Vehicle control device

Abstract

To prevent or avoid slippage of a clutch provided between an engine and a motor while preventing deterioration in drivability during power-on upshift of a transmission.SOLUTION: When the torque capacity of a clutch is limited during power-on upshift when an engine is running, an amount of torque down in torque down control executed by motor torque down control is reduced as compared with a case where the torque capacity is not limited, and an amount of torque down in torque down control executed by ignition retard control is increased. Therefore, the net output torque of the engine can be reduced while an amount of torque down for canceling inertia torque generated due to the power-on upshift is secured. Accordingly, during the power-on upshift of a transmission, slippage of the clutch provided between the engine and the motor can be prevented or avoided while deterioration in drivability is prevented.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle that includes a clutch provided between an engine and an electric motor, and a transmission provided between the electric motor and drive wheels. [Background technology]

[0002] A control device for a vehicle including an engine functioning as a driving force source, an electric motor functioning as the driving force source and connected to a power transmission path between the engine and driving wheels so as to be capable of transmitting power, a clutch provided between the engine and the electric motor in the power transmission path, and a transmission provided between the electric motor and the driving wheels in the power transmission path is well known. For example, a control device for a hybrid vehicle described in Patent Document 1 is such a control device. Patent Document 1 discloses that, during a power-on upshift of the transmission, in the inertia phase during a shift transition, torque-down control is executed in priority to engine torque control, so as to temporarily reduce the input torque of the transmission by controlling the torque of the electric motor, thereby suppressing an increase in the transmission output torque due to the inertia torque. Note that such torque-down control contributes to suppressing a shift shock and suppressing deterioration of drivability. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-140993 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are cases where the torque capacity of the clutch is limited due to, for example, some abnormality. In this case, if torque down control during power-on upshift of the transmission is realized by torque control of the electric motor, the engine rotation speed is reduced by upshifting while maintaining the engine output torque, so the torque that the clutch needs to transmit is the original engine output torque plus the inertia torque. In this case, the torque that the clutch needs to transmit may exceed the torque capacity of the clutch, causing the clutch to slip. Such clutch slippage may lead to a decrease in the durability of the clutch.

[0005] The present invention has been made against the background of the above circumstances, and its object is to provide a vehicle control device that can suppress or avoid slippage of a clutch provided between an engine and an electric motor while suppressing deterioration of drivability during power-on upshifting of the transmission. [Means for solving the problem]

[0006] The gist of a first aspect of the present invention is a control device for a vehicle including: (a) an engine functioning as a driving force source; an electric motor functioning as the driving force source and connected to a power transmission path between the engine and driving wheels so as to be capable of transmitting power; a clutch provided in the power transmission path between the engine and the electric motor; and a transmission provided in the power transmission path between the electric motor and the driving wheels, the control device including: (b) a shift control unit that performs shift control of the transmission; and (c) a control unit that temporarily controls an output torque of the driving force source to be increased or decreased during a transition in which an input rotation speed of the transmission is reduced in association with the power-on upshift during a power-on upshift, which is an upshift of the transmission performed with an accelerator pedal on. and (d) when the torque capacity of the clutch is limited during the power-on upshift during engine running in which the vehicle runs by outputting driving force from at least the engine of the driving power sources with the clutch engaged, the driving power source control unit reduces the torque down amount in the torque down control performed by electric motor torque down control that temporarily reduces the output torque of the electric motor and increases the torque down amount in the torque down control performed by ignition retard control that temporarily reduces the output torque of the engine, compared to when the torque capacity is not limited.

[0007] In addition, a second invention is a vehicle control device described in the first invention, in which, during the power-on upshift, when the torque capacity of the clutch is not limited, the driving force source control unit executes the torque down control by the electric motor torque down control, and when the torque capacity of the clutch is limited, the driving force source control unit executes the torque down control only by the ignition retard control.

[0008] Further, a third invention is directed to the vehicle control device described in the second invention, wherein when the torque capacity of the clutch is limited, the driving force source control unit does not permit the torque down control by the electric motor torque down control even if the torque down amount in the torque down control by the ignition retard control is insufficient for the required torque down amount required in the torque down control.

[0009] In addition, a fourth invention is a vehicle control device described in any one of the first to third inventions, wherein the shift control unit corrects the control state of the transmission by feedback control so that the progress state of the power-on upshift becomes a predetermined state. Effect of the Invention

[0010] According to the first aspect of the present invention, when the torque capacity of the clutch is limited during power-on upshift while the engine is traveling, the torque down amount in the torque down control executed by the electric motor torque down control for temporarily reducing the output torque of the electric motor is reduced and the torque down amount in the torque down control executed by the ignition retard control for temporarily reducing the output torque of the engine is increased, compared to when the torque capacity is not limited, so that the net output torque of the engine can be reduced while ensuring the torque down amount for offsetting the inertia torque generated with the power-on upshift. Therefore, during the power-on upshift of the transmission, the slippage of the clutch provided between the engine and the electric motor can be suppressed or avoided while suppressing deterioration of drivability.

[0011] According to the second aspect of the present invention, when the torque capacity of the clutch is not limited during a power-on upshift, torque-down control is executed by the electric motor torque-down control, so that it is possible to suppress deterioration of drivability while improving energy efficiency and low exhaust gas performance. On the other hand, when the torque capacity of the clutch is limited during a power-on upshift, torque-down control is executed only by the engine ignition retard control, so that it is possible to suppress or avoid clutch slippage while suppressing deterioration of drivability.

[0012] Furthermore, according to the third aspect of the invention, when the torque capacity of the clutch is limited, even if the torque down amount in the torque down control using ignition retard control is insufficient for the required torque down amount, the torque down control using the electric motor torque down control is not permitted. Therefore, the negative torque due to the electric motor torque down control from the electric motor side of the clutch, which is considered to be a detrimental factor in suppressing clutch slippage, is not applied to the clutch, and clutch slippage can be further suppressed or avoided.

[0013] According to the fourth aspect of the present invention, the control state of the transmission is corrected by feedback control so that the progress of the power-on upshift is in a predetermined state, thereby suppressing shift shock and suppressing deterioration of drivability. When the torque down amount is insufficient in the torque down control executed at the time of the power-on upshift, the control state of the transmission is corrected by feedback control due to the slow progress of the shift, thereby suppressing deterioration of drivability. In this case, since the shortage of the torque down amount is small, the correction amount of the control state of the transmission by feedback control is suppressed and shift shock is suppressed. By suppressing the correction amount of the control state of the transmission, the burden on the transmission is reduced and deterioration of the shift performance, for example, the durability of the transmission is suppressed. [Brief description of the drawings]

[0014] [Figure 1]1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and a control system for various controls in the vehicle. [Diagram 2] FIG. 11 is a diagram illustrating a torque down control executed at the time of a power-on upshift during HV running. [Diagram 3] FIG. 11 is a diagram illustrating a sharing state of a required torque down amount in the torque down control executed at the time of a power-on upshift during HV running. [Figure 4] 1 is a flowchart illustrating the main control operations of an electronic control device, and is a flowchart illustrating the control operations for suppressing or avoiding slippage of the K0 clutch while suppressing deterioration of drivability during a power-on upshift of an automatic transmission. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0016] Fig. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and is also a diagram illustrating the main parts of the control functions and control system for various controls in the vehicle 10. In Fig. 1, the vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG that function as a driving power source SP for traveling. The vehicle 10 also has driving wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the driving wheels 14.

[0017] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, etc., provided in the vehicle 10 is controlled by an electronic control device 90 described later, whereby an engine torque Te, which is an output torque of the engine 12, is controlled.

[0018] The electric motor MG is a rotating electric machine having a function as a motor that generates mechanical power from electric power and a function as a generator that generates electric power from mechanical power, and is a so-called motor generator. The electric motor MG is connected to a battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The battery 54 is an electricity storage device that supplies and receives electric power to the electric motor MG. The electric motor MG controls the inverter 52 by an electronic control device 90 described later, thereby controlling the MG torque Tm, which is the output torque of the electric motor MG. For example, when the rotation direction of the electric motor MG is a positive rotation that is the same as the rotation direction when the engine 12 is operating, the MG torque Tm is a power running torque when it is a positive torque on the acceleration side, and a regenerative torque when it is a negative torque on the deceleration side. The electric motor MG generates electric power by the power of the engine 12, for example, and the battery 54 charges the electric power from the electric motor MG. The electric power also means electric energy when there is no particular distinction. The power also means torque and force when there is no particular distinction.

[0019] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and the like, in a case 18 that is a non-rotating member attached to the vehicle body. The K0 clutch 20 is a clutch provided between the engine 12 and the electric motor MG in a power transmission path between the engine 12 and the drive wheels 14. The torque converter 22 is connected to the engine 12 via the K0 clutch 20. The automatic transmission 24 is connected to the torque converter 22 and is interposed in a power transmission path between the torque converter 22 and the drive wheels 14. The automatic transmission 24 is a transmission provided between the electric motor MG and the drive wheels 14 in a power transmission path between the engine 12 and the drive wheels 14. The power transmission device 16 also includes a propeller shaft 28 connected to a transmission output shaft 26 that is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, and the like. The power transmission device 16 also includes an engine connecting shaft 34 that connects the engine 12 and the K0 clutch 20, an electric motor connecting shaft 36 that connects the K0 clutch 20 and the torque converter 22, and the like.

[0020] The electric motor MG is connected to the electric motor connecting shaft 36 in the case 18 so as to be capable of transmitting power. That is, the electric motor MG is connected to a power transmission path between the engine 12 and the drive wheels 14, in particular, to a power transmission path between the K0 clutch 20 and the torque converter 22. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 so as to be capable of transmitting power without passing through the K0 clutch 20.

[0021] The torque converter 22 includes a pump wheel 22a connected to the motor connecting shaft 36, and a turbine wheel 22b connected to a transmission input shaft 38 that is an input rotating member of the automatic transmission 24. The torque converter 22 is a fluid type power transmission device that transmits driving force from a driving force source SP from the motor connecting shaft 36 to the transmission input shaft 38 via fluid. The torque converter 22 includes an LU clutch 40 that serves as a direct clutch that connects the pump wheel 22a and the turbine wheel 22b, that is, that connects the motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a known lock-up clutch.

[0022] The automatic transmission 24 is a known planetary gear type automatic transmission including, for example, one or more planetary gear devices (not shown) and a plurality of engagement devices CB. The engagement devices CB are, for example, known hydraulic friction engagement devices. The engagement devices CB have their respective torque capacities, or CB torque Tcb, changed by the CB hydraulic pressure PRcb, or regulated hydraulic pressure, supplied from the hydraulic control circuit 56, thereby switching between operating states, such as an engaged state and a released state, i.e., control states.

[0023] The automatic transmission 24 is a stepped transmission in which one of a plurality of gear stages (also called gear stages) with different speed ratios (also called gear ratios) γat (=AT input rotation speed Ni / AT output rotation speed No) is formed by engaging one of the engagement devices CB. The automatic transmission 24 switches between gear stages formed according to the accelerator operation of the driver (=operator) and the vehicle speed V by an electronic control device 90 described later. The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38, and is the input rotation speed of the automatic transmission 24. The AT input rotation speed Ni is the same value as the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22. The AT input rotation speed Ni can be expressed by the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26, and is the output rotation speed of the automatic transmission 24.

[0024] The K0 clutch 20 is a hydraulic friction engagement device constituted by, for example, a multi-plate or single-plate clutch. The K0 clutch 20 switches between control states such as an engaged state and a released state by changing the torque capacity of the K0 clutch 20, that is, the K0 torque Tk0, by the K0 oil pressure PRk0, that is, the regulated oil pressure supplied from the hydraulic control circuit 56.

[0025] In the vehicle 10, when the K0 clutch 20 is in an engaged state, the engine 12 and the torque converter 22 are connected to each other so as to transmit power. On the other hand, when the K0 clutch 20 is in a disengaged state, power transmission between the engine 12 and the torque converter 22 is interrupted. Since the electric motor MG is connected to the torque converter 22, the K0 clutch 20 functions as a clutch that connects and disconnects the engine 12 from the electric motor MG.

[0026] In the power transmission device 16, when the K0 clutch 20 is engaged, the power output from the engine 12 is transmitted from the engine connecting shaft 34 to the driving wheels 14 via the K0 clutch 20, the electric motor connecting shaft 36, the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order. Moreover, the power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the driving wheels 14 via the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order, regardless of the control state of the K0 clutch 20. In this manner, the power transmission device 16 transmits the driving force source torque Tsp, which is the output torque of the driving force source SP, to the driving wheels 14. The driving force source torque Tsp is the total torque of the engine torque Te and the MG torque Tm.

[0027] The vehicle 10 includes the MOP 58, which is a mechanical oil pump, the EOP 60, which is an electric oil pump, and a pump motor 62. The MOP 58 is connected to the pump impeller 22a, and is rotated by a driving force source SP to discharge hydraulic oil OIL used in the power transmission device 16. The pump motor 62 is a motor dedicated to the EOP 60 for rotating the EOP 60. The EOP 60 is rotated by the pump motor 62 to discharge hydraulic oil OIL. The hydraulic oil OIL discharged by the MOP 58 and the EOP 60 is supplied to a hydraulic control circuit 56. The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, and the like, which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and / or the EOP 60.

[0028] The vehicle 10 further includes an electronic control device 90 including a control device for the vehicle 10. The electronic control device 90 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, and the like, and the CPU executes various controls of the vehicle 10 by performing signal processing according to a program previously stored in the ROM while utilizing the temporary storage function of the RAM. The electronic control device 90 includes computers for engine control, electric motor control, hydraulic control, and the like as necessary.

[0029] The electronic control device 90 receives various signals based on detection values ​​from various sensors provided in the vehicle 10 (for example, an engine rotation speed sensor 70, a turbine rotation speed sensor 72, an output rotation speed sensor 74, a MG rotation speed sensor 76, an accelerator opening sensor 78, a throttle valve opening sensor 80, an air flow meter 82, a brake switch 84, a battery sensor 86, an oil temperature sensor 88, etc.) and outputs various signals (for example, an engine rotation speed Ne which is the rotation speed of the engine 12, a turbine rotation speed Nt which is the same value as the AT input rotation speed Ni, an AT output rotation speed No which corresponds to the vehicle speed V, a rotation speed of the electric motor MG The various inputs to the hydraulic control circuit 56 include the MG rotation speed Nm, which is the rotation speed of the engine 12, the accelerator opening θacc, which is the amount of accelerator operation by the driver which indicates the magnitude of the driver's acceleration operation, the throttle valve opening θth, which is the opening of the electronic throttle valve, the intake air amount Qair of the engine 12, a brake-on signal Bon, which is a signal indicating a state in which the brake pedal for operating the wheel brakes is being operated by the driver, the battery temperature THbat, the battery charge / discharge current Ibat and the battery voltage Vbat of the battery 54, and the hydraulic oil temperature THoil, which is the temperature of the hydraulic oil OIL in the hydraulic control circuit 56.

[0030] The electronic control device 90 outputs various command signals (e.g., an engine control command signal Se for controlling the engine 12, an MG control command signal Sm for controlling the electric motor MG, a CB hydraulic control command signal Sbc for controlling the engagement device CB, a K0 hydraulic control command signal Sk0 for controlling the K0 clutch 20, an LU hydraulic control command signal Slu for controlling the LU clutch 40, an EOP control command signal Seop for controlling the EOP 60, etc.) to each device (e.g., the engine control device 50, the inverter 52, the hydraulic control circuit 56, the pump motor 62, etc.) provided in the vehicle 10.

[0031] The electronic control device 90 includes a driving force source control means, that is, a driving force source control section 92, and a gear shift control means, that is, a gear shift control section 94 in order to realize various controls in the vehicle 10.

[0032] The driving force source control unit 92 includes a function as engine control means, i.e., engine control unit 92a, that controls the operation of the engine 12, and a function as electric motor control means, i.e., electric motor control unit 92b, that controls the operation of the electric motor MG via the inverter 52, and is a hybrid control means, i.e., a hybrid control unit, that performs hybrid drive control by the engine 12 and the electric motor MG using these control functions.

[0033] The driving force source control unit 92 calculates the driving demand amount of the vehicle 10 by the driver, for example, by applying the accelerator opening θacc and the vehicle speed V to a driving demand amount map. The driving demand amount map is a relationship that is experimentally or design-wise determined and stored in advance, that is, a predetermined relationship. The driving demand amount is, for example, the required driving torque Trdem at the driving wheels 14. In other words, the required driving torque Trdem [Nm] is the required driving power Prdem [W] at the vehicle speed V at that time. The driving demand amount can also be the required driving force Frdem [N] at the driving wheels 14, the required AT output torque at the transmission output shaft 26, or the like. In calculating the driving demand amount, the AT output rotation speed No, or the like, can be used instead of the vehicle speed V.

[0034] The driving force source control unit 92 outputs an engine control command signal Se for controlling the engine 12 and an MG control command signal Sm for controlling the electric motor MG so as to realize the required driving power Prdem, taking into consideration the transmission loss, the auxiliary load, the gear ratio γat of the automatic transmission 24, the chargeable power Win and the dischargeable power Wout of the battery 54, etc. The engine control command signal Se is, for example, a command value for the engine power Pe, which is the power of the engine 12 that outputs the engine torque Te at the engine rotation speed Ne at that time. The MG control command signal Sm is, for example, a command value for the power consumption Wm of the electric motor MG that outputs the MG torque Tm at the MG rotation speed Nm at that time.

[0035] The chargeable power Win of the battery 54 is the maximum power that can be input, which specifies the limit on the input power of the battery 54, and indicates the input limit of the battery 54. The dischargeable power Wout of the battery 54 is the maximum power that can be output, which specifies the limit on the output power of the battery 54, and indicates the output limit of the battery 54. The chargeable power Win and dischargeable power Wout of the battery 54 are calculated by the electronic control device 90, for example, based on the battery temperature THbat and the battery charge amount SOC. The battery charge amount SOC is a charge state value [%] of the battery 54 that indicates the charge state corresponding to the charge amount of the battery 54, and is calculated by the electronic control device 90, for example, based on the battery charge / discharge current Ibat and the battery voltage Vbat.

[0036] When the required driving torque Trdem can be satisfied only by the output of the electric motor MG, the driving power source control unit 92 sets the driving mode to the motor driving (=EV driving) mode. In the EV driving mode, the driving power source control unit 92 performs EV driving in which the vehicle runs by outputting driving force only from the electric motor MG of the driving power source SP when the K0 clutch 20 is in the released state. On the other hand, when the required driving torque Trdem cannot be satisfied without using at least the output of the engine 12, the driving power source control unit 92 sets the driving mode to the engine driving mode, i.e., hybrid driving (=HV driving) mode. In the HV driving mode, the driving power source control unit 92 performs engine driving, i.e., HV driving in which the vehicle runs by outputting driving force only from the engine 12 of the driving power source SP when the K0 clutch 20 is in the engaged state. On the other hand, even if the required driving torque Trdem can be satisfied only by the output of the electric motor MG, the driving power source control unit 92 establishes the HV driving mode when the battery charge amount SOC is less than the engine start threshold SOCest or when the engine 12 or the like needs to be warmed up. The engine start threshold SOCest is a predetermined threshold for determining that the battery charge SOC is at a level at which the engine 12 needs to be forcibly started to charge the battery 54.

[0037] The shift control unit 94 judges whether or not to shift the automatic transmission 24 by using, for example, a shift map which is a predetermined relationship, and outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 as necessary to execute shift control of the automatic transmission 24. The shift map is a predetermined relationship having a shift line for judging whether or not to shift the automatic transmission 24 on a two-dimensional coordinate system having, for example, vehicle speed V and required driving torque Trdem as variables. In the shift map, the AT output rotation speed No or the like may be used instead of the vehicle speed V, and the required driving force Frdem, accelerator opening θacc, throttle valve opening θth or the like may be used instead of the required driving torque Trdem.

[0038] Here, during a power-on upshift, which is an upshift of the automatic transmission 24 performed with the accelerator on, an inertia torque Tint of the driving force source SP occurs due to a reduction in the AT input rotation speed Ni. The occurrence of such an inertia torque Tint may cause a shift shock and lead to deterioration of drivability. For this reason, during a power-on upshift of the automatic transmission 24, the driving force source control unit 92 executes a torque-down control CTtd that temporarily reduces the driving force source torque Tsp during a transition in which the AT input rotation speed Ni is reduced due to the power-on upshift, that is, during the inertia phase during the transition of the power-on upshift. In the torque-down control CTtd, the driving force source control unit 92 temporarily reduces the driving force source torque Tsp so as to realize the required torque-down amount Tqtddem. The required torque down amount Tqtddem is the required value of the torque down amount Tqtd, which is the amount of driving force source torque Tsp reduced by the torque down control CTtd, i.e., the torque down amount Tqtd required in the torque down control CTtd, and is, for example, a torque of a magnitude that offsets the generated inertia torque Tint and is determined in advance based on the gear step between which the upshift is performed, the AT input rotation speed Ni before the upshift, etc.

[0039] FIG. 2 is a diagram for explaining the torque-down control CTtd executed at the time of power-on upshift during HV running. In FIG. 2, as the AT input rotation speed Ni is lowered by the power-on upshift, the inertia torque Tint is input to the automatic transmission 24 (see arrows A and B in the figure). In the torque-down control CTtd for offsetting this inertia torque Tint, a highly responsive torque-down is required, which reduces the driving force source torque Tsp in accordance with the generation of the inertia torque Tint. Examples of the torque-down control CTtd that can realize a highly responsive torque-down include the electric motor torque-down control CTtdmg that temporarily reduces the MG torque Tm, and the ignition retard control CTtdsd that temporarily reduces the engine torque Te. The electric motor torque-down control CTtdmg is advantageous in improving energy efficiency and low exhaust gas performance compared to the ignition retard control CTtdsd, and is therefore used preferentially for the torque-down control CTtd (see arrow C in the figure).

[0040] Also, the K0 torque Tk0 may be limited due to some kind of abnormality. For example, some kind of abnormality may be caused by a failure in which the K0 clutch solenoid valve among the multiple solenoid valves in the hydraulic control circuit 56 does not output the K0 hydraulic pressure PRk0, or a failure in which the control state of the K0 clutch 20 cannot be switched to the engaged state due to a drop in the source pressure such as the line pressure supplied to the K0 clutch solenoid valve. In the case of such a failure, the K0 clutch 20 is switched to the engaged state as necessary by a fail-safe operation FS that forcibly switches the K0 clutch 20 to the engaged state. The fail-safe operation FS is a control operation in which, when a failure occurs in which the control state of the K0 clutch 20 cannot be switched to an engaged state due to an abnormality in the K0 clutch solenoid valve or the line pressure control solenoid valve, that is, when a failure occurs in which the desired K0 hydraulic pressure PRk0 is not output from the K0 clutch solenoid valve, an abnormality hydraulic control command signal is output to the hydraulic control circuit 56 by the electronic control device 90 as necessary to switch the oil path in the hydraulic control circuit 56 so that the K0 hydraulic pressure PRk0 capable of maintaining the engaged state of the K0 clutch 20 is supplied to the actuator of the K0 clutch 20 without passing through the K0 clutch solenoid valve. The hydraulic control circuit 56 is configured in advance to be able to supply the K0 hydraulic pressure PRk0 capable of maintaining the engaged state of the K0 clutch 20 to the actuator of the K0 clutch 20 without passing through the K0 clutch solenoid valve. This makes it possible to perform evacuation running using the driving force from the engine 12 when a failure occurs in which the control state of the K0 clutch 20 cannot be switched to an engaged state.

[0041] The K0 torque Tk0 during the execution of the fail-safe operation FS is set smaller than the maximum value of the controllable K0 torque Tk0 under normal circumstances when no abnormality occurs, that is, the K0 torque Tk0 is limited. If the engine torque Te exceeds the limited K0 torque Tk0, the K0 clutch 20 may slip, which may result in a decrease in durability of the K0 clutch 20. Therefore, the driving force source control unit 92 performs engine torque limitation to control the engine torque Te within a range equal to or less than the K0 torque Tk0 during the execution of the fail-safe operation FS in order to prevent the K0 clutch 20 from slipping during the execution of the fail-safe operation FS. The engine torque Te that is the subject of the engine torque limitation is the engine torque Te controlled by adjusting the intake air amount Qair of the engine 12 to realize the required driving torque Trdem by the driver, that is, the engine torque Te controlled by controlling the throttle valve opening θth (see arrow D in FIG. 2).

[0042] Incidentally, when the K0 torque Tk0 is limited by the implementation of the failsafe operation FS during a power-on upshift while the HV is running, the total torque obtained by adding the inertia torque of the engine 12 caused by the engine speed Ne being reduced by the upshift to the engine torque Te controlled by the throttle valve opening θth in relation to the limited K0 torque Tk0 is input to the K0 clutch 20, so that the total torque may exceed the K0 torque Tk0 by the inertia torque of the engine 12, which may cause slippage of the K0 clutch 20. In addition, during a power-on upshift while the HV is running, the torque down control CTtd is basically implemented by the electric motor torque down control CTtdmg. As a result, the engine torque Te resulting from control of the throttle valve opening θth, which becomes a positive torque, is applied to the rotating member on the input side of the K0 clutch 20, i.e., on the engine 12 side (see arrow D in FIG. 2), while the torque resulting from the motor torque down control CTtdmg, which becomes a negative torque, is applied to the rotating member on the output side of the K0 clutch 20, i.e., on the electric motor MG side (see arrow C in FIG. 2). Therefore, the K0 clutch 20 is brought into a state in which the occurrence of slippage is encouraged.

[0043] During the fail-safe operation FS, evacuation driving performance is more important than energy efficiency and low exhaust gas performance, so it is not necessarily necessary to give priority to the electric motor torque down control CTtdmg over the torque down control CTtd during power-on upshift during HV driving.

[0044] Therefore, when the K0 torque Tk0 is limited during a power-on upshift of the automatic transmission 24 during HV running, the driving force source control unit 92 reduces the torque down amount Tqtd in the torque down control CTtd executed by the electric motor torque down control CTtdmg and increases the torque down amount Tqtd in the torque down control CTtd executed by the ignition retard control CTtdsd, compared to when the K0 torque Tk0 is not limited. For example, when the K0 torque Tk0 is not limited, the entire required torque down amount Tqtddem is allocated to the torque down amount Tqtd by the electric motor torque down control CTtdmg. On the other hand, when the K0 torque Tk0 is limited, a part or the entire required torque down amount Tqtddem is allocated to the torque down amount Tqtd by the ignition retard control CTtdsd. As a result, when the K0 torque Tk0 is limited, the net engine torque Te is reduced by the required torque down amount Tqtddem allocated to the torque down amount Tqtd by the ignition retard control CTtdsd, thereby suppressing or avoiding slippage of the K0 clutch 20. In addition, the engine torque Te of the positive torque applied to the rotating member on the engine 12 side of the K0 clutch 20 is reduced, and the absolute value of the torque by the motor torque down control CTtdmg of the negative torque applied to the rotating member on the electric motor MG side of the K0 clutch 20 is also reduced, so that the K0 clutch 20 is brought into a state in which occurrence of slippage is suppressed. Furthermore, when the K0 torque Tk0 is limited, only the allocation of the required torque down amount Tqtddem is changed, and the torque down control CTtd is executed so as to realize the required torque down amount Tqtddem for the entire drive system from the engine 12 to the drive wheels 14, thereby suppressing gear shift shock and suppressing deterioration of drivability.

[0045] FIG. 3 is a diagram for explaining the distribution state of the required torque down amount Tqtddem in the torque down control CTtd executed at the time of power-on upshift during HV running. In FIG. 3, inertia torque of the engine 12 occurs as the AT input rotation speed Ni is lowered by the power-on upshift (see arrows E and F in the figure). In the torque down control CTtd for offsetting the inertia torque Tint caused by the lowering of the AT input rotation speed Ni, including the inertia torque of the engine 12, if there is no restriction on the K0 torque Tk0, the entire required torque down amount Tqtddem is distributed to the torque down amount Tqtd by the electric motor torque down control CTtdmg (see arrow G in the figure). At this time, since the K0 torque Tk0 of the K0 clutch 20 is not restricted, the K0 torque Tk0 for transmitting the total torque obtained by adding the inertia torque of the engine 12 to the engine torque Te by the control of the throttle valve opening θth can be secured. On the other hand, in the torque down control CTtd, when there is a limit on the K0 torque Tk0, for example, the entire required torque down amount Tqtddem is allocated to the torque down amount Tqtd by the ignition retard control CTtdsd (see arrow H in the figure). Therefore, when there is a limit on the K0 torque Tk0, the total torque (see arrow J in the figure) of the engine torque Te (>0) (see arrow I in the figure) by controlling the throttle valve opening θth and the torque down amount Tqtd (<0) by the ignition retard control CTtdsd is set to the net engine torque Te. In other words, the net engine torque Te is reduced by the torque down amount Tqtd by the ignition retard control CTtdsd with respect to the engine torque Te controlled within a range equal to or less than the K0 torque Tk0 when the fail-safe operation FS is performed. As a result, even if a torque obtained by adding the inertia torque of the engine 12 to the net engine torque Te is input to the K0 clutch 20 in a state in which the K0 torque Tk0 is limited, slippage of the K0 clutch 20 is suppressed or avoided.

[0046] More specifically, the driving force source control unit 92 determines whether the vehicle 10 is running in HV mode.

[0047] When the driving force source control unit 92 determines that the vehicle 10 is running as an HV, the shift control unit 94 determines whether or not a power-on upshift of the automatic transmission 24 is being performed. When the shift control unit 94 determines that a power-on upshift of the automatic transmission 24 is being performed, the shift control unit 94 determines whether or not an inertia phase has started during the transition of the power-on upshift. The shift control unit 94 determines whether or not an inertia phase has started during the transition of the power-on upshift, for example, based on whether or not the AT input rotation speed Ni has deviated from the synchronous rotation speed before the power-on upshift (=No × gear ratio γat at the gear before the power-on upshift) by a predetermined rotation speed or more for determining the start of the inertia phase. The shift control unit 94 also determines whether or not the power-on upshift has been completed.

[0048] When the shift control unit 94 determines that the inertia phase has started during the power-on upshift transition, it corrects the control state of the automatic transmission 24 by feedback control so that the progress of the power-on upshift during the inertia phase becomes a predetermined state. The progress of the power-on upshift is, for example, a rotation change state of the AT input rotation speed Ni. The predetermined state is, for example, a predetermined change rate of the AT input rotation speed Ni for achieving both rapid completion of the shift and suppression of shift shock. Correcting the control state of the automatic transmission 24 means, for example, correcting the CB oil pressure PRcb of the engagement device CB involved in the shift, particularly correcting the CB oil pressure PRcb of the engagement side engagement device that is switched to an engaged state during the power-on upshift transition.

[0049] The driving force source control unit 92 determines whether or not the K0 torque Tk0 has been limited by performing the fail-safe operation FS.

[0050] When the driving force source control unit 92 determines that the vehicle 10 is running as an HV, determines that the automatic transmission 24 is performing a power-on upshift by the shift control unit 94, and determines that the inertia phase has started, and determines that the K0 torque Tk0 is not limited, the driving force source control unit 92 executes the torque down control CTtd by the electric motor torque down control CTtdmg. Note that, when the torque down amount Tqtd by the electric motor torque down control CTtdmg is insufficient for the required torque down amount Tqtddem required in the torque down control CTtd, the torque down control CTtd may be executed by the electric motor torque down control CTtdmg and the ignition retard control CTtdsd. On the other hand, when it determines that the K0 torque Tk0 is limited, the driving force source control unit 92 executes the torque down control CTtd only by the ignition retard control CTtdsd. When the driving force source control unit 92 determines that the power-on upshift has been completed by the shift control unit 94, the driving force source control unit 92 ends the torque down control CTtd.

[0051] When the K0 torque Tk0 is limited, the torque down amount Tqtd by the ignition retard control CTtdsd may be insufficient for the required torque down amount Tqtddem. In this case, it is possible to allocate the torque down amount Tqtd that cannot be realized by the ignition retard control CTtdsd out of the required torque down amount Tqtddem to the torque down amount Tqtd by the electric motor torque down control CTtdmg. However, the torque down amount Tqtd by the electric motor torque down control CTtdmg is considered to be an unfavorable factor in suppressing slippage of the K0 clutch 20. Alternatively, a slight shortage of the torque down amount Tqtd for the required torque down amount Tqtddem can be absorbed by the feedback control during the inertia phase by the shift control unit 94, by increasing and correcting the CB oil pressure PRcb of the engagement side engagement device due to the slow progress of the shift. For this reason, once the entire required torque down amount Tqtddem has been allocated to the torque down amount Tqtd by the ignition retard control CTtdsd, the torque down amount Tqtd of the required torque down amount Tqtddem that cannot be realized by the ignition retard control CTtdsd is not allocated to the torque down amount Tqtd by the electric motor torque down control CTtdmg. In other words, when the K0 torque Tk0 is limited, even if the torque down amount Tqtd in the torque down control CTtd by the ignition retard control CTtdsd is insufficient for the required torque down amount Tqtddem, the driving force source control unit 92 does not permit the torque down control CTtd by the electric motor torque down control CTtdmg.

[0052] FIG. 4 is a flowchart illustrating the main control operations of the electronic control device 90, which are executed, for example, repeatedly, to suppress or avoid slippage of the K0 clutch 20 while suppressing deterioration of drivability during a power-on upshift of the automatic transmission 24.

[0053] In FIG. 4, first, in step S10 (hereinafter, step will be omitted) corresponding to the function of the driving force source control unit 92, it is determined whether the vehicle 10 is running as an HV. If the determination in S10 is negative, this routine is terminated. If the determination in S10 is positive, in S20 corresponding to the function of the shift control unit 94, it is determined whether the automatic transmission 24 is performing a power-on upshift. If the determination in S20 is negative, this routine is terminated. If the determination in S20 is positive, in S30 corresponding to the function of the shift control unit 94, it is determined whether the inertia phase during the power-on upshift transition has started. If the determination in S30 is negative, this S30 is repeatedly executed. If the determination in S30 is positive, in S40 corresponding to the function of the driving force source control unit 92, it is determined whether the K0 torque Tk0 is limited by the implementation of the fail-safe operation FS. If the determination in S40 is positive, in S50 corresponding to the function of the driving force source control unit 92, the torque-down control CTtd is executed by only the ignition retard control CTtdsd of the engine 12. Next, in S60 corresponding to the function of the shift control unit 94, the CB oil pressure PRcb of the engagement side engagement device is corrected by feedback control so that the rotation change state of the AT input rotation speed Ni becomes a predetermined state. Next, in S70 corresponding to the function of the shift control unit 94, it is determined whether the power-on upshift is completed. If the determination in S70 is negative, the process returns to the above S50. If the determination in S40 is negative, in S80 corresponding to the function of the driving force source control unit 92, the torque-down control CTtd is executed by the electric motor torque-down control CTtdmg. Next, in S90 corresponding to the function of the shift control unit 94, the CB oil pressure PRcb of the engagement side engagement device is corrected by feedback control so that the rotation change state of the AT input rotation speed Ni becomes a predetermined state. Next, in S100, which corresponds to the function of the gear shift control unit 94, it is determined whether or not the power-on upshift has been completed. If the determination in S100 is negative, the process returns to S80.If the determination in S70 above is positive, or if the determination in S100 above is positive, the torque down control CTtd is ended in S110, which corresponds to the function of the driving force source control section 92.

[0054] As described above, according to this embodiment, when the K0 torque Tk0 is limited during a power-on upshift of the automatic transmission 24 during HV driving, the torque-down amount Tqtd in the torque-down control CTtd executed by the electric motor torque-down control CTtdmg is made smaller and the torque-down amount Tqtd in the torque-down control CTtd executed by the ignition retard control CTtdsd is made larger than when the K0 torque Tk0 is not limited, so that the net engine torque Te can be reduced while ensuring the torque-down amount Tqtd for offsetting the inertia torque Tint generated with the power-on upshift. Therefore, during a power-on upshift of the automatic transmission 24, it is possible to suppress or avoid slippage of the K0 clutch 20 while suppressing deterioration of drivability.

[0055] Furthermore, according to this embodiment, when the K0 torque Tk0 is not limited during a power-on upshift of the automatic transmission 24, the torque-down control CTtd is executed by the electric motor torque-down control CTtdmg, so that it is possible to suppress deterioration of drivability and improve energy efficiency and low exhaust gas performance at the same time. On the other hand, when the K0 torque Tk0 is limited during a power-on upshift of the automatic transmission 24, the torque-down control CTtd is executed only by the ignition retard control CTtdsd of the engine 12, so that it is possible to suppress or avoid slippage of the K0 clutch 20 while suppressing deterioration of drivability.

[0056] Furthermore, according to this embodiment, when the K0 torque Tk0 is limited, even if the torque down amount Tqtd in the torque down control CTtd by the ignition retard control CTtdsd is insufficient for the required torque down amount Tqtddem, the torque down control CTtd by the motor torque down control CTtdmg is not permitted, so that the negative torque by the motor torque down control CTtdmg from the motor MG side of the K0 clutch 20, which is considered to be an unfavorable factor in suppressing slippage of the K0 clutch 20, is not applied to the K0 clutch 20, and slippage of the K0 clutch 20 can be further suppressed or avoided.

[0057] In addition, according to this embodiment, the control state of the automatic transmission 24 is corrected by feedback control so that the progress of the power-on upshift is in a predetermined state, so that shift shock is suppressed and deterioration of drivability is suppressed. In addition, when the torque down amount Tqtd is insufficient in the torque down control CTtd executed at the time of the power-on upshift, the feedback control increases and corrects the CB hydraulic pressure PRcb of the engaging side engagement device due to the slow progress of the shift, so that deterioration of drivability is suppressed. At this time, since the shortage of the torque down amount Tqtd is small, the increase correction amount of the CB hydraulic pressure PRcb of the engaging side engagement device by the feedback control is suppressed, and the shift shock is suppressed. By suppressing the increase correction amount of the CB hydraulic pressure PRcb, the burden on the engagement device CB is reduced, and deterioration of the shift performance, for example, the durability of the engagement device CB is suppressed.

[0058] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the present invention can be applied to other embodiments.

[0059] For example, in the above embodiment, a planetary gear type automatic transmission is exemplified as the automatic transmission 24, but the present invention is not limited to this. The automatic transmission 24 may be a synchronous mesh type parallel two-shaft automatic transmission including a known DCT (Dual Clutch Transmission). In short, the present invention can be applied to any vehicle that includes a driving force source including an engine and an electric motor, a clutch provided between the engine and the electric motor, and a transmission that transmits the output torque of the driving force source to the driving wheels.

[0060] In the above embodiment, the torque converter 22 is used as the fluid transmission device, but the present invention is not limited to this. For example, instead of the torque converter 22, another fluid transmission device that does not amplify torque, such as a fluid coupling, may be used as the fluid transmission device. Alternatively, the fluid transmission device does not necessarily have to be provided, and may be replaced with, for example, a starting clutch.

[0061] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0062] 10: Vehicle 12: Engine 14: Drive wheel 20:K0 clutch (clutch) 24: Automatic transmission (transmission) 90: Electronic control device (control device) 92: Driving force source control unit 94: Gear shift control unit MG: Electric motor SP: Power source

Claims

1. A control device for a vehicle including an engine that functions as a driving force source, an electric motor that functions as the driving force source and is connected to a power transmission path between the engine and driving wheels so as to be capable of transmitting power, a clutch provided in the power transmission path between the engine and the electric motor, and a transmission provided in the power transmission path between the electric motor and the driving wheels, A shift control unit that controls the shift of the transmission; a driving force source control unit that executes a torque down control for temporarily reducing an output torque of the driving force source during a transition in which an input rotation speed of the transmission is reduced in association with a power-on upshift, which is an upshift of the transmission performed in an accelerator-on state; Contains the driving force source control unit, when the torque capacity of the clutch is limited during the power-on upshift during engine running in which the vehicle is running by outputting driving force from at least the engine of the driving force sources with the clutch in an engaged state, reduces the amount of torque down in the torque down control performed by electric motor torque down control that temporarily reduces the output torque of the electric motor, and increases the amount of torque down in the torque down control performed by ignition retard control that temporarily reduces the output torque of the engine, compared to when the torque capacity is not limited.

2. 2. The vehicle control device according to claim 1, wherein, during the power-on upshift, when the torque capacity of the clutch is not limited, the driving force source control unit executes the torque down control by the electric motor torque down control, whereas when the torque capacity of the clutch is limited, the driving force source control unit executes the torque down control only by the ignition retard control.

3. 3. The vehicle control device according to claim 2, wherein the driving force source control unit does not permit the torque down control by the electric motor torque down control even if the torque down amount in the torque down control by the ignition retard control is insufficient for a required torque down amount required in the torque down control when the torque capacity of the clutch is limited.

4. 4. The vehicle control device according to claim 1, wherein the shift control unit corrects a control state of the transmission by feedback control so that a progress state of the power-on upshift is in a predetermined state.

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