Control device of vehicle

Abstract

To suppress a feeling of strangeness from being given to an occupant.SOLUTION: A control device of a vehicle, which controls an engine, a first motor and a second motor, executes air-fuel ratio lean control by which an air-fuel ratio of the engine is leaned, when at least one of a first condition that fuel cut of the engine is permitted, a second condition that the fuel cut of the engine is prohibited and motoring of the engine by the first motor is not required and a third condition that fuel cut of the engine is prohibited and vehicle speed is above predetermined vehicle speed is satisfied, in a case where a temperature of a filter is above a predetermined temperature. This can suppress a feeling of strangeness from being given to an occupant.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a control device for a vehicle. [Background technology]

[0002] Conventionally, a vehicle control device of this type has been proposed for use in a vehicle equipped with an engine having a filter attached to the exhaust system for removing particulate matter, and an automatic transmission (see, for example, Patent Document 1). This device cuts off the engine fuel supply when the engine is decelerating and the temperature correlation value of the lubricating oil of the automatic transmission is higher than a judgment value. When the amount of particulate matter deposited on the filter exceeds a first accumulation amount, the judgment value is made smaller than the value before the accumulation amount exceeded the first accumulation amount. This increases the opportunities for fuel cut and therefore the opportunities for filter regeneration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-148097 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned vehicle control device, when the filter temperature reaches or exceeds a predetermined temperature during filter regeneration, the fuel cut is prohibited and the engine fuel injection is performed. At this time, depending on the operating condition of the engine, an abnormal noise may be generated, causing discomfort to the passengers.

[0005] The main objective of the vehicle control device disclosed herein is to suppress any discomfort felt by the occupants. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] A first vehicle control device according to the present disclosure includes: A vehicle control device for use in a vehicle including an engine having an exhaust system equipped with a filter for removing particulate matter, a first motor, a planetary gear having three rotating elements connected to the engine, the first motor, and a drive shaft connected to an axle, a second motor connected to the drive shaft, and an electricity storage device for exchanging electricity with the first and second motors, the vehicle control device comprising: When the temperature of the filter is equal to or higher than a predetermined temperature, and at least one of a first condition permitting fuel cut of the engine, a second condition prohibiting fuel cut of the engine and no request for motoring of the engine by the first motor, and a third condition prohibiting fuel cut of the engine and the vehicle speed is equal to or higher than a predetermined vehicle speed, a lean air-fuel ratio control is executed to make the air-fuel ratio of the engine lean. The gist of the present invention is as follows.

[0008] In the first vehicle control device of the present disclosure, the motoring request may be made when a maximum allowable input power that may be input to the power storage device is less than a predetermined power. In this case, the lean air-fuel ratio control may prohibit a fuel cut of the engine when the temperature of the filter is equal to or higher than the predetermined temperature, and when the motoring request is made and the vehicle is decelerating, control the first motor so that the engine speed becomes a predetermined speed at which no abnormal noise occurs, and control the air-fuel ratio of the engine to be lean.

[0009] A second vehicle control device according to the present disclosure includes: A vehicle control device is used in a vehicle including an engine having an exhaust system equipped with a filter for removing particulate matter and a motor capable of motoring the engine, the vehicle control device controlling the engine and the motor, When the temperature of the filter is equal to or higher than a predetermined temperature, and when performing lean air-fuel ratio control to make the air-fuel ratio of the engine lean, the motor is controlled so that the rotational speed of the engine becomes a predetermined rotational speed that is a rotational speed of the engine at which no abnormal noise occurs. The gist of the present invention is as follows.

[0010] In the second vehicle control device of the present disclosure, the predetermined rotation speed may be a lower limit rotation speed of a predetermined range of rotation speeds of the engine that is set in advance as a range of rotation speeds within which no abnormal noise occurs. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a vehicle control device according to the present embodiment. [Diagram 2] FIG. 2 is a diagram showing an outline of the configuration of an engine 22. [Diagram 3] 11 is a flowchart showing an example of a high temperature processing routine executed by the HVECI 70. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with a vehicle control device of the present embodiment. FIG. 2 is a schematic diagram showing the configuration of an engine 22. As shown in FIG. 1, the hybrid vehicle 20 of the present embodiment includes the engine 22, an engine electronic control unit (hereinafter referred to as "engine ECU") 24, a planetary gear 30, motors MG1 and MG2 (first and second motors), a motor electronic control unit (hereinafter referred to as "motor ECU") 40, inverters 41 and 42, a battery 50 as an electricity storage device, and a hybrid electronic control unit (hereinafter referred to as HVECU) 70. Here, the engine ECU 24, the motor ECU 40, and the HVECU 70 correspond to the vehicle control device.

[0013] The engine 22 is configured as a four-cylinder internal combustion engine that uses fuel such as gasoline or diesel and outputs power through four strokes: intake, compression, expansion (explosive combustion), and exhaust. As shown in FIG. 2, the engine 22 has a port injection valve 126 that injects fuel into an intake port, and an in-cylinder injection valve 127 that injects fuel into a cylinder. The engine 22 can be operated in any one of a port injection mode, an in-cylinder injection mode, and a common injection mode by having the port injection valve 126 and the in-cylinder injection valve 127. In the port injection mode, air cleaned by the air cleaner 122 is sucked into the intake pipe 123 and passes through the throttle valve 124 and the surge tank 125, and fuel is injected from the port injection valve 126 downstream of the surge tank 125 of the intake pipe 123, and the air and fuel are mixed. This mixture is then drawn into the combustion chamber 129 via the intake valve 128, where it is explosively combusted by an electric spark from the spark plug 130, and the reciprocating motion of the piston 132, which is pushed down in the cylinder bore 131 by the energy of the mixture, is converted into the rotational motion of the crankshaft 23. In the in-cylinder injection mode, air is drawn into the combustion chamber 129 in the same manner as in the port injection mode, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and compression stroke, and is explosively combusted by an electric spark from the spark plug 130, to obtain the rotational motion of the crankshaft 23. In the shared injection mode, fuel is injected from the port injection valve 126 when air is drawn into the combustion chamber 129, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and compression stroke, and is explosively combusted by an electric spark from the spark plug 130, to obtain the rotational motion of the crankshaft 23. These injection modes are switched based on the operating state of the engine 22. Exhaust discharged from the combustion chamber 129 to an exhaust pipe 134 via an exhaust valve 133 is discharged into the outside air via an exhaust system purification device 135 and a PM filter 136. The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components in the exhaust such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The PM filter 136 is formed as a porous filter from ceramics, stainless steel, or the like, and collects particulate matter (PM) such as soot in the exhaust.Instead of the PM filter 136, a four-way catalyst that combines the purification function of a three-way catalyst with the function of trapping particulate matter may be used.

[0014] The operation of the engine 22 is controlled by an engine ECU 24. Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, a flash memory for storing and holding data, an input / output port, and a communication port.

[0015] Signals from various sensors required for controlling the operation of the engine 22 are input to the engine ECU 24 via an input port. Examples of signals input to the engine ECU 24 include a crank angle θcr from a crank position sensor 140 that detects the rotational position of the crankshaft 23 of the engine 22, and a coolant temperature Tw from a water temperature sensor 142 that detects the temperature of the coolant for the engine 22. Other examples of signals input to the engine ECU 24 include cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes the intake valve 128 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 133. Other examples of the pressure sensor include a throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, an intake air amount Qa from an air flow meter 123a attached upstream of the throttle valve 124 of the intake pipe 123, an intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 of the intake pipe 123, and a surge pressure Ps from a pressure sensor 125a attached to a surge tank 125. Other examples of the pressure sensor include a front air-fuel ratio AF1 from a front air-fuel ratio sensor 137 attached upstream of the purification device 135 of the exhaust pipe 134, a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 138 attached downstream of the purification device 135 of the exhaust pipe 134, and a differential pressure ΔP from a differential pressure sensor 136a that detects a differential pressure before and after the PM filter 136 (a differential pressure between the upstream side and the downstream side).

[0016] From the engine ECU 24, various control signals for controlling the operation of the engine 22 are output via an output port. Examples of signals output from the engine ECU 24 include a control signal to the throttle valve 124, a control signal to the port injection valve 126, a control signal to the in-cylinder injection valve 127, and a control signal to the ignition plug 130.

[0017] The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates a load factor (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) KL based on the intake air amount Qa from the air flow meter 123a and the rotation speed Ne of the engine 22. Furthermore, the engine ECU 24 calculates a PM accumulation amount Qpm as the accumulation amount of particulate matter accumulated on the PM filter 136 based on a differential pressure ΔP from the differential pressure sensor 136a, and calculates a filter temperature Tf as the temperature of the PM filter 136 based on the rotation speed Ne of the engine 22 and the load factor KL.

[0018] As shown in Fig. 1, the planetary gear 30 is configured as a single pinion type planetary gear mechanism. A rotor of a motor MG1 is connected to a sun gear of the planetary gear 30. A drive shaft 36 that is connected to drive wheels 39a, 39b via a differential gear 38 is connected to a ring gear of the planetary gear 30. A crankshaft 23 of the engine 22 is connected to a carrier of the planetary gear 30 via a damper 28.

[0019] The motor MG1 is configured as, for example, a synchronous generator motor, and as described above, its rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured as, for example, a synchronous generator motor, and its rotor is connected to the drive shaft 36. The inverters 41, 42 are used to drive the motors MG1, MG2, and are connected to the battery 50 via a power line 54. The motors MG1, MG2 are rotationally driven by the motor ECU 40 controlling the switching of a plurality of switching elements (not shown) of the inverters 41, 42.

[0020] Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, a flash memory for storing and holding data, an input / output port, and a communication port. Signals from various sensors required for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input port. Examples of signals input to the motor ECU 40 include the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from a rotational position sensor (not shown) that detects the rotational positions of the rotors of the motors MG1 and MG2, and the phase currents Iu1, Iv1, Iu2, and Iv2 of the motors MG1 and MG2 from a current sensor (not shown) that detects the phase currents flowing through the phases of the motors MG1 and MG2. The motor ECU 40 outputs switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the electrical angles θe1, θe2 and rotation speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position sensors.

[0021] The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel-hydrogen secondary battery, and as described above, is connected to the inverters 41, 42 via the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as the "battery ECU") 52.

[0022] Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing a processing program, a RAM for temporarily storing data, a flash memory for storing and holding data, an input / output port, and a communication port. Signals from various sensors required for managing the battery 50 are input to the battery ECU 52 via an input port. Examples of signals input to the battery ECU 52 include the voltage Vb of the battery 50 from a voltage sensor (not shown) attached between the terminals of the battery 50, the current Ib of the battery 50 from a current sensor (not shown) attached to the output terminal of the battery 50, and the temperature Tb of the battery 50 from a temperature sensor (not shown) attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the power storage ratio SOC of the battery 50 based on an integrated value of the current Ib of the battery 50 from the current sensor. The power storage ratio SOC is the ratio of the capacity of the power that can be discharged from the battery 50 to the total capacity of the battery 50. The battery ECU 52 also sets an output limit Wout as a maximum allowable output power that may be output from the battery 50 and an input limit Win as a maximum allowable input power that may be input, based on the power storage ratio SOC and the temperature Tb of the battery 50. The output limit Wout and input limit Win of the battery 50 are set with a certain degree of leeway so as not to cause deterioration of the battery 50.

[0023] Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing a processing program, a RAM for temporarily storing data, a flash memory for storing and holding data, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. Examples of signals input to the HVECU 70 include an ignition signal from an ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operation position of a shift lever 81. Other examples include an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 88. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

[0024] The hybrid vehicle 20 of this embodiment thus configured runs in a hybrid drive mode (HV drive mode) in which the engine 22 is operated, or in an electric drive mode (EV drive mode) in which the engine 22 is stopped, through cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 40. In these drive modes, the engine 22 and the motors MG1 and MG2 are controlled so that a drive torque Td* required of the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V is output to the drive shaft 36.

[0025] In the hybrid vehicle 20 of this embodiment, when the engine 22 is operated autonomously (idling), a pressing torque that presses the planetary gear 30 in one direction is output from the motor MG1. This suppresses the generation of abnormal noises such as teeth rattling of the planetary gear 30 caused by torque pulsation when the engine 22 is operated autonomously.

[0026] Furthermore, in the hybrid vehicle 20 of this embodiment, the PM filter 136 is regenerated by supplying air (oxygen) to the PM filter 136 by cutting fuel in the engine 22, and burning the particulate matter accumulated in the PM filter 136.

[0027] In the hybrid vehicle 20 of this embodiment, when air (oxygen) is supplied to the PM filter 136 by fuel cut of the engine 22, the temperature of the PM filter 136 rises due to the combustion of particulate matter. In order to prevent the PM filter 136 from reaching a high temperature due to such a temperature rise, when a predetermined time tfc has elapsed since the start of fuel cut of the engine 22, fuel cut is prohibited and the engine 22 is operated with an output according to the accelerator opening Acc. When the input limit Win is less than the predetermined power Winref, such as when the battery 50 is at a low temperature, a motoring request for the engine 22 (hereinafter referred to as a "predetermined motoring request") for preventing the battery 50 from being charged with power exceeding the input limit Win is determined to have been made, and the engine 22 and the motors MG1 and MG2 are controlled so that the above-mentioned running torque Td* is output to the drive shaft 36 while consuming power by motoring the engine 22 with the motor MG1. When the engine 22 is motored by the motor MG1, a torque in a direction to reduce the rotation speed acts on the drive shaft 36 via the planetary gear 30, so that a shortage of braking force acting on the drive shaft 36 during deceleration can be suppressed.

[0028] Next, the operation of the hybrid vehicle 20 of this embodiment configured as described above, particularly the operation when suppressing the PM filter 136 from reaching a high temperature, will be described. FIG. 3 is a flowchart showing an example of a high temperature processing routine executed by the HVECI 70. The high temperature processing routine is repeatedly executed when the filter temperature Tf becomes equal to or higher than a predetermined temperature T1 while the engine 22 is in operation, until the filter temperature Tf becomes equal to or lower than a predetermined temperature T2 lower than the predetermined temperature T1. Here, the predetermined temperature T1 is a threshold value for determining whether or not there is a possibility that the PM filter 136 will reach a high temperature, and is set to a temperature lower than the maximum temperature Tfmax allowed for the PM filter 136 (for example, a temperature 10° C., 20° C., or 30° C. lower than the maximum temperature Tfmax). The predetermined temperature T2 is a temperature lower than the predetermined temperature T1 (for example, a temperature 10° C., 20° C., or 30° C. lower than the predetermined temperature T1).

[0029] When this routine is executed, the engine ECU 24 executes a process of inputting the vehicle speed V (S100). The vehicle speed V detected by the vehicle speed sensor 88 is input.

[0030] Next, it is determined whether or not fuel cut is prohibited (S110). When fuel cut is not prohibited (when the first condition permitting fuel cut is satisfied), it is determined that a predetermined motoring request has not been made, and the first air-fuel ratio lean control is executed (S140), and this routine is terminated. In the first air-fuel ratio lean control, a first lean command is sent to the engine ECU 24, and the engine 22 is motored by the motor MG1 so that the rotation speed Ne of the engine 22 becomes the predetermined rotation speed N1, and torque commands Tm1* and Tm2* of the motors MG1 and MG2 are set and sent to the motor ECU 40 so that the above-mentioned running torque Td* is output to the drive shaft 36. The engine ECU 24, which has received the first lean command, controls the engine 22 so that the air-fuel ratio becomes a predetermined value AFl (lean) higher than the theoretical air-fuel ratio. The motor ECU 40, which has received the torque commands Tm1* and Tm2*, drives the motors MG1 and MG2 with the torque commands Tm1* and Tm2*. The predetermined rotation speed N1 is a rotation speed that is set in advance by experiments, analysis, machine learning, etc. as the minimum rotation speed at which the engine 22 can be operated without misfire when the air-fuel ratio is set to a predetermined value AFl1. The predetermined value AFl is a rotation speed that is set in advance by experiments, analysis, machine learning, etc. as the air-fuel ratio when the first air-fuel ratio lean control is executed. In this way, by executing the first air-fuel ratio lean control, the amount of air supplied to the PM filter 136 can be made smaller than when a fuel cut is executed and made larger than when the engine 22 is controlled so that the air-fuel ratio becomes the stoichiometric air-fuel ratio. This makes it possible to suppress a rise in the temperature of the PM filter 136 while regenerating the PM filter 136. When a predetermined motoring request is made and the engine 22 is motored by the motor MG1, it becomes difficult to output the above-mentioned pressing torque from the motor MG1. If the air-fuel ratio is increased, the combustion in the engine 22 becomes unstable, so that there is a high possibility that abnormal noise will occur if the first air-fuel ratio lean control is executed when a predetermined motoring request is made. In this embodiment, the first air-fuel ratio lean control is executed when fuel cut is permitted, i.e., when a specified motoring request is not made, so that the generation of abnormal noise can be suppressed and the discomfort felt by the occupants can be suppressed.

[0031] When fuel cut is prohibited in S110, it is then determined whether or not a predetermined motoring request is made (S120). When a predetermined motoring request is not made (when the second condition is satisfied), the first air-fuel ratio lean control is executed (S140), and this routine is terminated. This makes it possible to suppress the temperature rise of the PM filter 136 while regenerating the PM filter 136. Also, as described above, if the first air-fuel ratio lean control is executed when a predetermined motoring request is made, there is a high possibility that abnormal noise will occur. In this embodiment, when a predetermined motoring request is not made, that is, when there is a low possibility that abnormal noise will occur, the first air-fuel ratio lean control is executed, so that the generation of abnormal noise can be suppressed, and discomfort felt by the occupants can be suppressed.

[0032] When a predetermined motoring request is made in S120, it is next determined whether the vehicle speed V is equal to or higher than a predetermined vehicle speed Vref (S130). The predetermined vehicle speed Vref is a vehicle speed determined in advance by experiments, analysis, machine learning, etc. as a vehicle speed at which the occupant will have difficulty perceiving an abnormal sound such as a teeth rattle of the planetary gear 30 due to the driving sound, etc. When the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref (when the third condition is established), it is determined that the occupant will have difficulty perceiving an abnormal sound even if the engine 22 is motored by the motor MG1 and an abnormal sound is generated, and the first air-fuel ratio lean control is executed (S140), and this routine is terminated. As a result, even if an abnormal sound is generated, it is difficult for the occupant to perceive it due to the driving sound, so that it is possible to suppress the occupant from feeling uncomfortable.

[0033] When the vehicle speed V is less than the predetermined vehicle speed Vref in S130, it is determined that the passenger is likely to recognize the abnormal sound, and it is determined whether or not there is a deceleration request (S150). When there is a deceleration request, the second air-fuel ratio lean control is executed (S160), and this routine is terminated. In the second air-fuel ratio lean control, a second lean command is sent to the engine ECU 24, and the engine 22 is motored by the motor MG1 so that the rotation speed Ne of the engine 22 becomes the predetermined rotation speed N2, and torque commands Tm1* and Tm2* of the motors MG1 and MG2 are set and sent to the motor ECU 40 so that the above-mentioned running torque Td* is output to the drive shaft 36. The engine ECU 24, which has received the second lean command, controls the engine 22 so that the air-fuel ratio becomes a predetermined value AFl2 that is larger than the predetermined value AFl. The motor ECU 40, which has received the torque commands Tm1* and Tm2*, drives the motors MG1 and MG2 with the torque commands Tm1* and Tm2*. The predetermined rotation speed N2 is higher than the predetermined rotation speed N1, and is a rotation speed determined in advance by experiments, analysis, machine learning, etc. as a lower limit value (lower limit rotation speed) of a predetermined range of rotation speeds of the engine 22 in which abnormal noise is unlikely to occur when the engine 22 is motored by the motor MG1. Since the predetermined rotation speed N2 is set higher than the predetermined rotation speed N1, it is possible to suppress a shortage of braking force acting on the drive shaft 36 during deceleration. In addition, by executing the second air-fuel ratio lean control, the amount of air supplied to the PM filter 136 is made smaller than when a fuel cut is executed and made larger than when the air-fuel ratio is set to the stoichiometric air-fuel ratio or the predetermined value AFl1. This makes it possible to suppress a rise in the temperature of the PM filter 136 while regenerating the PM filter 136. Furthermore, when the engine 22 is motored to the predetermined rotation speed N2, the planetary gear 30 is pressed against one side, compared to when the predetermined rotation speed N1 is used, resulting in a situation in which abnormal noise is unlikely to occur. Since the second air-fuel ratio control is executed in a state where such abnormal noise is unlikely to occur, it is possible to suppress the passengers from feeling uncomfortable.

[0034] When there is no deceleration request in S150, the stoichiometric air-fuel ratio control is executed (S170) and this routine ends. In the stoichiometric air-fuel ratio control, a normal control command is sent to the engine ECU 24, and the engine 22 is motored by the motor MG1 so that the rotation speed Ne of the engine 22 becomes the predetermined rotation speed N1, and torque commands Tm1*, Tm2* of the motors MG1, MG2 are set and sent to the motor ECU 40 so that the above-mentioned running torque Td* is output to the drive shaft 36. The engine ECU 24, which has received the normal control command, controls the engine 22 so that the air-fuel ratio becomes the stoichiometric air-fuel ratio. The motor ECU 40, which has received the torque commands Tm1*, Tm2*, drives the motors MG1, MG2 with the torque commands Tm1*, Tm2*. In this way, when fuel cut is prohibited, a specified motoring request is made, the vehicle speed V is less than the specified vehicle speed Vref, and there is no deceleration request, the air-fuel ratio is not made lean, thereby suppressing the generation of abnormal noise and preventing the occupants from feeling uncomfortable.

[0035] According to the hybrid vehicle 20 equipped with the vehicle control device of the present embodiment described above, when the filter temperature Tf of the PM filter 136 is equal to or higher than a predetermined temperature T1, when fuel cut of the engine 22 is permitted, when fuel cut of the engine 22 is prohibited and no request for motoring of the engine 22 by the motor MG1 is made, and when fuel cut of the engine 22 is prohibited and the vehicle speed V is equal to or higher than a predetermined vehicle speed Vref, and at least one of the third conditions is satisfied, a first air-fuel ratio lean control is executed to make the air-fuel ratio of the engine 22 lean, thereby making it possible to suppress discomfort felt by the occupants when the air-fuel ratio lean control is executed.

[0036] Furthermore, since the predetermined motoring request is made when the input limit Win is less than the predetermined power Winref, a shortage of the braking force acting on the drive shaft 36 can be suppressed.

[0037] Furthermore, the second air-fuel ratio lean control prohibits fuel cut of the engine 22 when the filter temperature Tf is equal to or higher than a predetermined temperature Tfref, and when a predetermined motoring request is made and the vehicle is decelerating, controls the motor MG1 so that the rotation speed of the engine 22 becomes a predetermined rotation speed N2 that is a rotation speed of the engine 22 at which no abnormal noise occurs, and since this control makes the air-fuel ratio of the engine 22 lean, it is possible to suppress any discomfort felt by the occupants and to suppress a shortage of braking force acting on the drive shaft 36.

[0038] In the above embodiment, when the vehicle speed V is less than the predetermined vehicle speed Vref in S130, the second air-fuel ratio lean control is performed when there is a deceleration request, and the stoichiometric air-fuel ratio control is performed when there is no deceleration request. However, when the vehicle speed V is less than the predetermined vehicle speed Vref, the first air-fuel ratio lean control may be performed when there is a deceleration request, and the stoichiometric air-fuel ratio control may be performed when there is no deceleration request. Also, when the vehicle speed V is less than the predetermined vehicle speed Vref, the stoichiometric air-fuel ratio control may be performed regardless of the presence or absence of a deceleration request.

[0039] In the above embodiment, the first air-fuel ratio control is executed in S140, but since it is sufficient to control the engine 22 so that the air-fuel ratio becomes lean, for example, the second air-fuel ratio control may be executed.

[0040] In the above embodiment, the predetermined motoring request is made in S120 when the input limit Win is less than the predetermined power Winref. However, the predetermined motoring request may be made based on other requirements.

[0041] In the above-described embodiment, when the filter temperature Tf is equal to or higher than the predetermined temperature Tfref, the first air-fuel ratio control, the second air-fuel ratio control, or the stoichiometric air-fuel ratio control is executed in steps S110 to S150 depending on whether or not fuel cut is prohibited, whether or not a predetermined motoring request is made, whether or not the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref, and whether or not a deceleration request is made. However, in another embodiment, when the filter temperature Tf is equal to or higher than the predetermined temperature Tfref, the second air-fuel ratio lean control may be executed. In this case, the control in the other embodiment may be applied to any vehicle provided that the vehicle is equipped with an engine and a motor capable of motoring the engine.

[0042] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0043] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0044] The present disclosure is applicable to the vehicle control device manufacturing industry and the like. [Explanation of symbols]

[0045] 24 Engine electronic control unit (engine ECU), 40 Motor electronic control unit (motor ECU), 50 Battery electronic control unit (battery ECU), 70 Hybrid electronic control unit (HVECU).

Claims

1. A vehicle control device for use in a vehicle including an engine having an exhaust system equipped with a filter for removing particulate matter, a first motor, a planetary gear having three rotating elements connected to the engine, the first motor, and a drive shaft connected to an axle, a second motor connected to the drive shaft, and an electricity storage device for exchanging electricity with the first and second motors, the vehicle control device comprising: When the temperature of the filter is equal to or higher than a predetermined temperature, and at least one of a first condition permitting fuel cut of the engine, a second condition prohibiting fuel cut of the engine and no request for motoring of the engine by the first motor, and a third condition prohibiting fuel cut of the engine and the vehicle speed is equal to or higher than a predetermined vehicle speed, a lean air-fuel ratio control is executed to make the air-fuel ratio of the engine lean. Vehicle control device.

2. The vehicle control device according to claim 1, The motoring request is made when a maximum allowable input power that may be input to the power storage device is less than a predetermined power. Vehicle control device.

3. The vehicle control device according to claim 2, The lean air-fuel ratio control is a control that prohibits fuel cut of the engine when the temperature of the filter is equal to or higher than the predetermined temperature, and when the motoring request is made and the vehicle is decelerating, controls the first motor so that the engine speed becomes a predetermined speed that is a speed of the engine at which no abnormal noise occurs, and makes the air-fuel ratio of the engine lean. Vehicle control device.

4. A vehicle control device is used in a vehicle including an engine having an exhaust system equipped with a filter for removing particulate matter and a motor capable of motoring the engine, the vehicle control device controlling the engine and the motor, When the temperature of the filter is equal to or higher than a predetermined temperature, and when performing lean air-fuel ratio control to make the air-fuel ratio of the engine lean, the motor is controlled so that the rotational speed of the engine becomes a predetermined rotational speed that is a rotational speed of the engine at which no abnormal noise occurs. Vehicle control device.

5. The vehicle control device according to claim 3 or 4, The predetermined rotation speed is a lower limit rotation speed of a predetermined range of rotation speeds of the engine that is determined in advance as a range in which no abnormal noise occurs. Vehicle control device.

Images