JP2024005118A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a shock when starting an engine, and suppress deterioration of energy efficiency when operating regenerative braking by an electric motor.

SOLUTION: Since slip control is performed before the start of an engine during motor traveling, the start of the engine can be quickly performed, and a shock due to torque fluctuation accompanying the start of the engine can be suppressed. In addition, when the engine is not started and the input torque to a second clutch is less than a predetermined torque during motor traveling, the slip control is ended and the second clutch is brought into an engaged state, so that when regenerative braking is operated with accelerator-off and brake-on, the second clutch is easily brought into the engaged state. Therefore, it is possible to suppress a shock at the time of starting the engine, and to suppress deterioration of the energy efficiency at the time of operating the regenerative braking by an electric motor.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a control device for a vehicle that includes a clutch between an engine, an electric motor, and drive wheels.

an engine, an electric motor connected to a power transmission path between the engine and drive wheels so as to be capable of transmitting power, a first clutch provided between the engine and the electric motor in the power transmission path, and a first clutch provided between the engine and the electric motor in the power transmission path; 2. Description of the Related Art A vehicle control device including a second clutch provided between the electric motor and the drive wheels in a transmission path is well known. For example, the vehicle control device described in Patent Document 1 is one such example. Patent Document 1 discloses that when the first clutch is in a released state and the second clutch is in an engaged state, the first clutch is controlled toward the engaged state while the motor is running using only the electric motor as a power source. It is disclosed that when starting the engine, the second clutch is placed in a slip state or a released state.

Patent No. 5794377

Here, when starting the engine while the motor is running, it is conceivable to control the second clutch to a slip state before the start of the engine starting, for example, from the viewpoint of suppressing starting shock and improving response. By the way, if the engine does not start while the second clutch is controlled to be in the slip state and the brake pedal is further depressed, regenerative braking by the electric motor is activated while the second clutch is in the slip state. . In this case, a portion of the driven torque from the drive wheels that is transmitted to the electric motor is lost due to slipping of the second clutch, resulting in a decrease in regeneration efficiency, and as a result, there is a risk that energy efficiency will deteriorate.

The present invention was made against the background of the above-mentioned circumstances, and its purpose is to suppress the shock when starting the engine, and to suppress the deterioration of energy efficiency when the regenerative braking by the electric motor is activated. An object of the present invention is to provide a vehicle control device that can perform the following functions.

The gist of the first invention is as follows: (a) an engine, an electric motor connected to a power transmission path between the engine and drive wheels so as to be capable of transmitting power; and the engine and the electric motor in the power transmission path. A control device for a vehicle comprising: a first clutch provided between the electric motor and the driving wheels in the power transmission path; and a second clutch provided between the electric motor and the drive wheels in the power transmission path, the control device comprising: Switching from motor running in which the first clutch is disengaged to run using only the electric motor as a power source to engine running in which the first clutch is engaged and at least the engine is used as a power source, This is executed when slip control is performed in which the second clutch is in a slip state, and (c) during the motor running, the slip control is performed before starting the engine in conjunction with switching to engine running. If the engine does not start while the motor is running and the input torque to the second clutch is less than a predetermined torque, the slip control is terminated and the second clutch is The purpose is to bring the two into an engaged state.

According to the first invention, since slip control is performed before the engine starts while the motor is running, the engine can be started quickly and shocks caused by torque fluctuations caused by the engine start can be avoided. Can be suppressed. In addition, if the engine does not start while the motor is running and the input torque to the second clutch is less than a predetermined torque, the slip control is terminated and the second clutch is brought into an engaged state. Therefore, when the regenerative braking is activated when the accelerator is turned off and the brake is turned on, the second clutch is likely to be brought into the engaged state. Therefore, it is possible to suppress shock when starting the engine, and it is also possible to suppress deterioration of energy efficiency when operating regenerative braking by the electric motor.

1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and a diagram illustrating main parts of a control function and a control system for various controls in the vehicle. FIG. 3 is a diagram showing a predetermined relationship between WSC input torque and WSC target differential rotation speed. This is a flowchart explaining the main part of the control operation of the electronic control device, and is a flowchart explaining the control operation for suppressing shock when starting the engine 12 and suppressing deterioration of energy efficiency when operating regenerative braking by electric motor MG. be. 4 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 3 is executed. FIG.

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

FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, as well as a diagram illustrating main parts of a control function and a control system for various controls in the vehicle 10. In FIG. 1, a vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG, which function as a power source. The vehicle 10 also includes drive wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14.

Engine 12 is a known internal combustion engine. In the engine 12, an engine control device 50 provided in the vehicle 10 is controlled by an electronic control device 90, which will be described later, so that an engine torque Te, which is the torque of the engine 12, is controlled.

The electric motor MG is a known rotating electrical machine that has 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 . In the electric motor MG, the inverter 52 is controlled by an electronic control device 90, which will be described later, so that the MG torque Tm, which is the torque of the electric motor MG, is controlled. For example, when the rotational direction of the electric motor MG is positive rotation, which is the same rotational direction as the engine 12 is operating, the MG torque Tm is a power running torque when the positive torque is the acceleration side where power is generated from the battery 54. The MG torque Tm is, for example, a regenerative torque in the case of positive rotation and a negative torque on the deceleration side where power is generated by the power of the engine 12 or the driven force input from the drive wheels 14 side. The above-mentioned electric power also means electric energy unless otherwise specified. The above-mentioned power also includes driving force, torque, and force unless otherwise specified.

The power transmission device 16 includes an engagement/disengagement clutch K0, a starting clutch WSC, an automatic transmission 20, a reduction gear mechanism 22, and a differential gear 24 connected to the reduction gear mechanism 22 in a case 18 that is a non-rotating member attached to the vehicle body. etc. The engagement/disengagement clutch K0 is a first clutch provided between the engine 12 and the electric motor MG in the power transmission path between the engine 12 and the drive wheels 14. The starting clutch WSC is a second clutch provided between the electric motor MG and the driving wheels 14 in the power transmission path between the engine 12 and the driving wheels 14. The reduction gear mechanism 22 is connected to a transmission output gear 26 that is an output rotating member of the automatic transmission 20.

The power transmission device 16 also includes a pair of drive shafts 28 connected to a differential gear 24 and the like. The power transmission device 16 also includes, within the case 18, an engine connection shaft 30 that connects the engine 12 and the disconnection clutch K0, a motor connection shaft 32 that connects the disconnection clutch K0 and the starting clutch WSC, and the like. . The power transmission device 16 also includes, within the case 18, a mechanical oil pump 34, a transmission member 36 that connects the motor connecting shaft 32 and the mechanical oil pump 34, and the like. The transmission member 36 is composed of, for example, a sprocket and a chain. The mechanical oil pump 34 is driven by a power source (engine 12, electric motor MG) and discharges hydraulic oil OIL used in the power transmission device 16.

The electric motor MG is connected to the electric motor connection shaft 32 within the case 18 so as to be capable of transmitting power. That is, the electric motor MG is connected to the power transmission path between the engine 12 and the driving wheels 14 so as to be capable of transmitting power.

The engagement/disengagement clutch K0 is, for example, a known friction engagement device. The disengagement clutch K0 is engaged by changing the K0 torque capacity Tk0, which is the torque capacity of the disengagement clutch K0, by the regulated K0 oil pressure PRk0 supplied from the hydraulic control circuit 56 provided in the vehicle 10. operating states, such as a slip state, a slip state, and a release state, that is, a control state can be switched.

The starting clutch WSC is, for example, a wet friction engagement device configured by a multi-plate clutch pressed by a hydraulic actuator. The control state of the starting clutch WSC is switched by changing the WSC torque capacity Twsc, which is the torque capacity of the starting clutch WSC, by the regulated WSC oil pressure PRwsc supplied from the hydraulic control circuit 56.

The input side member of the starting clutch WSC is integrally connected to the motor connecting shaft 32. The output side member of the starting clutch WSC is integrally connected to a transmission input shaft 38 that is an input rotating member of the automatic transmission 20. The hydraulic actuator included in the starting clutch WSC includes a piston, a return spring, an oil chamber, and the like. In the starting clutch WSC, when the WSC hydraulic pressure PRwsc is supplied to the oil chamber, the piston moves in the direction of the plurality of friction plates of the starting clutch WSC against the biasing force of the return spring, and the WSC torque capacity Twsc is increased by the WSC hydraulic pressure PRwsc. The control state is switched by changing. In the starting clutch WSC, when the oil chamber is filled with hydraulic oil OIL and the clearance between the plurality of friction plates is closed by the pressing force of the piston, that is, the pack clearance of the starting clutch WSC is set to be closed. Packing is complete. Starting clutch WSC generates WSC torque capacity Twsc by further increasing WSC oil pressure PRwsc from the packing completion state. The WSC oil pressure PRwsc to complete the pack filling state is the WSC oil pressure PRwsc to make the piston reach the stroke end and the WSC torque capacity Twsc is not generated, that is, the pack stroke end (=PSE) pressure PRpse. It is. In this embodiment, the WSC torque capacity Twsc when the WSC oil pressure PRwsc is the PSE pressure PRpse is referred to as the PSE torque Tpse. When the WSC oil pressure PRwsc is greater than or equal to the PSE pressure PRpse, the WSC torque capacity Twsc is increased in proportion to the WSC oil pressure PRwsc. Note that since the starting clutch WSC is a wet friction engagement device, in the stroke back region where the WSC oil pressure PRwsc is equal to or lower than the PSE pressure PRpse, a WSC torque capacity Twsc corresponding to the drag loss is generated.

The automatic transmission 20 is a known planetary gear type automatic transmission that includes, for example, a planetary gear device and an engagement device CB. The engagement device CB includes, for example, a plurality of known friction engagement devices. The control state of each engagement device CB is switched by changing the CB torque capacity Tcb, which is the torque capacity of each engagement device CB, by the regulated CB oil pressure PRcb supplied from the oil pressure control circuit 56.

The automatic transmission 20 is configured to engage one of the engagement devices CB so that one of a plurality of gears with different gear ratios γat (=input rotational speed Ni/output rotational speed No) is engaged. One of the following gears is formed. The input rotational speed Ni is the rotational speed of the transmission input shaft 38, and is the input rotational speed of the automatic transmission 20. The input rotational speed Ni is also the rotational speed of the output side member of the starting clutch WSC. The output rotational speed No is the rotational speed of the transmission output gear 26, and is the output rotational speed of the automatic transmission 20.

Hydraulic oil OIL discharged by at least one of the mechanical oil pump 34 and the electric oil pump 58 provided in the vehicle 10 and driven by the pump motor 60 is supplied to the hydraulic control circuit 56 .

Vehicle 10 includes a wheel brake device 62. Each wheel of vehicle 10, including drive wheels 14, is equipped with a wheel brake 64. The wheel brake device 62 applies a wheel braking torque TBw, which is a braking torque TB by the wheel brake 64, to the wheels in accordance with a command from an electronic control device 90, which will be described later. The wheel brake device 62 normally applies a wheel braking torque TBw corresponding to the brake operation amount Bra. On the other hand, the wheel brake device 62 applies a wheel braking torque TBw of a magnitude necessary for each control, for example, when the automatic brake function is activated or during regeneration control. The brake operation amount Bra is a signal representing the magnitude of the brake pedal depression operation by the driver, that is, the magnitude of the brake operation, corresponding to the depression force on the brake pedal.

The vehicle 10 further includes an electronic control device 90 as a controller including a control device for the vehicle 10. The electronic control device 90 includes, for example, a so-called microcomputer equipped with a CPU, RAM, ROM, input/output interface, etc., and executes various controls of the vehicle 10.

The electronic control device 90 includes various signals (for example, the rotational speed of the engine 12 Engine rotation speed Ne, MG rotation speed Nm which is the rotation speed of electric motor MG and also the rotation speed of the input side member of starting clutch WSC, input rotation speed Ni, output rotation speed No corresponding to vehicle speed V, accelerator opening θacc, Throttle valve opening θth, brake-on signal Bon, brake operation amount Bra, battery temperature THbat, battery charging/discharging current Ibat, battery voltage Vbat, hydraulic oil temperature THoil, which is the temperature of hydraulic oil OIL, etc. are supplied, respectively.

The electronic control device 90 sends various command signals (for example, engine control command signal Se, MG control command signal Sm, CB hydraulic control command signal Scb) to each device 50, 52, 56, 60, 62, etc. provided in the vehicle 10. , K0 hydraulic control command signal Sk0, WSC hydraulic control command signal Swsc, electric oil pump control command signal Seop, brake control command signal Sbra, etc.) are output, respectively.

The electronic control device 90 includes a power source control means, that is, a power source control section 92, a clutch control means, that is, a clutch control section 94, and a brake control means, that is, a brake control section 96, in order to realize various controls in the vehicle 10. .

The power source control unit 92 includes a function of controlling the operation of the engine 12 and a function of controlling the operation of the electric motor MG, and uses these control functions to execute hybrid drive control etc. by the engine 12 and the electric motor MG. .

The power source control unit 92 calculates the amount of drive required by the driver for the vehicle 10, for example, by applying the accelerator opening θacc and the vehicle speed V to the required amount of drive map. The required drive amount map is a relationship for determining the required drive amount that has been determined and stored in advance experimentally or by design, that is, is predetermined. The required drive amount is, for example, the required drive torque Trdem [Nm] at the drive wheels 14. Looking at it from another perspective, the required drive torque Trdem is the required drive power Prdem [W] at the vehicle speed V at that time. As the required drive amount, the required driving force Frdem [N] for the drive wheels 14, etc. can also be used. The power source control unit 92 takes into account transmission loss, auxiliary equipment load, gear ratio γat of the automatic transmission 20, etc., and generates an engine control command signal Se that controls the engine 12 so as to realize the required driving power Prdem. It outputs an MG control command signal Sm that controls the electric motor MG.

If the required drive power Prdem can be covered only by the output of the electric motor MG, the power source control unit 92 sets the drive mode for driving the vehicle 10 to the BEV drive mode. The BEV drive mode is a motor drive mode in which motor travel (=BEV travel) in which the vehicle travels using only the electric motor MG as a power source is possible when the engagement/disengagement clutch K0 is released. On the other hand, if the required drive power Prdem cannot be met without using at least the output of the engine 12, the power source control unit 92 sets the drive mode to the engine drive mode, that is, the HEV drive mode. The HEV drive mode is a hybrid drive mode in which engine running using at least the engine 12 as a power source, that is, hybrid driving (=HEV driving), is possible when the engagement/disengagement clutch K0 is engaged. On the other hand, even if the required drive power Prdem can be covered only by the output of the electric motor MG, the power source control unit 92 does not control the power source when the battery 54 needs to be charged or the engine 12 etc. needs to be warmed up. , establishes the HEV drive mode.

The power source control unit 92 determines whether there is an engine start request to switch the control state of the engine 12 from a stopped state to an operating state. For example, the power source control unit 92 determines whether, in the BEV drive mode, the required drive power Prdem has increased beyond the range that can be covered only by the output of the electric motor MG, or whether it is necessary to warm up the engine 12, etc. Alternatively, it is determined whether there is an engine start request based on whether or not charging of the battery 54 is necessary.

When the power source control unit 92 determines that there is an engine start request, the clutch control unit 94 controls the engagement/disengagement clutch K0 to execute start control of the engine 12. For example, the clutch control unit 94 controls the K0 torque capacity Tk0 for transmitting the cranking torque Tcr to the engine 12 to control the disengaged clutch K0 in the disengaged state toward the engaged state. Outputs hydraulic control command signal Sk0. The cranking torque Tcr is a predetermined torque necessary for cranking the engine 12 to increase the engine rotational speed Ne.

When the power source control unit 92 determines that there is an engine start request, it controls the engine 12 and the electric motor MG to execute start control of the engine 12. For example, the power source control section 92 outputs the MG control command signal Sm for the electric motor MG to output the cranking torque Tcr in accordance with the switching of the engagement/disengagement clutch K0 to the engaged state by the clutch control section 94. Further, the power source control unit 92 outputs an engine control command signal Se for starting fuel supply, engine ignition, etc. in conjunction with cranking of the engine 12.

The clutch control unit 94 makes a shift judgment of the automatic transmission 20 using a shift map having a predetermined relationship, for example, and sends a CB hydraulic control command signal Scb for switching the gear stage of the automatic transmission 20 as necessary. Output. The shift map is a predetermined relationship having a shift line for determining the shift of the automatic transmission 20 on a two-dimensional coordinate using, for example, the vehicle speed V and the required drive torque Trdem as variables.

The braking control unit 96 controls, for example, the accelerator operation by the driver (for example, the accelerator opening θacc, the rate of decrease in the accelerator opening θacc), the vehicle speed V, the slope of the downhill road, the brake operation by the driver (for example, the brake operation amount Bra, the brake operation The required braking torque TBdem is set based on the rate of increase in the amount Bra. The braking control unit 96 generates the braking torque TB of the vehicle 10 so that the required braking torque TBdem is obtained while the vehicle 10 is decelerating. The required braking torque TBdem is basically a required braking torque with respect to the wheel braking torque TBw, and is realized by the wheel braking torque TBw, but for example, from the viewpoint of improving energy efficiency, it may be given priority to the regenerative braking torque TBr. This will be realized. The regenerative braking torque TBr is a braking torque TB obtained by regenerative braking of the electric motor MG, that is, regenerative braking.

Here, the power source control unit 92 executes the switch from BEV driving to HEV driving while performing slip control CNslp of starting clutch WSC. The slip control CNslp is a control that puts the starting clutch WSC in a slip state. Thereby, starting shock due to torque fluctuations accompanying starting control of the engine 12 can be suppressed. The starting shock is caused by, for example, a control error in the engine torque Te when the engagement/disengagement clutch K0 is half-engaged, during synchronization, or after synchronization.

During execution of the slip control CNslp, the clutch control unit 94 controls the starting clutch WSC with a WSC torque capacity Twsc that corresponds to the WSC input torque Tinw that realizes the required drive torque Trdem for the vehicle 10. That is, during execution of slip control CNslp, clutch control unit 94 controls starting clutch WSC so as to obtain WSC torque capacity Twsc equivalent to WSC input torque Tinw that realizes required drive torque Trdem. The WSC input torque Tinw is the input torque to the starting clutch WSC. The WSC input torque Tinw that realizes the required drive torque Trdem is a torque obtained by converting the required drive torque Trdem onto the motor coupling shaft 32, taking into account loss, for example, or the WSC required torque.

The power source control unit 92 controls the MG power Pm, which is the output of the electric motor MG that realizes the requested drive power Prdem, in a state where the starting clutch WSC is controlled so that the WSC torque capacity Twsc is equivalent to the WSC requested torque. Slip control CNslp is performed by increasing the amount by a certain amount. The increase in MG power Pm is consumed by putting the starting clutch WSC into the slip state, but the MG power Pm that realizes the required drive power Prdem is transmitted to the drive wheels 14.

When the accelerator is depressed, the electric motor MG alone will not provide enough driving force, so it is necessary to quickly shift to HEV driving. On the other hand, during BEV driving, the power source control unit 92 performs slip control CNslp before starting the engine 12 in conjunction with the switch to HEV driving. That is, during BEV driving, the power source control unit 92 performs slip control CNslp in preparation for starting the engine 12. In this embodiment, the slip control CNslp performed during BEV driving is referred to as BEV WSC slip control CNslpev.

When starting the engine 12 when the accelerator is off or when the accelerator is depressed, the electric motor MG alone is less likely to lack driving force compared to starting when the accelerator is depressed, so after it is determined that there is an engine start request, the starting clutch WSC may be brought into a slip state while slowly suppressing shocks and acceleration fluctuations. From another perspective, if the accelerator is returned and the brake is turned on without the engine 12 being started during BEV driving, regenerative braking by the electric motor MG is activated while the starting clutch WSC remains in the slip state. In this case, there is a risk that the regeneration efficiency will decrease due to slipping of the starting clutch WSC, and the energy efficiency will deteriorate.

Therefore, the power source control unit 92 executes the BEV WSC slip control CNslpev when the WSC input torque Tinw is relatively large, and executes the BEV WSC slip control CNslpev when the WSC input torque Tinw is relatively small. Not executed. That is, if the engine 12 is not started during BEV driving and the WSC input torque Tinw is less than the predetermined torque Tinf, the power source control unit 92 ends the BEV WSC slip control CNslpev and starts the vehicle. Clutch WSC is brought into engagement.

The predetermined torque Tinf is, for example, the lower limit of the WSC torque capacity Twsc, or a value obtained by subtracting a predetermined variation from the lower limit of the WSC torque capacity Twsc. From the viewpoint of quickly increasing the WSC torque capacity Twsc, the clutch control unit 94 changes the WSC torque capacity Twsc, that is, the PSE torque Tpse, when controlling the starting clutch WSC to the packing completion state, by increasing the WSC torque capacity Twsc from the WSC torque capacity Twsc. Controlled as a lower limit value.

During BEV driving, starting clutch WSC is switched between an engaged state and a slip state at a predetermined torque Tinf. In particular, there is a concern about engagement shock when the starting clutch WSC is brought into the engaged state. On the other hand, the WSC target differential rotational speed ΔNwsctgt in the BEV WSC slip control CNslpev is changed according to the WSC input torque Tinw. For example, the smaller the WSC input torque Tinw is, the smaller the WSC target differential rotational speed ΔNwsctgt is set. The WSC target rotational speed difference ΔNwsctgt is a target value of the WSC rotational speed difference ΔNwsc. The WSC differential rotational speed ΔNwsc is a differential rotational speed of the starting clutch WSC, and is a slip amount that is the rotational speed difference between the input rotational speed and the output rotational speed of the starting clutch WSC. The WSC target rotational speed difference ΔNwsctgt is the target slip amount. The input rotational speed of the starting clutch WSC is the rotational speed of the input side member of the starting clutch WSC, and is the same value as the MG rotational speed Nm. The output rotational speed of the starting clutch WSC is the rotational speed of the output side member of the starting clutch WSC, and is the same value as the input rotational speed Ni. That is, the WSC rotational speed difference ΔNwsc is the rotational speed difference between the MG rotational speed Nm and the input rotational speed Ni. In this embodiment, the value obtained by subtracting the input rotation speed Ni from the MG rotation speed Nm is defined as the WSC differential rotation speed ΔNwsc (=Nm-Ni).

FIG. 2 is a diagram showing a predetermined relationship between the WSC input torque Tinw and the WSC target differential rotational speed ΔNwsctgt. In FIG. 2, the WSC target rotational speed difference ΔNwsctgt is set to a smaller value as the WSC input torque Tinw becomes smaller. When executing the BEV WSC slip control CNslpev, the power source control unit 92 calculates the WSC target differential rotation speed ΔNwsctgt by applying the WSC input torque Tinw to the relationship shown in FIG. A target MG rotation speed Nmtgt, which is a target value, is set. The target MG rotation speed Nmtgt is the value obtained by adding the input rotation speed Ni to the WSC target rotation speed difference ΔNwsctgt (=ΔNwsctgt+Ni). The power source control unit 92 controls the MG power Pm by feedback control so that the MG rotational speed Nm becomes the target MG rotational speed Nmtgt.

In this way, the slip control CNslp adjusts the WSC differential rotational speed ΔNwsc to the WSC input torque Tinw while the starting clutch WSC is controlled by the WSC torque capacity Twsc that corresponds to the WSC input torque Tinw that realizes the required drive torque Trdem. This is rotation speed control in which the MG power Pm is controlled so that the smaller the WSC target difference rotation speed ΔNwsctgt is, the smaller the WSC target difference rotation speed ΔNwsctgt is.

When the WSC input torque Tinw decreases and approaches the predetermined torque Tinf, the power source control unit 92 sets the WSC target differential rotational speed ΔNwsctgt so that the starting clutch WSC does not slip unintentionally even if the WSC torque capacity Twsc varies. Execute WSC slip control CNslpev at BEV with a zero value. In this way, when the WSC input torque Tinw decreases to the vicinity of the predetermined torque Tinf, the power source control unit 92 sets the WSC target differential rotational speed ΔNwsctgt to zero until the WSC input torque Tinw falls below the predetermined torque Tinf. Set to value.

BEV WSC slip control CNslpev can reduce regenerative loss during regenerative braking due to slip of starting clutch WSC and suppress engagement shock of starting clutch WSC.

FIG. 3 is a flowchart illustrating a main part of the control operation of the electronic control device 90, which is a control for suppressing shock when starting the engine 12 and suppressing deterioration of energy efficiency when operating regenerative braking by the electric motor MG. This is a flowchart illustrating the operation, which is repeatedly executed during BEV driving, for example.

In FIG. 3, each step of the flowchart corresponds to a function of the power source control section 92. In step (hereinafter, step will be omitted) S10, it is determined whether the WSC input torque Tinw has fallen below the "predetermined torque Tinf-α". “α” is a hysteresis amount provided in determining whether to execute the BEV WSC slip control CNslpev. If the determination in S10 is negative, it is determined in S20 whether or not the WSC input torque Tinw exceeds a predetermined torque Tinf. If the determination in S10 is affirmative, the BEV WSC slip control CNslpev is terminated in S30, and the starting clutch WSC is brought into and maintained in the engaged state. If the determination in S20 is affirmative, the BEV WSC slip control CNslpev is activated in S40. If the determination in S20 is negative, this routine is ended. As is clear from the flowchart in FIG. 3, the BEV WSC slip control CNslpev may be activated and deactivated repeatedly, and terminating the BEV WSC slip control CNslpev means stopping the BEV WSC slip control CNslpev. I agree to do so.

FIG. 4 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 3 is executed. FIG. 4 is a diagram showing an example of a case where the accelerator pedal is released during BEV driving, for example. In FIG. 4, the BEV WSC slip request flag, which is a request flag for executing the BEV WSC slip control CNslpev, is turned on during BEV driving, and the BEV WSC slip control is performed in preparation for starting the engine 12. CNslpev is being executed (see [1]). Since the accelerator pedal is released, the engine 12 is not started and the WSC input torque Tinw is reduced. In accordance with the decrease in the WSC input torque Tinw, the WSC target differential rotation speed ΔNwsctgt is decreased toward the zero value, and the command value of the MG rotation speed Nm corresponding to the target MG rotation speed Nmtgt is decreased (see [2]). . When the WSC input torque Tinw is reduced to near the predetermined torque Tinf, the WSC target differential rotational speed ΔNwsctgt is set to a zero value (see [3]). The WSC torque capacity Twsc is reduced with a delay relative to the WSC input torque Tinw due to a delay in hydraulic response and the like. The lower limit of the WSC torque capacity Twsc is the PSE torque Tpse (see [4]). When the WSC input torque Tinw falls below the predetermined torque Tinf, the BEV WSC slip request flag is turned off, the BEV WSC slip control CNslpev is terminated, and a WSC engagement instruction is issued to switch the starting clutch WSC to the engaged state. is output (see time t1). Thereafter, the WSC torque capacity Twsc is increased, and the starting clutch WSC is switched to the engaged state (see after time t2). When the WSC input torque Tinw is a negative torque, the starting clutch WSC is brought into a fully engaged state (see [5]).

As described above, according to this embodiment, since the BEV WSC slip control CNslpev is performed, the engine 12 can be started promptly and the starting shock of the engine 12 can be suppressed. In addition, if the WSC input torque Tinw is lower than the predetermined torque Tinf, the BEV WSC slip control CNslpev is terminated, so that the starting clutch WSC is likely to be engaged when regenerative braking by the electric motor MG is activated. . Therefore, it is possible to suppress a shock when starting the engine 12, and it is also possible to suppress deterioration of energy efficiency when operating regenerative braking by the electric motor MG.

Furthermore, according to this embodiment, the BEV WSC slip control CNslpev is a rotational speed control that controls the MG power Pm so that the WSC differential rotational speed ΔNwsc becomes the WSC target differential rotational speed ΔNwsctgt. The target slip state is appropriately set.

Furthermore, according to this embodiment, the smaller the WSC input torque Tinw, the smaller the WSC target rotational speed difference ΔNwsctgt is set, so the engagement shock of the starting clutch WSC when the accelerator pedal is released is suppressed. be done.

Further, according to this embodiment, when the WSC input torque Tinw decreases to the vicinity of the predetermined torque Tinf, the WSC target differential rotational speed ΔNwsctgt is set to a zero value, so the engagement shock of the starting clutch WSC is suppressed. Furthermore, unintended slipping of the starting clutch WSC is suppressed.

Further, according to this embodiment, since the PSE torque Tpse is set as the lower limit value of the WSC torque capacity Twsc, the WSC torque capacity Twsc can be quickly increased. Further, the predetermined torque Tinf is the lower limit value of the WSC torque capacity Twsc or a value obtained by subtracting a predetermined variation from the lower limit value of the WSC torque capacity Twsc, so that the WSC input torque Tinw is less than the predetermined torque Tinf. By terminating the WSC slip control CNslpev at the time of BEV after falling below, unintended slip of the starting clutch WSC is suppressed.

Although the embodiments of the present invention have been described above in detail based on the drawings, the present invention can also be applied to other aspects.

For example, in the embodiment described above, the starting clutch WSC was exemplified as the second clutch provided between the electric motor MG and the driving wheels 14 in the power transmission path between the engine 12 and the driving wheels 14, but this embodiment Not limited to. For example, instead of the starting clutch WSC, an engagement device CB that can bring the automatic transmission 20 into a power transmission disabled state, that is, into a neutral state, may be used as the second clutch. Alternatively, if the vehicle 10 is equipped with a fluid transmission device such as a torque converter instead of the starting clutch WSC, a lock-up clutch provided in the fluid transmission device may be used as the second clutch. Note that when the starting clutch WSC is used as the second clutch, the automatic transmission 20 does not necessarily need to be provided.

The above-mentioned embodiment is merely one embodiment, and the present invention can be implemented with various changes and improvements based on the knowledge of those skilled in the art.

10: Vehicle 12: Engine 14: Drive wheel 90: Electronic control device (control device)
K0: Disconnect clutch (first clutch)
MG: Electric motor WSC: Starting clutch (second clutch)

Claims (4)

an engine, an electric motor connected to a power transmission path between the engine and drive wheels so as to be capable of transmitting power, a first clutch provided between the engine and the electric motor in the power transmission path, and a first clutch provided between the engine and the electric motor in the power transmission path; A control device for a vehicle, comprising: a second clutch provided between the electric motor and the drive wheels in a transmission path,
Switching from motor running in which the first clutch is disengaged to run using only the electric motor as a power source to engine running in which the first clutch is engaged and at least the engine is used as a power source, This is executed when slip control is being performed in which the second clutch is in a slip state,
While the motor is running, the slip control is performed before starting the engine upon switching to the engine running, and the engine is not started while the motor is running, and the second clutch is not activated. A control device for a vehicle, characterized in that when input torque to is less than a predetermined torque, the slip control is terminated and the second clutch is brought into an engaged state. The slip control includes controlling the input rotational speed of the second clutch in a state where the second clutch is controlled with a torque capacity that corresponds to the input torque to the second clutch that realizes the required drive torque for the vehicle. 2. The rotation speed control according to claim 1, wherein the output of the electric motor is controlled so that the slip amount, which is the rotation speed difference from the output rotation speed, is set to a target slip amount that is smaller as the input torque is smaller. Control device for the vehicle described. When the input torque to the second clutch decreases to near the predetermined torque, the target slip amount is set to a zero value until the input torque falls below the predetermined torque. 2. The vehicle control device according to item 2. The torque capacity when the second clutch is controlled to be in a pack packing completion state where the pack clearance is reduced is set as the lower limit value of the torque capacity of the second clutch,
4. The predetermined torque is a lower limit value of the torque capacity of the second clutch, or a value obtained by subtracting a predetermined variation from the lower limit value. The control device for the vehicle described in section.

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