JP2023008333A - Controller of hybrid vehicle - Google Patents

Abstract

To provide a controller of a hybrid vehicle which can suppress, even when the start request of an internal combustion engine and the shift request of an automatic transmission are executed at the same time, occurrence of shock in accompany with start control of an engine to restrain decrease of drivability.SOLUTION: An electronic control device 90 of a hybrid vehicle 10 includes: a K0 clutch 20 which is arranged in a power transmission path PT between an engine 12 and an electric motor MG; and an automatic transmission 24 which is arranged in the power transmission path PT between the electric motor MG and a drive wheel 14. The electronic control device thereof determines, when (A) a start control of an engine 12 is performed during transmission control of the automatic transmission 24, (a-1) whether there is a possibility that the K0 clutch 20 is synchronized by execution of the start control during the period when transmission phase of the automatic transmission 24 is an inertia phase or not, and delays, (a-2) when it is determined that there is a possibility that the K0 clutch 20 is synchronized during the period of the inertia phase, execution of the start control.SELECTED DRAWING: Figure 1

Description

The present invention includes a friction engagement device disposed between an internal combustion engine and an electric motor in a power transmission path, and an automatic transmission disposed between the electric motor and drive wheels in the power transmission path. The present invention relates to a control device for a hybrid vehicle equipped with.

A hybrid vehicle comprising a friction engagement device disposed between an internal combustion engine and an electric motor in a power transmission path, and an automatic transmission disposed between the electric motor and drive wheels in the power transmission path 2. Description of the Related Art There is known a method of starting an internal combustion engine by causing an electric motor to output cranking torque and controlling engagement of a friction engagement device when conditions for starting the internal combustion engine are satisfied. For example, the one described in Patent Document 1 is it.

JP 2021-54165 A

In the method described in Patent Document 1, when the start request for the internal combustion engine and the shift request for the automatic transmission occur at the same time, the rotation speed of the rotation shaft on the electric motor side in the friction engagement device fluctuates due to shift control. , there is a possibility that the synchronization of the rotation speed of the frictional engagement device is not performed at an appropriate timing, resulting in a shock.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to reduce the shock associated with engine start control even when the start request for the internal combustion engine and the shift request for the automatic transmission occur at the same time. It is an object of the present invention to provide a control device for a hybrid vehicle capable of suppressing the occurrence of drivability and suppressing deterioration of drivability.

The gist of the first invention is an internal combustion engine and an electric motor as a driving force source for running, and a power transmission path between the internal combustion engine and the drive wheels, which is disposed between the internal combustion engine and the electric motor. and an automatic transmission disposed between the electric motor and the drive wheels in the power transmission path, the control device comprising: (A) the internal combustion When a request for starting the engine is detected, the frictional engagement device is engaged to start the start control for starting the internal combustion engine by the electric motor; (b-1) when the shift phase of the automatic transmission is the inertia phase, whether or not there is a possibility that the friction engagement device will be synchronized by the execution of cranking in the start control; (b-2) If it is determined that there is a possibility that the frictional engagement devices will be synchronized during the period of the inertia phase, the execution of cranking in the starting control is delayed.

According to the hybrid vehicle control apparatus of the first aspect of the invention, (A) when a request for starting the internal combustion engine is detected, start control is performed to engage the friction engagement device and start the internal combustion engine by the electric motor. (B) when the start control is executed during shift control of the automatic transmission, (b-1) the start control during the period in which the shift phase of the automatic transmission is the inertia phase; (b-2) It is determined that there is a possibility that the frictional engagement devices will be synchronized during the period of the inertia phase. In this case, the execution of cranking in the starting control is delayed. If it is determined that there is a possibility that the friction engagement device will be synchronized due to the execution of cranking in the start control while the shift phase of the automatic transmission is the inertia phase, fluctuations in the rotation speed of the electric motor during shift control may cause shock. Therefore, in such a case, by delaying the execution of cranking in the start control, fluctuations in the rotational speed of the electric motor during the shift control are suppressed, suppressing the occurrence of a shock associated with the engine start control, thereby suppressing the driver. The deterioration of the ability is suppressed.

According to the control device for a hybrid vehicle of the second invention, in the first invention, if it is determined that there is no possibility that the friction engagement device will be synchronized during the period of the inertia phase, the clutch in the start control Ranking execution cannot be delayed. If it is determined that there is no possibility that the friction engagement device will be synchronized due to the execution of cranking in the start control during the period in which the shift phase of the automatic transmission is the inertia phase, fluctuations in the rotation speed of the electric motor during shift control There is no risk of shock due to Therefore, in such a case, the engine is quickly started by not delaying the execution of cranking in the starting control, and the deterioration of drivability is suppressed.

1 is a schematic configuration diagram of a hybrid vehicle equipped with an electronic control device according to an embodiment of the present invention, and a functional block diagram showing main parts of control functions for various controls in the hybrid vehicle; FIG. FIG. 2 is an example of a flow chart for explaining the control operation of the electronic control unit shown in FIG. 1; FIG. FIG. 3 is an example of a time chart when the flowchart of FIG. 2 is executed when the K0 clutch synchronization prediction point is within the range of the inertia phase prediction period.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following examples, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, etc. of each part are not necessarily drawn accurately.

1 is a schematic configuration diagram of a hybrid vehicle 10 (hereinafter simply referred to as "vehicle 10") including an electronic control unit 90 according to an embodiment of the present invention, and also shows main parts of control functions for various controls in the vehicle 10. FIG. It is a functional block diagram representing.

The vehicle 10 includes an engine 12 and an electric motor MG, which are driving force sources for running, and a power transmission device 16 provided in a power transmission path PT between the engine 12 and drive wheels 14 . Vehicle 10 is a hybrid vehicle.

Engine 12 is a well-known internal combustion engine. An engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, and the like provided in the vehicle 10 is controlled by an electronic control device 90, which will be described later, to control the engine 12. The engine torque Te, which is the output torque of the engine 12, is controlled by the engine 12. [Nm] is controlled. Note that the engine 12 corresponds to the "internal combustion engine" in the present invention.

The power transmission device 16 includes, in order from the engine 12 side, a damper 42, a K0 clutch 20, an electric motor connecting shaft 36, a torque converter 22, an automatic transmission 24, etc. in a case 18, which is a non-rotating member attached to the vehicle body. The power transmission device 16 includes a propeller shaft 28 connected to a transmission output shaft 26 which is an output rotating member of an automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, and a pair of gears connected to the differential gears 30. A drive shaft 32 and the like are provided.

The power transmission device 16 includes an engine connection shaft 34 that connects the engine 12 and the damper 42 . The damper 42 is a well-known damper device, such as a pendulum damper, that absorbs the pulsation of the engine 12 and transmits its rotation.

The K0 clutch 20 is a clutch arranged between the engine 12 and the electric motor MG in the power transmission path PT between the engine 12 and the drive wheels 14 . The electric motor connecting shaft 36 connects the K0 clutch 20 and the torque converter 22 . The K0 clutch 20 is a hydraulic friction engagement device composed of, for example, a multi-plate or single-plate clutch. The K0 clutch 20 is controlled by the K0 hydraulic pressure PRk0 [Pa], which is the regulated hydraulic pressure supplied from the hydraulic control circuit 56, and the K0 torque Tk0 [Nm], which is the transmission torque capacity of the K0 clutch 20 (the engagement force of the K0 clutch 20). is changed, the operating state, that is, the control state, such as the engaged state and the disengaged state, is switched. Hereinafter, unless otherwise distinguished, "engagement" of the K0 clutch 20 includes full engagement and half engagement (slip engagement).

In the vehicle 10, when the K0 clutch 20 is engaged, the engine 12 and the torque converter 22 are connected via the damper 42 and the K0 clutch 20 so that power can be transmitted. On the other hand, when the K0 clutch 20 is in the released state, power transmission between the engine 12 and the torque converter 22 is interrupted. K0 clutch 20 functions as a clutch that connects and disconnects engine 12 and electric motor MG. When the K0 clutch 20 is in the engaged state, one end of the electric motor connecting shaft 36 is connected to the engine 12 via the damper 42 so that the motor connecting shaft 36 is rotationally driven by the engine 12 . The K0 clutch 20 corresponds to the "friction engagement device" in the present invention.

Torque converter 22 is a known torque converter. The torque converter 22 includes a pump impeller 22a connected to an electric motor connecting shaft 36, a turbine impeller 22b connected to a transmission input shaft 38 which is an input rotating member of the automatic transmission 24, a pump impeller 22a and a turbine. and a lockup clutch 40 that directly connects to the blade wheel 22b. Torque converter 22 is a hydrodynamic transmission device that transmits driving force for driving from each of the driving force sources for driving (engine 12, electric motor MG) from electric motor connecting shaft 36 to transmission input shaft 38 via fluid. Torque converter 22 is connected to engine 12 via K0 clutch 20 and damper 42 . The automatic transmission 24 is connected to the torque converter 22 and provided in a transmission path between the torque converter 22 and the drive wheels 14 in the power transmission path PT. The torque converter 22 and the automatic transmission 24 each form part of a power transmission path PT between the driving force source for running (the engine 12 and the electric motor MG) and the drive wheels 14 .

The electric motor MG is a rotating electric machine having a function as an electric 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 which will be described later. The battery 54 is a power storage device that transfers electric power to and from the electric motor MG. In the electric motor MG, the electric motor torque Tm [Nm], which is the output torque of the electric motor MG, is controlled by controlling the inverter 52 by an electronic control unit 90 which will be described later. For example, when the rotation direction of the electric motor MG is the same as that during operation of the engine 12, which is positive rotation, the positive torque on the acceleration side is the power running torque, and the negative torque on the deceleration side is the regenerative torque. be. Electric power is also synonymous with electrical energy, if not specifically distinguished. The power is also synonymous with torque and force unless otherwise specified.

The electric motor MG is connected to the electric motor connecting shaft 36 within the case 18 so as to be able to transmit power. In other words, the electric motor MG is connected to the transmission path between the K0 clutch 20 and the torque converter 22 in the power transmission path PT so that power can be transmitted. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 without the K0 clutch 20 so that power can be transmitted.

The automatic transmission 24 is disposed between the driving force source (the engine 12 and the electric motor MG) and the drive wheels 14 in the power transmission path PT. It is a known planetary gear type automatic transmission that is arranged between the wheels 14 and includes, for example, one or more sets of planetary gear devices (not shown) and a plurality of transmission engagement devices CB. The shift engagement device CB is, for example, a known hydraulic friction engagement device. CB torque Tcb [Nm], which is the transmission torque capacity of each gear shift engagement device CB, is changed by CB hydraulic pressure PRcb [Pa], which is the regulated hydraulic pressure supplied from the hydraulic control circuit 56. , a control state such as an engaged state or a disengaged state is switched.

In the automatic transmission 24, for example, by engaging any one of the shift engaging devices CB, the gear ratio (also referred to as gear ratio) γat (=AT input rotation speed Ni [rpm]/AT output rotation speed) It is a stepped transmission in which one of a plurality of gear stages (also referred to as gear stages) having different speeds No [rpm] is formed. The automatic transmission 24 is involved in the shift of the automatic transmission 24 of the shift engagement device CB by an electronic control unit 90, which will be described later, according to the driver's accelerator operation, the vehicle speed V [km/h], etc. By switching the control state of a predetermined engagement device that is an engagement device, the gear stage to be formed is switched. The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38 and the input rotation speed of the automatic transmission 24 . The AT input rotation speed Ni has the same value as the turbine rotation speed Nt [rpm], which is the output rotation speed of the torque converter 22 . The AT input rotation speed Ni can be represented by the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26 and the output rotation speed of the automatic transmission 24 .

For example, in the shift control of the automatic transmission 24, the shift is executed by changing the grip of any shift engagement device CB. is executed, that is, a so-called clutch-to-clutch shift is executed. Here, the gearshift engagement device CB that is switched from the disengaged state to the engaged state in the clutch-to-clutch shift is referred to as the "engagement-side engagement device CBcon", and is switched from the engaged state to the disengaged state in the clutch-to-clutch shift. The shift engaging device CB will be referred to as a "disengagement side engaging device CBdis". Further, the CB oil pressure PRcb supplied to the hydraulic actuator that controls the connection/disconnection state of the engagement side engagement device CBcon is referred to as the "engagement side hydraulic pressure Pcon [Pa]". The CB hydraulic pressure PRcb supplied to the hydraulic actuator that controls is referred to as "disengagement side hydraulic pressure Pdis [Pa]".

The hydraulic control circuit 56 uses the hydraulic pressure of oil (hydraulic oil OIL) pumped from the MOP 58, which is a mechanical oil pump, or the EOP 60, which is an electric oil pump, as a source pressure, and supplies the necessary hydraulic oil OIL to each part in the case 18. do. For example, the hydraulic control circuit 56 includes a K0 electromagnetic valve SC for connection/disengagement control of the K0 clutch 20, and four transmission electromagnetic valves SL1 to SL4 (hereinafter referred to as Unless otherwise specified, it will be referred to as "speed-changing solenoid valve SL"). These solenoid valve SC for K0 and solenoid valve SL for speed change are, for example, well-known linear solenoid valves. a pressure regulating unit that regulates the pressure of the hydraulic oil OIL by driving the unit to generate the hydraulic pressure.

By controlling the drive current of the K0 solenoid valve SC, the hydraulic pressure supplied to the hydraulic actuator that controls the connection/disconnection state of the K0 clutch 20 is adjusted, thereby controlling the connection/disconnection state of the K0 clutch 20 . For example, when the drive current for the K0 solenoid valve SC is turned off (a state in which drive current does not flow), the K0 clutch 20 is released, and the drive current for the K0 solenoid valve SC is turned on (a state in which drive current flows). ), the K0 clutch 20 is engaged.

By controlling the on/off combination of each drive current for the shift solenoid valve SL, the drive current is supplied to each hydraulic actuator that controls the connection/disengagement state of the shift engagement device CB provided in the automatic transmission 24. Working oil pressure is adjusted. Thereby, the automatic transmission 24 is brought into a neutral state or a desired gear ratio γat is formed. The shift engagement device CB is, for example, a wet multi-plate hydraulic friction engagement device such as a brake or a clutch. For example, the indicated pressures for the engagement side hydraulic pressure Pcon and the disengagement side hydraulic pressure Pdis in a clutch-to-clutch shift are the engagement speed, release speed, and engagement shock of the engagement side engagement device CBcon and the disengagement side engagement device CBdis. is within the permissible range, it is controlled in accordance with a time chart for speed change predetermined experimentally or by design.

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 connection shaft 34 to the K0 clutch 20, the electric motor connection shaft 36, the torque converter 22, the automatic transmission 24, The power is transmitted to the drive wheels 14 through the propeller shaft 28, the differential gear 30, the drive shaft 32, and the like. Regardless of the control state of the K0 clutch 20, the power output from the electric motor MG is sequentially transmitted from the electric motor connecting shaft 36 through the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, and the like. is transmitted to the drive wheels 14.

The vehicle 10 includes a MOP 58, an EOP 60, a pump motor 62, and the like. The MOP 58 is connected to the pump impeller 22a, and is driven to rotate by the driving force source (engine 12, electric motor MG) for traveling, and discharges hydraulic oil OIL used in the power transmission device 16. FIG. The pump motor 62 is a dedicated EOP motor for rotating the EOP 60 . The EOP 60 is rotationally driven by the pump motor 62 to discharge hydraulic oil OIL. Hydraulic oil OIL discharged from the MOP 58 and the EOP 60 is supplied to the hydraulic control circuit 56 . The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, etc., each of which is adjusted based on the hydraulic oil OIL discharged from the MOP 58 and/or the EOP 60 .

The vehicle 10 has an electronic control unit 90 . The electronic control unit 90 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, and an input/output interface. Various controls of the vehicle 10 are executed by performing signal processing. The electronic control unit 90 includes computers for engine control, electric motor control, hydraulic control, etc., as required. The electronic control device 90 corresponds to the "control device" in the present invention.

The electronic control unit 90 includes various sensors provided in the vehicle 10 (for example, the engine rotation speed sensor 70, the turbine rotation speed sensor 72, the output rotation speed sensor 74, the electric motor rotation speed sensor 76, the accelerator opening sensor 78, the throttle valve Various signals based on values detected by the opening sensor 80, battery sensor 84, etc. (for example, the engine rotation speed Ne [rpm], which is the rotation speed of the engine 12, the turbine rotation speed Nt, which is the same value as the AT input rotation speed Ni, the vehicle speed AT output rotation speed No corresponding to V, motor rotation speed Nm [rpm] that is the rotation speed of the electric motor MG, accelerator opening θacc [%] that is the amount of accelerator operation by the driver representing the magnitude of the acceleration operation by the driver , throttle valve opening θth [%] which is the opening of the electronic throttle valve, battery temperature THbat [°C] of the battery 54, battery charging/discharging current Ibat [A], battery voltage Vbat [V], etc.) are input. be.

From the electronic control device 90, various command signals (for example, an engine signal for controlling the engine 12) are sent to each device (for example, the engine control device 50, the inverter 52, the hydraulic control circuit 56, the pump motor 62, etc.) provided in the vehicle 10. A control signal Se, an electric motor control signal Sm for controlling the electric motor MG, a CB hydraulic control signal Scb for controlling the shift engagement device CB, a K0 hydraulic control signal Sk0 for controlling the K0 clutch 20, and a lockup clutch. LU oil pressure control signal Slu for controlling 40, EOP control signal Seop for controlling EOP 60, etc.) are output respectively.

The electronic control unit 90 functionally includes a hybrid control means or hybrid control section 92, a clutch control means or clutch control section 94, a shift control means or shift control section 96, and a shock prediction means or shock prediction section 98. Prepare.

The hybrid control unit 92 functionally includes engine control means, that is, an engine control unit 92a, that controls the operation of the engine 12, and electric motor control means, that is, an electric motor control unit 92b that controls operation of the electric motor MG via the inverter 52. , hybrid drive control and the like by the engine 12 and the electric motor MG are executed by these control functions.

The hybrid control unit 92 calculates the amount of driving demand for 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 required drive amount map is a map in which the relationship between the accelerator opening θacc and the vehicle speed V and the required drive amount is obtained in advance experimentally or by design and stored. The required drive amount is, for example, the required drive torque Trdem [Nm] of the drive wheels 14 . In other words, the required drive torque Trdem is the required drive power Prdem [W] at the vehicle speed V at that time. As the required driving amount, the required driving force Frdem [N] at the driving wheels 14, the required AT output torque at the transmission output shaft 26, and the like can be used. In the calculation of the drive demand amount, the AT output rotation speed No or the like may be used instead of the vehicle speed V. FIG.

The hybrid control unit 92 considers the transmission loss, the auxiliary load, the gear ratio γat of the automatic transmission 24, the chargeable power Win [W] and the dischargeable power Wout [W] of the battery 54, etc., and determines the required drive power Prdem , an engine control signal Se for controlling the engine 12 and an electric motor control signal Sm for controlling the electric motor MG are output. The engine control signal Se is, for example, a command value of the engine power Pe [W], which is the power of the engine 12 that outputs the engine torque Te at the engine rotation speed Ne at that time. The electric motor control signal Sm is, for example, a command value for the power consumption Wm [W] of the electric motor MG that outputs the electric motor torque Tm at the electric motor rotation speed Nm at that time.

The chargeable power Win of the battery 54 is the maximum power that can be input that defines the limit of 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 that defines the limit of 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, for example, the battery temperature THbat and the state of charge value of the battery 54 (the ratio of the charge amount actually stored to the predetermined full charge capacity) SOC [%]. calculated by the electronic control unit 90 based on the

The hybrid control unit 92 sets the running mode to the motor running (=BEV running) mode when the required driving torque Trdem can be covered only by the output of the electric motor MG. In the BEV travel mode, the hybrid control unit 92 controls the BEV that travels by outputting the driving force for traveling only from the electric motor MG of the driving force sources for traveling (the engine 12 and the electric motor MG) when the K0 clutch 20 is released. Battery Electric Vehicle) to run. On the other hand, the hybrid control unit 92 sets the running mode to the engine running mode, that is, the hybrid running (=HEV running) mode when the required drive torque Trdem cannot be met without using at least the output of the engine 12 . In the HEV running mode, the hybrid control unit 92 outputs a running driving force from at least the engine 12 of the running driving force sources (the engine 12 and the electric motor MG) when the K0 clutch 20 is engaged so that the engine runs. Running, that is, HEV (Hybrid Electric Vehicle) running is performed. On the other hand, even when the required driving torque Trdem can be covered by the output of the electric motor MG alone, the hybrid control unit 92 controls the state of charge value SOC of the battery 54 to be less than a predetermined engine start threshold, or when the engine When warm-up of 12th grade is required, the HEV running mode is established. The engine start threshold is a predetermined threshold for determining the state of charge value SOC at which it is necessary to forcibly start the engine 12 and charge the battery 54 . In this manner, the hybrid control unit 92 automatically stops the engine 12 during HEV travel, restarts the engine 12 after stopping the engine, or starts the engine 12 during BEV travel, based on the required drive torque Trdem. Alternatively, the engine 12 is automatically stopped when the vehicle is stopped, and the engine 12 is restarted after the engine is stopped to switch between the BEV running mode and the HEV running mode.

The engine control unit 92a controls the engine torque Te so as to achieve the amount of drive required for the vehicle 10. FIG. The electric motor control unit 92b controls the electric motor torque Tm so as to achieve the amount of drive required for the vehicle 10. FIG. Specifically, in the BEV travel mode, the electric motor control unit 92b controls the electric motor torque Tm so as to achieve the required drive torque Trdem. In the HEV running mode, the engine control unit 92a controls the engine torque Te so as to achieve all or part of the required drive torque Trdem, and the electric motor control unit 92b controls the required drive torque Trdem with the engine torque Te. The motor torque Tm is controlled so as to compensate for the insufficient torque.

The hybrid control unit 92 functionally further includes start determination means, i.e., a start determination part 92c, which determines the start of the engine 12, and start control means, i.e., a start control part 92d, which executes start control of the engine 12.

The start determination unit 92c determines whether or not the start of the engine 12 has been requested. That is, the start determination unit 92c determines whether there is a request to start the engine 12 or not. For example, the start determination unit 92c (a) when the required drive torque Trdem in the BEV traveling mode exceeds a range that can be covered by the output of the electric motor MG alone, (b) when the engine 12 or the like needs to be warmed up, and (c) when the state-of-charge value SOC of the battery 54 is less than the engine start threshold value, it is determined that there is a request to start the engine 12 .

When the start determination unit 92 c determines that there is a request to start the engine 12 , the clutch control unit 94 controls the K0 clutch 20 so as to start the engine 12 . For example, the clutch control unit 94 controls the disengaged state so that the K0 torque Tk0 for transmitting the cranking torque Tcr, which is the torque for increasing the engine rotation speed Ne for cranking the engine 12, to the engine 12 side is obtained. A K0 hydraulic control signal Sk0 for controlling the K0 clutch 20 toward the engaged state is output to the hydraulic control circuit 56 . “Cranking” refers to outputting cranking torque Tcr [Nm] from the electric motor MG and engaging the K0 clutch 20 to start the engine 12. The engine connecting shaft 34 connected to the engine 12 is is to rotate. For example, in the start control of the engine 12, the K0 clutch command pressure PRk0_tgt is a K0 time predetermined experimentally or by design so that the engagement speed and engagement shock of the K0 clutch 20 are within the allowable range. Controlled according to the chart.

When the start determining unit 92 c determines that there is a request to start the engine 12 , the start control unit 92 d controls the engine 12 and the electric motor MG so as to start the engine 12 . For example, the start control unit 92d outputs an electric motor control signal Sm for the electric motor MG to output the cranking torque Tcr to the inverter 52 in accordance with the switching of the K0 clutch 20 to the engaged state by the clutch control unit 94. That is, when the engine 12 is started, the start control unit 92d outputs to the inverter 52 the electric motor control signal Sm for controlling the electric motor MG so that the electric motor MG outputs the cranking torque Tcr.

Cranking of the engine 12 is performed by the switching control of the K0 clutch 20 from the released state to the engaged state by the clutch control unit 94 and the output control of the cranking torque Tcr of the electric motor MG by the start control unit 92d.

When the start determination unit 92c determines that there is a request to start the engine 12, the start control unit 92d starts fuel supply and ignition in conjunction with cranking of the engine 12 by the K0 clutch 20 and the electric motor MG. engine control signal Se to the engine control device 50 . That is, when the engine 12 is started, the start control section 92d outputs an engine control signal Se for controlling the engine 12 so that the engine 12 starts operating to the engine control device 50 . In this manner, the start control unit 92d executes start control of the engine 12 when the start determination unit 92c determines that the start of the engine 12 is requested.

When starting the engine 12 during BEV travel, the start control unit 92d controls the electric motor torque Tm for BEV travel, that is, the electric motor torque Tm for generating the required drive torque Trdem, and the electric motor torque Tm corresponding to the cranking torque Tcr. is output from the electric motor MG. The start control unit 92d also determines whether or not the engine 12 is under start control, that is, whether or not the start control of the engine 12 has started but has not ended.

The shift control unit 96 determines the shift of the automatic transmission 24 using, for example, a shift map having a predetermined relationship, and outputs the CB hydraulic control signal Scb for executing the shift control of the automatic transmission 24 as necessary. is output to the hydraulic control circuit 56 . The shift map is a predetermined relationship having a shift line for judging the shift of the automatic transmission 24 on two-dimensional coordinates having, for example, the vehicle speed V and the required driving torque Trdem as variables. In the shift map, the AT output rotational speed No may be used instead of the vehicle speed V, and the required driving force Frdem, the accelerator opening θacc, the throttle valve opening θth, etc. may be used instead of the required driving torque Trdem. can be The shift control unit 96 determines whether or not the automatic transmission 24 is under shift control, that is, whether or not the shift control has started but has not ended.

The shift phase (shift stage) of the automatic transmission 24 includes a torque phase and an inertia phase. The torque phase is a phase in which the output torque of the automatic transmission 24 is changing within the shift period of the automatic transmission 24 (the period from the start of shift control to the end of shift control). The inertia phase refers to the period during which the automatic transmission 24 shifts, in which the turbine rotation speed Nt, which is equivalent to the rotation speed of the transmission input shaft 38, which is the input-side rotation member of the automatic transmission 24, is theoretically equal to that before the shift. Theoretical post-shift turbine rotational speed Nt_post [rpm] (post-shift gear This is the phase in which it changes to the theoretical turbine rotation speed Nt calculated from the gear ratio γat in the stage and the vehicle speed V). The torque phase is also a period during which the transmission torque capacities of the engagement side engagement device CBcon and the release side engagement device CBdis are changing.

When it is determined to execute the start control of the engine 12 during a period in which the shift control of the automatic transmission 24 is not being executed during BEV running, the start control of the engine 12 is executed by the start control unit 92d as described above. be. Further, when the shift control of the automatic transmission 24 is executed during a period in which the start control of the engine 12 is not executed by the start control unit 92d during BEV traveling, the shift control unit 96 executes the shift control as described above. executed.

By the way, a request to start the engine 12 may occur during shift control of the automatic transmission 24 (during execution of shift control) during BEV travel.

The shock prediction section 98 functionally includes inertia phase prediction means, namely inertia phase prediction section 98a, synchronization prediction means, namely synchronization prediction section 98b, and overlap determination means, namely overlap determination section 98c.

When the start determining unit 92 c determines that there is a request to start the engine 12 , the inertia phase predicting unit 98 a calculates a predicted period of the inertia phase in the shift phase of the automatic transmission 24 . For example, a predetermined gear shift time chart of the gear stage before the gear shift, the gear stage after the gear shift, and the command pressures of the engagement side working oil pressure Pcon and the disengagement side working oil pressure Pdis in the clutch-to-clutch shift, and the start of the inertia phase. The predicted start time point and predicted end time point of the inertia phase are calculated using a map in which the relationship between the predicted time point and the predicted end time point is predetermined experimentally or by design.

When the start determination unit 92c determines that there is a request to start the engine 12, the synchronization prediction unit 98b sets a synchronization prediction time at which the K0 clutch 20 is predicted to synchronize due to the execution of cranking in the start control of the engine 12. calculate. "The K0 clutch 20 is synchronized" means that the rotation speed (=Ne) of the K0 clutch 20 on the engine 12 side and the rotation speed (=Nm) of the electric motor MG side of the K0 clutch 20 match. For example, the electric motor rotation speed Nm at the start of shift control, a predetermined shift time chart of command pressures for the engagement side working oil pressure Pcon and disengagement side working pressure Pdis in clutch-to-clutch shift, and a predetermined K0 clutch command pressure PRk0_tgt. Synchronization prediction time point of the K0 clutch 20 is determined by using a time chart for K0 and a map in which the relationship between the starting method of the engine 12 and the synchronization prediction time point of the K0 clutch 20 is predetermined experimentally or by design. is calculated. That is, the indicated pressures of the engagement side operating pressure Pcon and the disengagement side operating pressure Pdis are controlled according to the shift time chart, the K0 clutch command pressure PRk0_tgt is controlled according to the K0 time chart, and the start of cranking, which will be described later, is delayed. Synchronization prediction time is calculated on the condition that it is not possible.

For example, the starting method of the engine 12 includes an early ignition starting method and a push starting method. In the early ignition starting method, the K0 clutch 20 is engaged and cranking is performed by the electric motor MG, and fuel is injected and ignited into the engine 12 before the synchronization of the K0 clutch 20, and once the combustion becomes possible to continue, the K0 clutch 20 is engaged. is released, and then the K0 clutch 20 is re-engaged. In the early ignition starting method, the engine 12 is started by injecting and igniting fuel near the compression TDC (Top Dead Center) when the engine speed Ne is low. The push-start method is a method in which the K0 clutch 20 is engaged to increase the engine rotation speed Ne by the electric motor MG, and after the K0 clutch 20 is synchronized, fuel is injected into the engine 12 and ignited to start the engine. Compared to the push start method, the early ignition start method uses the combustion torque (engine torque Te) of the engine 12 to start the engine 12, so that the assist torque for cranking the electric motor MG can be reduced, and the starting response is improved. Good nature. The assist torque is the torque transmitted to the engine 12 when the electric motor MG cranks, and has the same magnitude as the transmission torque capacity (engagement force of the K0 clutch 20) Tc of the K0 clutch 20 during start control of the engine 12. is. It should be noted that the "starting" of the engine 12 referred to here means that the engine 12 fully explodes (starts operation) and becomes capable of self-sustaining operation, and that the K0 clutch 20 is fully engaged. It also means a series of control operations related to starting the engine 12 up to .

When the inertia phase prediction section 98a calculates the prediction period of the inertia phase in the shift phase of the automatic transmission 24 and the synchronization prediction section 98b calculates the synchronization prediction time point of the K0 clutch 20, the overlap determination section 98c determines whether the K0 clutch 20 overlaps with the predicted period of the inertia phase (that is, whether the predicted period of synchronization of the K0 clutch 20 is within the range of the predicted period of the inertia phase). If the predicted synchronization time point of the K0 clutch 20 is within the range of the predicted inertia phase period, there is a possibility that the K0 clutch 20 will synchronize due to the execution of cranking during the period in which the shift phase of the automatic transmission 24 is the inertia phase. I agree that it is determined that there is. If the predicted synchronization time point of the K0 clutch 20 is outside the range of the inertia phase prediction period, there is a possibility that the K0 clutch 20 will be synchronized by the execution of cranking during the period in which the shift phase of the automatic transmission 24 is the inertia phase. I agree that it is determined that there is no

If the overlap determination unit 98c determines that the predicted synchronization time of the K0 clutch 20 and the predicted period of the inertia phase overlap, the overlap determination unit 98c outputs a delay request signal requesting a delay in the start of cranking in the starting control of the engine 12 to the clutch. It is output to the control section 94 and the starting control section 92d. When the delay request signal is input from the overlap determination unit 98c, the clutch control unit 94 and the start control unit 92d control the K0 clutch 20 and the start control unit 92d so that the predicted synchronization time of the K0 clutch 20 and the predicted period of the inertia phase do not overlap. The start of cranking of the engine 12 by the electric motor MG is delayed. This control for delaying the start of cranking corresponds to "delaying the execution of cranking in starting control" in the present invention. When the overlap determination unit 98c determines that the predicted synchronization time of the K0 clutch 20 and the predicted period of the inertia phase do not overlap, the overlap determination unit 98c outputs a delay request signal requesting a delay in the start of cranking in the start control of the engine 12. It is not output to the clutch control section 94 and the starting control section 92d. The clutch control unit 94 and the start control unit 92d do not delay the start of cranking of the engine 12 by the K0 clutch 20 and the electric motor MG unless the delay request signal is input from the overlap determination unit 98c.

FIG. 2 is an example of a flow chart for explaining the control operation of the electronic control unit 90 shown in FIG. The flowchart of FIG. 2 is executed when there is a request to start the engine 12 .

First, in step S10 (hereinafter, step is omitted) corresponding to the function of the shift control section 96, it is determined whether or not the automatic transmission 24 is under shift control. If the determination in S10 is affirmative, in S20 corresponding to the function of the inertia phase prediction section 98a, the predicted start time and predicted end time of the inertia phase in the shifting phase of the automatic transmission 24 are calculated. After execution of S20, in S30 corresponding to the function of the start control section 92d, it is determined whether or not the engine 12 is under start control.

If the determination in S30 is affirmative, in S40 corresponding to the function of the synchronization prediction section 98b, the synchronization prediction time point of the K0 clutch 20 is calculated by executing cranking in the start control of the engine 12. FIG. After execution of S40, in S50 corresponding to the function of the overlap determination unit 98c, the predicted synchronization time of the K0 clutch 20 calculated in S40 and the predicted period of the inertia phase calculated in S20 (from the predicted start time of the inertia phase to the predicted end of the inertia phase) are calculated. It is determined whether or not the period up to the point in time) overlaps.

If the determination of S10 is negative, if the determination of S30 is negative, or if the determination of S50 is positive, S60 corresponding to the functions of the clutch control unit 94 and the start control unit 92d is executed. , cranking of the engine 12 is performed by the K0 clutch 20 and the electric motor MG, and the process ends. If the determination in S50 is negative, in S70 corresponding to the function of the overlap determination section 98c, a delay request signal requesting a delay in the start of cranking in the starting control of the engine 12 is output. After executing S70, S60 is executed, and the process ends.

FIG. 3 is an example of a time chart when the flowchart of FIG. 2 is executed when the predicted synchronization time of the K0 clutch 20 is within the range of the predicted period of the inertia phase. The horizontal axis in FIG. 3 is time t [ms].

In FIG. 3, the delay request signal is a signal requesting a delay in the start of cranking execution, and indicates whether or not there is a delay request. In the delay request signal, ON is a signal that requests delay, and OFF is a signal that does not request delay. In the K0 clutch command pressure PRk0_tgt shown in FIG. 3, the present embodiment in which the start of cranking is delayed is indicated by the solid line, and the comparative example in which the start of cranking is not delayed (according to the time chart for K0 described above). example) is indicated by a dashed line.

Before the time point t1, the lockup clutch 40 is engaged during BEV travel, and the electric motor rotation speed Nm is increasing due to the accelerator operation by the driver.

At time t1, for example, power-on upshift control is started. A power-on upshift is an upshift that is executed by increasing the accelerator opening θacc by the driver's accelerator operation (eg, depression of an accelerator pedal). When the shift control of the power-on upshift is started, the reduction control to decrease the disengagement side working oil pressure Pdis is started and the increase control to increase the engagement side working oil pressure Pcon is started, and the torque phase in the shift control is started. be. Also, at time t1, the lockup clutch 40 starts switching from the engaged state to the disengaged state. By switching the lock-up clutch 40 to the released state, the electric motor connecting shaft 36 and the transmission input shaft 38 are connected via fluid, and the electric motor rotation speed Nm of the electric motor MG, which is the driving force source for running, is reduced to the turbine rotation speed. higher than Nt.

At time t2 (>t1), a request to start the engine 12 is generated and start control is started. Specifically, in a period after time t2 (constant pressure standby pressure period), the K0 clutch command pressure PRk0_tgt is a command pressure for executing so-called pack packing to close the pack clearance of the K0 clutch 20, and is the constant pressure in the state immediately before engagement. The indicated pressure corresponds to the standby pressure. In the constant pressure standby pressure period, the K0 clutch 20 is in a state just before engagement and the engine connection shaft 34 connected to the engine 12 cannot be rotated, so this is a state before the start of cranking. After the constant pressure standby pressure period, the K0 clutch command pressure PRk0_tgt is set to the engagement pressure (=cranking pressure) at which the K0 clutch 20 is engaged, so that the K0 clutch 20 is engaged and the engine connecting shaft 34 rotates. Let me. Cranking is started by setting the K0 clutch command pressure PRk0_tgt to the engagement pressure.

At time t2, the predicted period of the inertia phase is calculated to be the period from time t3 (>t2) to time t7 (>t3). Further, when cranking is started at time t4 (>t2) according to the K0 time chart without delaying the start of the execution of cranking, the predicted synchronization time of the K0 clutch 20 is calculated to be time t6. Since the predicted synchronization time t6 of the K0 clutch 20 overlaps with the predicted period of the inertia phase (period from time t3 to time t7), a delay request signal requesting a delay in the start of cranking is output. As a result, the start of cranking is delayed from time t4 to time t5 (>t4). The synchronization time of the K0 clutch 20 when the start of cranking is delayed to time t5 is time t8 (>t5). This time point t8 does not overlap the inertia phase prediction period (the period from time point t3 to time point t7). Specifically, the time t8 is a time after the predicted end time t7 of the inertia phase. Then, at time t9 (>t7), shift control ends.

According to this embodiment, (A) when a request to start the engine 12 is detected, the K0 clutch 20 is engaged to start the engine 12 by the electric motor MG, and (B) the automatic transmission 24 is started. (b-1) Possibility of synchronization of the K0 clutch 20 due to execution of cranking in the start control during the period in which the gear shift phase of the automatic transmission 24 is the inertia phase. (b-2) If it is determined that there is a possibility that the K0 clutch 20 will be synchronized during the period of the inertia phase, the start of cranking in the starting control is delayed. . If it is determined that there is a possibility that the K0 clutch 20 will be synchronized due to the execution of cranking in the start control during the period in which the shift phase of the automatic transmission 24 is the inertia phase, the fluctuation of the electric motor rotation speed Nm during the shift control may cause shock. Therefore, in such a case, by delaying the start of cranking execution in the starting control, fluctuations in the electric motor rotation speed Nm during the shift control are suppressed, and the occurrence of shock accompanying the starting control of the engine 12 is suppressed. , the deterioration of drivability is suppressed.

According to this embodiment, when it is determined that there is no possibility of the K0 clutch 20 synchronizing during the period of the inertia phase, the start of cranking in the starting control is not delayed. When it is determined that there is no possibility of the K0 clutch 20 synchronizing due to the execution of cranking in the start control during the period in which the shift phase of the automatic transmission 24 is the inertia phase, a shock due to the fluctuation of the rotational speed during the shift control there is no risk of occurrence. Therefore, in such a case, the engine 12 is quickly started by not delaying the start of cranking in the starting control, and the deterioration of drivability is suppressed.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other aspects.

In the above-described embodiment, the timing chart of FIG. 3 exemplifies the case where the start of cranking is delayed, but the present invention is not limited to this exemplification. For example, it is sufficient that the synchronization prediction point of the K0 clutch 20 and the inertia phase prediction period do not overlap. It is also possible to reduce the rate of increase of the engine rotation speed Ne by reducing the engagement pressure of . Thus, the control to lower the K0 clutch command pressure PRk0_tgt after the constant standby pressure period also corresponds to "delaying the execution of cranking in the starting control" in the present invention.

In the above-described embodiment, the time chart of FIG. 3 exemplifies the case where a request to start the engine 12 is generated while the shift phase of the automatic transmission 24 is the torque phase, but the present invention is not limited to this exemplification. . For example, the present invention can be applied even when a request to start the engine 12 is generated while the shift phase of the automatic transmission 24 is the inertia phase.

In the above-described embodiment, the automatic transmission 24 was of the planetary gear type, but the automatic transmission 24 of the present invention may be a stepped transmission of another configuration such as a constant mesh type parallel shaft type.

In the above-described embodiment, the time chart of FIG. 3 is for the case where a request to start the engine 12 is generated during the shift control of the power-on upshift of the automatic transmission 24, but the present invention is limited to the power-on upshift. It can also be applied when a request to start the engine 12 is generated during other shift control.

Although the torque converter 22 is used as the hydrodynamic transmission device in the above embodiment, the present invention is not limited to this aspect. For example, instead of the torque converter 22, another hydrodynamic transmission such as a fluid coupling that does not amplify torque may be used as the hydrodynamic transmission. Also, the hydrodynamic transmission device does not necessarily have to be provided, and may be replaced with, for example, a starting clutch.

It should be noted that what has been described above is merely an embodiment of the present invention, and the present invention can be implemented in a mode with various modifications and improvements based on the knowledge of those skilled in the art without departing from the scope of the invention.

10: Hybrid vehicle 12: Engine (internal combustion engine)
14: drive wheel 20: K0 clutch (friction engagement device)
24: Automatic transmission 90: Electronic control device (control device)
MG: electric motor PT: power transmission path

Claims (1)

an internal combustion engine and an electric motor as driving force sources for running; a frictional engagement device disposed between the internal combustion engine and the electric motor in a power transmission path between the internal combustion engine and driving wheels; A control device for a hybrid vehicle including an automatic transmission disposed between the electric motor and the drive wheels in a transmission path,
when a request to start the internal combustion engine is detected, engaging the frictional engagement device and starting control for starting the internal combustion engine by the electric motor;
When executing the starting control during shift control of the automatic transmission,
determining whether or not there is a possibility that the friction engagement device will be synchronized by executing cranking in the start control during a period in which the shift phase of the automatic transmission is the inertia phase;
A control device for a hybrid vehicle, wherein when it is determined that there is a possibility that the frictional engagement device will be synchronized during the period of the inertia phase, execution of cranking in the starting control is delayed.

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