JP2010179677A - Controller of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of an internal combustion engine capable of suppressing overcharging of a battery by taking influence of engine inertia into consideration, and adequately reducing engine torque. <P>SOLUTION: The controller of the internal combustion engine mounted on a hybrid vehicle has an engine, first and second motor generators, a battery, and a control means. An overcharging prediction means predicts the overcharging of the battery based on the rotational speed of the first motor generator and rotational speed increasing rate of the engine or rotational speed increasing rate of the first motor generator when charging power of the battery is limited. An engine torque reduction means reduces engine torque when the overcharging of the battery is predicted by the overcharging prediction means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine that prevents overcharging of a battery in a hybrid vehicle.

  2. Description of the Related Art Conventionally, a control device for an internal combustion engine that prevents overcharging of a battery in a hybrid vehicle is known. For example, in Patent Document 1, when the charged amount exceeds the first threshold value and is equal to or smaller than the second threshold value that is larger than the first threshold value, the motor torque reduction amount is set to a preset motor rotation speed and motor torque reduction amount. Is set based on a motor characteristic map indicating the above relationship, and a technique for setting a small engine torque reduction amount while effectively preventing overcharging of the power storage device is described. Patent Document 1 also describes a technique for reducing engine torque by performing ignition retard control. In addition, technologies related to the present invention are described in Patent Document 2 and Patent Document 3, respectively.

JP 2002-204506 A JP 2006-104992 A JP 2006-050748 A

  By the way, when the charge amount of the battery is limited, overcharge may occur due to the inertia of the engine rotation even in the normal state. Therefore, in this case, it is necessary to suppress the overcharge of the battery in consideration of the influence of the engine inertia. Patent Documents 1 to 3 do not take into account the above problems.

  The present invention has been made to solve the above-described problems, and it is possible to suppress overcharge of the battery by appropriately reducing the engine torque in consideration of the influence of the engine inertia. An object of the present invention is to provide a control device for an internal combustion engine.

  In one aspect of the present invention, there is provided a control device for an internal combustion engine mounted on a hybrid vehicle, the engine, first and second motor generators, and a battery that charges electric power generated by the first motor generator. And overcharging of the battery is predicted based on the rotation speed of the first motor generator and the engine speed increase rate or the first motor generator rotation speed rate when the charging power of the battery is limited. An overcharge predicting means and an engine torque reducing means for reducing the torque of the engine when the overcharge is predicted are provided.

  The control device for an internal combustion engine is mounted on a hybrid vehicle and includes an engine, first and second motor generators, a battery, and control means. The overcharge predicting means is, for example, an ECU (Electronic Control Unit), and when the charging power of the battery is limited, the rotation speed of the first motor generator and the engine speed increase rate (that is, the engine speed change amount) or the first The overcharge of the battery is predicted based on the rotation speed rate of one motor generator (that is, the amount of change in the rotation speed of the first motor generator). The engine torque reduction means is, for example, an ECU, and reduces the engine torque when overcharge of the battery is predicted by the overcharge prediction means. By doing in this way, the control apparatus of an internal combustion engine can estimate the charge amount of a battery appropriately, and can suppress overcharge.

  In one aspect of the control apparatus for an internal combustion engine, the engine further includes a catalyst installed on an exhaust passage, the engine has a variable valve timing mechanism, and the engine torque reducing means has a temperature of the catalyst of a predetermined temperature. In the following, when the engine oil temperature is equal to or higher than a predetermined oil temperature, the retard control of the ignition timing of the engine and the retard control of the valve timing in the variable valve timing mechanism are used together. The predetermined temperature is set to a range of the catalyst temperature at which the catalyst temperature becomes high due to the ignition retardation and the catalyst does not deteriorate. Further, the predetermined oil temperature is set in the range of the engine oil temperature that can ensure the responsiveness of the variable valve timing mechanism. By doing in this way, the control device of the internal combustion engine can reduce engine torque and suppress overcharge while suppressing responsiveness of the variable valve timing mechanism and suppressing fuel consumption deterioration and catalyst deterioration. it can.

  In another aspect of the control apparatus for an internal combustion engine, the engine torque reduction means may calculate an initial value of the retard amount of the ignition timing and an initial value of the retard amount of the valve timing by the inertia torque of the engine. Set the amount of retardation for each. By doing in this way, the control apparatus of an internal combustion engine can suppress an excessive engine torque fall, preventing an overcharge. That is, the control device for the internal combustion engine can prevent excessive discharge.

The schematic block diagram of the hybrid vehicle which concerns on this embodiment is shown. The schematic block diagram of an engine is shown. An example of the map used when calculating | requiring predetermined value Th4 is shown. It is a figure which shows the setting value of the engine speed increase rate guard value in normal time and in mode 4, respectively. It is a time chart which shows the outline | summary of the process in this embodiment. It is a time chart which shows the outline | summary of the process in a comparative example. 4 is a detailed time chart of mode 1 to mode 3. 6 is a detailed time chart of mode 4. It is a flowchart which shows the process sequence in this embodiment. It is a flowchart which shows the procedure of a mode selection process. 6 is a flowchart showing a processing procedure in mode 1; 6 is a flowchart illustrating a processing procedure in mode 2. 10 is a flowchart showing a processing procedure in mode 3. 10 is a flowchart showing a processing procedure in mode 4. It is a flowchart which shows the process sequence of control execution determination control 1. FIG. It is a flowchart which shows the process sequence of control execution determination control 2. FIG.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Device configuration]
FIG. 1 is a schematic configuration diagram of a hybrid vehicle to which an internal combustion engine control device according to each embodiment of the present invention is applied. Note that broken line arrows in the figure indicate signal input / output.

  Hybrid vehicle 100 mainly includes engine (internal combustion engine) 1, axle 2, drive wheels 3, first motor generator MG 1, second motor generator MG 2, power split mechanism 4, inverter 5, and the like. The battery 6 and the ECU 50 are provided.

  The axle 2 is a part of a power transmission system that transmits the power of the engine 1 and the second motor generator MG2 to the wheels 3. The wheels 3 are wheels of the hybrid vehicle 100, and only the left and right front wheels are particularly shown in FIG. The engine 1 is constituted by a gasoline engine or the like, and functions as a power source that outputs the main driving force of the hybrid vehicle 100. The engine 1 is controlled variously by the ECU 50.

  The first motor generator MG1 is configured to function mainly as a generator for charging the battery 6 or a generator for supplying electric power to the second motor generator MG2. Generate electricity. The first motor generator MG1 functions as a regenerative brake at the time of braking (deceleration), for example, and generates electric power by performing a regenerative motion. The second motor generator MG2 is mainly configured to function as an electric motor that assists (assists) the output of the engine 1.

  Power split device 4 corresponds to a planetary gear (planetary gear mechanism) configured with a sun gear, a ring gear, and the like, and is configured to be able to distribute the output of engine 1 to first motor generator MG1 and axle 2. ing.

  Inverter 5 is a DC / AC converter that controls input / output of electric power between battery 6 and first motor generator MG1 and second motor generator MG2.

  The battery 6 is configured to be capable of functioning as a power source for driving the first motor generator MG1 and / or the second motor generator MG2, and the first motor generator MG1 and / or the second motor. It is a storage battery configured to be able to charge power generated by the generator MG2.

  The ECU 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and performs various controls on each component in the hybrid vehicle 100. In particular, in the present embodiment, the ECU 50 predicts overcharge of the battery 6 and reduces the output torque of the engine 1 in order to suppress the overcharge. Thus, it functions as overcharge prediction means and engine torque reduction means in the present invention.

  Below, after demonstrating schematic structure of the engine 1, the process which ECU50 performs is demonstrated concretely.

[Schematic configuration of the engine]
FIG. 2 is a schematic configuration diagram of the engine 1 shown in FIG. A solid line arrow in the figure shows an example of a gas flow.

  The engine 1 mainly includes an intake passage 11, a throttle valve 12, a fuel injection valve 14a, an intake valve 14b, an ignition plug 14c, an exhaust valve 14d, a variable valve timing mechanism 14e, a cylinder 15a, and a piston. 15c, connecting rod 15d, exhaust passage 16, and catalyst 20. In FIG. 2, only one cylinder 15a is shown for convenience of explanation, but the engine 1 actually has a plurality of cylinders 15a.

  Intake air (air) introduced from outside passes through the intake passage 11, and the throttle valve 12 adjusts the flow rate of intake air passing through the intake passage 11. The opening degree of the throttle valve 12 is controlled by a control signal supplied from the ECU 50. The intake air that has passed through the intake passage 11 is supplied to the combustion chamber 15b. The fuel injected by the fuel injection valve (injector) 14a is supplied to the combustion chamber 15b.

  Further, the combustion chamber 15b is provided with an intake valve 14b and an exhaust valve 14d. The intake valve 14b controls communication / blocking between the intake passage 11 and the combustion chamber 15b by opening and closing. The intake valve 14b is controlled by a variable valve timing mechanism 14e for valve timing (valve opening timing or valve closing timing). For example, the intake valve 14b is switched between an advance angle and a retard angle of the valve timing.

  The variable valve timing mechanism 14e is hydraulic and is controlled by a control signal supplied from the ECU 50. On the other hand, the exhaust valve 14d controls the communication / blocking of the exhaust passage 16 and the combustion chamber 15b by opening and closing. Hereinafter, the variable valve timing mechanism is also expressed as “VVT”.

  In the combustion chamber 15b, the air-fuel mixture of intake air and fuel supplied as described above is burned by being ignited by the spark plug 14c. In this case, the piston 15c reciprocates by combustion, the reciprocating motion is transmitted to the crankshaft (not shown) via the connecting rod 15d, and the crankshaft rotates. Exhaust gas generated by combustion in the combustion chamber 15 b is exhausted from the exhaust passage 16.

  A catalyst 20 is installed on the exhaust passage 16. The catalyst 20 purifies the exhaust gas of the engine 1. The catalyst 20 is, for example, an oxidation catalyst, DPF (Diesel Particulate Filter), or NOx storage reduction catalyst. The ECU 50 calculates an estimated value of the temperature of the catalyst 20 (hereinafter simply referred to as “catalyst temperature estimated value Tb”) based on various sensors.

[Control method]
Next, the control of the ECU 50 in this embodiment will be specifically described. The ECU 50 limits (decreases) the output torque of the engine 1 (hereinafter referred to as “engine torque”) when overcharging of the battery 6 is predicted. At this time, the ECU 50 determines a means for retarding the ignition timing, a means for retarding the valve timing, and a limit value for the engine speed increase rate (hereinafter referred to as “engine speed increase rate”). One or a plurality of means for changing the guard value ReLim ”) is selected and executed. By doing in this way, ECU50 prevents the battery 6 from being overcharged reliably. Hereinafter, a process for selecting a means for reducing the engine torque according to the state of the vehicle 100 (hereinafter referred to as “mode selection”), a process for determining the timing for reducing the engine torque, and an engine torque reduction process will be described. After the description, the time chart of the overall processing and the processing flow in this embodiment will be described in order.

(Mode selection)
First, the mode selection will be specifically described. The ECU 50 performs mode selection based on the estimated catalyst temperature Tb and the oil temperature of the engine 1 (hereinafter simply referred to as “engine oil temperature To”).

  Specifically, the ECU 50 determines that the estimated catalyst temperature Tb is equal to or lower than a predetermined threshold (hereinafter referred to as “predetermined value Th2”), and the engine oil temperature To is a predetermined threshold (hereinafter referred to as “predetermined value Th3”). If it is less than that, the engine torque is reduced by using only means for retarding the ignition timing (retarding the ignition timing). Here, the predetermined value Th2 is set by experiment or the like to the upper limit value of the temperature of the catalyst 20 so that the catalyst temperature becomes high due to the ignition delay and the deterioration of the catalyst 20 does not proceed. The predetermined value Th3 is set by experimentation or the like to the lower limit value of the engine oil temperature To that can ensure the responsiveness of the variable valve timing mechanism 14e. That is, when it is determined that there is no possibility that the catalyst 20 is deteriorated due to the retard of the ignition timing and the engine oil temperature To is at a temperature at which the responsiveness of the variable valve timing mechanism 14e cannot be secured, the ECU 50 sets the ignition timing. The engine torque is reduced using only the retarding means. Hereinafter, this execution pattern is referred to as “mode 1”.

  On the other hand, when the estimated catalyst temperature Tb is equal to or lower than the predetermined value Th2 and the engine oil temperature To is equal to or higher than the predetermined value Th3, the ECU 50 retards the ignition timing and retards the valve timing (VVT retarded). Is used in combination to reduce engine torque. That is, in this case, the ECU 50 has no risk of deterioration of the catalyst 20 due to the retard of the ignition timing, and the engine oil temperature To is at a temperature at which the responsiveness of the variable valve timing mechanism 14e can be ensured. The engine torque is reduced by using both the retard angle and the VVT retard angle. Hereinafter, this execution pattern is referred to as “mode 2”.

  Further, when the estimated catalyst temperature value Tb is larger than the predetermined value Th2 and the engine oil temperature To is equal to or higher than the predetermined value Th3, the ECU 50 reduces the engine torque only by the VVT retardation. That is, in this case, the ECU 50 determines that the catalyst bed temperature may become high due to the retard of the ignition timing and the catalyst 20 may deteriorate, and the engine oil temperature To ensures the responsiveness of the variable valve timing mechanism 14e. Judge that it is at a possible temperature. Therefore, the ECU 50 uses only the VVT retardation. Hereinafter, this case is referred to as “mode 3”.

  On the other hand, when the estimated catalyst temperature value Tb is larger than the predetermined value Th2 and the engine oil temperature To is lower than the predetermined value Th3, the ECU 50 changes the engine speed increase rate guard value ReLim. That is, the ECU 50 determines that the ignition timing retardation or VVT retardation cannot be executed from the detected catalyst temperature estimated value Tb and the engine oil temperature To, and changes the engine speed increase rate guard value ReLim to a smaller value. Then reduce the engine torque. Hereinafter, this case is referred to as “mode 4”.

(Engine torque reduction processing timing)
Next, the timing of the engine torque reduction process will be described. In the case where the charging power limit of the battery 6 (hereinafter referred to as “charging power limit Win”) is provided, the ECU 50 has a charging power for inertia when the actual engine speed is larger than the required engine speed. When the predicted value exceeds the range of the charging power limit Win, the engine torque is reduced. Thereby, ECU50 can prevent overcharge of the battery 6 beforehand. Hereinafter, the control for determining the timing for reducing the engine torque is referred to as “control execution determination control 1”. The control execution determination control 1 is executed in the modes 1 to 3 described above.

  Hereinafter, the control execution determination control 1 will be described more specifically. The ECU 50 first compares the requested engine speed with the actual engine speed when the charging power limit Win is provided. When the actual engine speed is larger than the requested engine speed, it is determined that the battery 6 may be overcharged due to the charging power due to regeneration.

  Further, the ECU 50 predicts the charge power for inertia (hereinafter referred to as “predetermined value”) based on the engine speed increase rate and the rotation speed of the first motor generator MG1 (hereinafter referred to as “MG1 rotation speed”). Called Th4 "). In general, the power for the inertia is obtained from the gain value set by feedback control at the MG1 rotation speed, the change amount of the MG1 rotation speed or the change amount of the engine rotation speed (that is, the engine rotation speed increase rate), and the MG1 rotation speed. Predictable. Therefore, for example, for each gain value described above, a predetermined value Th4 corresponding to the amount of change in the MG1 rotation speed or the engine rotation speed increase rate and the MG1 rotation speed is obtained by experiments or the like to create a map. The ECU 50 holds this map in a memory or the like. Thereby, ECU50 can obtain | require predetermined value Th4 appropriately from the engine speed increase rate acquired from various sensors, and MG1 rotation speed.

  FIG. 3 is an example of a map of a predetermined value Th4 corresponding to the engine speed increase rate and the MG1 speed. In FIG. 3, the MG1 rotational speed corresponds to 1000 to 10,000, and the engine rotational speed increase rate corresponds to 5 to 15. In FIG. 3, the predetermined value Th4 is shown as an absolute value. Thus, by creating a map as shown in FIG. 3 based on experiments and the like, the ECU 50 can appropriately determine the predetermined value Th4.

  Then, the ECU 50 determines whether or not to execute the engine torque reduction process when the actual engine speed is larger than the requested engine speed and the predetermined value Th4 exceeds the range of the charging power limit Win. (Hereinafter referred to as “control execution flag”). Then, the ECU 50 turns off the control execution flag when the engine torque reduction process described later is completed. The control execution flag will be described in detail in the description of the flowchart. By doing as described above, the ECU 50 can appropriately set the timing of the engine torque reduction process.

(Engine torque reduction processing)
Next, engine torque reduction processing executed by the ECU 50 in modes 1 to 4 will be described.

1. Processing in Mode 1 The engine torque reduction processing executed by the ECU 50 in mode 1 will be described. The ECU 50 sets a predetermined ignition retard amount (hereinafter referred to as “initial ignition retard amount Lb0”) as a target set value for ignition retard control (hereinafter referred to as “set ignition retard amount Lb”). To do. The initial ignition retard amount Lb0 is set experimentally or theoretically to, for example, an ignition retard amount corresponding to the inertia of rotation of the engine 1, that is, the inertia torque. By doing in this way, ECU50 can suppress the fall of an excessive engine torque, and can prevent an excessive discharge, preventing an overcharge. When the inertia torque of the engine 1 is “Ie_trq”, the inertia moment of the engine 1 is “Ie”, and the engine speed change amount is “ΔNe”, the inertia torque Ie_trq is calculated using the following equation (1). .

Ie_trq = Ie × ΔNe Formula (1)
Then, the ECU 50 sets the set ignition delay amount Lb until a predetermined time width (hereinafter referred to as “predetermined time width Tw1”) elapses after setting the set ignition delay amount Lb to the initial ignition delay amount Lb0. The initial ignition delay amount Lb0 is fixed. The predetermined time width Tw1 is appropriately set by an experiment or the like, for example. Thereby, an engine torque falls. When the predetermined time width Tw1 has elapsed, the set ignition retardation amount Lb is swept up. That is, the ECU 50 gradually returns the ignition timing to the normal target set value. By doing in this way, ECU50 can reduce an engine torque and can suppress an overcharge.

2. Processing in Mode 2 Next, engine torque reduction processing executed by the ECU 50 in mode 2 will be described. The ECU 50 sets the initial ignition retardation amount Lb0 to the set ignition retardation amount Lb, and sets a predetermined VVT retardation to a target setting value of the VVT retardation amount (hereinafter referred to as “set VVT retardation amount Lv”). An amount (hereinafter referred to as “initial VVT retardation amount Lv0”) is set. The initial VVT retardation amount Lv0 is set experimentally or theoretically to, for example, a VVT retardation amount corresponding to the inertia torque of the engine 1. The inertia torque is calculated by the above equation (1). By doing in this way, ECU50 can suppress the fall of an excessive engine torque, and can prevent an excessive discharge, preventing an overcharge.

  Then, after setting the initial VVT retardation amount Lv0 to the set VVT retardation amount Lv, the ECU 50 fixes this setting until a predetermined time width Tw1 elapses. Further, the ECU 50 fixes this setting until a predetermined time width (hereinafter referred to as “predetermined time width Tw2”) elapses after the set ignition delay amount Lb is set to the initial ignition delay amount Lb0. The predetermined time width Tw2 is set to a time width smaller than the predetermined time width Tw1, and specifically, is set to an appropriate value through experiments or the like. With the above control, the engine torque is reduced. When the predetermined time width Tw2 has elapsed, the ECU 50 sweeps up the set ignition delay amount Lb. That is, the ECU 50 gradually returns the ignition timing to the normal target set value. When the predetermined time width Tw1 has elapsed, the ECU 50 sweeps up the set VVT retardation amount Lv. That is, the ECU 50 gradually returns the valve timing to the normal target set value.

  As described above, the ECU 50 can temporarily reduce the engine torque and suppress overcharge. Further, when the estimated catalyst temperature value Tb is equal to or lower than the predetermined value Th2 and the engine oil temperature To is equal to or higher than the predetermined value Th3, the ECU 50 uses both the ignition delay angle and the VVT delay angle to respond to the VVT response. It is possible to suppress deterioration of fuel consumption and deterioration of the catalyst 20 while securing the property.

3. Processing in Mode 3 Next, engine torque reduction processing executed by the ECU 50 in mode 3 will be described. The ECU 50 sets the initial VVT retardation amount Lv0 as the set VVT retardation amount Lv. Then, after setting the initial VVT retardation amount Lv0 to the set VVT retardation amount Lv, the ECU 50 fixes this setting until a predetermined time width (hereinafter referred to as “predetermined time width Tw3”) elapses. The predetermined time width Tw3 is set to a time width larger than the predetermined time width Tw1 used in mode 1 and the predetermined time width Tw2 used in mode 2, and specifically, is set to an appropriate value through experiments or the like. Thereby, an engine torque falls. When the predetermined time width Tw3 has elapsed, the set VVT retardation amount Lv is swept up. That is, the ECU 50 gradually returns the valve timing to the normal target set value. As described above, the ECU 50 can temporarily reduce the engine torque and suppress overcharge.

4). Processing in Mode 4 Next, engine torque reduction processing executed by the ECU 50 in mode 4 will be described. As described above, in mode 4, the ECU 50 decreases the engine torque by setting the engine speed increase rate guard value ReLim to a small value. This specific example will be described with reference to FIG. FIG. 4 is a diagram showing an engine speed increase rate guard value ReLim for each engine speed. In FIG. 4, the engine speed increase rate guard value ReLim (hereinafter referred to as “set value 1”) in the case of mode 1 to mode 3 and the engine speed increase rate guard value ReLim (hereinafter referred to as “set value 1”) in mode 4. This is referred to as “set value 2”. As shown in FIG. 4, the set value 2 is smaller than the set value 1 when compared at the same engine speed. By doing in this way, ECU50 can reduce an engine torque, even when the means by ignition retard and the means by VVT retard cannot be performed.

(Time chart)
Next, processing executed by the ECU 50 will be described using the time charts shown in FIGS. FIG. 5 is a time chart showing an outline of the processing of the present embodiment.

  FIG. 5 shows, from the top, the accelerator opening, the engine speed, the engine speed increase rate, the ignition timing, the VVT advance amount (VVT position), the torque of the first motor generator MG1 (hereinafter referred to as “MG1 torque”). ), Driving torque, and discharging / charging power of the battery 6 (hereinafter referred to as “battery power”). In FIG. 5, a graph B2 corresponds to a command value for engine speed, a graph B3 corresponds to an actual engine speed, and a graph B4 corresponds to a required engine speed. The graph B6 corresponds to the actual ignition timing, and the graph B7 corresponds to the target value of the ignition timing (that is, the set ignition delay amount Lb). Similarly, the graph B8 corresponds to the actual VVT advance amount, and the graph B9 corresponds to the target value of the VVT advance amount (that is, the set VVT retard amount Lv). Graph B11 corresponds to the required value of drive torque, and graph B12 corresponds to the actual value of drive torque. The graph B13 corresponds to the actual value of the battery power (in particular, the positive value corresponds to the discharge power and the negative value corresponds to the charge power), and the graph B14 limits the discharge power (hereinafter referred to as “discharge power limit Wout”). The graph B15 corresponds to the charging power limit Win.

  First, after the start of the time chart, the accelerator opening gradually increases based on a user operation or the like. Then, the ECU 50 starts the load operation of the engine 1 at a predetermined time t11. Thereby, the required value of engine speed becomes high.

  Then, at a predetermined time t12 after the time t11, the actual engine speed becomes larger than the required engine speed, and the battery power becomes the charging power. At this time, the control execution graph is turned ON. Therefore, after time t <b> 12, the ECU 50 executes any one of modes 1 to 4 depending on the state of the vehicle 100. Detailed timing charts of the engine speed, engine speed increase rate, ignition timing, VVT advance amount, and MG1 torque in each mode will be described later with reference to FIGS. 7 and 8.

  Then, at a predetermined time t13 after the time t12, the process executed in any one of the modes 1 to 4 ends. Accordingly, at this time, the control execution flag is turned OFF. As described above, by reducing the engine torque from time t12 to time t13, the ECU 50 eliminates the deviation between the requested engine torque and the actual engine torque, thereby preventing the occurrence of overcharging.

  Next, a case where the present invention is not applied (hereinafter referred to as “comparative example”) will be described with reference to FIG. FIG. 6 is an example of a time chart in the comparative example.

  FIG. 6 shows, in order from the top, the accelerator opening, the engine speed, the engine speed increase rate, the ignition timing, the VVT advance amount, the MG1 torque, the drive torque, and the battery power. In FIG. 6, a graph C2 corresponds to a command value for engine speed, a graph C3 corresponds to an actual engine speed, and a graph C4 corresponds to a required engine speed. The graph C6 corresponds to the actual ignition timing, and the graph C7 corresponds to the target ignition timing. Similarly, the graph C8 corresponds to the actual VVT advance amount, and the graph C9 corresponds to the target value of the VVT advance amount. The graph C11 corresponds to the required value of the driving torque, and the graph C12 corresponds to the actual value of the driving torque. The graph C13 corresponds to the actual value of the battery power, the graph C14 corresponds to the discharge power limit Wout, and the graph C15 corresponds to the charge power limit Win.

  First, after the start of the time chart, the accelerator opening gradually increases based on a user operation or the like. Then, the ECU 50 starts the load operation of the engine 1 at a predetermined time t21. Thereby, the required value of engine speed becomes high.

  Next, at a predetermined time t22 after time t21, the engine speed increase rate and the required engine speed decrease as the accelerator opening changes, and the MG1 torque decreases by feedback control to compensate for this ( Graph C4, graph C5, graph C10).

  At a predetermined time t23 after time t22, the actual engine speed is larger than the required engine speed (see graphs C3 and C4). Further, at time t23, the negative value of the MG1 torque becomes maximum. Accordingly, overcharge occurs in the battery 6 near time t23 (see graph C13).

  Then, at a predetermined time t24 after time t23, the required engine speed and the actual engine speed are again substantially the same. As a result, the MG1 torque returns by the amount of feedback compensation. At this time, the fluctuation of the MG1 torque due to the feedback control is larger than that shown in FIG. On the other hand, in the present embodiment, the ECU 50 can prevent overcharge by reducing the engine torque according to any one of the modes 1 to 4 according to the state of the vehicle 100.

  Next, detailed processing for modes 1 to 4 will be described with reference to FIGS. FIG. 7 is an example of a detailed time chart for mode 1 to mode 3.

  FIG. 7 shows, in order from the top, the engine speed and MG1 torque common to each mode, the control execution flag and ignition timing in mode 1, the control execution flag and ignition timing, VVT advance amount, and mode in mode 2. The control execution flag and the VVT advance amount in the case of 3 are shown. In FIG. 7, a graph D1 corresponds to a command value for engine speed, a graph D2 corresponds to an actual engine speed, and a graph D3 corresponds to a required engine speed. The graph D4 corresponds to the MG1 torque when any one of the modes 1 to 3 is executed and the feedforward control and the feedback control are performed, and the graph D5 is the feedforward control only. The graph D6 corresponds to the MG1 torque when the feedforward control and the feedback control are performed in the comparative example. Graph D8 corresponds to the actual ignition timing in mode 1, and graph D9 corresponds to the target value of the ignition timing in mode 1. The graph D11 corresponds to the actual ignition timing in mode 2, and the graph D12 corresponds to the target value of the ignition timing in mode 2. A graph D13 shows the actual VVT advance amount in mode 2, and a graph D14 corresponds to the target value of the VVT advance amount. The graph D16 corresponds to the actual VVT advance amount in mode 3, and the graph D17 corresponds to the target value of the VVT advance amount in mode 3.

  First, after starting the time chart, the ECU 50 starts the load operation of the engine 1 at time t11. Thereby, the required value of engine speed becomes high. At time t12, the actual engine speed is greater than the required engine speed, and the battery power is also charged. At this time, the control execution graphs in modes 1 to 3 are turned ON.

  When the control execution graph is ON, in the case of mode 1, the ECU 50 moves the target value of the ignition timing to the retard side by the initial ignition retard amount Lb0 during the predetermined time width Tw1 from the time t12. (See graph D9). As a result, the actual value of the ignition timing also moves to the retard side by the initial ignition retard amount Lb0 (see graph D8).

  Similarly, in mode 2, when the control execution flag is turned ON, the ECU 50 moves the ignition timing target value to the retard side by the initial ignition retard amount Lb0 during the predetermined time width Tw2 from time t12. (See graph D12). At the same time, the ECU 50 moves the target value of the VVT advance amount to the retard side by the initial VVT retard amount Lv0 during the predetermined time width Tw1 (see graph D14).

  In the case of mode 3, during a predetermined time width Tw3 from the predetermined time t11α before the control execution flag is turned ON, the ECU 50 sets the target value of the VVT advance amount to the retard side by the initial VVT retard amount Lv0. Move (see graph D17). Therefore, here, as an example, the ECU 50 changes the target value of the VVT advance amount before the control execution flag is turned ON.

  By executing any one of the processes in modes 1 to 3 described above, after time t12, the fluctuation in MG1 torque is smaller than that in the comparative example due to a decrease in the engine torque for the inertia (graphs D4 and D6). reference). In other words, the engine torque decreases, and the deviation between the required engine speed and the actual engine speed hardly occurs. And the fluctuation | variation of MG1 torque resulting from feedback control is lose | eliminated, and the overcharge of the battery 6 is suppressed. On the other hand, in the case of the comparative example, the MG1 torque fluctuates after time t12 due to the fact that the actual engine speed is larger than the required engine speed (see graph D6). Thereby, overcharge of the battery 6 occurs.

  Next, in mode 1, the ECU 50 fixes the ignition timing target value to the retard side by the initial ignition delay amount Lb0 over a predetermined time width Tw1, and then sets the ignition timing target value to the original ignition timing target value. Sweep up. Similarly, in mode 2, the ECU 50 sweeps up the target value of the ignition timing to the original target value of the ignition timing after the elapse of the predetermined time width Tw2 from time t12, and VVT after the elapse of the predetermined time width Tw1 from time t12. The target value of the retard amount is swept up to the original target value of the VVT retard amount. In mode 3, the ECU 50 sweeps up the target value of the VVT retardation amount to the original target value of the VVT retardation amount after the elapse of the predetermined time width Tw3 from the time t11α.

  Thereafter, at time t13, in any of the modes 1 to 3, the ECU 50 completes the sweep-up of the ignition timing and the VVT advance amount, and sets the control execution flag to OFF.

  As described above, in modes 1 to 3, the ECU 50 can appropriately reduce the engine torque to prevent overcharging. Similar to mode 1 and mode 2, in mode 3, the ECU 50 may move the target value of the VVT advance amount to the retard side by the initial VVT retard amount Lv0 over a predetermined time width Tw3 from time t12. .

  Next, processing in mode 4 will be described with reference to FIG. FIG. 8 is an example of a detailed time chart in mode 4.

  FIG. 8 shows the engine speed, MG1 torque, and engine speed increase rate in order from the top. In FIG. 8, graph E1 corresponds to the required engine speed, graph E2 corresponds to the actual engine speed in the comparative example, and graph E3 corresponds to the command value of the engine speed in the comparative example. The graph E4 corresponds to the actual engine speed in mode 4, and the graph E5 corresponds to the command value for the engine speed in mode 4. Graph E6 corresponds to MG1 torque when mode 4 is executed and feedforward control and feedback control are performed, and graph E7 corresponds to MG1 torque when only feedforward control is performed. Graph E8 corresponds to the engine speed increase rate in mode 4, and graph E9 corresponds to the engine speed increase rate in the comparative example.

  First, after starting the time chart, the ECU 50 starts the load operation of the engine 1 at time t11. At this time, the ECU 50 sets the engine speed increase rate guard value ReLim smaller than usual, for example, according to a map as shown in FIG. Therefore, in the case of mode 4, compared with the comparative example, the engine speed increase rate changes at a low value from time t11 to immediately before time t12.

  At time t12, the requested engine speed decreases with a decrease in the accelerator opening. In the comparative example, the actual engine speed is larger than the required engine speed (see graphs E1 and E2). On the other hand, in mode 4, the actual engine speed has not reached the required engine speed due to a change in the engine speed increase rate guard value or the like.

  At time t12α, in mode 4, the actual engine speed reaches the required engine speed (see graph E4). Accordingly, the ECU 50 reduces the engine speed increase rate (see graph E8). However, even in this case, in the case of mode 4, the inertia torque is reduced because the engine speed increase rate is set to be small. Therefore, the compensation amount by the feedback control of the MG1 torque is also reduced (see graph E6).

  As described above, the ECU 50 can appropriately reduce the engine torque and prevent overcharge even in the mode 4.

(Processing flow)
Next, a processing procedure in the present embodiment will be described. Here, first, the outline of the processing procedure performed by the ECU 50 in the present embodiment will be described, and then the mode selection processing, each of the modes 1 to 4 and the control execution determination control 1 executed in the modes 1 to 3 will be described. Processing will be described in order.

1. Overview FIG. 9 is a flowchart showing an overview of processing in this embodiment. The ECU 50 repeatedly executes the process of the flowchart according to a predetermined cycle, for example.

  First, the ECU 50 sets the engine speed increase rate guard value ReLim to the set value 1 (step S101). That is, as shown in FIG. 4, the ECU 50 sets the engine speed increase rate guard value ReLim to a normal value.

  Next, the ECU 50 starts mode selection control (step S102). This process will be described later with reference to FIG.

  Then, the ECU 50 determines whether or not the mode 1 is set (step S103). That is, the ECU 50 determines whether or not the mode 1 is selected by the mode selection control. When mode 1 is selected (step S103; Yes), the ECU 50 starts mode 1 control (step S106). Mode 1 control will be described later with reference to FIG.

  On the other hand, if it is not mode 1 (step S103; No), the ECU 50 next determines whether or not it is mode 2 (step S104). In the case of mode 2 (step S104; Yes), the ECU 50 starts control of mode 2 (step S107). Mode 2 control will be described later with reference to FIG.

  If it is not mode 2 (step S104; No), the ECU 50 determines whether or not it is mode 3 (step S105). And in the case of mode 3 (step S105; Yes), ECU50 starts control of mode 3 (step S108). Mode 3 control will be described later with reference to FIG.

  Next, when it is not mode 3 (step S105; No), ECU50 starts control of mode 4 (step S109). Mode 4 control will be described later with reference to FIG.

  Thus, the ECU 50 reliably prevents overcharge of the battery 6 by selecting and executing any one of the modes 1 to 4.

2. Mode Selection Next, a process executed by the ECU 50 in the mode selection control in step S102 will be described. FIG. 10 is an example of a flowchart showing the processing procedure of the mode selection process.

  First, the ECU 50 determines whether or not the estimated catalyst temperature value Tb is equal to or less than a predetermined value Th2 (step S201). The predetermined value Th2 is set, for example, to an upper limit value of the temperature at which the catalyst temperature becomes high due to the ignition retard and the deterioration of the catalyst 20 does not progress.

  If the estimated catalyst temperature Tb is equal to or lower than the predetermined value Th2 (step S201; Yes), the ECU 50 next determines whether or not the engine oil temperature To is equal to or higher than the predetermined value Th3 (step S202). For example, the predetermined value Th3 is set to a lower limit value of the temperature at which the responsiveness of the variable valve timing mechanism 14e can be ensured.

  When the engine oil temperature To is equal to or higher than the predetermined value Th3 (step S202; Yes), the ECU 50 sets the mode 2 (step S205). That is, in this case, the ECU 50 determines that both the ignition timing retardation and the VVT retardation can be executed. On the other hand, when the engine oil temperature To is less than the predetermined value Th3 (step S202; No), the ECU 50 sets the mode 1 (step S204). That is, in this case, the ECU 50 determines that the engine oil temperature To has not reached a temperature at which the responsiveness of the variable valve timing mechanism 14e can be ensured, and executes only the retard of the ignition timing.

  On the other hand, when the estimated catalyst temperature Tb is larger than the predetermined value Th2 (step S201; No), the ECU 50 determines whether or not the engine oil temperature To is equal to or higher than the predetermined value Th3 (step S203). When the engine oil temperature To is equal to or higher than the predetermined value Th3 (step S203; Yes), the ECU 50 sets the mode 3 (step S206). That is, in this case, the ECU 50 determines that only the VVT retardation can be executed. On the other hand, when the engine oil temperature To is less than the predetermined value Th3 (step S203; No), the ECU 50 sets the mode 4 (step S207). That is, in this case, the ECU 50 determines that both the retard of the ignition timing and the VVT retard cannot be executed.

  Thus, the ECU 50 can appropriately set a means for reducing the engine torque according to the state of the vehicle 100 based on the estimated catalyst temperature Tb and the engine oil temperature To.

3. Processing in Mode 1 Next, processing executed by the ECU 50 in the mode 1 control in step S106 will be described. FIG. 11 is an example of a flowchart illustrating a processing procedure in mode 1.

  First, the ECU 50 executes the control execution determination control 1 (step S301). Details of this processing will be described later with reference to FIG.

  Next, the ECU 50 determines whether or not the control execution flag is ON (step S302). The control execution flag is switched ON and OFF in the control execution determination control 1.

  If the control execution flag is ON (step S302; Yes), the ECU 50 determines whether or not the control execution flag has been turned ON this time (step S303). That is, the ECU 50 determines whether or not the control execution flag is OFF when the previous flowchart is executed, and whether or not the control execution flag is turned ON when the current flowchart is executed. On the other hand, when the control execution flag is not ON (step S302; No), the ECU 50 ends the process of the flowchart.

  Next, when it is determined in the process of step S303 that the control execution flag has been turned on this time (step S303; Yes), the ECU 50 sets an initial ignition retard amount Lb0 and a predetermined time width Tw1 ( Step S304). On the other hand, when it is determined from the previous process that the control execution flag is ON (step S303), the ECU 50 proceeds to step S305 without executing the process of step S304.

  Then, the ECU 50 determines whether or not the predetermined time width Tw1 has elapsed after execution of the control (step S305). That is, in this case, the ECU 50 determines whether or not the predetermined time width Tw1 has elapsed after the process of step S304. If it is determined that the predetermined time width Tw1 has elapsed after execution of the control (step S305; Yes), the ECU 50 advances the process to step S308.

  On the other hand, after the control, when the predetermined time width Tw1 has not elapsed (step S305; No), the ECU 50 sets the initial ignition retardation amount Lb0 to the set ignition retardation amount Lb (step S306). Then, the ECU 50 performs ignition delay control based on the set ignition delay amount Lb (step S307). Thereby, ECU50 can reduce an engine torque.

  Then, the ECU 50 sweeps up the set ignition retard amount Lb after the elapse of the predetermined time width Tw1 (step S308). That is, the ECU 50 gradually shifts the set ignition retard amount Lb to the advance side.

  Then, the ECU 50 determines whether or not the set ignition retardation amount Lb has become zero (step S309). Thus, ECU 50 determines whether or not the ignition timing has returned to the state before step S306 is executed.

  When the set ignition delay amount Lb becomes zero (step S309; Yes), the ECU 50 sets the control execution flag to OFF (step S310). On the other hand, when the set ignition delay amount Lb is not zero (step S309; No), the ECU 50 performs the ignition delay control based on the set ignition delay amount Lb (step S307).

  As described above, when the estimated catalyst temperature value Tb is equal to or lower than the predetermined value Th2 and the engine oil temperature To is lower than the predetermined value Th3, the ECU 50 controls the ignition timing to reduce the engine torque. Overcharge can be suppressed.

4). Mode 2 Processing Next, processing executed by the ECU 50 in the mode 2 control in step S107 will be described. FIG. 12 is an example of a flowchart illustrating a processing procedure in mode 2. Note that the processing from step S401 to step S403 is the same as that from step S301 to step S303 in FIG.

  When the ECU 50 determines that the control execution flag has been turned ON this time (step S403; Yes), the ECU 50 sets the initial ignition retardation amount Lb0, the initial VVT retardation amount Lv0, and the predetermined time widths Tw1 and Tw2, respectively. (Step S404). At this time, the predetermined time width Tw1 is set to a value larger than the predetermined time width Tw2.

  Then, the ECU 50 determines whether or not the predetermined time width Tw2 has elapsed after execution of the control (step S405). That is, the ECU 50 determines whether or not the predetermined time width Tw2 has elapsed after the process of step S404. Then, after the control is executed, when the predetermined time width Tw2 has elapsed (step S405; Yes), the process proceeds to step S408.

  On the other hand, when the predetermined time width Tw2 has not elapsed after execution of the control (step S405; No), the ECU 50 sets the initial ignition retard amount Lb0 to the set ignition retard amount Lb (step S406). Then, the ECU 50 performs ignition delay control based on the set ignition delay amount Lb (step S407). Thereby, ECU50 can reduce an engine torque.

  Next, the ECU 50 sweeps up the set ignition retard amount Lb (step S408). Then, the ECU 50 determines whether or not the set ignition retardation amount Lb has become zero (step S409). When the set ignition delay amount Lb becomes zero (step S409; Yes), the ECU 50 advances the process to step S410. On the other hand, if it is determined that the set ignition delay amount Lb is not zero (step S409; No), the ECU 50 continues to execute the ignition delay control based on the set ignition delay amount Lb in step S407.

  Next, the ECU 50 determines whether or not the predetermined time width Tw1 has elapsed after execution of the control (step S410). Then, after the control is executed, when the predetermined time width Tw1 has elapsed (step S410; Yes), the ECU 50 advances the process to step S413.

  On the other hand, if the predetermined time width Tw1 has not elapsed after execution of the control (step S410; No), the ECU 50 sets the initial VVT retardation amount Lv0 to the set VVT retardation amount Lv (step S411). Then, the ECU 50 performs VVT retardation control based on the set VVT retardation amount Lv (step S412). Thereby, ECU50 can reduce an engine torque.

  Next, the ECU 50 sweeps up the set VVT retardation amount Lv when the predetermined time width Tw1 has elapsed after execution of control (step S413). When the set VVT retardation amount Lv becomes zero (step S414; Yes), the ECU 50 sets the control execution flag to OFF (step S415). On the other hand, when the set VVT retard amount Lv is not zero (step S414; No), that is, when the set VVT retard amount Lv is being swept up, the ECU 50 continuously performs VVT based on the set VVT retard amount Lv. Delay angle control is performed (step S412).

  Thus, the ECU 50 reduces the engine torque by controlling the ignition timing and the valve timing when the estimated catalyst temperature Tb is equal to or lower than the predetermined value Th2 and the engine oil temperature To is equal to or higher than the predetermined value Th3. And overcharging of the battery 6 can be suppressed.

5). Processing in Mode 3 Next, processing executed by the ECU 50 in the mode 3 control in step S108 will be described. FIG. 13 is an example of a flowchart illustrating a processing procedure in mode 3. Note that the processing from step S501 to step S503 is the same as that from step S301 to step S303 in FIG.

  When the ECU 50 determines that the control execution flag has been turned ON this time (step S503; Yes), the ECU 50 sets an initial VVT retardation amount Lv0 and a predetermined time width Tw3 (step S504). At this time, the predetermined time width Tw3 is set to a value larger than the predetermined time width Tw1 and the predetermined time width Tw2.

  Next, the ECU 50 determines whether or not the predetermined time width Tw3 has elapsed after executing the control (step S505). If the predetermined time width Tw3 has elapsed (step S505; Yes), the ECU 50 advances the process to step S508.

  On the other hand, when the predetermined time width Tw3 has not elapsed (step S505; No), the ECU 50 sets the initial VVT retardation amount Lv0 to the set VVT retardation amount Lv (step S506). Then, the ECU 50 performs VVT retardation control based on the set VVT retardation amount Lv (step S507). Thereby, ECU50 can reduce an engine torque.

  Next, the ECU 50 sweeps up the set VVT retardation amount Lv when the predetermined time width Tw3 has elapsed after execution of the control (step S508).

  When the set VVT retardation amount Lv becomes zero (step S509; Yes), the control execution flag is set to OFF (step S310). On the other hand, when it is determined that the set VVT retard amount Lv is not zero (step S509; No), that is, when the set VVT retard amount Lv is being swept up, the ECU 50 continues to the set VVT retard amount Lv. Based on this, VVT retardation control is performed (step S507).

  As described above, when the estimated catalyst temperature value Tb is larger than the predetermined value Th2 and the engine oil temperature To is equal to or higher than the predetermined value Th3, the ECU 50 controls the valve timing to reduce the engine torque, and the battery 6 overcharge can be suppressed.

6). Processing in Mode 4 Next, processing executed by the ECU 50 in mode 4 control in step S109 will be described. FIG. 14 is an example of a flowchart illustrating a processing procedure in mode 4.

  The ECU 50 sets the engine speed increase rate guard value ReLim to the set value 2 (step S601). That is, as shown in FIG. 4, the ECU 50 sets the engine speed increase rate guard value ReLim to a value smaller than the set value 1 that is a normal value. Also by this, ECU50 can suppress the fluctuation | variation of MG1 torque resulting from feedback control.

  As described above, when the estimated catalyst temperature value Tb is larger than the predetermined value Th2 and the engine oil temperature To is lower than the predetermined value Th3, the ECU 50 limits the engine speed increase rate so that the excess of the battery 6 is exceeded. Charging can be suppressed.

7). Processing of Control Execution Determination Control 1 Next, processing of control execution determination control 1 will be described. FIG. 15 is an example of a flowchart of a processing procedure executed by the ECU 50 in the control execution determination control 1. The ECU 50 executes the processing of this flowchart in step S301, step S401, and step S501, respectively.

  First, the ECU 50 determines whether or not the actual engine speed is greater than the requested engine speed and the charge allowable power Win is greater than a predetermined value Th4 (step S701). The predetermined value Th4 is calculated based on, for example, a map of the engine speed increase rate and the MG1 speed as shown in FIG. Thereby, the ECU 50 predicts occurrence of overcharge of the battery 6.

  If the actual engine speed is larger than the required engine speed and the charging power limit Win is larger than the predetermined value Th4 (step S701; Yes), the ECU 50 next turns off the previous value of the control execution flag. It is determined whether or not (step S702). If the previous value of the control execution flag is OFF (step S702; Yes), the ECU 50 sets the control start flag to ON (step S703). Thus, the engine torque reduction process is executed in any one of modes 1 to 3.

  On the other hand, if the actual engine speed is equal to or less than the required engine speed or the charging power limit Win is equal to or less than the predetermined value Th4 (step S701; No), the ECU 50 determines that there is no possibility of overcharging and changes the control flag. do not do. Similarly, when the previous value of the control execution flag is already ON (step S702; No), the ECU 50 determines that the engine torque reduction process is being executed in any one of modes 1 to 3, and changes the control start flag. do not do.

  By doing as described above, the ECU 50 can appropriately predict the occurrence of overcharging and suppress unnecessary engine torque reduction processing when there is no risk of overcharging.

[Modification]
In the above description, in the modes 1 to 3, the ECU 50 executes the engine torque reduction process when the actual engine speed is larger than the required engine speed and the charging power limit Win is larger than the predetermined value Th4. . That is, the ECU 50 controls the timing of the engine torque reduction process by executing the control execution determination control 1. However, the method to which the present invention is applicable is not limited to this. Instead, the ECU 50 has a change in the required engine speed (hereinafter referred to as “Δ request Ne”) smaller than a predetermined value (hereinafter referred to as “predetermined value Th5”) and the charging power limit Win. Is larger than the predetermined value Th4 and the value obtained by subtracting the actual engine speed from the required engine speed is smaller than a predetermined value (hereinafter referred to as “predetermined value Th6”), engine torque reduction processing is executed. May be. The predetermined value Th5 and the predetermined value Th6 are respectively set to appropriate values through experiments or the like. This also allows the ECU 50 to execute the engine torque reduction process at an appropriate timing. Hereinafter, this control is referred to as “control execution determination control 2”.

  The control execution determination control 2 will be further described with reference to a flowchart. FIG. 16 is an example of a flowchart of a processing procedure executed by the ECU 50 in the control execution determination control 2. The ECU 50 executes the processing of this flowchart in step S401, step S501, and step S601, respectively.

  First, the ECU 50 determines whether the Δ request Ne is smaller than the predetermined value Th5, the charging power limit Win is larger than the predetermined value Th4, and a value obtained by subtracting the actual engine speed from the required engine speed is smaller than the predetermined value Th6. Determination is made (step S801). If Δ request Ne is smaller than predetermined value Th5, charging power limit Win is larger than predetermined value Th4, and a value obtained by subtracting actual engine speed from required engine speed is smaller than predetermined value Th6 (step S801; Yes). The ECU 50 determines whether or not the previous value of the control execution flag is OFF (step S802).

  Then, if the previous value of the control execution flag is OFF (step S802; Yes), the ECU 50 sets the control start flag to ON (step S803). Thus, the engine torque reduction process is executed in any one of modes 1 to 3.

  On the other hand, if Δ request Ne is equal to or greater than predetermined value Th5, charge power limit Win is equal to or smaller than predetermined value Th4, or a value obtained by subtracting the actual engine speed from the required engine speed is equal to or greater than predetermined value Th6 (step S801; No The ECU 50 determines that there is no risk of overcharging and does not change the control flag. Similarly, when the previous value of the control execution flag is already ON (step S802; No), the ECU 50 determines that the engine torque reduction process is being executed in any one of modes 1 to 3, and changes the control start flag. do not do.

  As described above, the ECU 50 can appropriately predict the occurrence of overcharge and suppress unnecessary engine torque reduction processing when there is no risk of overcharge.

1 engine (internal combustion engine)
3 Drive Wheel 4 Power Dividing Mechanism 5 Inverter 6 Battery 12 Throttle Valve 14b Intake Valve 14d Exhaust Valve 14e Variable Valve Timing Mechanism 50 ECU
MG1 first motor generator MG2 second motor generator 100 hybrid vehicle

Claims (3)

A control device for an internal combustion engine mounted on a hybrid vehicle,
Engine,
First and second motor generators;
A battery for charging electric power generated by the first motor generator;
Overcharge that predicts overcharge of the battery based on the rotation speed of the first motor generator and the engine speed increase rate or the first motor generator rotation speed rate when the charging power of the battery is limited Prediction means,
When the overcharge is predicted, engine torque reduction means for reducing the torque of the engine;
The control apparatus for an internal combustion engine according to claim 1, comprising: A catalyst installed on the exhaust passage;
The engine has a variable valve timing mechanism,
When the temperature of the catalyst is equal to or lower than the predetermined temperature and the engine oil temperature is equal to or higher than the predetermined oil temperature, the engine torque reduction means controls the retard of the ignition timing of the engine and the valve timing in the variable valve timing mechanism. 2. The control device for an internal combustion engine according to claim 1, wherein the retard angle control is used in combination.   The engine torque reducing means sets the initial value of the retard amount of the ignition timing and the initial value of the retard amount of the valve timing to the retard amount corresponding to the inertia torque of the engine, respectively. The internal combustion engine control device described.

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