JP2011085050A - Device and method for controlling internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for suppressing degradation in combustion caused by unanticipated recirculation of EGR gas when an EGR valve is fixed in an open state. <P>SOLUTION: This device for controlling an internal combustion engine includes: cylinder groups 301a, 301b; an intake passage 303 connected to the cylinder groups 301a, 301b; a throttle valve 305; individual exhaust passages 306a, 306b connected independently with respect to each cylinder group and merged on a downstream side; an EGR passage 308 recirculating the EGR gas from the individual exhaust passage 306a to the intake passage 303; and the EGR valve 309 disposed in the EGR passage 308. When it is detected that the EGR valve 309 is fixed in the open state, fuel cut control is performed with respect to the cylinder group 301a, and also the operating point of the internal combustion engine 300 is changed to the side of a high load. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an internal combustion engine control device and an internal combustion engine control method.

  By reducing the amount of EGR gas per cylinder by stopping fuel injection in some cylinders (fuel cut control) and increasing the intake air amount when the EGR valve is stuck in the open state A technique for maintaining good combustion is disclosed (see, for example, Patent Document 1 (paragraphs 13 and 44)).

JP-A-2005-207285 Japanese Patent Laid-Open No. 2007-075651 Japanese Patent Laid-Open No. 10-196463 JP 2009-137531 A

  By the way, in an internal combustion engine having a plurality of cylinder groups such as a V-type 6-cylinder internal combustion engine, a part of exhaust discharged from some specific cylinder groups is taken out as EGR gas, and the EGR gas is returned to all cylinder groups. The EGR system to be used is the mainstream. In particular, in such a large displacement internal combustion engine having a plurality of cylinder groups, it is necessary to improve fuel consumption, and it is necessary to recirculate a large amount of EGR gas in most of the operation region. In such an EGR system, in order to recirculate a large amount of EGR gas, it is essential to increase the size of the EGR passage and the EGR valve. However, if a large EGR valve is stuck in an open state due to a failure, deposit accumulation, or the like, an excessive amount of EGR gas recirculates in an uncontrollable manner, resulting in deterioration of combustion. Therefore, when the EGR valve is stuck in the open state, in order to prevent the introduction of excessive EGR gas to the internal combustion engine, it is conceived that fuel cut control is performed on the cylinder group from which the EGR gas is extracted to stop the combustion. Yes.

  However, when the fuel cut control is performed on the cylinder group for taking out the EGR gas, especially when the operating state of the internal combustion engine is in a low load range, the opening of the throttle valve is closed, the negative pressure in the intake passage is high, and the EGR gas is reduced. The back pressure of the cylinder group to be taken out becomes low. Then, the exhaust from the operating cylinder group other than the cylinder group from which the EGR gas is extracted flows back to the individual exhaust passage of the cylinder group from which the EGR gas is extracted from the merging site downstream of the individual exhaust path, and recirculates in the EGR path. Such unexpected EGR gas may be recirculated, resulting in deterioration of combustion. In particular, when the operating state of the internal combustion engine is in an extremely low load region, the combustion resistance is low. Therefore, if the EGR gas is recirculated unexpectedly, the combustion is likely to deteriorate, and the emission and catalyst deterioration may occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for suppressing deterioration of combustion caused by the recirculation of unexpected EGR gas when the EGR valve is fixed in an open state. There is.

In the present invention, the following configuration is adopted. That is, the present invention
A plurality of cylinder groups;
An intake passage connected to the plurality of cylinder groups;
A throttle valve disposed in the intake passage for controlling the intake air amount;
A plurality of individual exhaust passages that are connected independently for each cylinder group and merge downstream;
An EGR passage that takes a part of exhaust gas as an EGR gas from an individual exhaust passage connected to at least one EGR gas extraction cylinder group of the plurality of cylinder groups, and recirculates the EGR gas to the intake passage;
An EGR valve disposed in the EGR passage and controlling the amount of EGR gas;
An open sticking detection means for detecting that the EGR valve is stuck in the open state;
When the EGR valve detects that the EGR valve is stuck in the open state by the open sticking detection means, fuel cut control is performed on the EGR gas take-out cylinder group and the operating point of the internal combustion engine is changed to the high load side. Control means at the time of open fixation;
A control device for an internal combustion engine, comprising:

In the present invention, the following configuration is adopted. That is, the present invention
A plurality of cylinder groups;
An intake passage connected to the plurality of cylinder groups;
A throttle valve disposed in the intake passage for controlling the intake air amount;
A plurality of individual exhaust passages that are connected independently for each cylinder group and merge downstream;
An EGR passage that takes a part of exhaust gas as an EGR gas from an individual exhaust passage connected to at least one EGR gas extraction cylinder group of the plurality of cylinder groups, and recirculates the EGR gas to the intake passage;
An EGR valve disposed in the EGR passage and controlling the amount of EGR gas;
An open sticking detection means for detecting that the EGR valve is stuck in the open state;
Exhaust gas from the EGR gas take-out cylinder group when the EGR gas take-out cylinder group burns flows into the EGR passage when it is detected by the open adhering detection means that the EGR valve is stuck in the open state. In order to avoid this, the fuel cut control is performed on the EGR gas take-out cylinder group, and when the fuel cut control is performed on the EGR gas take-out cylinder group, the throttle valve is closed and the intake air is closed. The exhaust pressure of the operating cylinder group other than the EGR gas extraction cylinder group is low and the back pressure of the EGR gas extraction cylinder group performing the fuel cut control is low. Backflowing to the individual exhaust passage connected to the gas take-out cylinder group, the intake passage is passed through the EGR passage. In order to suppress the return to the internal combustion engine, the operating point of the internal combustion engine is changed to a high load side to increase the opening of the throttle valve to reduce the negative pressure in the intake passage and Control means at the time of open adhering to increase the back pressure;
A control device for an internal combustion engine, comprising:

  In the present invention, when the EGR valve is stuck in the open state, the fuel cut control is performed on the EGR gas take-out cylinder group, and the operating point of the internal combustion engine is changed to the high load side. By performing fuel cut control for the EGR gas extraction cylinder group, it is possible to prevent exhaust from the EGR gas extraction cylinder group from flowing into the EGR passage and returning to the intake passage when the EGR gas extraction cylinder group burns. it can. Also, by changing the operating point of the internal combustion engine to the high load side, the throttle valve opening can be increased, the negative pressure in the intake passage can be reduced, and the back pressure of the EGR gas extraction cylinder group can be increased. be able to. As a result, when performing fuel cut control on the EGR gas take-out cylinder group, the throttle valve opening degree seems to be closed, the negative pressure in the intake passage is high, and the back pressure in the EGR gas take-out cylinder group performing fuel cut control is low. The exhaust of the operating cylinder group other than the EGR gas take-out cylinder group is prevented from flowing back to the individual exhaust passage connected to the EGR gas take-out cylinder group from the merging portion downstream of the individual exhaust passage and returning to the intake passage through the EGR passage. can do. Therefore, when the EGR valve is stuck in the open state, it is possible to suppress the deterioration of combustion caused by the unexpected return of the EGR gas.

The control means at the time of open fixation is such that the required output is such that the throttle valve opening is closed, the negative pressure of the intake passage is high, and the back pressure of the EGR gas take-out cylinder group performing the fuel cut control is low. Exhaust gas from the operating cylinder group other than the gas extraction cylinder group flows backward from the merging portion downstream of the individual exhaust passage to the individual exhaust passage connected to the EGR gas extraction cylinder group, and returns to the intake passage through the EGR passage. The operating point of the internal combustion engine may be changed to the high load side when the output is equal to or lower than the predetermined output that is a threshold value, and the operating point of the internal combustion engine may not be changed to the high load side when the required output is higher than the predetermined output.

  Here, if the predetermined output is a (required) output less than that, the throttle valve is closed, the negative pressure of the intake passage is high, and the back pressure of the EGR gas take-out cylinder group performing the fuel cut control is low. The output of the operating cylinder group other than the EGR gas extraction cylinder group flows back to the individual exhaust passage connected to the EGR gas extraction cylinder group from the merging portion downstream of the individual exhaust passage, and returns to the intake passage through the EGR passage (operation region) ).

  According to the present invention, when the required output is equal to or less than the predetermined output at which the unexpected EGR gas recirculates, it is possible to prevent the unexpected EGR gas from recirculating.

  A motor generator that is a power source by electric power and generates electric power by regeneration, a battery that supplies electric power to the motor generator, stores electric power generated by regeneration of the motor generator, and an amount of storage of the battery A charge amount detection means for detecting, and when the open sticking detection means detects that the EGR valve is stuck in the open state by the open sticking detection means, the charge amount detection means When the charged amount of the battery to be detected is equal to or greater than a predetermined amount that is a threshold value that can supply electric power to the motor generator and the motor generator can serve as a drive source, the internal combustion engine is stopped and electric power is supplied from the battery. Before the required output is output by the motor generator and detected by the storage amount detecting means When the charged amount of the battery is smaller than the predetermined amount, the fuel cut control is performed on the EGR gas take-out cylinder group, and the operating point of the internal combustion engine is changed to a high load side that is higher than the required output, and the internal combustion engine It is preferable that electric power is generated by regeneration of the motor generator with a surplus output other than the required output, and the electric power is stored in the battery.

  Here, the predetermined amount is an amount of electricity that can be supplied to the motor generator and the motor generator can be a driving source when the amount of electricity stored in the battery is more than that.

  According to the present invention, the control is efficiently changed according to the storage amount of the battery, and when the internal combustion engine is operated, the operating point of the internal combustion engine is changed to the high load side that is higher than the required output. Unexpected EGR gas can be prevented from recirculating and can be stored in the battery with a surplus output.

  The motor generator for generating electric power by regeneration is further provided, and the control means at the time of open fixation is the EGR gas take-out cylinder group when the open fixation detection means detects that the EGR valve is fixed in the open state. And the EGR gas take-out cylinder group in which the EGR gas take-out cylinder group that performs the fuel cut control has a low back pressure. The exhaust gas from the operating cylinder group other than the non-operating cylinder group has a predetermined threshold value that flows back to the individual exhaust passage connected to the EGR gas extraction cylinder group from the merging portion downstream of the individual exhaust passage and returns to the intake passage through the EGR passage. The operating point of the internal combustion engine is changed to a higher load side than the output, and the motor output is changed with the excess output of the internal combustion engine at that time. It may generate power by the regeneration of Nereta.

Here, if the predetermined output is an output less than that, the throttle valve opening degree seems to be closed, the negative pressure in the intake passage is high, and the back pressure of the EGR gas take-out cylinder group that performs fuel cut control is low, and EGR The output of the operating cylinder group other than the gas extraction cylinder group flows back to the individual exhaust passage connected to the EGR gas extraction cylinder group from the merging portion downstream of the individual exhaust passage and returns to the intake passage through the EGR passage (operation region). It is.

  According to the present invention, since the internal combustion engine is operated so as not to be less than the predetermined output, it is possible to suppress the unexpected recirculation of EGR gas. In addition, it is possible to generate electric power with the surplus output of the internal combustion engine at that time and store it in a battery or output it with a motor generator, for example.

  An operating point variable means for enabling the operating point of the internal combustion engine to be changed on the equal output line is further provided, and the open-fixing time control means is configured to increase the operating point of the internal combustion engine on the equal output line by the operating point variable means. Change to the side.

  According to the present invention, it is possible to change the operating point of the internal combustion engine to the high load side without changing the output of the internal combustion engine, and to prevent the unexpected return of EGR gas.

  When there is a request for idling the internal combustion engine, the open adhering control means may idle up without changing the operating point of the internal combustion engine to the high load side.

  In the present invention, when the EGR valve is fixed in the open state, fuel cut control is performed on the EGR gas take-out cylinder group, and when there is a request for idling the internal combustion engine, the engine is idled. When the internal combustion engine is idled up, the operating point of the internal combustion engine is not changed to the high load side, but the throttle valve opening can be increased to reduce the negative pressure in the intake passage and the EGR gas take-out cylinder The group back pressure can be increased. As a result, when performing fuel cut control on the EGR gas take-out cylinder group, the throttle valve opening degree seems to be closed, the negative pressure in the intake passage is high, and the back pressure in the EGR gas take-out cylinder group performing fuel cut control is low. The exhaust of the operating cylinder group other than the EGR gas take-out cylinder group is prevented from flowing back to the individual exhaust passage connected to the EGR gas take-out cylinder group from the merging portion downstream of the individual exhaust passage and returning to the intake passage through the EGR passage. can do. Therefore, when the EGR valve is stuck in the open state, it is possible to suppress the deterioration of combustion caused by the unexpected return of the EGR gas.

  When there is a request for idling the internal combustion engine and there is an external load request, the open adhering control means has a request for idling up and idling the internal combustion engine without changing the operating point of the internal combustion engine to the high load side. However, when there is no external load request, the internal combustion engine may be stopped.

In the present invention, the EGR valve is fixed in the open state, the fuel cut control is performed on the EGR gas take-out cylinder group, and when there is a request for idling the internal combustion engine and there is an external load request, the engine is idled up. When the internal combustion engine is idled up, the operating point of the internal combustion engine is not changed to the high load side, but the throttle valve opening can be increased to reduce the negative pressure in the intake passage and the EGR gas take-out cylinder The group back pressure can be increased. As a result, when performing fuel cut control on the EGR gas take-out cylinder group, the throttle valve opening degree seems to be closed, the negative pressure in the intake passage is high, and the back pressure in the EGR gas take-out cylinder group performing fuel cut control is low. The exhaust of the operating cylinder group other than the EGR gas take-out cylinder group is prevented from flowing back to the individual exhaust passage connected to the EGR gas take-out cylinder group from the merging portion downstream of the individual exhaust passage and returning to the intake passage through the EGR passage. can do. Therefore, when the EGR valve is stuck in the open state, it is possible to suppress the deterioration of combustion caused by the unexpected return of the EGR gas. Moreover, the output of an external load request | requirement can also be obtained from an internal combustion engine by idle-up of an internal combustion engine. On the other hand, when there is a request for idling the internal combustion engine but there is no external load request, the internal combustion engine is stopped. A state in which the internal combustion engine is idling but there is no external load request is a state in which there is no required output to the internal combustion engine. Therefore, the fuel consumption can be prevented from deteriorating by stopping the internal combustion engine without operating it.

In the present invention, the following configuration is adopted. That is, the present invention
A plurality of cylinder groups;
An intake passage connected to the plurality of cylinder groups;
A throttle valve disposed in the intake passage for controlling the intake air amount;
A plurality of individual exhaust passages that are connected independently for each cylinder group and merge downstream;
An EGR passage that takes in a part of exhaust gas as an EGR gas from an individual exhaust passage connected to at least one EGR gas extraction cylinder group of the plurality of cylinder groups and recirculates the EGR gas to the intake passage;
An EGR valve disposed in the EGR passage and controlling the amount of EGR gas;
An open sticking detection means for detecting that the EGR valve is stuck in the open state;
An internal combustion engine control method comprising:
When the EGR valve detects that the EGR valve is stuck in the open state by the open sticking detection means, fuel cut control is performed on the EGR gas take-out cylinder group and the operating point of the internal combustion engine is changed to the high load side. This is a control method for an internal combustion engine.

  In the present invention, when the EGR valve is stuck in the open state, the fuel cut control is performed on the EGR gas take-out cylinder group, and the operating point of the internal combustion engine is changed to the high load side. By performing fuel cut control for the EGR gas extraction cylinder group, it is possible to prevent exhaust from the EGR gas extraction cylinder group from flowing into the EGR passage and returning to the intake passage when the EGR gas extraction cylinder group burns. it can. Also, by changing the operating point of the internal combustion engine to the high load side, the throttle valve opening can be increased, the negative pressure in the intake passage can be reduced, and the back pressure of the EGR gas extraction cylinder group can be increased. be able to. As a result, when performing fuel cut control on the EGR gas take-out cylinder group, the throttle valve opening degree seems to be closed, the negative pressure in the intake passage is high, and the back pressure in the EGR gas take-out cylinder group performing fuel cut control is low. The exhaust of the operating cylinder group other than the EGR gas take-out cylinder group is prevented from flowing back to the individual exhaust passage connected to the EGR gas take-out cylinder group from the merging portion downstream of the individual exhaust passage and returning to the intake passage through the EGR passage. can do. Therefore, when the EGR valve is stuck in the open state, it is possible to suppress the deterioration of combustion caused by the unexpected return of the EGR gas.

  According to the present invention, when the EGR valve is stuck in the open state, it is possible to suppress the deterioration of combustion caused by the unexpected return of the EGR gas.

1 is a diagram illustrating a schematic configuration of a hybrid vehicle according to a first embodiment. 1 is a diagram illustrating a schematic configuration of an internal combustion engine according to a first embodiment. It is a figure which shows a mode that the operating point of the internal combustion engine which concerns on Example 1 is changed to the high load side used as an output higher than a request | requirement output. 3 is a flowchart showing a control routine 1 at the time of open adhering according to the first embodiment. It is a figure which shows the valve-opening opening degree of the EGR valve which the unexpected EGR gas at the time of the fuel cut control with respect to the output which concerns on Example 2 recirculates, and the excessive temperature rise of the catalyst provided in the exhaust passage arises. 7 is a flowchart showing a control routine 2 during open adhering according to the second embodiment. 10 is a flowchart showing an open adhering control routine 3 according to a third embodiment. 10 is a flowchart showing an open adhering control routine 4 according to a fourth embodiment. 10 is a flowchart showing a control routine 5 at the time of open fixing according to a fifth embodiment. It is a figure which shows a mode that the operating point of the internal combustion engine which concerns on Example 6 is changed to the high rotation side on an equal output line. 12 is a flowchart showing an open adhering control routine 6 according to a sixth embodiment.

  Specific examples of the present invention will be described below.

<Example 1>
FIG. 1 is a diagram illustrating a schematic configuration of a hybrid vehicle including an internal combustion engine to which the control device for an internal combustion engine according to the present embodiment is applied. A hybrid vehicle 100 shown in FIG. 1 includes an axle 110, wheels 120, an ECU 200, an internal combustion engine 300, a motor generator A (hereinafter referred to as MGA) 400, a motor generator B (hereinafter referred to as MGB) 500, a power split mechanism 600, and an inverter 700. And a battery 800.

  The axle 110 is an axis for transmitting the output from the internal combustion engine 300 and the MGB 500 to the wheels 120. The wheel 120 is a member that transmits the output transmitted through the axle 110 to the road surface, and is shown as one wheel on each side in FIG. It has four.

  The ECU 200 is an electronic control unit that controls the overall operation of the hybrid vehicle 100. ECU 200 executes various controls according to a control program stored in the ROM.

  The internal combustion engine 300 is an internal combustion engine having two cylinder groups 301a and 301b shown in FIG. The internal combustion engine 300 is a power source (output source) for the hybrid vehicle 100. The detailed configuration of the internal combustion engine 300 will be described later.

  The MGA 400 functions as a generator that generates (generates) electric power mainly by regeneration using the output from the internal combustion engine 300. The MGA 400 supplies the generated power to the battery 800 or supplies it to the MGB 500.

  The MGB 500 serves as a power source (output source) for the hybrid vehicle 100 based on the power supplied from the battery 800 or the power supplied from the MGA 400. The MGB 500 functions as an electric motor that outputs alone or assists the output of the internal combustion engine 300. Further, the MGB 500 may function as a generator that generates electric power by regeneration using the output of the hybrid vehicle 100.

  The MGA 400 and the MGB 500 are configured as, for example, a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator wound with a three-phase coil that forms a rotating magnetic field. These may be of other types. In the present embodiment, the case where the hybrid vehicle 100 is provided with two motor generators will be described, but only one motor generator may be provided. In the present embodiment, the motor generator is one that serves both as an electric motor and a generator. However, the motor generator may be provided separately as an electric motor and a generator.

  The power split mechanism 600 is a planetary gear mechanism that can distribute the output of the internal combustion engine 300 to the MGA 400 and the axle 110.

Inverter 700 converts the DC electricity extracted from battery 800 into AC electricity and supplies it to MGA 400 and MGB 500. Further, AC electricity, which is electric power generated by the MGA 400, is converted into DC electricity and supplied to the battery 800. Further, there is a case where AC electricity that is electric power generated by the MGB 500 is converted into DC electricity and supplied to the battery 800.

  The battery 800 is a power supply source that supplies power that enables the MGA 400 and the MGB 500 to operate, and is a storage battery that can store (charge) the supplied power. The battery 800 is provided with an SOC sensor 801 that detects the amount of electricity stored in the battery 800. The SOC sensor 801 is connected to the ECU 200 via electric wiring, and an output signal of the SOC sensor 801 is input to the ECU 200. The SOC sensor 801 corresponds to the charged amount detection means of the present invention.

  Next, the internal combustion engine 300 will be described. FIG. 2 is a diagram illustrating a schematic configuration of an internal combustion engine to which the control device for an internal combustion engine according to the present embodiment is applied and an intake system / exhaust system thereof. An internal combustion engine 300 shown in FIG. 2 is a V-type six-cylinder water-cooled four-stroke cycle gasoline engine having two cylinder groups 301a and 301b each having three cylinders. In this embodiment, the case of having two cylinder groups is illustrated, but the present invention can also be applied to a case of a plurality of cylinder groups having three or more cylinder groups. Each cylinder group 301a, 301b of the internal combustion engine 300 is provided with a fuel injection valve 302 that supplies fuel into each cylinder of the respective cylinder group 301a, 301b. In this embodiment, the fuel injection valve 302 is provided in each cylinder and injects fuel into the cylinder. However, the present invention is not limited to this, and the fuel injection valve 302 may be provided at the intake port of each cylinder.

  An intake passage 303 that supplies intake air to each of the cylinder groups 301a and 301b is connected to each of the cylinder groups 301a and 301b of the internal combustion engine 300. The intake passage 303 branches off at the intake manifold immediately before each of the cylinder groups 301a and 301b, but one upstream from the branching position is gathered. An air flow meter 304 is arranged in the middle of one intake passage 303 upstream from the branch position of the intake manifold. The air flow meter 304 outputs a signal corresponding to the amount of fresh air (intake amount) sucked from the outside flowing through the intake passage 303. An air flow meter 304 measures the amount of fresh air in the internal combustion engine 300. A throttle valve 305 is disposed in one intake passage 303 downstream of the air flow meter 304 and upstream of the intake manifold branch position. The throttle valve 305 controls the amount of fresh air (intake amount) flowing through the intake passage 303. The intake passage 303 and the devices arranged in the intake passage 303 constitute an intake system of the internal combustion engine 300.

  On the other hand, individual exhaust passages 306a and 306b that are independent for each cylinder group are connected to the cylinder groups 301a and 301b of the internal combustion engine 300, respectively. The cylinder groups 301a and 301b and the individual exhaust passages 306a and 306b are provided in the same number. On the downstream side of the individual exhaust passages 306a and 306b, a merged exhaust passage 307 is connected to join the individual exhaust passages 306a and 306b together. That is, the individual exhaust passages 306a and 306b join downstream, and the joining portion is a portion where the most downstream end of the individual exhaust passages 306a and 306b and the most upstream end of the joining exhaust passage 307 are connected. Each exhaust passage constitutes an exhaust system of the internal combustion engine 300.

In the internal combustion engine 300, a part of the exhaust gas flowing in the individual exhaust passage 306a is returned (recirculated) to one intake passage 303 downstream of the throttle valve 305 and upstream of the intake manifold branch position. ) EGR (Exhaust Gas Recirculation) passage 30
8 is provided. The exhaust gas recirculated by the EGR passage 308 is referred to as EGR gas. The EGR passage 308 connects the individual exhaust passage 306a and the intake passage 303 with a single pipe. Through this EGR passage 308, a part of the exhaust discharged from one cylinder group 301a is sent to both cylinder groups 301a and 301b of the internal combustion engine 300 as EGR gas. An EGR valve 309 that controls the amount of EGR gas flowing through the EGR passage 308 by adjusting the passage cross-sectional area of the EGR passage 308 is disposed in the EGR passage 308. The EGR valve 309 is
It is opened and closed by an electric actuator. In this embodiment, the EGR passage 308 is connected to the intake passage 303 upstream of the intake manifold. However, the present invention is not limited to this, and it may be connected to the intake manifold itself. The cylinder group 301a in this embodiment corresponds to the EGR gas extraction cylinder group of the present invention.

  The internal combustion engine 300 configured as described above is controlled by the ECU 200 in accordance with the driving conditions and the driver's request. The ECU 200 is connected to an air flow meter 304, an accelerator opening sensor 311 that outputs an electric signal corresponding to the amount of depression of an accelerator pedal, and a crank position sensor 312 that detects the engine speed of the internal combustion engine 300 via electric wiring. Then, the output signals of these various sensors are input to the ECU 200. On the other hand, the fuel injection valve 302, the throttle valve 305, and the electric actuators of the EGR valve 309 are connected to the ECU 200 via electric wiring, and these devices are controlled by the ECU 200. Then, the ECU 200 changes the opening degree of the EGR valve 309 provided in the EGR passage 308 according to the operation state of the internal combustion engine 300 derived from the output signals of various sensors, so that each of the cylinder groups 301a and 301b. The amount of EGR gas supplied to each cylinder is controlled so as to be an optimum amount. The internal combustion engine 300 of the present embodiment is a V-type 6-cylinder internal combustion engine with a large displacement and needs to improve fuel consumption. Therefore, a large amount of EGR gas is recirculated in most operating regions. For this reason, the EGR passage 308 and the EGR valve 309 are enlarged.

  By the way, the EGR valve 309 may be abnormally stuck in the opened state due to, for example, a failure or deposit accumulation. If an abnormality occurs in which the EGR valve 309 is stuck while the valve is open, it is difficult to control the amount of EGR gas flowing into each cylinder group 301a, 301b of the internal combustion engine 300 to a desired amount. As a result, if the amount of EGR gas flowing into the cylinder groups 301a and 301b becomes excessively large with respect to the operating state of the internal combustion engine 300, the combustion state in each cylinder of each cylinder group 301a and 301b may deteriorate. is there. Thus, if the combustion state of each cylinder deteriorates due to an excessive increase in the EGR gas amount, drivability deterioration due to increased cycle fluctuation or misfire, and engine stall may occur.

  On the other hand, when the EGR valve 309 is stuck in the open state, fuel cut control for stopping the fuel injection from the fuel injection valve 302 is performed on the cylinder group 301a from which the EGR gas is taken out, and the combustion is stopped. It is considered to prevent the introduction of excessive EGR gas. However, when the fuel cut control is performed on the cylinder group 301a, particularly when the operating state of the internal combustion engine 300 is in a low load region, the opening of the throttle valve 305 is closed, the negative pressure in the intake passage 303 is high, and the cylinder group 301a. The back pressure is low. Then, the exhaust from the cylinder group 301b, which is the operating cylinder group, flows back to the individual exhaust passage 306a of the cylinder group 301a from the merged portion with the merged exhaust passage 307 downstream of the individual exhaust passage 306b, and recirculates through the EGR passage 308. The result is an unexpected EGR gas. In this way, if the fuel cut control is only performed on the cylinder group 301a from which the EGR gas is taken out, the unexpected EGR gas may recirculate and the combustion may deteriorate. In particular, when the operating state of the internal combustion engine 300 is in an extremely low load region, the combustion resistance is low, and therefore, if the EGR gas is recirculated unexpectedly, the combustion easily deteriorates, and the exhaust emission exhausted from the internal combustion engine 300 deteriorates. There is a risk of deterioration of the catalyst disposed in the exhaust passage.

  Therefore, in this embodiment, when it is detected that the EGR valve 309 is stuck in the open state, one of the following two controls A1 and B1 is performed.

As the control A1, when it is detected that the EGR valve 309 is stuck in the open state, the charged amount of the battery 800 detected by the SOC sensor 801 is a threshold at which the MGB 500 can serve as a drive source by supplying power to the MGB 500 Is equal to or greater than the predetermined amount PQ, the internal combustion engine 300 is stopped, power is supplied from the battery 800, and the required output is output by the MGB 500. The required output is an output transmitted to the wheels 120 in order to move the hybrid vehicle 100.

  Here, the predetermined amount PQ is an amount of electricity that can be supplied to the MGB 500 and the MGB 500 can serve as a drive source when the amount of electricity stored in the battery 800 is more than that.

  Further, as the control B1, when it is detected that the EGR valve 309 is stuck in the open state, the EGR gas is taken out when the charged amount of the battery 800 detected by the SOC sensor 801 is smaller than the predetermined amount PQ. While performing fuel cut control on the cylinder group 301a, the operating point of the internal combustion engine 300 is changed to a high load side where the output is higher than the required output, and power is generated by regeneration of the MGA 400 with a surplus output other than the required output of the internal combustion engine 300. And the electric power is stored in the battery 800. Here, changing the operating point of the internal combustion engine 300 to the high load side where the output is higher than the required output, as shown in FIG. 3, is higher than the required output line obtained from the engine speed and torque. Change to output. The amount of change of the output to the high load side may be a predetermined constant amount, or becomes larger as the charged amount of the battery 800 detected by the SOC sensor 801 in order to store the battery 800 at an early stage is smaller. Also good.

  According to the control A1 of this embodiment, the required output is output by the MGB 500, and the internal combustion engine 300 is stopped. Since the internal combustion engine 300 is stopped, the exhaust gas is not discharged from the internal combustion engine 300, and the EGR gas does not recirculate even when the EGR valve 309 is stuck in the open state.

  According to the control B1 of the present embodiment, the fuel cut control is performed on the cylinder group 301a from which the EGR gas is taken out, and the operating point of the internal combustion engine 300 is changed to the high load side where the output is higher than the required output. By performing fuel cut control on the cylinder group 301a, it is possible to avoid exhaust from the cylinder group 301a flowing into the EGR passage 308 and returning to the intake passage 303 when the cylinder group 301a burns. Also, by changing the operating point of the internal combustion engine 300 to the high load side, the opening of the throttle valve 305 can be increased, the negative pressure in the intake passage 303 can be reduced, and the back pressure in the cylinder group 301a can be increased. Can be made. As a result, when performing fuel cut control on the cylinder group 301a, the opening of the throttle valve 305 seems to be closed, the negative pressure in the intake passage 303 is high, and the back pressure of the cylinder group 301a that performs fuel cut control is low. Suppressing the exhaust of the cylinder group 301b, which is a cylinder group, from flowing back to the individual exhaust passage 306a connected to the cylinder group 301a from the merging portion downstream of the individual exhaust passage 306b and returning to the intake passage 303 via the EGR passage 308. Can do. Further, when the operating point of the internal combustion engine 300 is changed to a high load side where the output is higher than the required output, electric power is generated by regeneration of the MGA 400 with a surplus output other than the required output of the internal combustion engine 300, and the electric power is supplied to the battery. Since the power is stored in 800, all the output of the internal combustion engine 300 does not remain and can be utilized.

  As described above, according to the two controls A1 and B1 of this embodiment, the EGR gas recirculates when the control is efficiently changed according to the amount of charge of the battery 800 and the EGR valve 309 is stuck in the opened state. It is possible to suppress the deterioration of combustion caused by. In addition, when the internal combustion engine 300 operates while the EGR valve 309 is fixed in the open state, the operating point of the internal combustion engine 300 is changed to the high load side where the output is higher than the required output. It is possible to store the battery 800 with a surplus output while suppressing the recirculation of the EGR gas.

Next, the open fixing time control routine 1 performed when the EGR valve 309 is stuck in the open state will be described based on the flowchart shown in FIG. FIG. 4 is a flowchart showing the open fixing control routine 1. This routine is repeatedly executed by the ECU 200 every predetermined time. The ECU 200 that executes this routine corresponds to the open-adhesion time control means of the present invention.

  In step S101, it is determined whether or not the EGR valve 309 is stuck in the opened state. For example, when the EGR gas amount becomes excessively large and the detection value of the pressure sensor arranged in the intake passage 303 becomes larger than a desired value, or the detection value of the EGR valve opening sensor provided in the EGR valve 309 is desired. The EGR valve 309 when the value of the EGR gas is excessively large and the detection value of the temperature sensor disposed in the intake passage 303 becomes higher than a desired value. Can be determined to be stuck in the open state. The ECU 200 that executes this step corresponds to the open adhesion detection means of the present invention. If it is determined in step S101 that the EGR valve 309 is stuck in the opened state, the process proceeds to step S102. If it is determined in step S101 that the EGR valve 309 is not stuck in the open state, this routine is temporarily terminated.

  In step S102, it is determined whether or not the charged amount of the battery 800 detected by the SOC sensor 801 is equal to or greater than a predetermined amount PQ. If an affirmative determination is made in step S102 that the amount is greater than or equal to the predetermined amount PQ, the process proceeds to step S103. If it is determined in step S102 that the amount is not equal to or greater than the predetermined amount PQ, the process proceeds to step S104.

  In step S103, the internal combustion engine 300 is stopped, electric power is supplied from the battery 800, and a required output is output by the MGB 500 (motor running). After the processing of this step, this routine is once ended.

  In step S104, fuel cut control (F / C control) is performed on the cylinder group 301a that takes in EGR gas. The fuel cut control is control for stopping fuel injection from the fuel injection valve 302. As a result, the cylinder group 301a only performs intake and exhaust without burning, so that fresh air that is not used for combustion returns to the intake passage 303 as it is. Then, combustion is performed only in each cylinder of the cylinder group 301b, and the internal combustion engine 300 is operated.

  In step S105, the operating point of the internal combustion engine 300 is changed to the high load side where the output is higher than the required output. Thereby, the opening degree of the throttle valve 305 can be increased, the negative pressure of the intake passage 303 can be reduced, and the back pressure of the cylinder group 301a can be increased.

  In step S106, the MGA 400 is regenerated with a surplus output other than the required output of the internal combustion engine 300. Thereby, electric power is generated and the electric power is stored in the battery 800. After the processing of this step, this routine is once ended.

  Note that the control for processing steps S101, S102, and S103 corresponds to the control A1. Control for processing steps S101, S102, S104, S105, and S106 corresponds to the control B1.

<Example 2>
In this embodiment, the operating point of the internal combustion engine 300 is changed to the high load side when the required output is equal to or less than a predetermined output PO at which the unexpected EGR gas recirculates. In the present embodiment, parts different from the above-described embodiment will be described, and description of parts similar to the above-described embodiment will be omitted.

When it is detected that the EGR valve 309 is stuck in the open state, if the fuel cut control is performed on the cylinder group 301a, the opening of the throttle valve 305 is closed, the negative pressure in the intake passage 303 is high, and the cylinder The back pressure of the group 301a is low when the operating state of the internal combustion engine 300 is in a low load range. That is, only when the operating state of the internal combustion engine 300 is in the low load range, the exhaust from the cylinder group 301b, which is the operating cylinder group, is separated from the merging site with the merging exhaust passage 307 downstream of the individual exhaust passage 306b. It flows backward to the exhaust passage 306a and recirculates through the EGR passage 308, resulting in unexpected EGR gas. As shown in FIG. 5, when the fuel cut control is performed for the cylinder group 301a, the operating state of the internal combustion engine 300 is in a low load range, particularly even if the opening degree of the EGR valve 309 increases to 80% or 100%. In an extremely low load range, idling, or the like, unexpected EGR gas recirculates and an excessive temperature rise of the catalyst provided in the exhaust passage occurs. Conversely, if the operating state of the internal combustion engine 300 is not in the low load range, the opening of the throttle valve 305 is greatly opened, the negative pressure in the intake passage 303 is low, and the back pressure in the cylinder group 301a is high, indicating the operating cylinder group. Exhaust gas from the cylinder group 301b does not flow back to the individual exhaust passage 306a, and unexpected EGR gas does not recirculate.

  Therefore, in this embodiment, when it is detected that the EGR valve 309 is stuck in the open state, any of the control A2, B2 similar to the control A1, B1 of the first embodiment and the other control C is selected. The control was done.

  As the control A2, the control output A1, the required output is that the throttle valve 305 is closed, the negative pressure in the intake passage 303 is high, the back pressure of the cylinder group 301a performing the fuel cut control is low, and the operating cylinder group Or less than a predetermined output PO that becomes a threshold value at which the exhaust of the cylinder group 301b flows backward from the merging portion downstream of the individual exhaust passage 306b to the individual exhaust passage 306a connected to the cylinder group 301a and recirculates to the intake passage 303 via the EGR passage 308. When to do.

  Here, when the predetermined output PO is an output less than that, the opening degree of the throttle valve 305 seems to be closed, the negative pressure of the intake passage 303 is high, and the back pressure of the cylinder group 301a performing the fuel cut control is low, The output of the cylinder group 301b, which is the operating cylinder group, flows back from the merging portion downstream of the individual exhaust passage 306b to the individual exhaust passage 306a connected to the cylinder group 301a and returns to the intake passage 303 via the EGR passage 308 (operation region). ). This predetermined output PO changes according to the valve opening fixed opening of the EGR valve 309 fixed in the valve open state. As the valve opening fixing opening increases, the negative pressure in the intake passage 303 increases and the back pressure in the cylinder group 301a decreases even if the output is small, so the predetermined output PO decreases. The predetermined output PO can be calculated from a map obtained from the opening degree of the throttle valve 305 and a preset operating state of the internal combustion engine 300.

  As the control B2, the control B1 is performed when the requested output is equal to or less than the predetermined output PO.

  As the control C, when the required output is higher than the predetermined output PO, the fuel cut control is performed on the cylinder group 301a from which the EGR gas is extracted. In this control C, the operating point of the internal combustion engine 300 is not changed to the high load side.

  According to the control A2 of this embodiment, the same effect as the control A1 of the first embodiment can be obtained. According to the control B2 of the present embodiment, the same effect as the control B1 of the first embodiment can be obtained when the required output is equal to or less than the predetermined output PO at which the unexpected EGR gas recirculates. According to the control C of the present embodiment, when the required output is higher than the predetermined output PO, the control B2 is not performed, so that the output of the internal combustion engine 300 is not increased beyond the required output, and fuel consumption deterioration can be suppressed.

Next, the open fixing time control routine 2 performed when the EGR valve 309 is stuck in the open state will be described based on the flowchart shown in FIG. FIG. 6 is a flowchart showing the open fixing control routine 2. This routine is repeatedly executed by the ECU 200 every predetermined time. The ECU 200 that executes this routine corresponds to the open-adhesion time control means of the present invention. Since this routine is obtained by adding the processes of steps S201 to S203 to the control routine 1 at the time of opening and fixing described in the first embodiment, the added processes will be described and the parts described in the first embodiment will be described. Will not be described.

  If it is determined in step S101 that the EGR valve 309 is stuck in the opened state, the process proceeds to step S201.

  In step S201, it is determined whether the fixed opening degree of the EGR valve 309 is equal to or larger than a predetermined opening degree PD. The predetermined opening degree PD is a fixing opening degree that is a threshold value at which unexpected EGR gas recirculates when fuel cut control is performed on the cylinder group 301a from which the EGR gas is extracted when the predetermined opening degree PD is higher than that. . If it is determined in step S201 that the sticking opening is equal to or greater than the predetermined opening PD, the process proceeds to step S202. If it is determined in step S201 that the fixed opening is not greater than or equal to the predetermined opening PD, the process proceeds to step S203.

  In step S202, it is determined whether the requested output is equal to or less than a predetermined output PO. If it is determined in step S202 that the requested output is equal to or less than the predetermined output PO, the process proceeds to step S102. The processing after step S102 is the same as that in the first embodiment. If it is determined in step S202 that the requested output is not less than or equal to the predetermined output PO, the process proceeds to step S203.

  In step S203, fuel cut control (F / C control) is performed on the cylinder group 301a that takes in EGR gas. As a result, the cylinder group 301a only performs intake and exhaust without burning, so that fresh air that is not used for combustion returns to the intake passage 303 as it is. Then, combustion is performed only in each cylinder of the cylinder group 301b, and the internal combustion engine 300 is operated. After the processing of this step, this routine is once ended.

  The control for processing steps S101, S201, S202, S102, and S103 corresponds to the control A2. Control for processing steps S101, S201, S202, S102, S104, S105, and S106 corresponds to the control B2. Control for processing steps S101, S201, S202, and S203 corresponds to the control C.

<Example 3>
In this embodiment, when there is a request for idling the internal combustion engine 300, the operating point of the internal combustion engine 300 is not changed to the high load side, but idles up. In the present embodiment, parts different from the above-described embodiment will be described, and description of parts similar to the above-described embodiment will be omitted.

  When there is a request for idling the internal combustion engine 300, the internal combustion engine 300 is in a self-sustained operation, and therefore, the regeneration of the MGA 400 cannot be performed simultaneously with a surplus output other than the required output of the internal combustion engine 300. The same applies to the case of the one-bank operation in which it is detected that the EGR valve 309 is stuck in the opened state, the fuel cut control is performed on the cylinder group 301a, and the operation is performed only by the cylinder group 301b.

  Therefore, in the present embodiment, when the control B2 of the second embodiment is performed, if there is a request for idling the internal combustion engine 300, the operating point of the internal combustion engine 300 is not changed to the high load side but is idled up. did.

In the present embodiment, like the control B2 in the second embodiment, the EGR valve 309 is fixed in the open state, the fuel cut control is performed on the EGR gas extraction cylinder group 301a, and the internal combustion engine 300 is idled at that time. When there is, idle up. If the internal combustion engine 300 is idled up, the operating point of the internal combustion engine 300 is not changed to the high load side, but the opening of the throttle valve 305 can be increased to reduce the negative pressure in the intake passage 303 and The back pressure of the cylinder group 301a can be increased. As a result, when performing fuel cut control on the cylinder group 301a, the opening of the throttle valve 305 seems to be closed, the negative pressure in the intake passage 303 is high, and the back pressure of the cylinder group 301a that performs fuel cut control is low. Suppressing the exhaust of the cylinder group 301b, which is a cylinder group, from flowing back to the individual exhaust passage 306a connected to the cylinder group 301a from the merging portion downstream of the individual exhaust passage 306b and returning to the intake passage 303 via the EGR passage 308. Can do. Therefore, when the EGR valve 309 is stuck in the open state, it is possible to suppress the deterioration of combustion caused by the unexpected return of the EGR gas.

  Next, the open fixing time control routine 3 performed when the EGR valve 309 is fixed in the open state will be described based on the flowchart shown in FIG. FIG. 7 is a flowchart showing the control routine 3 during open fixation. This routine is repeatedly executed by the ECU 200 every predetermined time. The ECU 200 that executes this routine corresponds to the open-adhesion time control means of the present invention. Since this routine is obtained by adding the processing of steps S301 and S302 to the open adhering control routine 2 described in the second embodiment, the added processing will be described and the portion described in the second embodiment will be described. Will not be described.

  If it is determined in step S102 that the amount is not equal to or greater than the predetermined amount PQ, the process proceeds to step S301.

  In step S301, it is determined whether or not there is a request for idling the internal combustion engine 300. If it is determined in step S301 that there is an idling request, the process proceeds to step S302. If it is determined in step S301 that there is no idling request, the process proceeds to step S104. The processing after step S104 is the same as that in the first embodiment.

  In step S302, the internal combustion engine 300 is idled up. The idling up is mainly to increase the engine speed of the cylinder group 301b which is the operating cylinder group. However, in addition to this, the fuel injected from the fuel injection valve 302 of each cylinder in the cylinder group 301b may be increased to perform rich combustion. Further, the ignition timing of each cylinder in the cylinder group 301b may be changed to the advance side. After the processing of this step, this routine is once ended.

<Example 4>
In this embodiment, when there is a request for idling the internal combustion engine 300 and there is an external load request, there is a request for idling up and idling the internal combustion engine 300 without changing the operating point of the internal combustion engine 300 to the high load side. However, when there is no external load request, the internal combustion engine 300 is stopped. In the present embodiment, parts different from the above-described embodiment will be described, and description of parts similar to the above-described embodiment will be omitted.

  In the third embodiment, when the control B2 of the second embodiment is performed, if there is a request for idling the internal combustion engine 300, all idle up. However, if the engine is idled, an extra output is generated, resulting in a deterioration in fuel consumption. On the other hand, when the internal combustion engine 300 is simply idling, the required output is not required for the internal combustion engine 300.

  Therefore, in this embodiment, when the control B2 of the second embodiment is performed, if there is a request for idling the internal combustion engine 300 and there is an external load request, the operating point of the internal combustion engine 300 is not changed to the high load side. When there is a request for idling up and idling the internal combustion engine 300, but there is no external load request, the internal combustion engine 300 is stopped.

  Here, the external load request is an output (load) requested from the internal combustion engine 300 by an air conditioner, an audio, an auxiliary machine, or the like.

  In this embodiment, like the control B2 in the second embodiment, the EGR valve 309 is fixed in the open state, the fuel group control is performed on the cylinder group 301a, the internal combustion engine 300 is required to be idle, and the external load request is required. When there is, idle up. If the internal combustion engine 300 is idled up, the operating point of the internal combustion engine 300 is not changed to the high load side, but the opening of the throttle valve 305 can be increased to reduce the negative pressure in the intake passage 303 and The back pressure of the cylinder group 301a can be increased. As a result, when performing fuel cut control on the cylinder group 301a, the opening of the throttle valve 305 seems to be closed, the negative pressure in the intake passage 303 is high, and the back pressure of the cylinder group 301a that performs fuel cut control is low. Suppressing the exhaust of the cylinder group 301b, which is a cylinder group, from flowing back to the individual exhaust passage 306a connected to the cylinder group 301a from the merging portion downstream of the individual exhaust passage 306b and returning to the intake passage 303 via the EGR passage 308. Can do. Therefore, when the EGR valve 309 is stuck in the open state, it is possible to suppress the deterioration of combustion caused by the unexpected return of the EGR gas. Further, an output (load) of an external load request can be obtained from the internal combustion engine 300 by idling up the internal combustion engine 300.

  On the other hand, when there is a request for idling the internal combustion engine 300 but there is no external load request, the internal combustion engine 300 is stopped. The state where the internal combustion engine 300 is idling but there is no external load request is a state where there is no required output to the internal combustion engine 300. Therefore, the internal combustion engine 300 is stopped without being operated, thereby suppressing deterioration in fuel consumption. Can do.

  Next, the open fixing time control routine 4 performed when the EGR valve 309 is stuck in the opened state will be described based on the flowchart shown in FIG. FIG. 8 is a flowchart showing the open fixing time control routine 4. This routine is repeatedly executed by the ECU 200 every predetermined time. The ECU 200 that executes this routine corresponds to the open-adhesion time control means of the present invention. Since this routine is obtained by adding the processes of steps S401 and S402 to the open fixing control routine 3 described in the third embodiment, the added processes will be described and the parts described in the above embodiment will be described. Will not be described.

  If it is determined in step S301 that there is an idling request, the process proceeds to step S401.

  In step S401, it is determined whether there is an external load request. If it is determined in step S401 that there is an external load request, the process proceeds to step S302. The processing after step S302 is the same as that in the third embodiment. If it is determined in step S401 that there is no external load request, the process proceeds to step S402.

  In step S402, the internal combustion engine 300 is stopped. After the processing of this step, this routine is once ended.

  In this embodiment, in step S401, it is determined whether there is an external load request. However, the present invention is not limited to this. In step S401, it may be determined whether or not the external load request is equal to or greater than a predetermined value. In this case, when the external load request is not equal to or greater than a predetermined value, the internal combustion engine 300 is stopped and the external load request is satisfied with electric power from the battery 800.

<Example 5>
In this embodiment, the operating point of the internal combustion engine 300 is always changed to the high load side rather than the predetermined output PO. In the present embodiment, parts different from the above-described embodiment will be described, and description of parts similar to the above-described embodiment will be omitted.

  As described in Example 2, the unexpected EGR gas does not recirculate unless the operating state of the internal combustion engine 300 is in the low load range.

  Therefore, in this embodiment, when it is detected that the EGR valve 309 is stuck in the open state, fuel cut control is performed on the cylinder group 301a, and the opening of the throttle valve 305 is closed, and the intake passage 303 is closed. The negative pressure of the cylinder group 301a performing the fuel cut control is low and the exhaust pressure of the cylinder group 301b, which is the operating cylinder group, is connected to the cylinder group 301a from the merging site downstream of the individual exhaust passage 306b. The operating point of the internal combustion engine 300 is changed to a higher load side than the predetermined output PO, which is a threshold value that flows back to the passage 306a and returns to the intake passage 303 via the EGR passage 308, and the surplus output of the internal combustion engine 300 at that time Electric power was generated by regeneration of MGA400.

  Here, the predetermined output PO is the same as the predetermined output PO in the second embodiment, and when the output is less than that, the opening degree of the throttle valve 305 seems to be closed, the negative pressure of the intake passage 303 is high, and The back pressure of the cylinder group 301a that performs fuel cut control is low, and the exhaust of the cylinder group 301b that is the operating cylinder group flows backward from the merged portion downstream of the individual exhaust passage 306b to the individual exhaust passage 306a connected to the cylinder group 301a. This is an output (operating region) that returns to the intake passage 303 via the passage 308.

  According to the present embodiment, since the internal combustion engine 300 is operated so as not to be less than or equal to the predetermined output PO, it is possible to suppress the unexpected recirculation of EGR gas. Moreover, electric power can be generated by the surplus output of the internal combustion engine 300 at that time, and can be stored in the battery 800 or output by the MGB 500, for example.

  Next, the open fixing time control routine 5 performed when the EGR valve 309 is stuck in the open state will be described based on the flowchart shown in FIG. FIG. 9 is a flowchart showing the control routine 5 during open fixation. This routine is repeatedly executed by the ECU 200 every predetermined time. The ECU 200 that executes this routine corresponds to the open-adhesion time control means of the present invention. Since this routine is obtained by adding the process of step S501 to steps S101, S104, and S106 of the open fixing time control routine 1 described in the first embodiment, the added process will be described. The description of the parts described in the above embodiment is omitted.

  If it is determined in step S101 that the EGR valve 309 is stuck in the opened state, the process proceeds to step S104. From step S104, the process proceeds to step S501.

  In step S501, the operating point of the internal combustion engine 300 is changed to a higher load side than the predetermined output PO. Here, it is assumed that the internal combustion engine 300 continues to maintain a constant output in which the operating point of the internal combustion engine 300 is changed to a higher load side than the predetermined output PO, and if the required output is higher than the predetermined output, the MGB 500 assists, If the requested output is lower than a certain output, regeneration is performed with MGA400. After the process of step S501, the process proceeds to step S106. After the process of step S106, this routine is once ended. Here, the electric power generated by the regeneration in step S106 can be stored in the battery 800, for example, or output as an assist by the MGB 500.

<Example 6>
In this embodiment, when it is detected that the EGR valve 309 is stuck in the open state, the operating point of the internal combustion engine 300 is changed to the high load side on the equal output line. In the present embodiment, parts different from the above-described embodiment will be described, and description of parts similar to the above-described embodiment will be omitted.

  The internal combustion engine 300 according to the present embodiment may not be the hybrid vehicle 100 but may include a CVT that can change the operating point of the internal combustion engine 300 on the equal output line. CVT corresponds to the operating point changing means of the present invention. In this embodiment, when it is detected that the EGR valve 309 is stuck in the open state, the operating point of the internal combustion engine 300 is changed to the high load side on the equal output line by CVT. This is because the gear ratio of the internal combustion engine 300 is changed by CVT, and the output generated from the engine speed and the load (torque) is maintained on the equal output line as shown in FIG. The operation state of 300 is changed.

  According to the present embodiment, the operating point of the internal combustion engine 300 can be changed to the high load side without changing the output of the internal combustion engine 300, and the unexpected return of EGR gas can be suppressed as in the above embodiment. .

  Next, the open fixing time control routine 6 performed when the EGR valve 309 is fixed in the open state will be described based on the flowchart shown in FIG. FIG. 11 is a flowchart showing the control routine 6 during open fixation. This routine is repeatedly executed by the ECU 200 every predetermined time. The ECU 200 that executes this routine corresponds to the open-adhesion time control means of the present invention. Since this routine is obtained by adding the process of step S601 to steps S101 and S104 of the open adhering control routine 1 described in the first embodiment, the added process will be described. The description of the part described in the example is omitted.

  If it is determined in step S101 that the EGR valve 309 is stuck in the opened state, the process proceeds to step S104. From step S104, the process proceeds to step S601.

  In step S601, the operating point of the internal combustion engine 300 is changed to the high load side on the equal output line by CVT. That is, the gear ratio of the internal combustion engine 300 is changed by CVT, and the output generated from the engine speed and the load (torque) is maintained on the equal output line as shown in FIG. Change the operating state of. This also changes the operating state of the internal combustion engine 300 to the high load side, so that the same effect as in the above embodiment can be obtained. After the processing of this step, this routine is once ended.

  The control device for an internal combustion engine according to the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the gist of the present invention. Further, the control method realized in the above embodiment is also the control method of the internal combustion engine according to the present invention.

100 Hybrid vehicle 110 Axle 120 Wheel 200 ECU
300 Internal combustion engines 301a and 301b Cylinder group 302 Fuel injection valve 303 Intake passage 304 Air flow meter 305 Throttle valves 306a and 306b Individual exhaust passage 307 Merged exhaust passage 308 EGR passage 309 EGR valve 311 Accelerator opening sensor 312 Crank position sensor 600 Power split mechanism 700 Inverter 800 Battery 801 SOC sensor

Claims (9)

A plurality of cylinder groups;
An intake passage connected to the plurality of cylinder groups;
A throttle valve disposed in the intake passage for controlling the intake air amount;
A plurality of individual exhaust passages that are connected independently for each cylinder group and merge downstream;
An EGR passage that takes a part of exhaust gas as an EGR gas from an individual exhaust passage connected to at least one EGR gas extraction cylinder group of the plurality of cylinder groups, and recirculates the EGR gas to the intake passage;
An EGR valve disposed in the EGR passage and controlling the amount of EGR gas;
An open sticking detection means for detecting that the EGR valve is stuck in the open state;
When the EGR valve detects that the EGR valve is stuck in the open state by the open sticking detection means, fuel cut control is performed on the EGR gas take-out cylinder group and the operating point of the internal combustion engine is changed to the high load side. Control means at the time of open fixation;
A control apparatus for an internal combustion engine, comprising: A plurality of cylinder groups;
An intake passage connected to the plurality of cylinder groups;
A throttle valve disposed in the intake passage for controlling the intake air amount;
A plurality of individual exhaust passages that are connected independently for each cylinder group and merge downstream;
An EGR passage that takes a part of exhaust gas as an EGR gas from an individual exhaust passage connected to at least one EGR gas extraction cylinder group of the plurality of cylinder groups, and recirculates the EGR gas to the intake passage;
An EGR valve disposed in the EGR passage and controlling the amount of EGR gas;
An open sticking detection means for detecting that the EGR valve is stuck in the open state;
Exhaust gas from the EGR gas take-out cylinder group when the EGR gas take-out cylinder group burns flows into the EGR passage when it is detected by the open adhering detection means that the EGR valve is stuck in the open state. In order to avoid this, the fuel cut control is performed on the EGR gas take-out cylinder group, and when the fuel cut control is performed on the EGR gas take-out cylinder group, the opening of the throttle valve is closed and the intake air is closed. The exhaust pressure of the operating cylinder group other than the EGR gas extraction cylinder group is low and the back pressure of the EGR gas extraction cylinder group performing the fuel cut control is low. Backflowing to the individual exhaust passage connected to the gas take-out cylinder group, the intake passage is passed through the EGR passage. In order to suppress the return to the internal combustion engine, the operating point of the internal combustion engine is changed to a high load side to increase the opening of the throttle valve to reduce the negative pressure in the intake passage and Control means at the time of open adhering to increase the back pressure;
A control apparatus for an internal combustion engine, comprising:   The control means at the time of open fixation is such that the required output is such that the throttle valve opening is closed, the negative pressure of the intake passage is high, and the back pressure of the EGR gas take-out cylinder group performing the fuel cut control is low. Exhaust gas from the operating cylinder group other than the gas extraction cylinder group flows backward from the merging portion downstream of the individual exhaust passage to the individual exhaust passage connected to the EGR gas extraction cylinder group, and returns to the intake passage through the EGR passage. The operating point of the internal combustion engine is changed to a high load side when the output is equal to or lower than a predetermined output that is a threshold value, and the operating point of the internal combustion engine is not changed to a high load side when the required output is higher than the predetermined output. The control apparatus for an internal combustion engine according to claim 1 or 2. A motor generator that becomes a power source by electric power and generates electric power by regeneration,
A battery for supplying electric power to the motor generator and storing electric power generated by regeneration of the motor generator;
A storage amount detection means for detecting a storage amount of the battery;
Further comprising
The open adhering time control means is configured such that when the open adhering detection means detects that the EGR valve is adhering in an open state, the electric storage amount of the battery detected by the electric storage amount detecting means is the motor generator. When the electric power is supplied to the motor generator and the motor generator is greater than a predetermined amount that is a threshold that can serve as a drive source, the internal combustion engine is stopped, electric power is supplied from the battery, and the motor generator outputs a required output, and the electric storage When the stored amount of the battery detected by the amount detection means is smaller than the predetermined amount, fuel cut control is performed on the EGR gas take-out cylinder group, and the operating point of the internal combustion engine is higher than the required output. The power is generated by regeneration of the motor generator with a surplus output other than the required output of the internal combustion engine. Control apparatus for an internal combustion engine according to any one of claims 1 to 3, the power is generated, characterized in that accumulated in the battery. A motor generator for generating electric power by regeneration;
The open adhering control means performs fuel cut control on the EGR gas take-out cylinder group when the open adhering detection means detects that the EGR valve is adhering in the open state, and controls the throttle valve. The exhaust pressure of the operating cylinder group other than the EGR gas extracting cylinder group is low, and the exhaust pressure of the EGR gas extracting cylinder group performing the fuel cut control is low. The operating point of the internal combustion engine is higher in load than a predetermined output that becomes a threshold value that flows back to the individual exhaust passage connected to the EGR gas take-out cylinder group from the merging portion downstream of the EGR passage and returns to the intake passage through the EGR passage. The electric power is generated by regeneration of the motor generator with an excessive output of the internal combustion engine at that time Control apparatus for an internal combustion engine according to any one of 1 to 3. It further comprises operating point variable means for changing the operating point of the internal combustion engine on the equal output line,
The internal combustion engine according to any one of claims 1 to 3, wherein the open-fixing time control means changes the operating point of the internal combustion engine to a high load side on an equal output line by the operating point variable means. Engine control device.   7. The control device according to claim 1, wherein the open-adhesion control means idles up without changing the operating point of the internal combustion engine to a high load side when there is a request for idling the internal combustion engine. The control apparatus of the internal combustion engine described in 1.   When there is a request for idling the internal combustion engine and there is an external load request, the open adhering control means has a request for idling up and idling the internal combustion engine without changing the operating point of the internal combustion engine to the high load side. 8. The control apparatus for an internal combustion engine according to claim 7, wherein the internal combustion engine is stopped when there is no external load request. A plurality of cylinder groups;
An intake passage connected to the plurality of cylinder groups;
A throttle valve disposed in the intake passage for controlling the intake air amount;
A plurality of individual exhaust passages that are connected independently for each cylinder group and merge downstream;
An EGR passage that takes in a part of exhaust gas as an EGR gas from an individual exhaust passage connected to at least one EGR gas extraction cylinder group of the plurality of cylinder groups and recirculates the EGR gas to the intake passage;
An EGR valve disposed in the EGR passage and controlling the amount of EGR gas;
An open sticking detection means for detecting that the EGR valve is stuck in the open state;
An internal combustion engine control method comprising:
When the EGR valve detects that the EGR valve is stuck in the open state by the open sticking detection means, fuel cut control is performed on the EGR gas take-out cylinder group and the operating point of the internal combustion engine is changed to the high load side. A control method of an internal combustion engine characterized by the above.

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