JP3897001B2 - Control device for hybrid vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a hybrid vehicle provided with a driving force control motor capable of generating power by the engine and assisting torque to the engine.
[0002]
[Prior art]
In recent years, hybrid vehicles have been developed in which an engine and a motor are combined, and the motor generates electricity by the engine as needed, or auxiliary driving force is applied (hereinafter referred to as torque assist or simply assist). (For example, Patent Document 1). In this hybrid vehicle, in an area where the engine output corresponding to the traveling load (hereinafter referred to as target engine output) is low, the engine output is set higher than the target engine output, and the motor generates power with the surplus output and the energy is stored in the battery. Store in. On the other hand, in a region where the target engine output is high, torque assist is performed by setting the engine output lower than the target engine output and supplementing the insufficient output with the motor output (driving the motor with the energy stored in the battery).
[0003]
That is, since the actual engine output fluctuation range can be set narrower than the target engine output fluctuation range, the engine can be easily operated in a high-efficiency region, and fuel consumption and exhaust gas purification performance can be improved.
[0004]
On the other hand, in order to suppress the generation of nitrogen carbide (NOx) and soot in the combustion of a direct injection engine such as a diesel engine (an engine provided with fuel injection means in the combustion chamber), in recent years, premixed compression ignition combustion (hereinafter, A new combustion mode called “premixed combustion” has been proposed (for example, Patent Document 2). In this combustion mode, in order to prevent premature ignition and to suppress the generation of the above substances, a large amount of exhaust gas is recirculated to the intake air (hereinafter, the exhaust gas recirculated to the intake air is referred to as EGR gas), and the compression top dead center of the cylinder. The fuel and the fuel are sufficiently mixed by injecting fuel in the middle of the previous compression stroke, and then the air-fuel mixture is self-ignited and burned at the end of the compression stroke.
[0005]
However, if the intake air at the time of combustion contains a lot of EGR gas, the amount of air contained in the intake air is reduced accordingly, so it is difficult to realize such a combustion mode on the high speed rotation and high load side of the engine. It is. For this reason, conventionally, premixed combustion is performed as described above mainly in the operating region on the low speed rotation and low load side, and at this time, the ratio of the EGR gas contained in the intake air (hereinafter referred to as the EGR rate) is compared. Control over the first set value that is higher than the upper limit, mainly in the operating region on the high speed rotation or high load side, the fuel injection mode is switched to perform fuel injection near the top dead center of the compression stroke, and Combustion is performed in a state where the EGR rate is controlled to be equal to or lower than a second set value lower than the first set value (hereinafter referred to as diffusion combustion).
[0006]
[Patent Document 1]
JP 2002-242721 A
[Patent Document 2]
JP 2000-110669 A
[0007]
[Problems to be solved by the invention]
As described above, in the premixed combustion, there are many advantages such as being able to suppress the generation of NOx and soot, and when switching from the diffusion combustion state to the premixed compression ignition combustion, switching is performed immediately. There is a request. When such switching is performed, it is necessary to switch the EGR rate from the low side to the high side, and it is also necessary to switch the recirculation amount of the EGR gas.
[0008]
However, in general, there is a response delay in the increase in the recirculation amount of the EGR gas, and in order to avoid pre-ignition during the response delay period, switching from the diffusion combustion state to the premixed combustion is performed. I had to be late. Therefore, it is required to make the response delay of the increase in the EGR gas recirculation amount as short as possible.
[0009]
Further, when switching from the diffusion combustion state to the premixed combustion, the engine output torque may vary due to the fluctuation of the EGR rate, and a torque shock may occur.
[0010]
In view of such circumstances, the present invention is capable of quickly switching the recirculation amount of the EGR gas to the engine and preventing the occurrence of a torque shock or the like so as to smoothly switch the recirculation amount. Is to provide.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides an operating state detecting means for detecting an operating state of an engine, and a first combustion mode in which combustion is performed with an EGR rate increased when the exhaust temperature from the engine is equal to or higher than a predetermined temperature And engine control means for switching between the second combustion mode in which combustion is performed with the EGR rate being reduced in accordance with the operating state detected by the operating state detecting means, and a driving force control motor that is drivingly connected to the engine A motor control device that switches between a power generation state generated by the rotation of the engine and a state in which the engine is assisted according to the operating state of the engine, and the intake passage to change the EGR rate. A control device for a hybrid vehicle comprising an intake air flow rate control valve, which is set by being switched by the engine control means EGR rate setting means for setting a target EGR rate according to the firing mode is provided, and the intake passage control valve is set by the EGR rate setting means when switching from the second combustion mode to the first combustion mode. The motor control means is configured to control from the value corresponding to the target EGR rate to the EGR rate increasing side, and when the motor control unit switches from the second combustion mode to the first combustion mode, Decrease in engine torque accompanying an increase in EGR rate within a period during which the EGR rate is increasing In order to absorb the torque, the driving force control motor is controlled to perform torque assist.
[0012]
With this configuration, the intake passage control valve is controlled to be larger than a value corresponding to the target EGR rate set by the EGR rate setting means when switching from the second combustion mode to the first combustion mode. Is done. That is, the EGR gas is controlled so as to be easily taken in a larger amount. Therefore, the EGR gas can be taken into the intake passage more quickly, and the recirculation amount of the EGR gas to the engine can be switched more quickly.
[0013]
Note that when switching from the second combustion mode to the first combustion mode, the amount of recirculation of the EGR gas increases, so that the combustion is suppressed and the torque of the engine is reduced. Cause. In particular, when the recirculation amount of the EGR gas is quickly switched, a sudden torque fluctuation occurs and the torque shock increases.
[0014]
Therefore, as described above, the motor control means As a result, the engine torque decreases as the EGR rate increases during the period during which the EGR rate increases. When the driving force control motor is controlled so as to absorb torque, torque assist may be assisted when switching from the second combustion mode to the first combustion mode. It is possible to prevent the torque shock from occurring.
[0015]
Therefore, according to the configuration of the present invention, the amount of EGR gas recirculated to the engine can be switched quickly, and the switching can be performed smoothly by preventing the occurrence of torque shock or the like.
[0016]
In the hybrid vehicle control device, the driving force control motor may be the engine. Decrease in torque Detection means for detecting that the torque control motor is in a specific state where only insufficient torque assist can be absorbed, and when the driving force control motor is in the specific state, the intake flow rate control valve is set to the target EGR rate. More preferably, it is configured to control to a corresponding value.
[0017]
According to this configuration, the driving force control motor is the engine. Decrease in torque When the engine is in a state where only insufficient torque assist can be absorbed, the intake air amount control valve changes the intake flow rate control valve to the target EGR when switching from the second combustion mode to the first combustion mode. Since control is performed to a value according to the rate, that is, switching is performed in a state where the amount of change in the EGR rate is small, the amount of torque decrease in the engine of the EGR gas is reduced, and a rapid torque change can be suppressed. Become. Therefore, even when sufficient torque assist cannot be performed by the driving force control motor, the occurrence of the torque shock can be suppressed.
[0018]
In the case where the driving force control motor cannot sufficiently perform the torque assist, as described above, the amount of change in the EGR rate is reduced when switching from the second combustion mode to the first combustion mode. Switching is performed according to the state, and the increase rate of the recirculation amount of the EGR gas becomes slow. That is, the rate of decrease in the amount of air sucked into the engine becomes slow. When switching to the combustion injection mode corresponding to the first combustion mode in such a state, if the first combustion mode is the premixed combustion mode and the second combustion mode is the diffusion combustion mode, sufficient air Only the fuel injection timing is performed early in a state where the amount is not decreased, and there is a possibility that knocking may occur due to premature ignition.
[0019]
Therefore, in the hybrid vehicle control device, the engine control means delays switching to the fuel injection mode corresponding to the first combustion mode when in the specific state, that is, in a state where the torque assist is not performed. If it is configured to control in this manner, it is possible to suppress the occurrence of the pre-ignition and to prevent the knocking from occurring.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
FIG. 1 is a schematic system block diagram in the present embodiment. The engine 3 is a diesel engine, and a motor 1 (driving force control motor) is connected to a main shaft (crankshaft) via a motor connecting shaft 2. The motor 1 can generate electric power by being reversely driven by the engine 3 while applying rotational driving force to the engine 3 by using electricity as a power source (torque assist). A transmission 4, a propeller shaft 5, a drive shaft 6 and a drive wheel 7 are connected to the engine 3 in this order, and the driving force of the motor 1 and the engine 3 is shifted to an appropriate rotational speed and transmitted to the drive wheel 7.
[0022]
The engine 3 is connected to an intake passage 11 for taking in intake air for combustion into the combustion chamber and an exhaust passage 12 for discharging exhaust gas after combustion. Further, an EGR passage 13 that communicates the intake passage 11 and the exhaust passage 12 is provided, and an EGR valve 14 is provided in the passage. Then, the EGR gas is recirculated to the intake passage 11 by opening the EGR valve 14, and the recirculation amount of the EGR gas is adjusted by controlling the throttle amount of the EGR valve 14 by an ECU 30 described later.
[0023]
Further, an intake throttle valve 15 is provided upstream of the portion of the intake passage 11 where it joins the EGR passage 13. (Intake passage control valve) Is arranged. The intake throttle valve 15 adjusts the amount of air and EGR gas taken into the engine 3 from the intake passage 11, that is, changes the EGR rate. Specifically, when the opening degree of the intake throttle valve 15 is reduced, the amount of air taken into the combustion chamber of the engine 3 from the intake passage 11 is reduced, while the amount of the EGR gas taken in is increased. When the opening of the intake throttle valve 15 is increased, the amount of air taken into the combustion chamber of the engine 3 from the intake passage 11 is increased, while the amount of the EGR gas taken in can be adjusted to decrease. It becomes possible. This adjustment is performed by controlling the intake throttle valve 15 by an ECU 30 described later.
[0024]
An oxidation catalyst 21 is provided downstream of the branch point of the exhaust passage 12 with the EGR passage 13. The oxidation catalyst 21 oxidizes and purifies HC, CO, etc. contained in the exhaust. A temperature sensor 36 that detects the temperature of the exhaust gas flowing into the oxidation catalyst 21 is provided immediately upstream of the oxidation catalyst 21.
[0025]
A DPF 22 (a diesel engine particulate filter) is provided further downstream of the oxidation catalyst 21. The DPF 22 collects and purifies particulate matter that is particulate matter such as soot contained in the exhaust gas. A pressure sensor 37 is provided immediately upstream of the DPF 22 and a pressure sensor 38 is provided immediately downstream of the DPF 22 to detect the exhaust pressure.
[0026]
A battery 32 is connected to the motor 1 via an inverter 31. At the time of torque assist, electric power is supplied from the battery 32 via the inverter 31 so that the motor 1 can obtain a predetermined output. At the time of power generation, the power generated by the motor 1 is charged to the battery 32 via the inverter 31.
[0027]
Further, an accelerator opening sensor 33 that detects the accelerator opening by the operation of the driver is provided.
[0028]
The ECU 30 is a control unit that controls the engine 3, the EGR valve 14, and the intake throttle valve 15, an engine operation state detection unit that detects an operation state of the engine 3, an EGR rate setting unit that sets a target EGR rate, And the function as an engine control means which switches and sets the combustion mode of the engine 3 is provided.
[0029]
The operating state detection means detects the rotational speed of the engine 3 and the accelerator opening detected from the accelerator opening sensor 33.
[0030]
The EGR rate setting means sets a target EGR rate in accordance with the combustion mode set by switching the combustion mode by the engine control means.
[0031]
Further, the engine control means detects the engine detected by the operation state detection means when the exhaust gas in the exhaust passage 12 detected by a temperature sensor 36 described later is equal to or higher than a certain temperature (200 ° C. in the present embodiment). 3 is switched between the premixed combustion mode (first combustion mode) and the diffusion combustion mode (second combustion mode) according to the operation state of No. 3, and when switching from the premixed combustion mode to the diffusion combustion mode. The intake throttle valve 15 is configured to control the EGR rate increasing side from a value corresponding to the target EGR rate set by the EGR rate setting means.
[0032]
The ECU 30 also has a function for controlling the motor 1, and detects that the motor control means for controlling the motor 1 and a specific state in which torque assist to the engine 3 by the motor 1 cannot be performed. It also has a function as a detecting means.
[0033]
The motor control means switches between a state of performing motor assist for the engine 3 and a power generation state generated by the rotation of the engine 3 in accordance with the operation state of the engine 3 detected based on the operation state detection means. In the switching from the diffusion combustion mode to the premixed combustion mode, the motor 1 is controlled so as to perform torque assist so as to absorb the change in the engine output based on the control of the intake throttle valve 15.
[0034]
The ECU 30 receives detection signals from the temperature sensor 36, the pressure sensor 37, the pressure sensor 38, and the accelerator opening sensor 33, as well as the current position, the destination, and the driving environment in the route from the navigation system 34. Information (city area, uphill road, etc.) is input. Based on the engine speed data received from the engine 3 and the detection signal data received from the temperature sensor 36, pressure sensor 37, pressure sensor 38, accelerator opening sensor 33, etc. Control of fuel injection (injection timing, injection amount), EGR valve 14 and intake throttle valve 15 is performed.
[0035]
Furthermore, the ECU 30 controls the motor 1 by inputting voltage and current information between the inverter 31 and the battery 32 and issuing a motor torque command to the inverter 31. If the torque value of the motor torque command is positive, the torque assist state is entered, and if it is negative, the power generation state is entered. When it is zero, it becomes a neutral state (N) that is neither. Hereinafter, such control of the motor 1 is referred to as ISG control.
[0036]
Next, the ISG control at the normal time of this embodiment will be described with reference to FIG. FIG. 2 is a characteristic diagram showing ISG control characteristics, where the horizontal axis represents the accelerator opening and the vertical axis represents the motor torque (output torque of the motor 1). As shown in the figure, when the motor torque is a positive value, torque assist in which driving force is applied from the motor 1 to the engine 3 is performed (assist region). Conversely, when the motor torque is a negative value, power generation is performed in which driving force is applied to the motor 1 from the engine 3 (power generation region). Further, a neutral N region where motor torque = 0, that is, neither power generation nor torque assist is provided. As a general characteristic of ISG control, as shown in the line in FIG. 2, when the accelerator opening is a low opening, a power generation region is formed, and when the accelerator opening is a high opening, an assist region is formed. The N area is set.
[0037]
Hereinafter, the control of the present embodiment will be described with reference to FIGS.
[0038]
FIG. 3 shows a processing procedure for determining the combustion mode of the engine 3 among the engine control means. After the start, in step S11, it is determined from the temperature detected by the temperature sensor 36 that the exhaust temperature before the oxidation catalyst 21 is a predetermined temperature. In the present embodiment, it is determined that the temperature is 200 ° C. or higher. If NO, the diffusion combustion mode is selected in step S21. If YES, in step S13, based on the current engine speed (engine speed) detected by the ECU 30 and the accelerator opening, the diffusion combustion mode (first combustion mode) is selected or premixed It is determined whether the region is a region for selecting a combustion mode (second combustion mode). The determination as to which of the combustion mode regions corresponds is made based on the map of FIG. FIG. 4 is a map for determining the combustion mode from the engine speed and the accelerator opening, and determines that the premixed combustion mode is selected when both the engine speed and the accelerator opening are in the low region. In other parts, it is determined that the region is a region for selecting the diffusion combustion mode. In step S15, it is determined in step S13 whether or not the operating state corresponds to a region for selecting the premixed combustion mode. If YES, the premix combustion mode is selected in step S17, and the process proceeds to step S18. In step S18, it is determined whether or not there is a transition from the diffusion combustion mode to the premixed combustion mode. If this transition has occurred (YES in step S18), a transition command from the diffusion combustion mode to the premixed combustion mode is issued in step S19. If there is no transition (NO in step S18), Do not issue a transition order.
[0039]
If NO in step S15 (if not set to premixed combustion), the diffusion combustion mode is selected in step S21, and the process proceeds to step S22. In step S22, it is determined whether or not there is a transition from the premixed combustion mode to the diffusion combustion mode. If this transition occurs (YES in step S22), a transition command from the premixed combustion mode to the diffusion combustion mode is issued in step S23. If there is no transition (NO in step S22), Do not issue a transition order.
[0040]
Next, control related to switching of the combustion mode will be described with reference to FIG.
[0041]
After the start, it is determined in step S31 whether combustion is currently performed in the diffusion combustion mode. If YES, in step S33, it is determined whether or not there is a command to shift from the diffusion combustion mode to the premixed combustion mode, and if this command is present (in the case of YES), detection means for detecting whether the state is the specific state. (Corresponding to steps S41 to S45) is activated. If there is no command (NO), the combustion mode is not switched, fuel injection and EGR gas are controlled in the diffusion combustion mode in step S61, and further, in S63, the motor 1 corresponding to the operating state is controlled. Control, that is, control of the motor 1 based on the ISG control as described above is performed.
[0042]
The detection means first determines in step S41 whether the remaining battery level is equal to or greater than a predetermined value. If NO, the second control mode is executed in step S51. Details of the second control mode will be described later. If YES, it is determined in step S43 that the battery temperature is equal to or lower than a predetermined value. If NO in step S43, the second control mode is executed in step S51. If YES, it is determined in step S45 that the motor temperature is equal to or lower than a predetermined value. If NO in step S45, a second control mode described later is executed in step S51, and if YES, a first control mode described later is executed in step S47. Details of the first control mode will also be described later.
[0043]
If it is determined in step S31 that the mode is not the diffusion combustion mode, that is, NO, it is determined in step S71 whether or not there is a command to shift from the premix combustion mode to the diffusion combustion mode. If this command is present (in the case of YES), the third control mode is executed. If this command is not present (in the case of NO), fuel injection and EGR gas control in the premixed combustion mode are performed in step S81. In step S83, the motor 1 is controlled according to the operating state, that is, the motor 1 is controlled based on the ISG control as described above. Details of the third control mode will also be described later.
[0044]
Hereinafter, the first control mode to the third control mode will be described with reference to FIGS.
[0045]
FIG. 6 is a diagram showing the first control mode, and the horizontal axis indicates time. The first combustion mode is a control for switching the combustion mode from the diffusion combustion mode to the premixed combustion mode as described above. The first combustion mode is controlled to increase the EGR rate by increasing the target EGR, and from the compression top dead center of the cylinder. Control is performed so that fuel is injected in the middle of the previous compression stroke.
[0046]
In this control, first, the opening of the intake throttle valve 15 is decreased, the opening of the EGR valve 14 is increased to a state corresponding to the target EGR rate, and the opening of the intake throttle valve 15 is decreased.
[0047]
The opening degree of the intake passage control valve 15 is smaller than the opening degree corresponding to the target EGR rate. That is, the intake throttle valve 15 is controlled to increase the EGR rate from the value corresponding to the target EGR rate.
[0048]
When such control is performed, the intake amount of the air amount drops sharply and the EGR rate increases rapidly. On the other hand, the torque of the engine 3 rapidly decreases as the EGR rate increases.
[0049]
Therefore, in order to absorb this torque decrease, the torque of the motor 1 (hereinafter referred to as “motor torque”) is applied to the engine 3 at a higher level to perform torque assist.
[0050]
Then, as the EGR rate increases, the opening degree of the intake throttle valve 15 is gradually increased to set the opening degree of the intake throttle valve 15 corresponding to the target EGR rate. Accordingly, the increase rate of the EGR rate is gradually suppressed, and the EGR rate is controlled so as to gradually approach the target EGR rate.
[0051]
In addition, since the rate of increase in the EGR rate is suppressed and the rate of change in the torque decrease is also suppressed, the occurrence of the torque shock is also suppressed. Therefore, the motor torque is decreased and the torque assist amount is decreased.
[0052]
Further, when the EGR rate becomes the target EGR rate, the fuel injection timing is switched from the mode corresponding to the diffusion combustion mode to the mode corresponding to the premixed combustion mode. That is, the mode is switched from the mode in which fuel is injected near the compression top dead center of the cylinder to the mode in which fuel is injected in the middle of the compression stroke considerably before the compression top dead center of the cylinder.
[0053]
Note that the traveling torque transmitted to the drive wheels 7 through the propeller shaft 5 and the drive shaft 6 slightly decreases with respect to the switching of the combustion mode, but is maintained at a substantially constant value.
[0054]
FIG. 7 is a diagram showing the second control mode, and the horizontal axis indicates time. The second combustion mode is a control for switching the combustion mode from the diffusion combustion mode to the premixed combustion mode when it is detected that the detection means is in a specific state where torque assist by the motor 1 cannot be sufficiently performed.
[0055]
In this control, the intake throttle valve 15 is opened. Degree The opening degree is controlled according to the target EGR rate, and the opening degree is smaller than the opening degree corresponding to the target EGR rate as in the first control mode.
[0056]
That is, the intake throttle valve 15 is controlled to a value corresponding to the target EGR rate. When such control is performed, the increase rate of the EGR rate becomes slower than that in the first control mode, and the torque of the engine 3 is suppressed from rapidly decreasing. Therefore, torque assist is performed with the motor torque applied to the engine 3 being low.
[0057]
Then, the EGR rate converges to the target EGR rate, and the rate of increase of the EGR rate becomes low. Accordingly, the motor torque amount is also reduced.
[0058]
Further, when the EGR rate becomes the target EGR rate, the fuel injection timing is switched from the mode corresponding to the diffusion combustion mode to the mode corresponding to the premixed combustion mode.
[0059]
Note that the switching timing of the combustion injection timing is delayed because the change rate of the EGR rate is slower than that in the first control mode.
[0060]
In addition, the traveling torque is slightly reduced with respect to the switching of the combustion mode as in the first control mode, but is maintained at a substantially constant value.
[0061]
FIG. 8 is a diagram showing the third control mode, and the horizontal axis indicates time. As described above, the first combustion mode is a control for switching the combustion mode from the premixed combustion mode to the diffusion combustion mode. Control is performed so that fuel is injected in the compression stroke in the vicinity.
[0062]
In this control, first, the opening degree of the intake throttle valve 15 is increased, the opening degree of the EGR valve 14 is decreased to a state corresponding to the target EGR rate, and the opening degree of the intake throttle valve 15 is increased. The opening degree of the intake passage control valve 15 is controlled to be an opening degree corresponding to the target EGR rate. In addition, the injection timing is switched to the injection timing corresponding to the diffusion combustion mode simultaneously with the switching of the combustion mode.
[0063]
When such control is performed, the EGR rate decreases, and as the EGR rate decreases, the torque of the engine 3 also increases (not shown), and finally converges to a state where the EGR rate becomes the target EGR rate. To do.
[0064]
Although torque assist by the motor 1 is not illustrated, it is appropriately performed according to the torque assist amount required for the engine 3.
[0065]
As mentioned above, although embodiment of this invention was described, the specific structure of the apparatus of this invention is not limited to the said embodiment, A various change is possible within a claim.
[0066]
For example, in the present embodiment, the engine 3 is a diesel engine, and the corresponding particulate filter is a DPF 22. However, the present embodiment is not limited to a diesel engine, and the engine 3 may be a gasoline engine, and a particulate filter for a gasoline engine may be used instead of the DPF.
[0067]
In addition, the present embodiment is described only when switching from the diffusion combustion mode to the premixed combustion mode, but is not limited to this case. For example, even when the EGR amount is increased while maintaining the state of the diffusion combustion mode, or when only the EGR amount is increased while maintaining the state of the premixed combustion mode, the configuration of this embodiment may be employed. Good. By adopting this configuration, the EGR rate can be increased rapidly, and the generation of substances such as NOx and soot can be reduced.
[0068]
Furthermore, although the oxidation catalyst 21 is provided upstream of the DPF 22 in this embodiment, the oxidation catalyst 21 may not be provided, and the DPF 22 may also have an oxidation catalytic action (oxidation catalyst supporting DPF).
[0069]
【The invention's effect】
As described above, according to the control apparatus for a hybrid vehicle of the present invention, the intake passage control valve sets the target EGR rate set by the EGR rate setting means when switching from the second combustion mode to the first combustion mode. Therefore, the EGR gas is more easily taken in in a larger amount, and the EGR gas can be taken into the intake passage more quickly. Accordingly, it is possible to more quickly switch the recirculation amount of the EGR gas to the engine.
[0070]
Further, the motor control means As a result, the engine torque decreases as the EGR rate increases during the period during which the EGR rate increases. When the driving force control motor is controlled so as to absorb torque, torque assist may be assisted when switching from the second combustion mode to the first combustion mode. It is possible to prevent the torque shock from occurring.
[0071]
Therefore, according to the configuration of the present invention, the amount of EGR gas recirculated to the engine can be switched quickly, and the switching can be performed smoothly by preventing the occurrence of torque shock or the like.
[Brief description of the drawings]
FIG. 1 is a schematic system block diagram of a control apparatus for a hybrid vehicle according to an embodiment of the present invention.
FIG. 2 is a characteristic diagram showing ISG control characteristics of the embodiment.
FIG. 3 is a flowchart showing a control of a portion for determining a combustion mode in the control of the embodiment.
FIG. 4 is a map for determining a combustion mode from an engine speed and an accelerator opening in the embodiment.
FIG. 5 is a flowchart showing control related to switching of a combustion mode in the control of the embodiment.
FIG. 6 is a characteristic diagram showing a state of the first control mode of the embodiment.
FIG. 7 is a characteristic diagram showing a state of the second control mode of the embodiment.
FIG. 8 is a characteristic diagram showing a state of a third control mode of the embodiment.
[Explanation of symbols]
1 Motor (Motor for driving force control)
3 Engine
15 Inlet throttle valve (intake passage control valve)
30 ECU (operating state detection means, EGR rate setting means, engine control means, motor control means, detection means)

Claims (3)

An operating state detecting means for detecting the operating state of the engine;
When the exhaust gas temperature from the engine is equal to or higher than a predetermined temperature, the operating state detection means includes a first combustion mode in which combustion is performed with an increased EGR rate and a second combustion mode in which combustion is performed with a reduced EGR rate. Engine control means for switching according to the detected operating state;
A driving force control motor drivingly connected to the engine;
Motor control means for switching between a power generation state generated by the rotation of the engine and a state of assisting the engine according to the operating state of the engine;
A control device for a hybrid vehicle, comprising: an intake flow control valve provided in the intake passage to change the EGR rate;
EGR rate setting means for setting a target EGR rate according to the combustion mode set by switching the combustion mode by the engine control means ,
When switching from the second combustion mode to the first combustion mode, the intake passage control valve is configured to control the EGR rate increasing side from a value corresponding to the target EGR rate set by the EGR rate setting means. And
When the motor control means switches from the second combustion mode to the first combustion mode, the motor control means is for controlling the driving force so as to absorb a decrease in engine torque accompanying an increase in the EGR rate within a period during which the EGR rate is increasing . A control apparatus for a hybrid vehicle, characterized in that control is performed so that torque assist is performed by a motor. In the hybrid vehicle control device according to claim 1,
Detecting means for detecting that the driving force control motor is in a specific state where only insufficient torque assist can be performed to absorb the decrease in the engine torque ;
A control apparatus for a hybrid vehicle, characterized in that when the driving force control motor is in the specific state, the intake flow control valve is controlled to a value corresponding to the target EGR rate. The control apparatus for a hybrid vehicle according to claim 2,
A control apparatus for a hybrid vehicle, characterized in that, when in the specific state, control is performed so as to delay switching to a fuel injection mode corresponding to the first combustion mode.

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