerns on 5th Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
An abnormality determination device that performs abnormality determination of a compression ignition internal combustion engine according to the first embodiment will be described with reference to FIGS. 1 and 2.

(Basic configuration of vehicle)
First, a basic configuration of a vehicle equipped with an abnormality determination device for an internal combustion engine according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram schematically showing the basic configuration of a vehicle equipped with the abnormality determination device for an internal combustion engine according to the first embodiment. The vehicle equipped with the abnormality determination device for an internal combustion engine according to the present embodiment is a so-called in-line four-cylinder reciprocating internal combustion engine in which four cylinders from # 1 cylinder “1a” to # 4 cylinder are arranged in a line. 1 shows an embodiment applied to a so-called “diesel engine” (hereinafter referred to as “engine 1” as appropriate). The engine 1 is used, for example, as a driving source for driving an automobile, and the driving force generated by the engine 1 is transmitted to wheels through a clutch, a transmission, a differential gear, and a drive shaft, not shown.

  As shown in FIG. 1, the engine 1 includes an electronic throttle valve 2, an AFM (Air Flow Meter) 2a, cylinders # 1 to # 4, an intake passage 3, an intake manifold 3M, an exhaust manifold 4, an intercooler 5, an intake air filter. Air filter 5f, turbocharger 6 equipped with variable diffuser 6n, compressor 6a, turbine 6b, angle sensor 6s for measuring the angle of the rectifying blades of variable diffuser 6n, and supercharging pressure of the intake system of engine 1 A supercharging pressure sensor 7s, a DPNR (Diesel Particulate-NOx active Reduction system) catalyst 8, an exhaust purification unit 9, a fuel addition valve 10, an EGR passage 11, an EGR catalyst 12, an EGR cooler 13, an EGR valve 14, and an exhaust throttle valve 15 , Muffler 16, ECU 20, injector 30, common rail 31, fuel pump 32, engine speed is measured Because of the crank angle sensor 33, a pressure sensor 40 for measuring the pressure in the cylinder, continuously variable transmission 50, and the intake air amount adjustment of the throttle valve (so-called diesel throttle valve) is configured to include a 70.

  The engine 1 is comprehensively controlled by the ECU 20. The ECU 20 constitutes one specific example of “abnormality determination means”, “supercharging pressure estimation means”, and “control means” according to the present invention. In particular, the storage unit provided in the ECU 20 can store various input data such as the detected cetane number, and a predetermined program or a predetermined map used when the ECU 20 functions as an estimation unit. Is stored.

  The continuously variable transmission 50 is a continuously variable transmission such as a CVT (Continuous Variable Transmission), for example, and can continuously change the output state of the engine 1 such as the rotational speed and rotational torque of the engine 1.

  The continuously variable transmission 50 constitutes a specific example of “continuously variable transmission means” according to the present invention. A specific example of the “movable member” according to the present invention is configured by a member that changes the angle of the rectifying blade (so-called movable wing) of the variable diffuser 6n. A specific example of the “diffuser rectifier blade” according to the present invention is configured by the rectifier blade of the variable diffuser 6n. Another specific example of the “movable member” according to the present invention is configured by a valve body that changes the opening degree of the throttle valve 70 for adjusting the intake air amount. Another specific example of the “movable member” according to the present invention is configured by the valve body that changes the opening degree of the EGR valve 14. Further, the angle sensor 6s that measures the angle of the rectifying blade of the variable diffuser 6n constitutes one specific example of the “position measuring means” according to the present invention. The supercharging pressure sensor 7s constitutes a specific example of “supercharging pressure measuring means” according to the present invention. Further, a specific example of the “intake system accelerator opening” according to the present invention is configured by the opening of the electronic throttle valve 2. The turbocharger 6, the compressor 6a, and the turbine 6b constitute a specific example of the “supercharger” according to the present invention. The injector 30 constitutes one specific example of “fuel supply means” according to the present invention.

  As shown in FIG. 1, the engine 1 is mounted on a vehicle as a driving power source, and the recirculation system of the engine 1, that is, the so-called EGR (Exhaust Gas Recirculation) system is connected to the cylinders # 1 to # 4. The intake passage 3 and the exhaust passage 4 are connected, and the intake passage 3 includes an air filter 5f for intake air filtration, an intercooler 5, a compressor 6a of the turbocharger 6, and a throttle valve 70 for adjusting the intake air amount. The exhaust passage 4 is provided with a turbine 6b of a turbocharger 6, respectively. An exhaust purification unit 9 including a DPNR catalyst 8 which is an example of a storage reduction type NOx catalyst as an exhaust purification means downstream of the turbine 6b in the exhaust passage 4 and a fuel as a reducing agent upstream of the DPNR catalyst 8 And a fuel addition valve 10 as a fuel addition means for adding. The exhaust passage 4 and the intake passage 3 are connected by an EGR passage 11, and the EGR passage 11 has an EGR catalyst 12, an EGR cooler 13, and an EGR from the upstream side to the downstream side with reference to the flowing direction of the reflux gas. A valve 14 is provided.

  The turbocharger 6 is a turbocharger including a variable diffuser 6n, and the supercharging pressure at the outlet of the compressor 6a can be changed by changing the angle of the rectifying blades of the provided variable diffuser 6n. it can. The angle sensor 6s measures the angle of the rectifying blade of the variable diffuser 6n.

  The intake system of the engine 1 flows from an air duct for taking in outside air (not shown) to an AFM (Air Flow Meter) 2a, an electronic throttle valve 2, an intake passage 3, and further from the cylinder # 1 via an intake port. It is configured to be sucked into the combustion chamber in # 4. The intake port is provided with an intake valve that opens and closes the intake port. On the other hand, in the exhaust system of the engine 1, exhaust gas is discharged from the combustion chambers in the cylinders # 1 to # 4 to the atmosphere via the exhaust port, the exhaust passage 4 (not shown), the DPNR catalyst 8, and the muffler 16. It is comprised so that.

  The fuel addition valve 10 is provided for adding a fuel upstream of the DPNR 8 to generate a reducing atmosphere necessary for releasing NOx absorbed in the DPNR 8 and for S regeneration of the DPNR 8. The fuel addition operation of the fuel addition valve 10 is controlled by an engine control unit (ECU) 20. The ECU 20 operates the engine 1 by operating various devices such as an injector 30 for injecting fuel into the cylinders # 1 to # 4 and a pressure adjusting valve for the common rail 31 that stores fuel pressure supplied from the fuel pump 32 to the injector 30. It is a well-known computer unit that controls the state. The ECU 20 controls the fuel injection operation of the injector 30 so that the air-fuel ratio given as the mass ratio between the air sucked into the engine 1 and the fuel added from the injector 30 is controlled to be leaner than the stoichiometric air-fuel ratio.

  The DPNR catalyst 8 stores nitrogen oxides (NOx) when the exhaust air-fuel ratio is leaner than the stoichiometric air-fuel ratio, and stores NOx when the exhaust air-fuel ratio is richer than the stoichiometric air-fuel ratio or the stoichiometric air-fuel ratio. Is released and reduced to nitrogen (N2). Since there is an upper limit on the amount of NOx that can be stored in the DPNR catalyst 8, NOx reduction is performed at predetermined intervals to release NOx from the catalyst 14 and reduce it to N2 so that the stored NOx amount does not reach this upper limit. The exhaust purification performance of the DPNR catalyst 8 is maintained in a high state. The DPNR catalyst 8 is poisoned by sulfur oxide (SOx) contained in the exhaust gas. Therefore, the DPNR catalyst 8 is heated to a temperature range in which sulfur (S) is released from the NOx catalyst, and the exhaust air-fuel ratio is made richer than the stoichiometric air-fuel ratio or the stoichiometric air-fuel ratio to recover the sulfur poisoning to thereby recover the DPNR catalyst 8. S reproduction for reproducing the function is performed at predetermined intervals. Hereinafter, NOx reduction and S regeneration may be collectively referred to as function regeneration processing. These function regeneration processes are performed by adding fuel from the fuel addition valve 10 into the exhaust passage 4 upstream of the DPNR catalyst 8.

  In the present invention, the NOx storage reduction catalyst may be any catalyst that can hold NOx in the catalyst, and whether it is absorbed or adsorbed is not limited by the term of storage. Moreover, the aspect of SOx poisoning is not limited. Furthermore, the mode of NOx and SOx release is not limited.

  Operations of various actuators are controlled by an engine control unit (ECU) 20. The ECU 20 is configured as a computer including a microprocessor and peripheral devices such as RAM and ROM necessary for its operation, and is a member that changes the angle of the rectifying blades of the variable diffuser 6n based on signals input from various sensors. It is a known computer unit that operates various devices to control the operating state of the engine 1. The ECU 20 has passed through a supercharging pressure sensor 7s that outputs a signal corresponding to the supercharging pressure of the intake system, for example, a crank angle sensor 33 that outputs a signal corresponding to the crankshaft angle of the engine 1, and the exhaust purification unit 9. An exhaust temperature sensor that outputs a signal corresponding to the temperature of the exhaust, an AFM (Air Flow Meter) 2a, and the like are connected. The ECU 20 controls the operating state of the engine 1 with reference to these output signals. Further, the ECU functions as “abnormality determination means”, “supercharging pressure estimation means”, and “control means” according to the present invention by executing routines shown in FIGS. Details of these routines will be described later. There are various other objects to be controlled by the ECU 20, but the illustration is omitted here.

(Operation principle of internal combustion engine abnormality determination device)
Next, the operation principle of the abnormality determination device for the internal combustion engine according to the first embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing an operation flow in the internal combustion engine abnormality determination device according to the first embodiment. The operation shown in FIG. 2 is repeatedly executed at a predetermined cycle such as several microseconds.

  First, as shown in FIG. 2, the ECU 20 obtains information on the angle of the rectifying blade of the variable diffuser 6n measured by the angle sensor 6s and the supercharging pressure of the intake system measured by the supercharging pressure sensor 7s. (Step S101).

  Next, it is determined whether the supercharging pressure of the intake system measured by the supercharging pressure sensor 7s has exceeded a predetermined value under the control of the ECU 20 (step S102). Here, the predetermined value according to the first embodiment is typically a value that reduces fluctuations in torque output from an engine such as 150 (KPa: Kilo Pascal), and is experimental, empirical, and theoretical. Or can be specifically defined individually by simulation or the like. This predetermined value may be a value that reduces the emission of harmful exhaust gas in addition to a value that reduces the fluctuation of the torque, and may be individually specified by experiment, empirical, theoretical, or simulation. Can be defined. The predetermined value constitutes an example of the predetermined value according to the present invention.

  As a result of the determination in step S102, when it is determined that the measured supercharging pressure of the intake system has exceeded a predetermined value under the control of the ECU 20 (step S102: Yes), the measurement is further performed under the control of the ECU 20. It is determined whether or not the deviation between the actual angle of the rectifying blades of the variable diffuser 6n and the indicated angle instructed by the ECU 20 exceeds a predetermined threshold (step S103). Here, typically, the predetermined threshold value according to the first embodiment is preferably a value that reduces the change in the supercharging pressure, such as a magnitude of 20% of the indicated angle, and is experimental, empirical, theoretical, Alternatively, it can be specifically defined by simulation or the like.

  As a result of the determination in step S103, when it is determined that the deviation between the measured actual angle of the rectifying blade of the variable diffuser 6n and the instruction angle instructed by the ECU 20 exceeds a predetermined threshold (step S103: Yes), Under the control of the ECU 20, the fuel injection amount is fixed to a constant value (step S104). Here, the constant value according to the first embodiment may typically be a value of the fuel injection amount according to the supercharging pressure immediately before starting the abnormality determination process. Or this fixed value may be typically the value of the injection quantity of the fuel injected just before starting the said abnormality determination process. Thus, since the fuel injection amount is substantially equal before and after the start of the abnormality determination process, it is possible to effectively reduce fluctuations in torque output from the engine.

  Next, under the control of the ECU 20, the angle of the rectifying blades of the variable diffuser 6n is changed (step S105).

  Next, under the control of the ECU 20, it is determined whether or not the boost pressure of the intake system measured by the boost pressure sensor 7s has changed with a change in the angle of the rectifying blades of the variable diffuser 6n (step). S106). Here, when it is determined that the boost pressure of the intake system measured by the boost pressure sensor 7s has changed with the change of the angle of the rectifying blades of the variable diffuser 6n (step S106: Yes), the ECU 20 It is determined that an abnormality has occurred in the angle sensor 6s (step S107).

  On the other hand, if the result of determination in step S106 is that it is not determined that the measured boost pressure of the intake system has changed due to the change in the angle of the rectifying blades of the variable diffuser 6n, in other words, When it is determined that the supply pressure does not change with the change of the angle of the rectifying blade of the variable diffuser 6n (step S106: No), the ECU 20 is fixed to the movable member that changes the angle of the rectifying blade of the variable diffuser 6n. Then, it is determined that an abnormality has occurred in the variable diffuser 6n such as not operating (step S108).

  On the other hand, as a result of the determination in step S103 described above, if it is not determined that the deviation between the measured actual angle of the rectifying blades of the variable diffuser 6n and the indicated angle instructed by the ECU 20 exceeds the predetermined threshold, in other words, When it is determined that the deviation between the angle of the angle and the indicated angle does not exceed the predetermined threshold value (step S103: No), no abnormality has occurred in the supercharging pressure sensor 7s and the variable diffuser 6n under the control of the ECU 20. It is determined that the state is normal (step S109).

  On the other hand, if it is not determined that the measured boost pressure of the intake system exceeds a predetermined value as a result of the determination in step S102 described above, in other words, it is determined that the measured boost pressure of the intake system does not exceed the predetermined value. If it is determined (step S102: No), the abnormality determination process is terminated under the control of the ECU 20.

  Thus, according to the first embodiment, the abnormality determination process is executed when the supercharging pressure of the intake system exceeds a predetermined value, and the fuel injection amount is fixed to a constant value during the abnormality determination process. . Thereby, it is possible to execute the abnormality determination process in the supercharging pressure sensor 7s and the variable diffuser 6n while effectively reducing fluctuations in torque output from the engine.

  In particular, according to the first embodiment, the abnormality determination process is executed under a state in which the supercharging pressure of the intake system exceeds the predetermined value described above, and fluctuations in torque output from the engine can be reduced. This is useful in practice because it can reduce the emission of harmful exhaust gases. This is very useful in practice when the internal combustion engine is a diesel engine because the effect of reducing fluctuations in the output torque of the engine is remarkably high. In addition, according to the first embodiment, the abnormality determination is performed while injecting fuel into the engine by an injection amount fixed to a constant value, that is, during driving of the engine that is not F / C (Fuel Cut). Since the process can be executed and the opportunity for executing the abnormality determination process can be made frequently, it is very useful in practice.

  In the comparative example of the abnormality determination process in which the fuel injection amount is not fixed to a constant value, when there is an abnormality in the supercharging pressure sensor 7s of the supercharging pressure sensor 7s and the variable diffuser 6n, the abnormality determination process is performed. The supercharging pressure changes with a change in the angle of the rectifying blades of the variable diffuser 6n, and the fuel injection amount changes with the change in the supercharging pressure regardless of the abnormality determination process. For this reason, there is a high possibility that the fluctuation of the torque output from the engine will increase during the abnormality determination process, and thus the driver's driving comfort, so-called drivability, is likely to deteriorate. A technical problem arises.

(Second Embodiment)
(Operating principle)
Next, the abnormality determination process in the abnormality determination device for the internal combustion engine according to the second embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing an operation flow in the internal combustion engine abnormality determination device according to the second embodiment. The operation shown in FIG. 3 is repeatedly executed at a predetermined cycle such as several microseconds. The components of the second embodiment are substantially the same as those of the first embodiment described above, and in the second embodiment, the same step numbers are assigned to processes that are substantially the same as those of the first embodiment described above. These descriptions will be omitted as appropriate.

  As a result of the determination in step S103 described above, when it is determined that the deviation between the measured actual angle of the rectifying blades of the variable diffuser 6n and the instruction angle instructed by the ECU 20 exceeds a predetermined threshold (step S103: Yes) Then, under the control of the ECU 20, the intake system supercharging pressure after execution of the abnormality determination process is predicted based on the information related to the intake system supercharging pressure measured before the abnormality determination process is executed ( Step S201). Typically, the ECU 20 assumes that the angle of the rectifying blades of the variable diffuser 6n does not change from the current value, and records the history information regarding the supercharging pressure of the intake system measured before executing the abnormality determination process. Based on this, the supercharging pressure of the intake system after execution of the abnormality determination process is predicted.

  Next, under the control of the ECU 20, the fuel injection amount is set based on the predicted boost pressure and the accelerator opening of the intake system of the engine operated by the vehicle driver, and the set injection amount Only the fuel is injected (step S202). An example of “estimated supercharging pressure” according to the present invention is configured by the predicted supercharging pressure according to the present embodiment.

  Subsequently, as described above, under the control of the ECU 20, the angle of the rectifying blades of the variable diffuser 6n is changed (step S105), and the above-described steps S106 to S109 are executed.

  Thus, according to the second embodiment, the abnormality determination process is executed when the boost pressure of the intake system exceeds a predetermined value, and the predicted boost pressure and the intake air of the engine are calculated during the abnormality determination process. Set based on the accelerator opening of the system. Thus, it is possible to execute abnormality determination processing in the supercharging pressure sensor 7s and the variable diffuser 6n while more effectively reducing fluctuations in torque output from the engine. In particular, according to the second embodiment, since the fuel injection amount is set on the assumption that the angle of the rectifying blade of the variable diffuser 6n does not change from the current value, the angle of the rectifying blade of the variable diffuser 6n Even when an abnormality that does not operate due to the movable member that changes the state is actually generated, the abnormality determination process can be executed while reducing fluctuations in the output torque of the engine, which is very useful in practice.

(Third embodiment)
(Operating principle)
Next, the abnormality determination process in the abnormality determination device for the internal combustion engine according to the third embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing an operation flow in the internal combustion engine abnormality determination device according to the third embodiment. The operation shown in FIG. 4 is repeatedly executed at a predetermined cycle such as several microseconds. In addition, the components of the third embodiment are substantially the same as those of the first and second embodiments described above, and in the third embodiment, the processing substantially similar to that of the first and second embodiments described above is performed. The same step numbers are given, and explanations thereof are omitted as appropriate.

  Through step S101 described above, it is determined whether the supercharging pressure of the intake system measured by the supercharging pressure sensor 7s exceeds the second predetermined value under the control of the ECU 20 (step S301). Here, the second predetermined value according to the third embodiment is typically a value that reduces fluctuations in torque output from the engine, such as 150 (KPa: Kilo Pascal), and is experimental and empirical. It can be defined individually, concretely, theoretically, or by simulation. The second predetermined value constitutes another example of the predetermined value according to the present invention.

  As a result of the determination in step S301, when it is determined that the measured boost pressure of the intake system has exceeded the second predetermined value under the control of the ECU 20 (step S301: Yes), as described above, the ECU 20 Under the control, it is determined whether or not the deviation between the measured actual angle of the rectifying blades of the variable diffuser 6n and the indicated angle instructed by the ECU 20 exceeds a predetermined threshold value (step S103).

  As a result of the determination in step S103, when it is determined that the deviation between the measured actual angle of the rectifying blade of the variable diffuser 6n and the instruction angle instructed by the ECU 20 exceeds a predetermined threshold (step S103: Yes), Under the control of the ECU 20, the fuel injection amount is set based on the ideal air-fuel ratio (step S302).

  Next, under the control of the ECU 20, the angle of the rectifying blades of the variable diffuser 6n is changed (step S303).

  Next, under the control of the ECU 20, in the continuously variable transmission 50, so-called CVT (Continuous Variable Transmission), shift control is executed so that fluctuations in engine output torque are reduced (step S304). Typically, the gear ratio or the gear ratio of the continuously variable transmission 50 is changed so that the fluctuation of the output torque of the engine is more absorbed by the continuously variable transmission 50.

  On the other hand, if it is not determined that the measured boost pressure of the intake system has exceeded the second predetermined value as a result of the determination in step S102 described above, in other words, the measured boost pressure of the intake system has the second predetermined value. When it determines with not exceeding (step S102: No), an abnormality determination process is complete | finished under control of ECU20.

  As described above, according to the third embodiment, the abnormality determination process is executed when the boost pressure of the intake system exceeds the second predetermined value, and the continuously variable transmission, so-called CVT, is performed during the abnormality determination process. The gear ratio is controlled so that fluctuations in engine output torque are reduced. Thus, it is possible to execute abnormality determination processing in the supercharging pressure sensor 7s and the variable diffuser 6n while more effectively reducing fluctuations in torque output from the engine. In particular, according to the third embodiment, since the fuel injection amount is set based on the ideal air-fuel ratio, the abnormality determination process can be executed while reducing the emission of harmful exhaust gas. It is very useful.

(Fourth embodiment)
(Basic configuration)
Next, the basic configuration of the abnormality determination device for an internal combustion engine according to the fourth embodiment will be described with reference to FIG. FIG. 5 is a schematic diagram schematically showing the basic configuration of a vehicle equipped with the abnormality determination device for an internal combustion engine according to the fourth embodiment. Note that, in the fourth embodiment shown in FIG. 5, the same reference numerals are assigned to substantially the same components as those in the first embodiment described above, and description thereof will be omitted as appropriate.

  The engine 1 provided in the abnormality determination device for an internal combustion engine according to the fourth embodiment includes an electronic throttle valve 2, an AFM (Air Flow Meter) 2a, cylinders # 1 to # 4, an intake passage 3, an intake manifold 3M, and an exhaust manifold. 4, an intercooler 5, an air filter 5f for intake air filtration, a turbocharger 6 having a variable diffuser 6n, a compressor 6a, a turbine 6b, an angle sensor 6s for measuring the angle of the rectifying blades of the variable diffuser 6n, and the engine 1 A supercharging pressure sensor 7s for measuring the supercharging pressure of the intake system, a DPNR (Diesel Particulate-NOx active Reduction system) catalyst 8, an exhaust purification unit 9, a fuel addition valve 10, an exhaust throttle valve 15, an exhaust muffler 16, an ECU 20, an injector 30 , Common rail 31, fuel pump 32, crank angle sensor 33 for measuring the engine speed, And a continuously variable transmission 50, a throttle valve 70 for adjusting the intake air amount, an EGR passage 90 capable of communicating the intake system and the exhaust system, and an EGR valve 95. ing. The engine 1 is comprehensively controlled by the ECU 20.

  The EGR passage 90 can communicate the intake system and the exhaust system without passing through the engine 1, the turbocharger 6, the compressor 6a, and the turbine 6b.

  The EGR valve 95 is provided in the EGR passage 90 and can change the flow area of the EGR passage 90.

  According to the fourth embodiment, the supercharging pressure can be easily changed by the EGR passage 90 and the EGR valve 95.

(Fifth embodiment)
(Basic configuration)
Next, the basic configuration of the abnormality determination device for an internal combustion engine according to the fifth embodiment will be described with reference to FIG. FIG. 6 is a schematic diagram schematically showing the basic configuration of a vehicle equipped with the abnormality determination device for an internal combustion engine according to the fifth embodiment. Note that, in the fifth embodiment shown in FIG. 6, the same reference numerals are assigned to substantially the same components as those in the first and fourth embodiments described above, and description thereof will be omitted as appropriate.

  The engine 1 provided in the abnormality determination device for an internal combustion engine according to the fifth embodiment includes an electronic throttle valve 2, an AFM (Air Flow Meter) 2a, cylinders # 1 to # 4, an intake passage 3, an intake manifold 3M, and an exhaust manifold. 4, an intercooler 5, an air filter 5f for intake air filtration, a turbocharger 6 having a variable diffuser 6n, a compressor 6a, a turbine 6b, an angle sensor 6s for measuring the angle of the rectifying blades of the variable diffuser 6n, and the engine 1 A supercharging pressure sensor 7s for measuring the supercharging pressure of the intake system, a DPNR (Diesel Particulate-NOx active Reduction system) catalyst 8, an exhaust purification unit 9, a fuel addition valve 10, an EGR passage 11, an EGR catalyst 12, an EGR cooler 13, EGR valve 14, exhaust throttle valve 15, muffler 16, ECU 20, injector 30, common rail 31, fuel pump 32, a crank angle sensor 33 for measuring the rotational speed of the engine, a pressure sensor 40 for measuring the pressure in the cylinder, a continuously variable transmission 50, a throttle valve 70 for adjusting the intake air amount, and an intake system and an exhaust system are communicated with each other. A possible EGR passage 90 and an EGR valve 95 are provided. The engine 1 is comprehensively controlled by the ECU 20.

  According to the fifth embodiment, in addition to the EGR passage 11 and the EGR valve 14, the supercharging pressure can be changed easily and with high accuracy by the EGR passage 90 and the EGR valve 95.

  In the first to fifth embodiments described above, it is provided in a member that changes the angle of the rectifying blade of the variable diffuser 6n provided in the turbocharger, a valve body of an EGR valve provided in the EGR device, or an intake passage. Although the movable member such as the valve body of the diesel throttle valve has been described, the present invention is, for example, an internal combustion engine that determines abnormality of the movable member that can change the supercharging pressure such as the valve body of a variable nozzle vane provided in a turbocharger. It can be applied to the abnormality determination apparatus.

  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. The determination device is also included in the technical scope of the present invention.

  The present invention can be used for an abnormality determination device for a compression ignition type internal combustion engine such as a diesel engine.

1 Engine 2 Electronic throttle valve 2a AFM (Air Flow Meter)
3 Intake passage 3M Intake manifold 4 Exhaust manifold 5 Intercooler 5f Air filter 6 for intake air filtration 6 Turbo supercharger 6a Compressor 6b Turbine 6n Variable diffuser 6s Angle sensor 7s Supercharging pressure sensor 8 for measuring the supercharging pressure of the intake system DPNR (Diesel Particulate-NOx active Reduction system) Catalyst 9 Exhaust purification unit 10 Fuel addition valve 11 EGR passage 12 EGR catalyst 13 EGR cooler 14 EGR valve 15 Exhaust throttle valve 16 Muffler 20 ECU
30 Injector 31 Common rail 32 Fuel pump 33 Crank angle sensor 40 for measuring the engine speed Pressure sensor 50 Continuously variable transmission 70 Throttle valve 90 for adjusting the intake air amount EGR passage
95 EGR valve # 1 to # 4 cylinder

Claims (5)

An internal combustion engine abnormality determination device that performs abnormality determination of a compression ignition internal combustion engine having a supercharging device capable of supercharging an intake system,
A movable member capable of changing the supercharging pressure by changing the position, changing the flow passage area of the supercharging device or the angle of the diffuser rectifying blade,
Fuel supply means for supplying fuel to the internal combustion engine;
A supercharging pressure measuring means for measuring the supercharging pressure;
When the measured supercharging pressure exceeds a predetermined value, the fuel supply means is controlled to fix the fuel supply amount to a predetermined amount based on the supercharging pressure before the start of the abnormality determination, and the abnormality An abnormality determining means that changes the position of the movable member for determination, and performs abnormality determination of the movable member based on a change in the supercharging pressure accompanying the change in the position of the movable member. An abnormality determination device for an internal combustion engine. A position measuring means for measuring the position of the movable member;
The abnormality determining means determines an abnormality of the position measuring means as the abnormality determination when the supercharging pressure changes with a change of the position of the movable member, and the abnormality determining means determines the abnormality with the change of the position of the movable member. The abnormality determination device for an internal combustion engine according to claim 1, wherein when the supercharging pressure does not change, an abnormality in fixing of the movable member is determined as the abnormality determination.   3. The abnormality of the internal combustion engine according to claim 1, wherein the abnormality determination unit controls the fuel supply unit so that the predetermined amount is fixed to an amount supplied immediately before the start of the abnormality determination. Judgment device. Further comprising a supercharging pressure estimation means for estimating a supercharging pressure after the start of the abnormality determination,
2. The fuel supply unit according to claim 1, wherein the abnormality determination unit controls the fuel supply unit to fix the predetermined amount to an amount based on the estimated supercharging pressure and an accelerator opening degree of the intake system. The abnormality determination device for an internal combustion engine according to any one of 3. An internal combustion engine abnormality determination device that performs abnormality determination of a compression ignition internal combustion engine having a supercharging device capable of supercharging an intake system,
A movable member capable of changing the flow area of the supercharging device by changing the position and changing the supercharging pressure;
A supercharging pressure measuring means for measuring the supercharging pressure;
When the measured supercharging pressure exceeds a predetermined value, the position of the movable member is changed for the abnormality determination, and based on the change in the supercharging pressure accompanying the change in the position of the movable member, An abnormality determining means for determining an abnormality of the movable member;
Continuously variable transmission means capable of continuously changing the output state of the internal combustion engine;
An abnormality determination device for an internal combustion engine, comprising: control means for controlling the continuously variable transmission means so as to reduce a change in output torque of the internal combustion engine when the abnormality is determined.