JP2011214548A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle, capable of suitably controlling a vehicle driving state regardless of the execution of exhaust air introduction to an engine air intake passage.SOLUTION: This device is applied to a vehicle having an internal combustion engine and an electric motor as a drive source. The device includes an EGR mechanism including an EGR passage which allows an air intake passage and an air exhaust passage of the internal combustion engine to communicate with each other and an EGR valve provided in the EGR valve. The device executes an EGR control to introduce and recirculate exhaust air in the exhaust passage through valve opening drive of the EGR valve and a valve opening prohibition control to prohibit the valve opening drive of the EGR valve when the temperature of the internal combustion engine is low. According to prohibition of the valve opening drive of the EGR valve through the valve opening prohibition control (S101: YES), the output of the internal combustion engine is reduced, compared with a case in which the valve opening drive is not prohibited (S103), and the output of the electric motor is increased (S104).

Description

  The present invention relates to a vehicle control apparatus that uses an internal combustion engine having an exhaust gas recirculation mechanism and an electric motor as drive sources.

  In recent years, vehicles that are operated using an electric motor as a drive source in addition to an internal combustion engine, so-called hybrid vehicles have been put into practical use (see, for example, Patent Document 1). Further, it is often used to attach an exhaust gas recirculation (EGR) mechanism for returning a part of gas (exhaust gas) discharged to the exhaust passage to the intake passage and recirculating the internal combustion engine. This exhaust gas recirculation mechanism includes an EGR passage communicating with an exhaust passage and an intake passage of an internal combustion engine and an EGR valve provided in the passage. The exhaust gas is recirculated from the exhaust passage of the internal combustion engine to the intake passage through the valve opening drive of the EGR valve.

  Here, in an internal combustion engine equipped with an EGR mechanism, when the EGR valve is driven to open while the temperature is low, high-temperature exhaust gas is introduced into the intake passage. Condensate may be generated in Such generation of condensed water is undesirable because it contributes to a decrease in the durability of the internal combustion engine. In addition, if the operation of the internal combustion engine is stopped and left in a state where condensed water is generated in a low-temperature environment, the condensed water may freeze and cause an EGR valve malfunction. .

  For this reason, conventionally, a device for prohibiting opening of the EGR valve when the temperature of the internal combustion engine is low has been proposed. According to such an apparatus, since the introduction of exhaust gas into the intake passage when the temperature of the internal combustion engine is low is prohibited, the above-described disadvantages due to the generation of condensed water and freezing can be avoided.

JP 2009-91961 A

  The internal combustion engine provided with the EGR mechanism has its operating characteristics set so that high output performance can be obtained in a stable operating state by executing exhaust introduction into the intake passage. For this reason, if the introduction of exhaust gas is simply prohibited due to the low temperature of the internal combustion engine, knocking frequently occurs to the extent that the effect of introducing the exhaust gas cannot be expected, leading to instability of the internal combustion engine and a decrease in output. There is a fear.

  In order to avoid such an inconvenience, it is conceivable to set the operating characteristics of the internal combustion engine so that high output performance can be obtained in a stable operation state without performing exhaust introduction into the intake passage. However, in this case, since the degree of freedom in setting the operating characteristics of the internal combustion engine becomes low, there is a possibility that the output performance of the internal combustion engine, and hence the running performance of the vehicle, may be deteriorated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle control device that can suitably control the vehicle operating state without depending on the execution status of exhaust introduction into the engine intake passage. There is.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
The invention according to claim 1 is applied to a vehicle having an internal combustion engine and an electric motor as drive sources, and an exhaust gas recirculation passage provided in the same passage as an exhaust gas recirculation passage communicating the intake passage and the exhaust passage of the internal combustion engine. An exhaust gas recirculation mechanism including an exhaust gas recirculation valve, and an exhaust gas recirculation control for introducing and recirculating exhaust gas in the exhaust gas passage to the intake air passage through opening of the exhaust gas recirculation valve; and temperature of the internal combustion engine In a vehicle control device that performs valve opening prohibition control for prohibiting the valve opening drive of the exhaust gas recirculation valve when the valve opening is low, when the valve opening drive is not prohibited in addition to prohibiting the valve opening drive The gist of the present invention is to provide output adjusting means for reducing the output of the internal combustion engine and increasing the output of the electric motor as compared with the above.

  According to the above configuration, if the engine temperature is high and the exhaust gas recirculation (EGR) valve opening drive, that is, the introduction of exhaust gas into the intake passage is not prohibited, the vehicle operation state is met at that time. In addition, the operation control of the internal combustion engine and the electric motor can be appropriately executed. In addition, when the introduction of exhaust gas into the intake passage is prohibited because the engine temperature is low, knocking is likely to occur, but since the knocking can be suppressed by limiting the engine output, the internal combustion engine It is possible to suppress the unstable operating state of the engine. In addition, since the engine output can be reduced by the increase in the output of the electric motor at this time, the decrease in the output performance of the vehicle can be suppressed, and the change in the vehicle operating state can also be suppressed. Thus, according to the above configuration, it is possible to suitably control the driving state of the vehicle without depending on the execution status of exhaust introduction into the intake passage of the internal combustion engine.

  According to a second aspect of the present invention, in the vehicle control device according to the first aspect, the output adjusting means reduces the output of the internal combustion engine by limiting the engine torque by a preset upper limit value. That is the gist.

According to the above configuration, it is possible to accurately suppress the operating region of the internal combustion engine from being a region where the engine torque and thus the engine output is large.
According to a third aspect of the present invention, in the vehicle control device according to the second aspect, the output adjusting means sets the upper limit value while changing the upper limit value based on the occurrence of knocking in the internal combustion engine. The gist.

  According to the above configuration, in the case where knocking occurs frequently despite the engine output being limited, the engine output is limited to a smaller level, such as when the engine output is further limited. The upper limit value can be changed accordingly. Therefore, occurrence of knocking can be suitably suppressed, and instability of the operating state of the internal combustion engine can be suitably suppressed.

  The gist of a fourth aspect of the present invention is the vehicle control apparatus according to the second or third aspect, wherein the output adjusting means calculates and sets the upper limit value based on an engine rotational speed. .

  Even when the output torque (engine torque) of the internal combustion engine is the same, the engine output increases as the rotational speed of the output shaft (engine rotational speed) of the internal combustion engine increases. According to the above configuration, since the upper limit value for the engine torque is set according to the engine speed, the output of the internal combustion engine can be appropriately limited.

  According to a fifth aspect of the present invention, in the vehicle control device according to the first aspect, the control device moves an engine operating point determined by the engine rotational speed and the engine torque on a predetermined operating line. The gist of the invention is that the operation control of the internal combustion engine is executed, and the output adjusting means reduces the output of the internal combustion engine by changing the operating line to a low torque side.

According to the above configuration, when the introduction of exhaust gas is prohibited, it is possible to accurately suppress the operation of the internal combustion engine in the operation region where the engine torque and thus the engine output is large.
According to a sixth aspect of the present invention, in the vehicle control device according to the fifth aspect, the output adjusting means changes to the high rotation side in accordance with changing the operation line to the low torque side. This is the gist.

  Knocking is likely to occur in an operation region where the engine speed is low, even in an operation region where the engine torque is large. According to the above configuration, the operation line when the introduction of exhaust gas is prohibited is changed so as to be separated in the rotational speed direction as well as being changed in the torque direction from the operation region where knocking is likely to occur. Can do. As a result, the operating line can be accurately separated from the operating region where knocking is likely to occur, so that the engine operating point can be accurately suppressed from becoming an operating region where knocking is likely to occur.

  A seventh aspect of the present invention is the vehicle control apparatus according to the fifth or sixth aspect, wherein the output adjusting means sets the operation line while changing the operation line based on the occurrence of knocking in the internal combustion engine. This is the gist.

  According to the above configuration, in the case where knocking occurs frequently despite the change of the operation line, the operation line is further changed so that the occurrence of knocking in the state where the operation line has been changed. The operating line can be changed accordingly. Therefore, occurrence of knocking can be suitably suppressed, and instability of the operating state of the internal combustion engine can be suitably suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows schematic structure of the drive system of the vehicle with which the control apparatus concerning 1st Embodiment which actualized this invention is applied. 1 is a schematic diagram showing a schematic configuration of an internal combustion engine and peripheral devices mounted on the vehicle. The schematic diagram which shows the control structure of the vehicle. The graph which shows the relationship between the power request | requirement in 1st Embodiment, and a target engine speed. The flowchart which shows the execution procedure of the change process concerning 1st Embodiment. The graph which shows the relationship between the power request | requirement and target engine rotational speed in 2nd Embodiment which actualized this invention. The flowchart which shows the execution procedure of the setting process concerning 2nd Embodiment.

(First embodiment)
A vehicle control apparatus according to a first embodiment embodying the present invention will be described.
First, a drive system of a hybrid vehicle to which the control device according to the present embodiment is applied will be described with reference to FIG.

  As shown in FIG. 1, this hybrid vehicle is equipped with an internal combustion engine ENG and two rotating machines (first rotating machine MG1 and second rotating machine MG2) as drive sources. The first rotating machine MG1 mainly functions as a generator for supplying charging power to a battery (not shown) and supplying driving power to the second rotating machine MG2. The second rotating machine MG2 mainly functions as an electric motor for applying rotational torque to the propeller shaft PS that is a drive shaft of the vehicle when a large output is required such as when the vehicle is accelerated or started. The transaxle of the vehicle is provided with a power distribution mechanism and two planetary gear mechanisms (a front planetary gear mechanism P1 and a rear planetary gear mechanism P2).

  An output shaft (crankshaft 19 to be described later) of the internal combustion engine ENG is connected to a carrier c1 of a front planetary gear mechanism P1 including three rotation elements of a sun gear s1, a carrier c1, and a ring gear r1. The sun gear s1 of the front planetary gear mechanism P1 is connected to the rotor of the first rotating machine MG1 so as to be integrally rotatable. The ring gear r1 of the front planetary gear mechanism P1 is connected to the ring gear r2 of the rear planetary gear mechanism P2 so as to be integrally rotatable. The rear planetary gear mechanism P2 includes a sun gear s2 that is connected to the output shaft OS of the transaxle, and is thus connected to the propeller shaft PS so as to be integrally rotatable, and a carrier c2 that is fixed so as not to rotate. The rotor of the second rotating machine MG2 is connected to the propeller shaft PS so as to be integrally rotatable.

Next, the internal combustion engine ENG and its peripheral devices will be described with reference to FIG.
As shown in FIG. 2, a throttle valve 12 is provided in the intake passage 11 of the internal combustion engine ENG. A throttle motor 13 is connected to the throttle valve 12. Then, the opening degree of the throttle valve 12 (throttle opening degree TA) is adjusted through the drive control (throttle control) of the throttle motor 13, thereby adjusting the amount of air taken into the combustion chamber 14 through the intake passage 11. The The intake passage 11 is provided with a fuel injection valve 15. Fuel is injected into the intake passage 11 through drive control (fuel injection control) of the fuel injection valve 15.

  The internal combustion engine ENG is provided with a spark plug 16 for igniting an air-fuel mixture composed of intake air and injected fuel inside the combustion chamber 14. An igniter 17 is connected to the spark plug 16. The spark plug 16 operates when a high voltage output from the igniter 17 is applied. Through the operation control (ignition timing control) of the igniter 17, the air-fuel mixture burns at an appropriate timing, the piston 18 reciprocates, and the crankshaft 19 as the output shaft of the internal combustion engine ENG rotates. The air-fuel mixture after combustion is sent out from the combustion chamber 14 to the exhaust passage 20 as exhaust.

  Further, an exhaust gas recirculation (EGR) mechanism 30 for returning a part of the exhaust gas flowing through the exhaust passage 20 to the intake passage 11 is attached to the internal combustion engine ENG. The EGR mechanism 30 includes an EGR passage 31 that connects a portion of the intake passage 11 downstream of the throttle valve 12 and the exhaust passage 20, an EGR valve 32 provided in the EGR passage 31, and an opening degree of the EGR valve 32. An EGR actuator 33 for adjusting the angle is provided. In the operation control (EGR control) of the EGR mechanism 30, the operation of the EGR actuator 33 is controlled according to the operating state of the internal combustion engine ENG, the opening degree of the EGR valve 32 (EGR opening degree) is controlled, and the operation is performed again through the EGR passage 31. The amount of exhaust gas (EGR gas) to be circulated (EGR amount) is adjusted.

Next, the control structure of the hybrid vehicle of the present embodiment will be described with reference to FIG.
As shown in FIG. 3, the hybrid vehicle is provided with three electronic control units (hybrid ECU 40, engine ECU 41, and rotating machine ECU 42) for controlling the driving state. These electronic control units capture the output signals of various sensors and execute various arithmetic processes. Based on the calculation results, these electronic control units perform various controls related to the operation of the hybrid vehicle such as the operation control of the internal combustion engine ENG and the operation control of the rotating machine. Execute.

  As various sensors, for example, a vehicle speed sensor 43 for detecting a vehicle traveling speed (vehicle speed SPD) and an operation amount (accelerator operation amount ACC) of an accelerator operation member 21 (for example, an accelerator pedal or an accelerator lever) are detected. And an intake air amount sensor 45 for detecting an intake air amount GA of the internal combustion engine ENG. In addition, the crank sensor 46 for detecting the rotation phase (crank angle CA) and the rotation speed (engine rotation speed NE) of the crankshaft 19 and the temperature for detecting the temperature of the cooling water (water temperature THW) of the internal combustion engine ENG. A sensor 47, a knock sensor 48 for detecting the occurrence of knocking in the internal combustion engine ENG, and the like are also provided.

  The hybrid ECU 40 comprehensively controls the driving state of the hybrid vehicle. Specifically, a control target value (required total output) for the rotational force of the propeller shaft PS (see FIG. 1) is calculated based on the accelerator operation amount ACC and the vehicle speed SPD, and the engine output is based on the required total output. Control target values (required engine outputs) and control target values (required rotating machine outputs) of the outputs of the first rotating machine MG1 and the second rotating machine MG2 are respectively calculated. The requested engine output is output to the engine ECU 41, and the requested rotating machine output is output to the rotating machine ECU 42. The engine ECU 41 executes operation control of the internal combustion engine ENG based on the requested engine output, and the rotation machine ECU 42 performs operation control of the first rotating machine MG1 and the second rotating machine MG2 based on the requested rotating machine output. Is done.

  The required engine output includes a control target value (power requirement Tkl) for the rotational torque (engine torque) applied to the crankshaft 19 by the operation of the internal combustion engine ENG and a control target value (target engine rotational speed) for the engine rotational speed NE. Tne) is calculated.

  In the present embodiment, as the relationship between the power request Tkl and the target engine rotation speed Tne, a relationship as shown by the operation line L1 in FIG. 4 is determined in advance. Specifically, in a region where the target engine speed Tne is relatively low, the power requirement Tkl increases as the target engine speed Tne increases. Further, in a region where the target engine speed Tne is high, the power demand Tkl becomes a constant value without depending on the target engine speed Tne. As the operation line L1, a set of engine operating points capable of operating the vehicle with the fuel consumption of the internal combustion engine ENG suppressed to a low level is obtained and set in advance based on the results of experiments and simulations. Yes. Thus, in the present embodiment, the operation control of the internal combustion engine ENG is executed such that the engine operating point determined by the engine torque and the engine rotational speed NE moves on the operating line L1.

  The engine ECU 41 performs operation control of the internal combustion engine ENG. Specifically, the control target values of various control parameters of the internal combustion engine ENG are calculated based on the required engine output (power request Tkl, target engine rotational speed Tne) input from the hybrid ECU 40, and these control target values are also stored. And control various control parameters.

  As the control target value, for example, a control target value (target throttle opening Tta) for the throttle opening TA is calculated. In the throttle control, the opening of the throttle valve 12 is controlled so that the target throttle opening Tta and the actual throttle opening TA coincide.

  As the control target value, a control target value (target fuel injection amount TQ) for the amount of fuel injected from the fuel injection valve 15 is calculated. In the fuel injection control, the fuel injection valve 15 is driven to open so that the same amount of fuel as the target fuel injection amount TQ is injected.

  Further, a control target value (target ignition timing TR) for the engine ignition timing is calculated as the control target value. In the ignition timing control, the operation of the ignition plug 16 (specifically, the igniter 17) is controlled so that the ignition operation by the ignition plug 16 is performed at the target ignition timing TR. In calculating the target ignition timing TR, control for setting the target ignition timing TR in accordance with the occurrence of knocking in the internal combustion engine ENG, so-called knock control is executed. This knock control is executed as follows.

  That is, first, the presence or absence of knocking in the internal combustion engine ENG is determined based on the detection signal of the knock sensor 48, and the knock control amount AKCS is changed / updated according to the determination result. This knock control amount AKCS changes the target ignition timing TR to the retarded timing when knocking occurs and changes to the advanced timing when knocking does not occur. Accordingly, it functions as a value for controlling the target ignition timing TR. Specifically, the knock control amount AKCS subtracts a predetermined value (for example, 0.4 ° CA) from the knock control amount AKCS when knocking occurs, while the knock control amount AKCS is decremented to a predetermined value (for example, 0. (01 ° CA) is added.

  Further, the knock learning amount AGKNK is changed / updated based on the knock control amount AKCS. This knock learning amount AGKNK is set to a relatively small value (a value at which the target ignition timing TR becomes a retarded timing) when knocking tends to occur frequently, while the number of occurrences of knocking When there is little, a relatively large value (a value at which the target ignition timing TR becomes an advance timing) is set. Specifically, knock learning amount AGKNK adds a predetermined value (for example, 0.5 ° CA) when knock control amount AKCS is larger than a predetermined value (for example, 1.0 ° CA), while knock control amount AKCS is predetermined. When the value is smaller than the value (for example, −1.0 ° CA), it is updated so as to subtract a predetermined value (for example, 0.5 ° CA).

In the knock control of the present embodiment, the target ignition timing TR is set based on the knock control amount AKCS and the knock learning amount AGKNK.
Further, as the control target value, a control target value (target EGR opening) for the EGR opening is calculated. In the EGR control, the operation of the EGR valve 32 (specifically, the EGR actuator 33) is controlled so that the target EGR opening matches the actual EGR opening. Through such EGR control, the EGR amount is adjusted to an amount commensurate with the operating state of the internal combustion engine ENG. In the present embodiment, when the target EGR opening is calculated, the valve opening prohibition control for prohibiting the valve opening drive of the EGR valve 32 when the water temperature THW is lower than a predetermined temperature Tlow (60 degrees in the present embodiment). Executed. By executing such valve opening prohibition control, when the temperature of the internal combustion engine ENG is low, high-temperature exhaust gas is not introduced into the intake passage 11, so that the generation of condensed water due to the introduction of exhaust gas into the intake passage 11 as described above. And inconvenience due to freezing of the condensed water is avoided.

  The rotating machine ECU 42 controls the operating states of the first rotating machine MG1 and the second rotating machine MG2. Specifically, the control target value Tmg1 of the control amount of the first rotating machine MG1 and the control target value Tmg2 of the control amount of the second rotating machine MG2 are calculated based on the requested rotating machine output input from the hybrid ECU 40. To do. The operation of the first rotating machine MG1 (specifically, the control circuit TR1) is controlled according to the control target value Tmg1, and the operation of the second rotating machine MG2 (specifically, the control circuit TR2) is controlled according to the control target value Tmg2. Is controlled. In the vehicle according to the present embodiment, the first rotating machine MG1 is connected to the battery BAT via the control circuit TR1, and the second rotating machine MG2 is connected to the battery BAT via the control circuit TR2.

  Here, as the internal combustion engine ENG of the present embodiment, an internal combustion engine that can maintain a stable operation state by performing exhaust introduction into the intake passage 11 is employed. Specifically, an internal combustion engine ENG having a structure in which the compression ratio is set high in order to improve output performance and the momentum of the airflow (specifically, tumble flow) generated in the combustion chamber 14 is increased is employed. . In such an internal combustion engine ENG, if the introduction of exhaust gas is simply prohibited through the valve opening prohibition control described above, knocking occurs frequently and the operating state becomes unstable as much as the effect of exhaust gas introduction cannot be expected.

  In view of this point, in the present embodiment, when the valve opening drive of the EGR valve 32 is prohibited through the valve opening prohibition control, the valve opening drive of the EGR valve 32 is not prohibited in accordance with the prohibition. The output of the internal combustion engine ENG (required engine output) is decreased and the outputs of the first rotating machine MG1 and the second rotating machine MG2 (required rotating machine output) are increased.

  As a result, when the opening driving of the EGR valve 32, that is, the introduction of exhaust gas into the intake passage 11 is prohibited, knocking is likely to occur due to the prohibition, but the internal combustion engine ENG is suppressed so as to suppress the occurrence. Therefore, the operation state of the internal combustion engine ENG can be suppressed from becoming unstable. In addition, the reduction in the output of the internal combustion engine ENG can be compensated for by increasing the outputs of the first rotary machine MG1 and the second rotary machine MG2, so that a reduction in the output performance of the vehicle can be suppressed. Thus, changes in the driving state of the vehicle can be suppressed. On the other hand, when the opening of the EGR valve 32 is not prohibited because the temperature of the internal combustion engine ENG is sufficiently high, the operation control of the internal combustion engine ENG or the first rotating machine MG1 is performed without restricting the output of the internal combustion engine ENG. And operation control of the 2nd rotary machine MG can be performed. That is, the operation control of the internal combustion engine ENG and the operation control of the first rotary machine MG1 and the second rotary machine MG are performed in accordance with the vehicle operation state in a state where exhaust introduction into the intake passage 11 of the internal combustion engine ENG is executed. Can be executed properly. As described above, according to the control apparatus of the present embodiment, the driving state of the vehicle is suitably controlled without depending on the execution status of exhaust introduction into the intake passage 11 of the internal combustion engine ENG.

  In the internal combustion engine ENG of the present embodiment, if the valve opening drive of the EGR valve 32 is prohibited through the valve opening prohibition control without changing the execution mode of the operation control, knocking occurs in the operation region where the engine torque is large. It happens frequently and the driving state becomes unstable. Therefore, in the present embodiment, the output of the internal combustion engine ENG is reduced by limiting the engine torque (specifically, the power requirement Tkl) with a predetermined upper limit value GD (see the broken line in FIG. 4). The upper limit value GD is an engine capable of operating the internal combustion engine ENG in a stable state without changing the execution mode of the operation control when the valve opening drive of the EGR valve 32 is prohibited through the valve opening prohibition control. An upper limit value for torque is obtained and set in advance based on the results of experiments and simulations. By limiting the power demand Tkl with such an upper limit value GD, it is possible to accurately suppress the operation of the internal combustion engine ENG in an operation region where the engine torque is large to the extent that the operation state of the internal combustion engine ENG may become unstable. become.

  Further, in the control device according to the present embodiment, although the occurrence of knocking can be suppressed by limiting the power demand Tkl by the upper limit value GD, there are various effects such as individual differences of the internal combustion engine ENG and the influence of changes over time. There remains a possibility that knocking will occur frequently due to factors. In order to reliably suppress such frequent occurrence of knocking, it is conceivable to increase the degree of restriction of the required engine output sufficiently. However, in this case, not only the output performance of the internal combustion engine ENG is lowered, but also the vehicle running performance is lowered.

  Here, in the control device according to the present embodiment, it is possible to grasp the occurrence of knocking based on the knock control amount AKCS in the knock control. Specifically, in a situation where knocking frequently occurs, knock control amount AKCS becomes a value smaller than a predetermined value JD (for example, “0”), while in a situation where occurrence of knocking is appropriately suppressed, knock control amount AKCS has the same predetermined value. It becomes a value larger than JD.

  In view of this point, in the present embodiment, the upper limit value GD is set while being changed according to the knock control amount AKCS, which is an index value of the occurrence state of such knocking. Specifically, when knock control amount AKCS becomes smaller than predetermined value JD, upper limit value GD is changed to a value that is smaller by predetermined value A, as indicated by a solid arrow in FIG. As a result, in the case where knocking occurs frequently even though the required engine output is limited, the required engine output (specifically, the power request Tkl) is further reduced. As described above, according to the present embodiment, the upper limit value GD is changed according to the occurrence state of knocking in a state where the requested engine output is limited, so that occurrence of knocking is suitably suppressed. Become.

Hereinafter, a process (change process) for changing the outputs of the internal combustion engine ENG, the first rotating machine MG1, and the second rotating machine MG2 in accordance with the execution mode of the valve opening prohibition control will be described in detail.
FIG. 5 is a flowchart showing a specific execution procedure of the change process. A series of processes shown in this flowchart is executed by the hybrid ECU 40 as an interrupt process at predetermined intervals.

  As shown in FIG. 5, in this process, first, it is determined whether or not the water temperature THW is lower than the predetermined temperature Tlow (step S101), and whether or not the power request Tkl is larger than the upper limit value GD is determined. (Step S102).

  If the water temperature THW is equal to or higher than the predetermined temperature Tlow (step S101: NO), it is determined that the opening of the EGR valve 32 is not prohibited at this time, and the process is temporarily terminated without executing the following process. Is done. Further, when the power request Tkl is equal to or less than the upper limit value GD (step S102: NO), the power request Tkl is so high that knocking frequently occurs although the opening of the EGR valve 32 is prohibited at this time. Assuming that it has not increased, this processing is temporarily terminated without executing the following processing.

  On the other hand, when the water temperature THW is lower than the predetermined temperature Tlow (step S101: YES) and the power request Tkl is larger than the upper limit value GD (step S102: YES), the EGR valve 32 is driven to open through the valve opening prohibition control at this time. Is prohibited, and it is determined that the power requirement Tkl is large enough to cause frequent knocking. Therefore, at this time, by setting the upper limit value GD as the power request Tkl, the power request Tkl is limited by the upper limit value GD (step S103). In the operation control of the internal combustion engine ENG, the relationship between the power demand Tkl and the target engine speed Tne is determined by the operation line L1 (see FIG. 4). Therefore, when the power demand Tkl is limited, the target engine speed is accordingly increased. Tne starts to decrease. Therefore, at this time, the output of the internal combustion engine ENG is limited.

  Further, the engine operation when the output of the internal combustion engine ENG is limited, that is, when the engine output is limited by the engine output and the upper limit value GD at the engine operating point (for example, point P1 in FIG. 4) corresponding to the vehicle operating state. The difference from the engine output at the point (point P2 in FIG. 4) is calculated, and the difference is added to the requested rotating machine output (step S104 in FIG. 5). In the process of step S104, a value (= Tkl × Tne) obtained by multiplying the power request Tkl by the target engine speed Tne is calculated and used as the engine output. In the present embodiment, the process of step S103 and the process of step S104 function as output adjustment means.

  Thereafter, it is determined whether knock control amount AKCS is smaller than predetermined value JD (step S105). When knock control amount AKCS is smaller than predetermined value JD (step S105: YES), it is determined that knocking may occur frequently, and predetermined predetermined value A is determined from upper limit value GD. The subtracted value is set as a new upper limit value GD (step S106). On the other hand, when knock control amount AKCS is greater than or equal to predetermined value JD (step S105: NO), the process of step S106 is not executed. After the upper limit GD is appropriately updated in a manner corresponding to the knock control amount AKCS as described above, the present process is temporarily terminated.

As described above, according to the present embodiment, the effects described below can be obtained.
(1) When prohibiting the valve opening drive of the EGR valve 32 through the valve opening prohibition control, the required engine output is reduced and requested in accordance with the prohibition compared to when the valve opening drive of the EGR valve 32 is not prohibited. Increased rotating machine output. Therefore, it is possible to suppress instability of the operating state of the internal combustion engine ENG and changes in the operating state of the vehicle when introduction of exhaust gas into the intake passage 11 is prohibited. Further, when the valve opening drive of the EGR valve 32 is not prohibited, the operation control of the internal combustion engine ENG or the second operation is performed so as to match the vehicle operation state in which the exhaust introduction into the intake passage 11 of the internal combustion engine ENG is executed. The operation control of the first rotating machine MG1 and the second rotating machine MG can be appropriately executed. Therefore, the operating state of the vehicle can be suitably controlled without depending on the execution status of exhaust introduction into the intake passage 11 of the internal combustion engine ENG.

  (2) The output of the internal combustion engine ENG is reduced by limiting the power request Tkl with the upper limit value GD. Therefore, it is possible to accurately suppress the operation of the internal combustion engine ENG in an operation region where the engine torque is large to the extent that the operation state of the internal combustion engine ENG may become unstable.

  (3) Since the upper limit value GD is set while being changed according to the knock control amount AKCS, the upper limit value GD is changed in accordance with the occurrence of knocking in a state where the requested engine output is limited. Can do. Therefore, occurrence of knocking can be suitably suppressed, and instability of the operating state of the internal combustion engine ENG can be suitably suppressed.

(Second Embodiment)
Hereinafter, a vehicle control apparatus according to a second embodiment that embodies the present invention will be described focusing on differences from the first embodiment. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The control device according to the present embodiment and the control device according to the first embodiment described above are the setting mode and request of the requested engine output when the opening of the EGR valve 32 is prohibited through the valve opening prohibition control. The setting mode of the rotating machine output is different.

Hereinafter, the setting aspect of the required engine output and the setting aspect of the required rotating machine output in the present embodiment will be described in detail.
In the control device according to the present embodiment, two different relationships are determined in advance as the relationship among the requested total output, the requested engine output, and the requested rotating machine output. One of these relationships (first relationship) is set to a relationship suitable for a situation in which the valve opening drive of the EGR valve 32 is not prohibited, and the other (second relationship) is the valve opening drive of the EGR valve 32. A relationship suitable for the prohibited situation is set. The second relationship is set such that the required engine output is small and the required rotating machine output is large compared to the first relationship. When the valve opening drive of the EGR valve 32 is not prohibited through the valve opening prohibition control, the required engine output and the required rotating machine output are calculated from the first relationship based on the required total output. On the other hand, when the valve opening drive of the EGR valve 32 is prohibited through the valve opening prohibition control, the required engine output and the required rotating machine output are calculated from the second relationship based on the required total output.

  Further, in the control device according to the present embodiment, as shown in FIG. 6, two different relationships (operation lines L2 and L3) are determined in advance as the relationship between the power request Tkl and the target engine speed Tne. Yes. In both of these relationships, in a region where the target engine speed Tne is relatively low, the power requirement Tkl increases as the target engine speed Tne increases. Further, in a region where the target engine speed Tne is high, the power request Tkl becomes a constant value without depending on the target engine speed Tne. In the present embodiment, calculation maps in which a plurality of relationships among the required engine output, the power request Tkl, and the target engine rotation speed Tne are determined are stored as these relationships. The power demand Tkl and the target engine speed Tne are calculated by interpolating the map values stored in the map.

  The relationship (third relationship) defined on the operation line L2 is a relationship commensurate with the required engine output calculated from the first relationship, and the internal combustion engine is operated in a situation where the valve opening drive of the EGR valve 32 is not prohibited. A set of engine operating points is set in which the vehicle can be operated in a state where the fuel consumption of the engine ENG is kept low. Specifically, the relationship between the required engine output, the power request Tkl and the target engine rotation speed Tne that satisfy such conditions is obtained in advance based on the results of experiments and simulations and stored in the hybrid ECU 40 in advance. When the valve opening drive of the EGR valve 32 is not prohibited through the valve opening prohibition control, the operation control of the internal combustion engine ENG is executed based on the third relationship. Thereby, the operation control of the internal combustion engine ENG is executed so that the engine operating point determined by the engine torque and the engine speed NE moves on the operating line L2.

  On the other hand, as the relationship (fourth relationship) defined for the operation line L3, a relationship corresponding to the required engine output calculated from the second relationship is set. Specifically, in a situation where valve opening drive of the EGR valve 32 is prohibited, in a stable state while avoiding engine operation in a specific region (region indicated by FI in the figure) that is likely to cause frequent knocking. A set of engine operating points at which the engine can be operated is obtained and set in advance based on the results of experiments and simulations. Specifically, as the fourth relationship, a relationship on the side where the engine torque is low (low torque side) and the side where the engine rotational speed NE is high (high rotation side) as compared with the third relationship is defined. ing. Specifically, the relationship between the required engine output that satisfies such conditions, the power request Tkl, and the target engine speed Tne is obtained in advance based on the results of experiments and simulations, and stored in the hybrid ECU 40 in advance. When the opening of the EGR valve 32 is prohibited because the temperature of the internal combustion engine ENG is low, the operation control of the internal combustion engine ENG is executed based on the fourth relationship. Thus, the engine operating point determined by the engine torque and the engine rotational speed NE is executed so as to move on the operation line L3.

  Here, knocking is likely to occur in an operation region where the engine rotational speed NE is low even in an operation region where the engine torque is large. In the present embodiment, when the valve opening drive of the EGR valve 32 is prohibited, the relationship between the power request Tkl and the target engine speed Tne is lower than the case where the valve opening drive of the EGR valve 32 is not prohibited. The relationship on the torque side and the relationship on the high rotation side are set. That is, the relationship between the power demand Tkl and the target engine speed Tne when the opening of the EGR valve 32 is prohibited is determined from the specific region FI that is likely to cause frequent knocking and the torque direction (vertical direction in the figure) and It is changed so as to be separated in both the rotational speed directions (left and right directions in the figure). As described above, according to the present embodiment, when the valve opening drive of the EGR valve 32 is prohibited, the relationship between the power request Tkl and the target engine speed Tne (the fourth relationship [operation line L3]) is as follows. The specific area FI that is likely to cause frequent knocking is surely separated. Therefore, it is possible to accurately suppress the engine operating point from becoming an area where the possibility of frequent knocking is high.

  Further, at this time, although the output of the internal combustion engine ENG (specifically, the required engine output) is reduced, the decrease is the output of the first rotary machine MG1 and the second rotary machine MG2 (specifically, the required rotary machine output). Since the increase is compensated for, the decrease in the output performance of the vehicle is suppressed, and the change in the driving state of the vehicle is also suppressed.

  Further, in the control device according to the present embodiment, although the occurrence of knocking can be suppressed by changing the operating line of the internal combustion engine ENG, there are various types of effects such as individual differences of the internal combustion engine ENG and the influence of changes over time. There remains a possibility that knocking will occur frequently due to factors. In order to reliably suppress such frequent occurrence of knocking, it is conceivable to set in advance an operation line on the lower torque side and on the higher rotation side. However, in this case, not only the output performance of the internal combustion engine ENG is lowered, but also the vehicle running performance is lowered.

  In view of this point, in the present embodiment, the operation line of the internal combustion engine ENG is set while being changed in accordance with the knock control amount AKCS that is an index value of the occurrence of knocking. Specifically, when the knock control amount AKCS becomes smaller than the predetermined value JD, the operation line L3 is changed to the low torque side and the high rotation side, as indicated by the black arrow in FIG. The As a result, the operating line is further changed in the case where knocking frequently occurs despite the operating line of the internal combustion engine ENG being changed in advance. As described above, according to the present embodiment, the operation line is changed according to the state of occurrence of knocking in a state where the operation line has been changed in advance, so that the occurrence of knocking is suitably suppressed. . In the present embodiment, the change of the operation line L3 (second relationship) is performed by subtracting a predetermined value from each power request Tkl stored in the calculation map, and at a predetermined value for each target engine speed Tne. And so on. Further, in accordance with the change of the operation line in this way, the relationship (the second relationship) among the requested total output, the requested engine output, and the requested rotating machine output is changed. Specifically, the relationship is changed so that a smaller value is calculated as the required engine output and a larger value is calculated as the required rotating machine output. As a result, the required engine output can be further reduced while suppressing a decrease in the output performance of the vehicle.

Hereinafter, a process (setting process) for setting the requested engine output and the requested rotating machine output will be described with reference to FIG.
FIG. 7 is a flowchart showing a specific execution procedure of the setting process. A series of processing shown in this flowchart is executed by the hybrid ECU 40 and the rotating machine ECU 42 as interruption processing at predetermined intervals.

As shown in FIG. 7, in this process, it is first determined whether or not the water temperature THW is lower than the predetermined temperature Tlow (step S201).
If the water temperature THW is equal to or higher than the predetermined temperature Tlow (step S201: NO), it is determined that the opening operation of the EGR valve 32 is not prohibited at this time, and the requested engine is determined from the first relationship based on the requested total output. The output and the required rotating machine output are calculated (step S202). Further, based on the requested engine output, the power request Tkl and the target engine speed Tne are calculated and set from the third relationship (see the operation line L2 in FIG. 6) (step S203). Further, control target values Tmg1, Tmg2 are calculated and set based on the required rotating machine output (step S204). Thereafter, this process is temporarily terminated.

  On the other hand, if the water temperature THW is lower than the predetermined temperature Tlow (step S201: YES), the valve opening drive of the EGR valve 32 is prohibited at this time, and the second relationship (first The required engine output and the required rotating machine output are calculated from the relationship (required engine output is smaller and required rotating machine output is larger) (step S205). Thereafter, the power request Tkl and the target engine speed Tne are calculated and set from the fourth relationship (see the operation line L3 in FIG. 6) based on the required engine output (step S206). In the present embodiment, the process of step S205 and the process of step S206 function as output adjustment means. Further, control target values Tmg1, Tmg2 are calculated and set based on the required rotating machine output (step S207).

  Thereafter, it is determined whether knock control amount AKCS is smaller than predetermined value JD (step S208). If the knock control amount AKCS is smaller than the predetermined value JD (step S208: YES), the second relationship is that the required engine output is small and the request is required because knocking may occur frequently. The relationship is changed so that the output of the rotating machine is large (step S209). Further, the fourth relationship (operation line L3) is changed to a relationship on the low torque side and on the high rotation side (step S210). On the other hand, when knock control amount AKCS is equal to or larger than predetermined value JD (step S208: NO), the process of step S209 and the process of step S210 are not executed. As described above, after the second relationship and the fourth relationship are appropriately updated in a manner corresponding to the knock control amount AKCS, the present process is temporarily terminated.

As described above, according to the present embodiment, the effects described in the following (4) to (6) can be obtained in addition to the effects described in (1) above.
(4) The output of the internal combustion engine ENG is reduced by changing the operating line of the internal combustion engine ENG to the low torque side. Therefore, when the EGR valve 32 is prohibited from being opened, it is possible to accurately suppress the internal combustion engine ENG from being operated in an operation region where the engine torque, and thus the engine output is large.

  (5) The operation line of the internal combustion engine ENG is changed to the high rotation side in accordance with the change to the low torque side. For this reason, the operating line of the internal combustion engine ENG when the valve opening drive of the EGR valve 32 is prohibited is changed so as to be separated from the specific region FI in which knocking is likely to occur in the torque direction, and is also separated in the rotational speed direction. Can be changed as follows. As a result, the operating line can be accurately separated from the specific area FI, and therefore, it is possible to accurately suppress the engine operating point from becoming an operating area where knocking is likely to occur.

  (6) Since the operation line L3 of the internal combustion engine ENG is changed in a manner corresponding to the knock control amount AKCS, the operation line depends on the occurrence of knocking when the operation line of the internal combustion engine ENG is changed. Can be changed. Therefore, occurrence of knocking can be suitably suppressed, and instability of the operating state of the internal combustion engine ENG can be suitably suppressed.

(Other embodiments)
Each of the above embodiments may be modified as follows.
-In 1st Embodiment, the change aspect of the upper limit GD based on the knocking occurrence condition can be changed arbitrarily. For example, the upper limit value GD is changed to a value on the low torque side when knocking occurs, while the upper limit value GD is changed to a value on the high load side when knocking does not occur. The upper limit value GD may be changed.

  -In 1st Embodiment, you may abbreviate | omit the structure (specifically the process of FIG.5 S105 and step S106) which changes the upper limit GD according to the generation | occurrence | production state of knocking.

  In the first embodiment, the upper limit value GD may be calculated and set based on the engine speed NE. Even if the engine torque is the same, the output of the internal combustion engine ENG increases as the engine speed NE increases. According to the above configuration, since the upper limit value GD for the engine torque is set according to the engine rotational speed NE, it is possible to appropriately limit the output of the internal combustion engine ENG.

  In the second embodiment, the required engine output can be changed without changing the relationship between the required total output and the required engine output between when the opening of the EGR valve 32 is prohibited and when it is not prohibited. Only the relationship between the power request Tkl and the target engine speed Tne may be changed. In this case, the output of the internal combustion engine ENG is smaller than the relationship when the valve opening drive is not prohibited as the relationship between the requested engine output, the power request Tkl and the target engine speed Tne when the EGR valve 32 is prohibited from opening the valve. It is sufficient to set a relationship in which the operation line of the internal combustion engine ENG is on the low torque side and on the high rotation side. Further, as the required rotating machine output when the opening of the EGR valve 32 is prohibited, the requested engine output when prohibited and the requested rotating machine output when not prohibited when compared with the value when the valve opening driving is not prohibited. It is sufficient to set a value that is larger by the difference of.

  In the second embodiment, the processing for changing the operation line of the internal combustion engine ENG to the low torque side and the high rotation side while suppressing the required engine output to be small is performed as follows: the power request Tkl before the change and the target engine rotation speed Only when the operating range determined by Tne is the operating region on the high torque side and the operating region on the low rotation side, in other words, the engine operating region that may become the specific region FI. May be.

  -In 2nd Embodiment, the change aspect of the action line based on the generation | occurrence | production state of knocking can be changed arbitrarily. For example, when knocking occurs, the operation line L3 is changed to the low torque side and high rotation side, while when knocking does not occur, the operation line L3 is changed to the high load side and low rotation side, etc. The operation line L3 may be changed in accordance with the update of the knock control amount AKCS.

-In 2nd Embodiment, you may abbreviate | omit the structure (specifically the process of FIG.6 S208-step S210) which changes the operation line L3 according to a knocking generation condition.
In the second embodiment, the operation line L3 may be simply changed to the low torque side instead of changing to the low torque side and the high rotation side.

  In each embodiment, a calculation map is set as the relationship between the required total output, the required engine output, and the required rotating machine output, and the relationship between the required engine output, the power requirement Tkl, and the target engine rotational speed Tne. In addition, a calculation formula can be set.

  When the valve opening drive of the EGR valve 32 is prohibited through the valve opening prohibition control instead of executing the changing process according to the first embodiment and the setting process according to the second embodiment, A predetermined constant value may be subtracted from the requested engine output, and the same constant value may be added to the requested rotating machine output. In short, when the valve opening drive of the EGR valve 32 is prohibited through the valve opening prohibition control, it is only necessary to decrease the required engine output and increase the required rotating machine output by the amount that compensates for the decrease.

  In each embodiment, the processing related to valve opening prohibition control based on the water temperature THW, the change processing according to the first embodiment (specifically, the processing in step S101 in FIG. 5), the second embodiment. The setting process (specifically, the process of step S201 in FIG. 7) is executed. These processes may be executed based on the temperature index value of the internal combustion engine ENG other than the water temperature THW, such as the temperature of the lubricating oil of the internal combustion engine ENG. Further, the above processes may be executed based on the temperature of the internal combustion engine ENG directly detected by a newly provided temperature sensor.

  The control device according to the present invention can be applied to a vehicle having only one electric motor, for example, as long as the vehicle has an internal combustion engine and an electric motor as drive sources.

  ENG ... Internal combustion engine, MG1 ... first rotating machine, MG2 ... second rotating machine, TR1, TR2 ... control circuit, P1 ... front planetary gear mechanism (s1 ... sun gear, c1 ... carrier, r1 ... ring gear), P2 ... rear Planetary gear mechanism (s2 ... sun gear, c2 carrier, r2 ... ring gear), OS ... transaxle output shaft, PS ... propeller shaft, 11 ... intake passage, 12 ... throttle valve, 13 ... throttle motor, 14 ... combustion chamber, DESCRIPTION OF SYMBOLS 15 ... Fuel injection valve, 16 ... Spark plug, 17 ... Igniter, 18 ... Piston, 19 ... Crankshaft, 20 ... Exhaust passage, 21 ... Accelerator operating member, 30 ... Exhaust gas recirculation (EGR) mechanism, 31 ... EGR passage, 32 ... EGR valve, 33 ... EGR actuator, 40 ... hybrid ECU, 41 ... engine ECU, 42 ... rotating machine E U, 43 ... vehicle speed sensor, 44 ... accelerator sensor, 45 ... intake air quantity sensor, 46 ... crank sensor, 47 ... temperature sensor, 48 ... knock sensor.

Claims (7)

An exhaust gas recirculation mechanism that is applied to a vehicle having an internal combustion engine and an electric motor as a drive source, and includes an exhaust gas recirculation passage that communicates an intake passage and an exhaust passage of the internal combustion engine, and an exhaust gas recirculation valve provided in the passage. An exhaust gas recirculation control for introducing and recirculating exhaust gas in the exhaust passage into the intake passage through valve opening drive of the exhaust gas recirculation valve; and the exhaust gas recirculation valve when the temperature of the internal combustion engine is low In a vehicle control device that executes valve opening prohibition control for prohibiting valve opening drive of
Along with the prohibition of the valve opening drive, there is provided an output adjusting means for decreasing the output of the internal combustion engine and increasing the output of the electric motor as compared with the case where the valve opening drive is not prohibited. Vehicle control device. The vehicle control device according to claim 1,
The vehicle control apparatus according to claim 1, wherein the output adjusting means reduces the output of the internal combustion engine by limiting the engine torque with a preset upper limit value. The vehicle control device according to claim 2,
The vehicle control apparatus characterized in that the output adjusting means sets the upper limit value while changing the upper limit value based on a state of occurrence of knocking in the internal combustion engine. The vehicle control device according to claim 2 or 3,
The vehicle control apparatus characterized in that the output adjusting means calculates and sets the upper limit value based on an engine speed. The vehicle control device according to claim 1,
The control device performs operation control of the internal combustion engine so that an engine operating point determined by the engine rotational speed and the engine torque moves on a predetermined operating line,
The vehicle control apparatus according to claim 1, wherein the output adjusting means reduces the output of the internal combustion engine by changing the operating line to a low torque side. The vehicle control device according to claim 5,
The vehicle control apparatus according to claim 1, wherein the output adjusting means changes the operation line to a high rotation side in accordance with changing the operation line to a low torque side. The vehicle control device according to claim 5 or 6,
The vehicle control apparatus characterized in that the output adjusting means sets the operating line while changing the operating line based on the occurrence of knocking in the internal combustion engine.

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