JP2023166125A - Control device for vehicle - Google Patents

Abstract

To perform regeneration processing of a filter when a drive force of an internal combustion engine is small.SOLUTION: A control device for a vehicle can perform second regeneration processing which regenerates a filter by combusting particulate substances, on a condition that an amount of accumulated particulate substances on the filter is equal to or larger than a preset regulation value. Torque applied to a crankshaft by a first motor generator is defined as motor torque. Torque generated by the combustion of fuel in a cylinder of an internal combustion engine is defined as combustion torque. Minimum torque at which the internal combustion engine can autonomously continue operation is defined as maintenance torque. In the second regeneration processing, the first motor generator and the internal combustion engine are controlled so that a sum of the motor torque and the combustion torque is equal to or greater than the maintenance torque, and that the combustion torque is less than the maintenance torque.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle control device.

The internal combustion engine of Patent Document 1 includes a cylinder, a fuel injection valve, a spark plug, an exhaust passage, a three-way catalyst, a filter, and a crankshaft. A cylinder is a space in which fuel is combusted. The fuel injection valve supplies fuel into the cylinder. A spark plug ignites fuel in a cylinder by spark discharge. The exhaust passage is connected to the cylinder. Exhaust gas from the cylinders is exhausted to the outside through an exhaust passage. A three-way catalyst is located within the exhaust passage. A three-way catalyst purifies hydrocarbons, carbon monoxide, and nitrogen oxides in the exhaust. The filter is located downstream of the three-way catalyst in the exhaust passage. The filter collects particulate matter contained in the exhaust gas. The crankshaft rotates based on the combustion of fuel within the cylinder.

The control device for an internal combustion engine disclosed in Patent Document 1 executes filter regeneration processing on the condition that the amount of particulate matter deposited on the filter is equal to or greater than a predetermined value. In this regeneration process, the control device retards the ignition timing of the spark plug and increases the target value of the rotational speed of the crankshaft. By retarding the ignition timing, the temperature of the exhaust gas flowing into the exhaust passage increases. Furthermore, by increasing the rotational speed of the crankshaft, the flow rate of gas passing through the cylinders and the exhaust passage increases. This makes it easier for oxygen and unburned fuel contained in the exhaust to reach the filter without being burned in the three-way catalyst. As a result, the particulate matter burns together with the fuel in the filter, thereby regenerating the filter.

Japanese Patent Application Publication No. 2018-127130

In a control device such as that disclosed in Patent Document 1, the driving force of the internal combustion engine needs to be large to some extent in order to perform filter regeneration processing. That is, in the control device as disclosed in Patent Document 1, the operating conditions of the internal combustion engine for regenerating the filter are limited. In particular, with the control device as disclosed in Patent Document 1, the filter regeneration process cannot be performed when the driving force of the internal combustion engine is small.

A vehicle control device for solving the above problems includes a cylinder which is a space in which fuel is combusted, a fuel injection valve for supplying fuel into the cylinder, an exhaust passage connected to the cylinder, and a position located within the exhaust passage. a three-way catalyst to purify the exhaust gas; a filter located downstream from the three-way catalyst in the exhaust passage to collect particulate matter contained in the exhaust gas; and a filter to clean the exhaust gas in the cylinder. A control device applied to a vehicle comprising an internal combustion engine having a crankshaft that rotates based on the engine, and a motor generator connected to the crankshaft and capable of applying torque to the crankshaft, the control device comprising: It is possible to perform a regeneration process of regenerating the filter by burning the particulate matter, provided that the amount of accumulated particulate matter on the filter is equal to or higher than a predetermined value, and the motor generator The torque applied to the crankshaft is defined as motor torque, the torque generated by combustion of fuel within the cylinder is defined as combustion torque, and the minimum torque that allows the internal combustion engine to continue operating independently is defined as maintenance torque. In the regeneration process, the motor generator and the internal combustion engine are controlled such that the sum of the motor torque and the combustion torque is equal to or greater than the maintenance torque, and the combustion torque is less than the maintenance torque. do.

According to the above configuration, compared to the case where the combustion torque is the same as the maintenance torque, the amount of intake air and the amount of fuel introduced into the cylinder are smaller, so the combustion speed of the fuel in the cylinder tends to be extremely low. . Therefore, unburned fuel and unconsumed oxygen flow from the cylinder to the exhaust passage. When the fuel reaches the three-way catalyst, the fuel burns in the three-way catalyst, increasing the temperature of the exhaust gas. These high-temperature exhaust gases reach the filter, and particulate matter deposited on the filter is also burned, thereby regenerating the filter. The situation in which the combustion torque is less than the maintenance torque is achieved by the motor generator applying motor torque to the crankshaft. Therefore, even in a situation where the sum of the motor torque and the combustion torque is close to the maintenance torque, that is, when the driving force of the internal combustion engine is small, the regeneration process can be executed.

FIG. 1 is a schematic configuration diagram of a vehicle. 3 is a flowchart showing combustion switching control.

<Schematic configuration of vehicle>
An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. First, the schematic configuration of vehicle 100 will be described.

As shown in FIG. 1, a vehicle 100 includes a spark ignition internal combustion engine 10. Vehicle 100 also includes a first motor generator 71 and a second motor generator 72 that have both the functions of an electric motor and a generator. Therefore, vehicle 100 is a so-called hybrid vehicle.

The internal combustion engine 10 includes a plurality of cylinders 11, a crankshaft 12, an intake passage 21, a throttle valve 22, a plurality of fuel injection valves 23, a plurality of ignition devices 24, an exhaust passage 26, a three-way catalyst 27, and a filter 28. There is.

The cylinder 11 is a space for burning a mixture of fuel and intake air. Internal combustion engine 10 includes four cylinders 11. In this specification, when the four cylinders 11 are collectively described, they are simply referred to as the cylinder 11, and when the four cylinders 11 are separately described, they are referred to as the first cylinder 11A, the second cylinder 11B, the third cylinder 11C, and the fourth cylinder 11D. Further, the crankshaft 12 is connected to a piston (not shown) located within each cylinder 11. The crankshaft 12 rotates due to combustion of a mixture of fuel and intake air in the cylinder 11 .

The intake passage 21 is connected to the cylinder 11. A portion of the intake passage 21 including the downstream end branches into four parts. Each branched passage is connected to each cylinder 11. The intake passage 21 introduces intake air into each cylinder 11 from the outside of the internal combustion engine 10 . Note that an intake valve (not shown) is located at a connection point between the intake passage 21 and each cylinder 11. The intake valve opens and closes a connection point between the intake passage 21 and the cylinder 11. The throttle valve 22 is located on the upstream side of the intake passage 21 when viewed from the branched portion. The throttle valve 22 adjusts the amount of intake air flowing through the intake passage 21.

The fuel injection valve 23 is located near the downstream end of the intake passage 21. The internal combustion engine 10 includes four fuel injection valves 23 corresponding to the four cylinders 11. The fuel injection valve 23 injects fuel supplied from a not-shown fuel tank into the intake passage 21. As a result, fuel from the fuel injection valve 23 is supplied to the cylinder 11. The ignition device 24 is located in the cylinder 11. The internal combustion engine 10 includes four ignition devices 24 corresponding to the four cylinders 11. The ignition device 24 ignites the mixture of fuel and intake air by spark discharge. Note that the four ignition devices 24 ignite the first cylinder 11A, the third cylinder 11C, the fourth cylinder 11D, and the second cylinder 11B in this order. In other words, the four cylinders 11 undergo a combustion stroke in the order of the first cylinder 11A, the third cylinder 11C, the fourth cylinder 11D, and the second cylinder 11B.

The exhaust passage 26 is connected to the cylinder 11. A portion of the exhaust passage 26 including the upstream end branches into four parts. Each branched passage is connected to each cylinder 11. The exhaust passage 26 discharges exhaust gas from each cylinder 11 to the outside of the internal combustion engine 10. Note that an exhaust valve (not shown) is located at a connection point between the exhaust passage 26 and each cylinder 11. The exhaust valve opens and closes the connection between the exhaust passage 26 and the cylinder 11.

The three-way catalyst 27 is located on the downstream side of the exhaust passage 26 when viewed from the branched portion. The three-way catalyst 27 purifies the exhaust gas flowing through the exhaust passage 26. Specifically, the three-way catalyst 27 purifies hydrocarbons, carbon monoxide, and nitrogen oxides in the exhaust gas. The filter 28 is located downstream of the three-way catalyst 27 in the exhaust passage 26 . The filter 28 collects particulate matter contained in the exhaust gas flowing through the exhaust passage 26.

The vehicle 100 includes a first planetary gear mechanism 40, a ring gear shaft 45, a second planetary gear mechanism 50, a speed reduction mechanism 62, a differential mechanism 63, and a plurality of drive wheels 64.
The first planetary gear mechanism 40 includes a sun gear 41, a ring gear 42, a plurality of pinion gears 43, and a carrier 44. Sun gear 41 is an external gear. Sun gear 41 is connected to first motor generator 71 . Ring gear 42 is an internal gear, and is located coaxially with sun gear 41. Each pinion gear 43 is located between sun gear 41 and ring gear 42. Each pinion gear 43 meshes with both the sun gear 41 and the ring gear 42. The carrier 44 supports the pinion gear 43. The pinion gear 43 can rotate on its own axis, and can also revolve by rotating together with the carrier 44. The carrier 44 is connected to the crankshaft 12.

Ring gear shaft 45 is connected to ring gear 42 . Further, the ring gear shaft 45 is connected to a drive wheel 64 via a speed reduction mechanism 62 and a differential mechanism 63. The reduction mechanism 62 reduces the rotational speed of the ring gear shaft 45 and outputs the reduced rotation speed. The differential mechanism 63 allows a difference in rotational speed to occur between the left and right drive wheels 64.

The second planetary gear mechanism 50 includes a sun gear 51, a ring gear 52, a plurality of pinion gears 53, a carrier 54, and a case 55. Sun gear 51 is an external gear. Sun gear 51 is connected to second motor generator 72 . Ring gear 52 is an internal gear and is located coaxially with sun gear 51. Ring gear 52 is connected to ring gear shaft 45. Each pinion gear 53 is located between sun gear 51 and ring gear 52. Each pinion gear 53 meshes with both the sun gear 51 and the ring gear 52. The carrier 54 supports the pinion gear 53. The pinion gear 53 is rotatable. Carrier 54 is fixed to case 55. Therefore, the pinion gear 53 is in a state where it cannot revolve.

Vehicle 100 includes a battery 75, a first inverter 76, and a second inverter 77. Battery 75 is a secondary battery. The first inverter 76 performs AC/DC power conversion between the first motor generator 71 and the battery 75. Further, the first inverter 76 adjusts the amount of power exchanged between the first motor generator 71 and the battery 75. The second inverter 77 performs AC/DC power conversion between the second motor generator 72 and the battery 75. The second inverter 77 adjusts the amount of power transferred between the second motor generator 72 and the battery 75.

The vehicle 100 includes an air flow meter 81 , a water temperature sensor 82 , an intake temperature sensor 83 , a crank angle sensor 84 , an accelerator operation amount sensor 85 , and a vehicle speed sensor 86 .
The air flow meter 81 detects an intake air amount GA, which is the amount of intake air flowing through the intake passage 21 per unit time. The water temperature sensor 82 detects the cooling water temperature THW, which is the temperature of the cooling water flowing through each part of the internal combustion engine 10 . The intake air temperature sensor 83 detects the intake air temperature THA, which is the temperature of intake air flowing through the intake passage 21 . The crank angle sensor 84 detects a crank angle SC, which is the rotational position of the crankshaft 12. The accelerator operation amount sensor 85 detects the accelerator operation amount ACC, which is the operation amount of the accelerator pedal operated by the driver. Vehicle speed sensor 86 detects vehicle speed SP, which is the speed of vehicle 100.

Vehicle 100 includes a control device 90. The control device 90 acquires a signal indicating the intake air amount GA from the air flow meter 81. The control device 90 acquires a signal indicating the cooling water temperature THW from the water temperature sensor 82. The control device 90 acquires a signal indicating the intake temperature THA from the intake temperature sensor 83. The control device 90 acquires a signal indicating the crank angle SC from the crank angle sensor 84. The control device 90 acquires a signal indicating the accelerator operation amount ACC from the accelerator operation amount sensor 85. Control device 90 acquires a signal indicating vehicle speed SP from vehicle speed sensor 86.

Control device 90 calculates vehicle required driving force, which is a required value of driving force necessary for vehicle 100 to travel, based on accelerator operation amount ACC and vehicle speed SP. Control device 90 determines torque distribution among internal combustion engine 10, first motor generator 71, and second motor generator 72 based on the vehicle required driving force. The control device 90 controls the output of the internal combustion engine 10 and the power running and regeneration of the first motor generator 71 and the second motor generator 72 based on the torque distribution of the internal combustion engine 10 , the first motor generator 71 , and the second motor generator 72 . and control. Specifically, the control device 90 controls the opening degree of the throttle valve 22, the amount of fuel injection from the fuel injection valve 23, the ignition timing of the ignition device 24, etc. by outputting a control signal to the internal combustion engine 10. Further, control device 90 controls first motor generator 71 via first inverter 76 by outputting a control signal to first inverter 76 . Furthermore, control device 90 controls second motor generator 72 via second inverter 77 by outputting a control signal to second inverter 77 .

Furthermore, when the vehicle 100 is traveling, the control device 90 selects either the EV mode or the HV mode as the traveling mode of the vehicle 100. Here, the EV mode is a driving mode in which the vehicle 100 is driven by driving one or more motor generators selected from the first motor generator 71 and the second motor generator 72 while stopping the internal combustion engine 10. Therefore, in the EV mode, the vehicle 100 is driven by the driving force of the first motor generator 71 and the driving force of the second motor generator 72. Further, the HV mode is a driving mode of the vehicle 100 in which the vehicle 100 is driven by driving the internal combustion engine 10 in addition to the first motor generator 71 and the second motor generator 72. Therefore, in the HV mode, the vehicle 100 is driven by the driving force of the internal combustion engine 10 in addition to the driving force of the first motor generator 71 and the second motor generator 72.

For example, the control device 90 selects the EV mode when there is a sufficient margin in the charging rate of the battery 75 and the above-mentioned required vehicle driving force is small. Examples of the vehicle required driving force being small include when the vehicle 100 starts, when the vehicle 100 is running under a light load with low acceleration, and the like. On the other hand, the control device 90 selects the HV mode, for example, when there is not enough margin in the charging rate of the battery 75.

The control device 90 calculates the engine rotational speed NE, which is the number of rotations of the crankshaft 12 per unit time, based on the crank angle SC. The control device 90 calculates the engine load factor KL based on the engine rotational speed NE and the intake air amount GA. Here, the engine load factor KL is the ratio of the current amount of cylinder inflow air to the cylinder inflow air amount when the internal combustion engine 10 is operated steadily with the throttle valve 22 fully open at the current engine speed NE. represents. Note that the cylinder inflow air amount is the amount of intake air that flows into each cylinder 11 during the intake stroke.

The control device 90 calculates the catalyst temperature TSC, which is the temperature of the three-way catalyst 27, based on the operating state of the internal combustion engine 10, such as the intake air filling efficiency and the engine rotational speed NE. Note that the intake air filling efficiency is a value obtained by dividing the mass of intake air actually introduced into the cylinder 11 from the intake passage 21 by the mass of intake air that can be introduced into the cylinder 11 under standard atmospheric conditions. Further, the control device 90 calculates the filter temperature TF, which is the temperature of the filter 28, based on the operating state of the internal combustion engine 10, such as the intake air filling efficiency and the engine rotational speed NE. The control device 90 calculates the amount of particulate matter deposited on the filter 28 per unit time based on the engine rotation speed NE, the engine load factor KL, and the filter temperature TF. Then, the control device 90 calculates the PM deposition amount PS, which is the amount of particulate matter deposited on the filter 28, by integrating the amount of particulate matter deposited on the filter 28 per unit time.

Note that the control device 90 may be configured as a circuit including one or more processors that execute various processes according to computer programs (software). Note that the control device 90 is configured as a circuit that includes one or more dedicated hardware circuits such as an application-specific integrated circuit (ASIC), or a combination thereof, that executes at least some of the various processes. You can. The processor includes a CPU and memory such as RAM and ROM. The memory stores program codes or instructions configured to cause the CPU to perform processes. Memory or computer-readable media includes any media that can be accessed by a general purpose or special purpose computer.

<Combustion switching control>
Next, combustion switching control performed by the control device 90 will be explained. Control device 90 repeatedly executes combustion switching control when HV mode is selected as the driving mode of vehicle 100.

As shown in FIG. 2, when the control device 90 starts combustion switching control, it proceeds to step S11. In step S11, the control device 90 determines whether the PM deposition amount PS is less than a predetermined value A. Here, the specified value A is a threshold value for determining whether regeneration of the filter 28 is necessary. The specified value A is predetermined, for example, as a design value of particulate matter for which it is determined that the filter 28 needs to be regenerated. When the control device 90 determines that the PM accumulation amount PS is less than the specified value A (S11: YES), the control device 90 advances the process to step S21.

In step S21, the control device 90 executes normal operation processing. In this normal operation process, the internal combustion engine 10 is controlled so that the amount of fuel consumed by the internal combustion engine 10 is minimized with respect to the output of the internal combustion engine 10 per unit time. In this control, the control device 90 controls the internal combustion engine 10 with reference to a predetermined map. The above map shows the combination of the engine rotational speed NE and the torque of the internal combustion engine 10 that minimizes the consumed fuel when the output of the internal combustion engine 10 is a certain level. When referring to the above map, the combination of the above engine rotational speed NE and the torque of the internal combustion engine 10 is determined in advance through experiments or the like. Then, the control device 90 stores the combination of the determined engine rotational speed NE and the torque of the internal combustion engine 10 as a map. Note that in the normal operation process, the internal combustion engine 10 is driven by supplying fuel to all four cylinders 11. After that, the control device 90 ends the current combustion switching control and advances the process to step S11 again.

On the other hand, when the control device 90 determines that the PM accumulation amount PS is equal to or greater than the specified value A (S11: NO), the control device 90 advances the process to step S12.
In step S12, the control device 90 determines whether the vehicle required driving force is equal to or greater than a predetermined value B. Here, an example of the predetermined value B is a value smaller than the maximum value of the driving force that can be realized by the first motor generator 71 and the second motor generator 72 by a certain value. Note that this constant value is a value secured in order to supplement the torque of the internal combustion engine 10 in a second regeneration process to be described later. When the control device 90 determines that the vehicle requested driving force is equal to or greater than the predetermined value B (S12: YES), the control device 90 advances the process to step S31.

In step S31, the control device 90 executes a first reproduction process. This first regeneration process is one of the processes for regenerating the filter 28. Here, a series of processes in which the four cylinders 11 undergo a combustion stroke once each, that is, a period in which the crankshaft 12 rotates twice is called one combustion cycle. In the first regeneration process, the control device 90 stops fuel supply to one of the four cylinders 11 in one combustion cycle. On the other hand, the control device 90 supplies fuel to the remaining three. At this time, the control device 90 sets the air-fuel ratio of the cylinder 11 to which fuel is supplied to be lower than the stoichiometric air-fuel ratio AFS, that is, 14.7. The control device 90 repeats stopping fuel supply to one cylinder 11 and supplying fuel to three cylinders 11 in a plurality of consecutive combustion cycles. Furthermore, the control device 90 opens and closes the intake valves and exhaust valves corresponding to the four cylinders 11 in the first regeneration process. Therefore, in the first regeneration process, a stop pattern is executed in which fuel supply to one cylinder 11 is stopped and intake air is circulated from the cylinder 11 to the exhaust passage 26. After execution of the stop pattern, a combustion pattern is executed in which fuel is continuously supplied to the three cylinders 11 in the order of the cylinders 11 undergoing a combustion stroke, and exhaust gas is caused to flow from the cylinders 11 to the exhaust passage 26. Moreover, these stop patterns and combustion patterns are repeated.

In the first regeneration process, an example of the cylinder 11 to which fuel supply is stopped is the third cylinder 11C. Further, in the first regeneration process, examples of the cylinders 11 to which fuel is supplied are the first cylinder 11A, the second cylinder 11B, and the fourth cylinder 11D.

Here, the torque generated by combustion of fuel within the cylinder 11 is defined as combustion torque. Specifically, the combustion torque is the average value of the torque generated in the crankshaft 12 due to the combustion of fuel within the four cylinders 11 in one combustion cycle. Furthermore, the minimum torque that allows the internal combustion engine 10 to continue operating independently is defined as the maintenance torque. In the first regeneration process, the control device 90 controls the internal combustion engine 10 so that the combustion torque becomes equal to or higher than the maintenance torque. That is, in the first regeneration process, the internal combustion engine 10 is operating independently.

In addition, in the first regeneration process, the control device 90 controls the first motor generator 71 and the second motor generator 72 to compensate for the insufficient driving force of the vehicle 100 due to the stoppage of combustion of the air-fuel mixture in the third cylinder 11C. Control. After step S31, the control device 90 ends the current combustion switching control and advances the process to step S11 again.

On the other hand, if the control device 90 determines that the vehicle requested driving force is less than the predetermined value B (S12: NO), the control device 90 advances the process to step S41.
In step S41, the control device 90 executes a second reproduction process. This second regeneration process is one of the processes for regenerating the filter 28. Here, the torque applied to the crankshaft 12 by the first motor generator 71 and the second motor generator 72 is defined as motor torque. In the second regeneration process, the control device 90 controls the first motor generator 71 and the second motor so that the sum of the motor torque and the combustion torque is greater than or equal to the maintenance torque, and the combustion torque is less than the maintenance torque. The generator 72 and the internal combustion engine 10 are controlled.

Specifically, in controlling the internal combustion engine 10, the process of supplying fuel to the four cylinders 11 is repeated in a plurality of consecutive combustion cycles. Further, the control device 90 opens and closes intake valves and exhaust valves corresponding to the four cylinders 11. Therefore, in the second regeneration process, fuel is supplied to the four cylinders 11 while exhaust gas is caused to flow from the cylinders 11 to the exhaust passage 26 . Furthermore, in the second regeneration process, the air-fuel ratio of the cylinder 11 is approximately the same as the stoichiometric air-fuel ratio AFS. However, the control device 90 controls the throttle valve 22 so that the amount of intake air introduced into the cylinder 11 in the second regeneration process is smaller than the minimum amount of intake air that can be introduced into the cylinder 11 in the normal operation process. Control. Further, the control device 90 determines that the amount of fuel supplied from the fuel injection valve 23 to the cylinder 11 in the second regeneration process is the minimum amount of fuel that can be supplied from the fuel injection valve 23 to the cylinder 11 in the normal operation process. The fuel injection valve 23 is controlled so that the amount of fuel is reduced compared to the amount of fuel. As a result, the combustion torque becomes less than the maintenance torque.

Further, the control device 90 controls the first motor generator 71 and the second motor generator 72 so as to compensate for the reduced combustion torque in the second regeneration process. As a result, the torques of the first motor generator 71 and the second motor generator 72 are applied to the crankshaft 12, so that the sum of the motor torque and the combustion torque becomes greater than or equal to the maintenance torque.

In addition, in the second regeneration process, the control device 90 controls the first motor generator 71 and the second motor generator 72 to compensate for the insufficient driving force of the vehicle 100 due to the reduction in combustion torque. . After step S41, the control device 90 ends the current combustion switching control and advances the process to step S11 again.

<Action of this embodiment>
In the vehicle 100, the first regeneration process is executed when the PM accumulation amount PS is equal to or greater than the specified value A and the vehicle required driving force is relatively large. When the first regeneration process is executed in this manner, the fuel that has not been completely burned in the cylinder 11 to which fuel is supplied and the oxygen that has passed through the cylinder 11 to which fuel supply is stopped flow to the exhaust passage 26. Then, the fuel burns in the three-way catalyst 27, increasing the temperature of the exhaust gas. When the high-temperature exhaust gas reaches the filter 28, the particulate matter deposited on the filter 28 is also burned, thereby regenerating the filter 28.

Further, in the vehicle 100, the second regeneration process is executed when the PM accumulation amount PS is equal to or greater than the specified value A and the vehicle required driving force is relatively small. In this second regeneration process, the sum of the motor torque and the combustion torque is greater than or equal to the maintenance torque, and the combustion torque is less than the maintenance torque. At this time, since the sum of the motor torque and the combustion torque is equal to or greater than the maintenance torque, the rotation of the crankshaft 12 of the internal combustion engine 10 does not stop even if the combustion torque is less than the maintenance torque. Furthermore, since the combustion torque is less than the maintenance torque, the amount of intake air and the amount of fuel introduced into the cylinder 11 are smaller than when the combustion torque is the same as the maintenance torque. Then, since the pressure inside the cylinder 11 decreases at the top dead center of the compression stroke, the combustion speed of the fuel inside the cylinder 11 tends to become extremely low during the combustion stroke. Then, the unburned fuel and the unconsumed oxygen flow from the cylinder 11 to the exhaust passage 26. When the fuel and oxygen reach the three-way catalyst 27 in this way, the fuel is combusted in the three-way catalyst 27, thereby increasing the temperature of the exhaust gas. When the high-temperature exhaust gas reaches the filter 28, the particulate matter deposited on the filter 28 is also burned, thereby regenerating the filter 28.

<Effects of this embodiment>
(1) In the second regeneration process, the first motor generator 71 and the second motor generator 72 apply torque to the crankshaft 12 to achieve a situation in which the combustion torque is less than the maintenance torque. Here, since the operating state of the internal combustion engine 10 would normally become unstable, the control device 90 sets the fuel injection amount and the opening degree of the throttle valve 22 so that the combustion torque is less than the maintenance torque. It is prohibited to do so. On the other hand, in this embodiment, the control device 90 cancels the above-mentioned prohibition and creates a situation where the combustion torque is less than the maintenance torque while using the first motor generator 71 and the second motor generator 72. Therefore, according to the second regeneration process, it is possible to regenerate the filter 28 even when the driving force of the internal combustion engine 10 is small.

(2) In the first regeneration process, the control device 90 controls the internal combustion engine 10 so that the combustion torque becomes equal to or higher than the maintenance torque. Therefore, according to the first regeneration process, it is possible to regenerate the filter 28 when the driving force of the internal combustion engine 10 is greater than that in the second regeneration process. Therefore, in this embodiment, the filter 28 can be regenerated over a wide range of the driving force of the internal combustion engine 10 by the first regeneration process and the second regeneration process.

(3) In the first regeneration process, there are cylinders 11 to which fuel supply is stopped and cylinders 11 to which fuel supply is performed. In such a first regeneration process, the torque generated by combustion of fuel in the cylinders 11 varies among the cylinders 11.

In this regard, in the second regeneration process, fuel is supplied to four cylinders 11, and the air-fuel ratio of each cylinder 11 is approximately the same as the stoichiometric air-fuel ratio AFS. Therefore, in the second regeneration process, for example, compared to the first regeneration process, it is possible to suppress variations in the torque generated by combustion of fuel in the cylinders 11 between the cylinders 11.

(4) In the vehicle 100, the second regeneration process is executed on the condition that the vehicle requested driving force is less than the predetermined value B. The predetermined value B is a value smaller than the maximum value of the driving force that can be realized by the first motor generator 71 and the second motor generator 72 by a certain value. Therefore, in a situation where the second regeneration process is executed, the driving force of the vehicle 100 that is insufficient due to the reduction in the combustion torque of the internal combustion engine 10 is replaced by the first motor generator 71 and the second motor generator 72. It is possible to supplement with driving force. As a result, even in a situation where the driving force of the internal combustion engine 10 decreases when executing the second regeneration process, it is possible to prevent the actual driving force of the vehicle 100 from becoming smaller than the vehicle required driving force.

(5) When the amount of intake air introduced into the cylinder 11 decreases as in the second regeneration process, the air-fuel ratio of the cylinder 11 is adjusted taking into account that the combustion speed of the fuel in the cylinder 11 tends to decrease. It is conceivable to make the air-fuel ratio lower than the stoichiometric air-fuel ratio AFS, that is, to increase the amount of fuel relative to the amount of air. The reason for this is that in the above case, even if the combustion speed of the fuel in the cylinder 11 becomes low due to a decrease in the pressure in the cylinder 11 at the top dead center of the compression stroke, the air-fuel ratio of the cylinder 11 is reduced to the stoichiometric This is because by setting the fuel ratio lower than AFS, the combustion speed of the fuel in the cylinder 11 can be increased. In other words, even if the combustion torque becomes small due to a decrease in the pressure inside the cylinder 11 at the top dead center of the compression stroke, the combustion torque can be reduced by making the air-fuel ratio of the cylinder 11 lower than the stoichiometric air-fuel ratio AFS. This is because it is possible to increase the

In this respect, in the second regeneration process, the air-fuel ratio of the cylinder 11 is approximately the same as the stoichiometric air-fuel ratio AFS. As a result, the amount of fuel consumed by the internal combustion engine 10 can be suppressed from increasing, compared to, for example, the case where the air-fuel ratio of the cylinder 11 is lower than the stoichiometric air-fuel ratio AFS. Note that even during the second regeneration process, the sum of the motor torque and the combustion torque is greater than or equal to the maintenance torque. Therefore, even if the combustion torque is small, there is little risk that the internal combustion engine 10 will stop.

<Example of change>
This embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- In the above embodiment, the first regeneration process of combustion switching control may be changed.
For example, in the first regeneration process, the cylinder 11 whose fuel supply is stopped is not limited to the third cylinder 11C, but may be any one of the first cylinder 11A, the second cylinder 11B, and the fourth cylinder 11D. Good too. Furthermore, the cylinders 11 to which fuel supply is stopped and the cylinders 11 to which fuel supply is performed may be changed for each combustion cycle.

- For example, in the first regeneration process, if the number of cylinders 11 to which fuel supply is stopped and the number of cylinders 11 to which fuel supply is performed are each one or more, the number of cylinders 11 to which fuel supply is stopped and the number of cylinders to which fuel supply is performed. The number 11 may be changed. Furthermore, the number of cylinders 11 to which fuel supply is stopped and the number of cylinders 11 to which fuel supply is performed may be changed for each combustion cycle. Therefore, the first reproduction process may be a process having the following contents. Here, "M" and "N" are integers of 1 or more. In the first regeneration process, the stop pattern and the combustion pattern may be alternately repeated while the internal combustion engine 10 continues to operate. Here, the stop pattern is a pattern in which intake air is caused to flow from the cylinders 11 to the exhaust passage 26 while stopping the fuel supply to M cylinders 11 in succession in the order of the cylinders 11 that undergo a combustion stroke. Further, the combustion pattern is a pattern in which fuel is supplied to N cylinders 11 in succession in the order of the cylinders 11 that undergo a combustion stroke, and exhaust gas is caused to flow from the cylinders 11 to the exhaust passage 26. Note that the total value of M and N does not need to match the total number of cylinders 11. Furthermore, if the total value of M and N does not match the total number of cylinders 11, the cylinders 11 to which fuel supply is stopped and the cylinders 11 to which fuel supply is performed are changed for each combustion cycle, or in some combustion cycles, There may be cases where there is no cylinder 11 to which fuel supply is to be stopped.

- For example, in the first regeneration process, there may be no cylinder 11 to which fuel supply is to be stopped. As a specific example, in the first regeneration process, the control device 90 controls the internal combustion engine 10 so as to supply fuel to the four cylinders 11 and make the air-fuel ratio of one cylinder 11 lower than the stoichiometric air-fuel ratio AFS. control. On the other hand, the control device 90 may control the internal combustion engine 10 to make the air-fuel ratios of the remaining three cylinders 11 higher than the stoichiometric air-fuel ratio AFS. Note that the above processing is called dither control processing or the like.

- Instead of the above-mentioned first reproduction process, other reproduction processes may be executed. For example, in a situation where the crankshaft 12 is rotating, a so-called fuel introduction process may be executed, in which fuel is supplied to each cylinder 11 but the fuel is not ignited. In this case as well, the unburned fuel and oxygen reach the three-way catalyst 27, so that the fuel is combusted in the three-way catalyst 27. Then, when the exhaust gas from the three-way catalyst 27 to the filter 28 reaches a high temperature, particulate matter is combusted in the filter 28. Note that if the exhaust gas from the three-way catalyst 27 to the filter 28 is sufficiently high temperature, only oxygen is supplied to the filter 28 by executing a fuel cut process that stops the supply of fuel to each cylinder 11. You can.

- In the above embodiment, the first regeneration process of combustion switching control may be omitted. Even if the first regeneration process is omitted in this way, the filter 28 can be regenerated by executing the second regeneration process.

- In the above embodiment, the process of step S12 of combustion switching control may be changed. For example, the predetermined value B may be set regardless of the maximum value of the driving force that can be realized by the first motor generator 71 and the second motor generator 72. Even in this case, if it is acceptable for the actual driving force of the vehicle 100 to be smaller than the vehicle required driving force when executing the second regeneration process in step S41, the predetermined value B may be set as described above. There is no problem with changing it.

- In the above embodiment, the second regeneration process of combustion switching control may be changed.
For example, in the second regeneration process, the air-fuel ratio of the cylinder 11 may be lower or higher than the stoichiometric air-fuel ratio AFS.

- For example, when executing the second regeneration process, if it is acceptable for the actual driving force of the vehicle 100 to be smaller than the vehicle requested driving force, the first motor generator 71 is configured to compensate for the driving force of the vehicle 100. Also, it is not necessary to control the second motor generator 72.

- In the above embodiment, the configuration of the vehicle 100 may be changed.
For example, the internal combustion engine 10 may include two or three cylinders 11, or may include five or more cylinders 11.

- For example, the number of motor generators included in vehicle 100 may be changed. That is, the present technique can be adopted as long as the vehicle 100 is equipped with a motor generator capable of applying torque to the crankshaft 12 of the internal combustion engine 10.

10... Internal combustion engine 11... Cylinder 12... Crankshaft 21... Intake passage 22... Throttle valve 23... Fuel injection valve 24... Ignition device 26... Exhaust passage 27... Three-way catalyst 28... Filter 40... First planetary gear mechanism 50... First 2 Planetary gear mechanism 62... Reduction mechanism 63... Differential mechanism 64... Drive wheel 71... First motor generator 72... Second motor generator 75... Battery 76... First inverter 77... Second inverter 81... Air flow meter 82... Water temperature sensor 83...Intake temperature sensor 84...Crank angle sensor 85...Accelerator operation amount sensor 86...Vehicle speed sensor 90...Control device 100...Vehicle

Claims (1)

A cylinder which is a space in which fuel is combusted, a fuel injection valve for supplying fuel into the cylinder, an exhaust passage connected to the cylinder, a three-way catalyst located in the exhaust passage to purify exhaust gas, and the exhaust passage. an internal combustion engine, comprising: a filter located on the downstream side as viewed from a three-way catalyst in the cylinder to collect particulate matter contained in the exhaust; and a crankshaft that rotates based on combustion of fuel in the cylinder;
a motor generator connected to the crankshaft and capable of applying torque to the crankshaft;
A control device applied to a vehicle equipped with a
It is possible to perform a regeneration process of regenerating the filter by burning the particulate matter, provided that the amount of particulate matter deposited on the filter is equal to or higher than a predetermined value,
The torque that the motor generator applies to the crankshaft is defined as motor torque, the torque generated by combustion of fuel within the cylinder is defined as combustion torque, and the minimum torque that allows the internal combustion engine to continue operating independently is defined as motor torque. When maintaining torque,
In the regeneration process, the motor generator and the internal combustion engine are controlled such that the sum of the motor torque and the combustion torque is greater than or equal to the maintenance torque, and the combustion torque is less than the maintenance torque. control device.

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