JP2009264149A - Controller of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress erroneous determination when determining the abnormality of an EGR device in a vehicle such as an automobile. <P>SOLUTION: The internal combustion engine controller (1) is applied to a vehicle including an internal combustion engine (11) and the EGR device (14) capable of partially recirculating exhaust gas discharged from the internal combustion engine from the discharge side to the intake side thereof. The internal combustion engine controller includes an abnormality determination means (23) for determining the existence of abnormality of the EGR means and a control means (23) for controlling the internal combustion engine so that the operating condition of the internal combustion engine is within a predetermined engine operation range (r) when determining the existence of abnormality. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of a control device for an internal combustion engine, such as an automobile engine, provided with an EGR (Exhaust Gas Recirculation) mechanism.

  In this type of control device, it is possible to accurately determine whether or not there is an abnormality in the EGR device due to, for example, deposits (deposits). As a method of determining this abnormality, for example, when the vehicle is running, the EGR valve is forcibly opened and closed, and the difference between the target opening and the actual opening (or, for example, the pressure change of the intake passage predicted from the target opening and the actual In many cases, the abnormality determination is performed by detecting a difference from the pressure change in the intake passage.

  For example, in Patent Document 1, when the target opening of the EGR valve is equal to or greater than the first determination value, it is determined as abnormal on the condition that the actual opening is equal to or less than the second determination value that is smaller than the first determination value. A technique for accurately determining the occurrence of an abnormality that causes deterioration in exhaust properties by determining that the condition is greater than the second determination value is normal.

  Patent Document 2 discloses a technique for adjusting the EGR rate to the ideal EGR rate by correcting the EGR rate according to the difference between the maximum in-cylinder pressure timing and the target in-cylinder pressure maximum timing. In particular, a technique is disclosed in which a case where a state in which the EGR rate far exceeds the ideal EGR rate is detected by detecting that the combustion has deteriorated is detected, and the EGR rate is quickly reduced.

JP 2008-19776 A JP-A-5-215004

  However, according to the technique disclosed in Patent Document 1, the engine operating state of the internal combustion engine when executing the abnormality determination is not taken into consideration. Then, depending on the engine operating state, it may be difficult to change the target opening greatly (that is, to increase the difference between when the EGR valve is opened and when it is closed). As a result, there is a technical problem that there is a possibility of erroneous determination due to the difference between the first determination value and the second determination value being reduced. Moreover, there is a technical problem that it is difficult to apply the technique disclosed in Patent Document 2 to abnormality determination.

  The present invention has been made in view of, for example, the above-described problems, and an object of the present invention is to propose a control device for an internal combustion engine that can suppress erroneous determination when an abnormality is determined in an EGR device.

  In order to solve the above problems, an internal combustion engine control apparatus according to the present invention is an EGR that can recirculate an internal combustion engine and exhaust gas exhausted from the internal combustion engine partially from the exhaust side to the intake side of the internal combustion engine. A control device for an internal combustion engine in a vehicle comprising means, wherein abnormality determining means for determining whether or not the EGR means is abnormal, and when the presence or absence of the abnormality is determined, the engine operating state of the internal combustion engine is predetermined. Control means for controlling the internal combustion engine so as to be within the engine operating range.

  According to the control device for an internal combustion engine of the present invention, a vehicle on which the control device is mounted includes, for example, an internal combustion engine that is an engine and exhaust gas that is exhausted from the internal combustion engine, partially from the exhaust side of the internal combustion engine. EGR means that can be recirculated to the side, for example, an external EGR device.

  For example, an abnormality determination unit including a memory, a processor, a comparator, and the like determines whether or not there is an abnormality in the EGR unit. Here, the “abnormality” according to the present invention typically means a deviation between the target opening and the actual opening of the EGR valve capable of adjusting the amount of exhaust gas recirculated from the intake side to the exhaust side. Means. Specifically, for example, the abnormality determination unit compares the target opening of the EGR valve with the actual opening to determine whether there is an abnormality. Alternatively, for example, the pressure change in the intake passage predicted from the target opening is compared with the actual pressure change in the intake passage to determine whether there is an abnormality.

  For example, the control means configured to include a memory, a processor, and the like controls the internal combustion engine so that the engine operating state of the internal combustion engine falls within a predetermined engine operating range when it is determined whether or not the EGR means is abnormal. . Here, “when the presence / absence of abnormality is determined” typically means, for example, from the time when an abnormality determination command signal is transmitted from an ECU (Electronic Control Unit) to the time when abnormality determination by the abnormality determination means ends. Means up to. Furthermore, it may include from a time point slightly later than a time point when the abnormality determination command signal is transmitted to a time point when a predetermined minute time has elapsed since the abnormality determination was completed.

  The “engine operating state” according to the present invention typically means a state determined according to the load (torque) and the rotational speed of the internal combustion engine. Note that the engine operating state may be determined according to, for example, the temperature of the internal combustion engine in addition to the load and the rotational speed of the internal combustion engine.

  The “predetermined engine operating region” according to the present invention is a region in which the influence on the combustion state is small or does not affect the combustion state at all even if the opening degree of the EGR valve is changed by a predetermined value or more (that is, valve opening). Means. More specifically, it means a region where the load on the internal combustion engine is relatively small and the negative pressure in the intake passage is relatively high (that is, the difference between the pressure in the intake passage and the atmospheric pressure is large). The “predetermined value” is such that the difference between the pressure of the intake passage when the EGR valve is opened and the pressure of the intake passage when the EGR valve is closed does not erroneously determine whether the EGR means is abnormal. It means a value that is sufficiently large (for example, about 10 kPa).

  According to the inventor's research, when determining the presence or absence of an abnormality in the EGR means, the target opening of the EGR valve is set larger than usual so that the presence or absence of the abnormality can be determined relatively easily. . However, when determining whether or not there is an abnormality in an engine operating state where there is a risk that torque fluctuation of the internal combustion engine will increase or misfire will occur if a relatively large amount of exhaust gas is recirculated, the target opening of the EGR valve is increased. It is difficult to set. Then, the difference between when the EGR valve is opened and when it is closed (specifically, the difference between the opening degree of the EGR valve or the pressure of the intake passage when the valve is opened and the pressure of the intake passage when the valve is closed) (Difference) becomes small, and there is a possibility of erroneous determination.

  Also, if the presence or absence of abnormality in the EGR means is determined by the difference in pressure in the intake passages when the EGR valve is opened and closed, whether or not there is an abnormality when the engine operating state of the internal combustion engine is in a high load state. In the determination, the negative pressure in the intake passage is low (that is, the difference between the pressure in the intake passage and the atmospheric pressure is small), and even if the EGR valve is driven, the pressure change in the supply passage is small and there is a possibility of erroneous determination. It turns out that there is.

  However, in the present invention, the internal combustion engine is controlled so that the engine operating state of the internal combustion engine is within a predetermined engine operating region when the control unit determines whether the EGR unit is abnormal. For this reason, the target opening degree of the EGR valve can be set relatively large while suppressing the torque fluctuation of the internal combustion engine or preventing the misfire of the internal combustion engine. Therefore, it is possible to determine the presence or absence of abnormality of the EGR means with relative ease.

  As a result, according to the control apparatus for an internal combustion engine of the present invention, it is possible to suppress erroneous determination when determining abnormality of the EGR means.

  In one aspect of the control apparatus for an internal combustion engine of the present invention, the control means changes the load of the internal combustion engine when the abnormality is determined, and the engine operating state is within the predetermined engine operating range. The internal combustion engine is controlled as follows.

  According to this aspect, since the engine operating state is brought into a predetermined engine operating region by changing the load of the internal combustion engine (typically, the load is reduced), the negative pressure in the intake passage is reduced. Can be relatively high. Therefore, the pressure difference in the intake passages when the EGR valve is opened and closed can be made relatively large, and the presence or absence of an abnormality in the EGR means can be determined relatively easily.

  In another aspect of the control device for an internal combustion engine of the present invention, the predetermined engine operating region is such that a change amount of the pressure of the intake passage connected to the internal combustion engine when the abnormality is determined is a predetermined pressure change amount. It is a larger area.

  According to this aspect, if the internal combustion engine is controlled so that the engine operating state of the internal combustion engine is within the engine operating range, the difference in pressure between the intake passages when the EGR valve is opened and closed is relatively large. can do. Here, “the amount of change in pressure in the intake passage” typically means the difference between the pressure when the EGR valve is opened and the pressure when the EGR valve is closed.

  The “predetermined pressure change amount” according to the present invention is a value that can be determined without misjudgment as to whether or not there is an abnormality in the EGR means, and is a value set in advance as a fixed value or a variable value according to some parameter. is there. Such a predetermined pressure change amount is, for example, 10 kPa, and the relationship between the opening degree of the EGR valve and the pressure of the intake passage is obtained for each engine operating state of the internal combustion engine, for example, empirically or experimentally or by simulation. Thus, based on the obtained relationship, the pressure of the intake passage at the target opening of the EGR valve set when the presence or absence of abnormality of the EGR means is determined, and the pressure of the intake passage when the EGR valve is closed May be set as a value that is predicted not to be erroneously determined (specifically, for example, as a value sufficiently larger than a measurement error).

  In this aspect, the EGR means has an EGR valve capable of adjusting the amount of exhaust gas to be recirculated, and the change amount is determined when the EGR valve is opened and when the EGR valve is closed. The pressure may be a difference from the pressure.

  If constituted in this way, the amount of change can be made relatively large, which is very advantageous in practice.

  In another aspect of the control device for an internal combustion engine of the present invention, the motor further includes a motor that drives the vehicle, a battery that supplies electric power to the motor, and a remaining charge detection unit that detects a remaining charge of the battery. When the presence / absence of the abnormality is determined, the control means controls the internal combustion engine according to the detected remaining charge amount so that the engine operation state falls within the predetermined engine operation region. .

  According to this aspect, the remaining charge detection means detects the remaining charge of the battery. The control means controls the internal combustion engine so that the engine operation state falls within a predetermined engine operation region according to the detected remaining charge when it is determined whether or not the EGR means is abnormal. Specifically, for example, when the detected remaining charge amount is, for example, 80% or more of the total charge amount, the control means outputs the rotation output of the internal combustion engine (that is, the load of the internal combustion engine and the rotation speed of the internal combustion engine). The internal combustion engine is controlled so that the product is reduced. Thereby, the negative pressure of the intake passage can be further increased, which is very advantageous in practice. If the required output cannot be satisfied due to a decrease in the rotational output of the internal combustion engine, the control means controls the motor to increase the rotational output of the motor so as to satisfy the required output.

  Alternatively, when the detected remaining charge is, for example, less than 50% of the total charge, the control means controls the internal combustion engine so that the rotational speed of the internal combustion engine increases. More specifically, the control means controls the internal combustion engine so that the load is low and the rotation is high. Thereby, the rotational output of the internal combustion engine can be increased while increasing the negative pressure in the intake passage. Furthermore, the battery can be charged by using the excessive rotational output of the internal combustion engine, which is very advantageous in practice.

  The “motor” according to the present invention is typically a motor for driving the vehicle, but may be a motor realized in, for example, a motor generator (motor generator). That is, as long as it can function as a motor, it may typically mean a motor / generator used in a hybrid vehicle.

  In an aspect including the remaining charge detection means, the control means reduces the rotational output of the internal combustion engine and reduces the engine operation on the condition that the detected remaining charge is larger than a first remaining charge threshold. The internal combustion engine may be controlled so that the state is within the predetermined engine operating range.

  If comprised in this way, the negative pressure of an intake passage can be made higher. As a result, when it is determined whether or not there is an abnormality in the EGR means, the pressure difference between the intake passages when the EGR valve is opened and when the EGR valve is closed can be further increased. The presence or absence of can be determined.

  The control means typically controls the motor so that the rotational output of the motor increases by the amount that the rotational output of the internal combustion engine decreases. As a result, fluctuations in rotational output can be prevented as a whole, which is very advantageous in practice.

  The “first charge remaining amount threshold value” according to the present invention determines whether or not to control the internal combustion engine so that the engine operation state falls within a predetermined engine operation region while reducing the rotational output of the internal combustion engine. It is a value that is set in advance as a fixed value or as a variable value according to some parameter. Such a first remaining charge threshold value is obtained by empirically or experimentally or by simulation, for example, by determining the relationship between the rotational output of the motor and the power consumption of the battery, and based on the determined relationship. What is necessary is just to set as a charge remaining amount which does not have a problem even if it increases the rotation output of a motor from the normal during the period which is performing abnormality determination of a means.

  In this aspect, the control means may further control the motor so as to further increase the rotational output of the motor on condition that the detected remaining charge amount is larger than the first remaining charge threshold value. .

  If comprised in this way, the fluctuation | variation of the whole rotation output by the rotation output of an internal combustion engine reducing can be prevented, and it is very advantageous practically.

  In an aspect including the remaining charge detection means, the control means increases the engine speed while increasing the engine speed on condition that the detected remaining charge is smaller than a second remaining charge threshold. The internal combustion engine may be controlled so that the state is within the predetermined engine operating range.

  With this configuration, it is possible to increase the rotational output of the internal combustion engine while increasing the negative pressure in the intake passage (that is, keeping the load of the internal combustion engine relatively low). As a result, the battery can be charged using the excessive rotational output of the internal combustion engine, which is very advantageous in practice.

  The “second charge remaining amount threshold value” according to the present invention determines whether or not to control the internal combustion engine so that the engine operating state is within a predetermined engine operating range while increasing the rotational speed of the internal combustion engine. It is a value that is set in advance as a fixed value or as a variable value according to some parameter. Such a second remaining charge threshold value is obtained by empirically or experimentally or by simulation, for example, by determining the relationship between the rotational output of the motor and the power consumption of the battery, and based on the determined relationship. What is necessary is just to set as a charge remaining amount with which electric power runs short, when a motor is driven during the period which is performing abnormality determination of a means.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment according to a start control device for an internal combustion engine of the present invention will be described based on the drawings.

<First Embodiment>
A first embodiment of an internal combustion engine control apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the configuration of the control device according to this embodiment.

  In FIG. 1, a vehicle on which the control device 1 according to the present embodiment is mounted includes an engine 11, a motor / generator (MG) 21, and a battery 22. Here, the “engine 11” and the “motor / generator 21” according to the present embodiment are examples of the “internal combustion engine” and the “motor” according to the present invention, respectively.

  An intake passage 12 and an exhaust passage 13 are connected to the engine 11. The EGR passage 14 has one end connected to the exhaust passage 13 and the other end connected to the intake passage 12. The EGR passage 14 is provided with an EGR valve 141. When the opening of the EGR valve is changed by an actuator (ACT) 142, the amount of exhaust gas recirculated from the exhaust side of the engine 11 to the intake side is reduced. Adjusted. Here, the “EGR passage 14”, “EGR valve 141”, and “actuator 142” according to the present embodiment are examples of the “EGR means” according to the present invention. One end of the EGR passage 14 may be connected to the upstream side of a catalyst (not shown) such as a three-way catalyst provided in the exhaust passage 13 or may be connected to the downstream side.

  The control device 1 includes a rotation speed sensor 31 that detects the rotation speed of the engine 11, a remaining charge sensor 32 that detects the remaining charge of the battery 22, an air flow meter 33 that detects the intake air amount, and an EGR valve. It is possible to determine whether or not there is an abnormality in the engine 141, and includes an ECU 23 that controls the actuator 142, the engine 11 and the motor / generator 21 when determining whether or not there is an abnormality in the EGR valve 141.

  The “remaining charge sensor 32” according to the present embodiment is an example of the “remaining charge detection unit” according to the present invention, and the “ECU 23” according to the present embodiment is the “abnormality determination unit” according to the present invention. ”And“ control means ”. In this embodiment, a part of the ECU 15 for various electronic controls is used as a part of the control device 1.

  Next, the operation of the control device 1 will be described with reference to FIG. FIG. 2 is a conceptual diagram showing the transition of the engine operating state of the engine according to this embodiment. The solid line T, solid line a, and dotted line b in the figure indicate the full load torque, the abnormality determination operation line, and the normal operation line, respectively. The solid line a and the dotted line b partially overlap.

  A region R surrounded by a broken line indicates an EGR region where the exhaust gas can be recirculated. A region r indicated by hatching in the region R is a “region with a sufficient EGR limit” as an example of the “predetermined engine operation region” according to the present invention. The alternate long and short dash line indicates an equi-output line. The output is lower on the left side in the figure.

  When the abnormality determination of the EGR valve 141 is not performed (typically during normal operation), the ECU 23 controls the engine 11 so that the engine operating state of the engine 11 changes on the dotted line b. When the engine operating state of the engine 11 is within the region R, the ECU 23 drives the EGR valve 141 to control the actuator 142 so that a predetermined amount of exhaust gas is recirculated to the intake passage 12.

  On the other hand, when the abnormality determination of the EGR valve 141 is performed, the ECU 23 controls the engine 11 so that the engine operating state of the engine 11 changes on the solid line a. Based on the rotational speed of the engine 11 detected by the rotational speed sensor 31 and the intake air amount detected by the air flow meter 33, the ECU 23 takes the intake passages 12 when the EGR valve 141 is opened and closed. Estimate the pressure inside. The ECU 23 determines whether or not the difference between the estimated pressure opening time and the valve closing time is the same as the pressure difference predicted from the target opening degree of the EGR valve 141, and performs abnormality determination. .

  If the abnormality determination of the EGR valve 141 is performed while the engine operating state of the engine 11 is changing on the dotted line b, there is a margin to the EGR limit (that is, the upper limit value of the engine torque at an engine speed with a region R). Therefore, if the opening degree of the EGR valve 141 is made larger than usual for abnormality determination, for example, the torque fluctuation of the engine 11 becomes large or misfires occur. On the other hand, if the opening degree of the EGR valve 141 is made the same as usual in order to prevent torque fluctuations and misfires, the difference in pressure when the EGR valve opens and closes becomes relatively small. There is a risk of it.

  However, in the present embodiment, the abnormality determination of the EGR valve 141 is performed when the engine operating state of the engine 11 is in the region r with a margin up to the EGR limit. For this reason, even if the opening degree of the EGR valve 141 is made larger than usual, it is possible to prevent the torque fluctuation of the engine 11 from becoming large or misfiring. In addition, since the opening degree of the EGR valve 141 is relatively large, the difference in pressure when the EGR valve 141 is opened and when the valve is closed can be relatively large. As a result, erroneous determination can be prevented.

  Next, the abnormality determination process for the EGR valve 141 executed by the ECU 23 while the vehicle equipped with the control device 1 configured as described above is running will be described with reference to the flowchart of FIG. This abnormality determination process is typically executed when the engine operating state of the engine 11 shifts to a region R that is an EGR region.

  In FIG. 3, for example, based on the rotational speed detected by the rotational speed sensor 31, the engine operating state of the engine 11 is predicted to shift into the region R, or the engine operating state shifts into the region R. When detecting this, the ECU 23 calculates a solid line a (see FIG. 2), which is an abnormality determination operation line (step S101). Note that the processing in step S101 may be executed after a predetermined time has elapsed since the engine operating state of the engine 11 has shifted to the region R.

  Next, the ECU 23 determines whether the engine operating state of the engine 11 is currently moving along the dotted line b or the solid line a that is a normal operation line (step S102). If it is determined that the position is changing on the dotted line b (step S102: Yes), the ECU 23 controls the engine 11 so that the engine operating state of the engine 11 is shifted to the solid line a (step S103), and then EGR. The abnormality determination of the valve 141 is executed. During the transition, the ECU 23 typically controls the engine 11 so that the engine operating state transitions on the equal output line. On the other hand, when it is determined that the transition is on the solid line a (step S102: No), the abnormality determination of the EGR valve 141 is executed.

  Next, the ECU 23 determines whether or not the abnormality determination has ended (step S104). If it is determined that the process has not been completed (step S104: No), the process of step S104 is repeated until it is determined that the process has been completed. On the other hand, when it is determined that the processing has ended (step S104: Yes), the ECU 23 controls the engine 11 so that the engine operating state of the engine 11 is shifted onto the dotted line b (step S105).

Second Embodiment
A second embodiment of the control device for an internal combustion engine of the present invention will be described with reference to FIGS. The second embodiment is the same as the configuration of the first embodiment except that the abnormality determination process executed by the ECU is partially different. Therefore, in the second embodiment, the description overlapping with that of the first embodiment is omitted, and the same reference numerals are given to the common portions in the drawings, and only FIGS. 4 and 5 are basically different only. The description will be given with reference. FIG. 4 is a conceptual diagram showing the transition of the engine operating state of the engine according to this embodiment.

  In FIG. 4, when the ECU 23 according to the present embodiment performs abnormality determination of the EGR valve 141, the remaining charge of the battery 22 detected by the remaining charge sensor 32 is, for example, 80% of the total charge. The engine 11 is controlled so that the engine operating state of the engine 11 shifts from the point p0 to the point p2, for example, on condition that it is larger than the remaining charge threshold value. Further, the ECU 23 controls the motor / generator 21 to compensate for the decreased output.

  As shown in FIG. 4, the engine torque is lower at the point p2 than at the point p1 which has shifted from the point p0 on the equal output line. Therefore, when the engine operating state shifts to the point p2, the negative pressure in the intake passage 12 can be made higher than when the engine operating state shifts to the point p1. As a result, when the presence / absence of abnormality of the EGR valve 141 is determined, the pressure difference between the intake passages when the EGR valve 141 is opened and when the EGR valve 141 is closed can be further increased. The presence / absence of the abnormality 141 can be determined.

  On the other hand, the ECU 23 changes the engine operating state of the engine 11 from, for example, the point p0 to the point p1 on the condition that the detected remaining charge of the battery 22 is smaller than the first remaining charge threshold (that is, the point p1). The engine 11 is controlled so as to shift on the equal output line. If the detected remaining charge level is “equal” to the first remaining charge threshold value, it may be included in either case.

  Next, the abnormality determination process for the EGR valve 141 executed by the ECU 23 according to the present embodiment will be described with reference to the flowchart of FIG.

  In FIG. 5, after the ECU 23 calculates the solid line a that is the operation line at the time of abnormality determination (step S101), the remaining charge sensor 32 detects the remaining charge of the battery 22 (step S201). Note that the process of step S201 may be executed before or after the process of step S101.

  Next, the ECU 23 determines whether the engine operating state of the engine 11 is currently moving along the dotted line b or the solid line a that is a normal operation line (step S202). When it is determined that the position is changing on the dotted line b (step S202: Yes), the ECU 23 sets a flag indicating that the engine 11 is controlled so that the engine operating state of the engine 11 is shifted to the solid line a ( Step S203).

  Subsequently, the ECU 23 determines whether or not the detected remaining charge is larger than a first remaining charge threshold (step S204). When it is determined that it is larger than the first remaining charge threshold (step S204: Yes), the ECU 23 requests the engine 11 that the engine operating state of the engine 11 that is changing on the dotted line b is on the solid line a and the current engine 11. After the engine 11 is controlled to shift to the engine operating state, which is an output that is lower than the output that has been performed by a predetermined value (step S205), the abnormality determination of the EGR valve 141 is executed. The ECU 23 controls the motor / generator 21 so as to compensate for the decreased output simultaneously with the process of step S205.

  On the other hand, when it is determined that it is smaller than the first charging threshold value (step S204: No), the ECU 23 requests the engine 11 that the engine 11 operating on the dotted line b is on the solid line a and the current engine 11 is present. After the engine 11 is controlled so as to shift to the engine operating state, which is the output that is being performed (step S206), abnormality determination of the EGR valve 141 is executed.

  When it is determined in step S202 that the ECU 23 has shifted on the dotted line b, the ECU 23 first controls the engine 11 so that the engine operating state of the engine 11 shifts to the solid line a. The engine 11 may be controlled so as to change the engine operating state in accordance with the detected remaining charge amount.

  In the process of step S202, when it is determined that the transition is on the solid line a (step S202: Yes), the ECU 23 controls the engine 11 according to the result of the process of step S204. That is, when it is determined that the detected remaining charge is larger than the first remaining charge threshold (step S204: Yes), the ECU 23 indicates that the engine operating state of the engine 11 that is changing on the solid line a is the current engine. The engine 11 is controlled to shift to an engine operating state in which the output is lower by a predetermined value than the output required for the engine 11 (step S205).

  On the other hand, when it is determined that it is smaller than the first remaining charge threshold value (step S204: No), the ECU 23 is currently requested to the engine 11 for the engine operating state of the engine 11 changing on the solid line a. The engine 11 is controlled so as to shift to the engine operating state to be output (or to maintain the current engine operating state when the current output is equal to the requested output) (step S206). .

  Next, the ECU 23 determines whether or not the abnormality determination has ended (step S207). When it is determined that the process has not been completed (step S207: No), the processes of steps S204 to S207 are repeated until it is determined that the process has been completed. On the other hand, when it is determined that the processing has been completed (step S207: Yes), the ECU 23 controls the engine 11 so that the engine operating state of the engine 11 shifts to the dotted line b (step S208).

<Third Embodiment>
A third embodiment of the control apparatus for an internal combustion engine of the present invention will be described with reference to FIGS. The third embodiment is the same as the configuration of the second embodiment except that the abnormality determination process executed by the ECU is partially different. Accordingly, the description of the third embodiment that is the same as that of the second embodiment will be omitted, and common parts in the drawings will be denoted by the same reference numerals, and FIG. 6 and FIG. The description will be given with reference. FIG. 6 is a conceptual diagram showing the transition of the engine operating state of the engine according to this embodiment. Note that a two-dot chain line c in the figure indicates an operation line at the time of abnormality determination at low SOC (Stage Of Charge).

  In FIG. 6, when the ECU 23 according to the present embodiment performs abnormality determination of the EGR valve 141, the engine operating state of the engine 11 is from the dotted line b that is the normal operation line to the solid line a that is the operation line at the time of abnormality determination. After controlling the engine 11 to shift upward (for example, from point p3 to point p4), the remaining charge level of the battery 22 is, for example, a second remaining charge threshold value that is 50% of the total charge amount On condition that the engine is small, the engine 11 is controlled so that the engine operating state shifts from the point p4 to a point p5 on the two-dot chain line c that is an operation line at the time of low SOC abnormality determination.

  As shown in FIG. 6, the output of the point p5 is higher than that of the point p4, and the engine torque is lower and the engine speed is higher than when the point p6 is shifted to the point p6 on the solid line a to obtain the same output. . Therefore, the output of the engine 11 can be increased while the negative pressure in the intake passage 12 is made relatively high. As a result, when it is determined whether or not there is an abnormality in the EGR valve 141, the pressure difference in the intake passages when the EGR valve 141 is opened and when the EGR valve 141 is closed can be made relatively large. The battery 22 can be charged using the output, which is very advantageous in practice.

  Note that the ECU 23 may control the motor / generator 21 so that the rotational output of the motor / generator 21 decreases. Thereby, power consumption can be suppressed and it is very advantageous practically.

  On the other hand, the ECU 23 typically controls the engine 11 to maintain the engine operating state of the engine 11 on condition that the detected remaining charge of the battery 22 is larger than the second remaining charge threshold value. . When the detected remaining charge is “equal” to the second remaining charge threshold, it may be included in either case.

  Next, the abnormality determination process for the EGR valve 141 executed by the ECU 23 according to the present embodiment will be described with reference to the flowchart of FIG.

  In FIG. 7, when the abnormality determination of the EGR valve 141 is performed, if the remaining charge amount detected by the remaining charge sensor 32 by the ECU 23 is smaller than the first remaining charge threshold value in the process of step S <b> 204 (see FIG. 5). In step S206 (see FIG. 5), after the engine 11 is controlled by the ECU 23 so that the engine operating state of the engine 11 shifts from the point p3 to the point p4 in FIG. 32 detects the remaining charge of the battery 22 (step S301).

  Subsequently, the ECU 23 determines whether or not the detected remaining charge level is smaller than the second remaining charge threshold value (step S302). When it determines with it being larger than the 2nd charge remaining amount threshold value (step S302: No), ECU23 performs abnormality determination of the EGR valve 141. FIG.

  On the other hand, when it is determined that the detected remaining charge is smaller than the second remaining charge threshold (step S302: Yes), the ECU 23 calculates a two-dot chain line c that is an operation line at the time of low SOC abnormality determination. The engine 11 is controlled so that the engine operating state of the engine 11 shifts from the point p4 to the point p5 on the two-dot chain line c (step S303), and the abnormality determination of the EGR valve 141 is executed.

  It should be noted that 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. An engine control device is also included in the technical scope of the present invention.

It is a block diagram which shows the structure of the control apparatus which concerns on 1st Embodiment. It is a conceptual diagram which shows transition of the engine operating state of the engine which concerns on 1st Embodiment. It is a flowchart which shows the abnormality determination process which ECU which concerns on 1st Embodiment performs. It is a conceptual diagram which shows transition of the engine operating state of the engine which concerns on 2nd Embodiment. It is a flowchart which shows the abnormality determination process which ECU which concerns on 2nd Embodiment performs. It is a conceptual diagram which shows transition of the engine operating state of the engine which concerns on 3rd Embodiment. It is a flowchart which shows the abnormality determination process which ECU which concerns on 3rd Embodiment performs.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Control apparatus, 11 ... Engine, 12 ... Intake passage, 13 ... Exhaust passage, 14 ... EGR passage, 21 ... Motor generator, 22 ... Battery, 23 ... ECU, 31 ... Revolution sensor, 32 ... Remaining charge sensor 33 ... Air flow meter, 141 ... EGR valve, 142 ... Actuator

Claims (8)

A control apparatus for an internal combustion engine in a vehicle comprising an internal combustion engine and EGR means capable of partially recirculating exhaust gas exhausted from the internal combustion engine from the exhaust side to the intake side of the internal combustion engine,
An abnormality determining means for determining the presence or absence of an abnormality in the EGR means;
A control device for an internal combustion engine, comprising: control means for controlling the internal combustion engine so that an engine operation state of the internal combustion engine falls within a predetermined engine operation region when the presence or absence of the abnormality is determined.   The control means controls the internal combustion engine so that the engine operating state is within the predetermined engine operating range while changing the load of the internal combustion engine when the abnormality is determined. The control device for an internal combustion engine according to claim 1.   2. The predetermined engine operating region is a region where a change amount of pressure in an intake passage connected to the internal combustion engine when the abnormality is determined is larger than a predetermined pressure change amount. 3. The control device for an internal combustion engine according to 2. The EGR means has an EGR valve capable of adjusting the amount of exhaust gas recirculated,
The control device for an internal combustion engine according to claim 3, wherein the amount of change is a difference between the pressure when the EGR valve is opened and the pressure when the EGR valve is closed. A motor for driving the vehicle;
A battery for supplying power to the motor;
And a remaining charge detection means for detecting the remaining charge of the battery,
When the presence or absence of the abnormality is determined, the control means controls the internal combustion engine according to the detected remaining charge amount so that the engine operation state is within the predetermined engine operation region. The control device for an internal combustion engine according to any one of claims 1 to 4, wherein:   The control means reduces the rotational output of the internal combustion engine on the condition that the detected remaining charge level is greater than a first remaining charge threshold value, and the engine operating state is within the predetermined engine operating range. The control apparatus for an internal combustion engine according to claim 5, wherein the internal combustion engine is controlled to be   The control means further controls the motor to increase the rotational output of the motor on condition that the detected remaining charge level is greater than the first remaining charge threshold value. Item 7. The control device for an internal combustion engine according to Item 6.   The control means increases the rotational speed of the internal combustion engine on the condition that the detected remaining charge level is smaller than a second remaining charge threshold value, and the engine operating state is within the predetermined engine operating range. The control apparatus for an internal combustion engine according to any one of claims 5 to 7, wherein the internal combustion engine is controlled so as to become.

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