JP7625922B2 - Vehicle control device - Google Patents

Description

The present invention relates to a control device for a vehicle equipped with an engine and an electric motor as a driving force source for driving, a clutch disposed between the engine and the electric motor, and an automatic transmission disposed between the driving force source for driving and the drive wheels.

In a vehicle equipped with an engine and an electric motor as a driving force source for traveling, a clutch disposed between the engine and the electric motor, and an automatic transmission disposed between the driving force source for traveling and the drive wheels, there is known a technology for simultaneously performing upshift control and engine start control when a request to start the engine occurs during upshift control of the automatic transmission. For example, one such technology is described in Patent Document 1.

JP 2010-149560 A

In the vehicle control device described in Patent Document 1, automatic transmission upshift control and engine start control are performed simultaneously, so at the start of the inertia phase of the upshift control, the input torque of the automatic transmission fluctuates with engine start, which can lead to deterioration of shift performance (for example, hesitation that causes a delay in the completion of shifting).

The present invention was made against the background of the above circumstances, and its purpose is to provide a vehicle control device that achieves both engine start responsiveness and shift performance when an engine start request occurs during shift control of an automatic transmission.

The gist of a first invention is: (a) a control device for a vehicle including an engine and an electric motor as a driving force source for driving, a clutch disposed between the engine and the electric motor, and an automatic transmission disposed between the driving force source for driving and drive wheels, (b) when a request to start the engine is generated before a shift phase of the automatic transmission ends a torque phase, the control device delays progression of the torque phase while starting cranking of the engine, and then cancels the delay in progression of the torque phase to advance the torque phase, (c) when the torque phase is progressing when the request to start the engine is generated, the control device interrupts progression of the torque phase and returns the shift phase to a state at the start of the torque phase, thereby delaying the progression of the torque phase, and (d) when the degree of progression of the torque phase at the time the request to start the engine is generated is within a predetermined range that is determined in advance for each gear stage before and after shifting in the automatic transmission, the control device delays the progression of the torque phase .

The gist of the second invention is that in the first invention, the release point for releasing the delay in the progression of the torque phase is set based on the degree of progression of the torque phase at the start point when the delay in the progression of the torque phase begins and the gear stages before and after the shift in the automatic transmission.

The gist of the third invention is that in the first invention, when a request to start the engine occurs during the gear shift preparation stage before the start of the torque phase, the start of the torque phase is delayed to slow down the progression of the torque phase.

According to the vehicle control device of the first aspect of the invention, when a request to start the engine occurs before the automatic transmission has finished the torque phase, the torque phase is delayed and cranking of the engine is started, and then the delay in the torque phase is released and the torque phase is advanced. In this way, the torque phase in the automatic transmission shift control is delayed while the start of engine cranking is prioritized, so that deterioration of engine start responsiveness is suppressed. In addition, since the start of the inertia phase of the shift control is after the start of engine cranking, the input torque of the automatic transmission is suppressed from fluctuating with the start of engine cranking (start of engine start), and a delay in the end of the shift is suppressed. In this way, both the engine start responsiveness and the shift performance are achieved.
Furthermore, if the torque phase is in progress when the engine start request is generated, the progress of the torque phase is interrupted and the shift phase is returned to the state at the start of the torque phase, thereby delaying the progress of the torque phase. As a result, if the engine start request is generated when the torque phase is in progress, the progress of the torque phase is interrupted and the shift phase is returned to the state at the start of the torque phase, thereby achieving both suppression of deterioration in engine start responsiveness and suppression of delay in the completion of shifting.
Furthermore, when the degree of progress of the torque phase at the time when the engine start request is generated is within a predetermined range that is predefined for each gear stage before and after the shift in the automatic transmission, the progress of the torque phase is delayed. As a result, when the degree of progress of the torque phase at the time when the engine start request is generated is within a predetermined range that is predefined for each gear stage before and after the shift in the automatic transmission, the progress of the torque phase is delayed and the start of engine cranking is prioritized. Whether or not to delay the progress of the torque phase is determined according to the degree of progress of the torque phase at the time when the engine start request is generated, it is easy to achieve both engine start responsiveness and shifting performance.

According to the vehicle control device of the second aspect of the invention, in the first aspect of the invention, a release time point for releasing the delay of the torque phase progression is set based on the degree of progression of the torque phase at a start time point when the delay of the torque phase progression is started and the gear stages before and after the shift in the automatic transmission. In this way, since the release time point for releasing the delay of the torque phase progression is set based on the degree of progression of the torque phase at a start time point when the delay of the torque phase progression is started and the gear stages before and after the shift in the automatic transmission, the release time point can be controlled so as not to be too late.

According to the vehicle control device of the third aspect of the invention, in the first aspect of the invention, when the engine start request occurs during the gear shift preparation stage before the start of the torque phase, the start of the torque phase is delayed, thereby delaying the progress of the torque phase. In this way, when the engine start request occurs during the progress of the torque phase, the start of the torque phase is delayed, thereby achieving both suppression of deterioration of engine start responsiveness and suppression of delay in the completion of gear shifting.

1 is a schematic configuration diagram of a vehicle equipped with an electronic control device according to an embodiment of the present invention, and is also a functional block diagram showing essential parts of control functions for various controls in the vehicle. 2 is an example of a flowchart illustrating a control operation of the electronic control device shown in FIG. 1 . 3 is an example of a time chart when the flowchart of FIG. 2 is executed during shift control of a power-on upshift of an automatic transmission during EV driving.

The following describes in detail the embodiments of the present invention with reference to the drawings. Note that in the following embodiments, the drawings have been appropriately simplified or modified, and the dimensional ratios and shapes of each part are not necessarily drawn accurately.

This is a schematic diagram of a vehicle 10 equipped with an electronic control device 90 according to an embodiment of the present invention, and is also a functional block diagram showing the main control functions for various controls in the vehicle 10.

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

The engine 12 is a well-known internal combustion engine. The engine 12 has an engine control device 50, which includes a throttle actuator, a fuel injection device, an ignition device, and the like, provided on the vehicle 10, controlled by an electronic control device 90 (described later), thereby controlling the engine torque Te [Nm], which is the output torque of the engine 12.

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 that 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 that is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, etc.

The power transmission device 16 includes an engine connecting shaft 34 that connects the engine 12 to a damper 42. The damper 42 is a well-known damper device, such as a pendulum damper, that transmits the rotation of the engine 12 while absorbing the pulsation of the engine 12.

The K0 clutch 20 is a clutch disposed between the engine 12 and the electric motor MG in the power transmission path 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 constituted by, for example, a multi-plate or single-plate clutch. The K0 clutch 20 switches between an engaged state, a released state, or a controlled state, by changing the K0 torque Tk0 [Nm], which is the transmission torque capacity (the engagement force of the K0 clutch 20), of the K0 clutch 20, by the K0 oil pressure PRk0 [Pa], which is the adjusted oil pressure supplied from the hydraulic control circuit 56. In the vehicle 10, when the K0 clutch 20 is in an engaged state, the engine 12 and the torque converter 22 are connected to each other 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 a released state, the power transmission between the engine 12 and the torque converter 22 is interrupted. The K0 clutch 20 functions as a clutch that connects and disconnects the engine 12 and the electric motor MG. When the K0 clutch 20 is engaged, one end of the electric motor connecting shaft 36 is connected to the engine 12 via a damper 42, and is rotated and driven by the engine 12. The K0 clutch 20 corresponds to the "clutch" in this invention.

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

The electric motor MG is a rotating electric machine that functions as an electric motor that generates mechanical power from electric power and 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 described later. The battery 54 is an electricity storage device that supplies and receives electric power to 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 device 90 described later. For example, when the rotation direction of the electric motor MG is forward rotation, which is the same as the rotation direction when the engine 12 is operating, the electric motor torque Tm is a power torque when it is a positive torque on the acceleration side, and a regenerative torque when it is a negative torque on the deceleration side. The electric power is also the same as electric energy when there is no particular distinction. The power is also the same as torque and force when there is no particular distinction.

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

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

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

For example, in the shift control of the automatic transmission 24, a shift is performed by switching one of the shift engagement devices CB, that is, a so-called clutch-to-clutch shift is performed by switching the shift engagement device CB between an engaged state and a released state. Here, the shift engagement device CB that is switched from a released state to an engaged state in the clutch-to-clutch shift is referred to as the "engagement side engagement device CBcon", and the shift engagement device CB that is switched from an engaged state to a released state in the clutch-to-clutch shift is referred to as the "release side engagement device CBdis". In addition, the CB hydraulic pressure PRcb supplied to the hydraulic actuator that controls the engagement/disengagement state of the engagement side engagement device CBcon is referred to as the "engagement side operating hydraulic pressure Pcon [Pa]", and the CB hydraulic pressure PRcb supplied to the hydraulic actuator that controls the engagement/disengagement state of the release side engagement device CBdis is referred to as the "release side operating hydraulic pressure Pdis [Pa]".

The hydraulic control circuit 56 uses the hydraulic pressure of the oil (hydraulic oil OIL) pumped from the mechanical oil pump MOP 58 and the electric oil pump EOP 60 as the source pressure to supply the necessary hydraulic oil OIL to each part in the case 18. For example, the hydraulic control circuit 56 is provided with a K0 solenoid valve SC for controlling the connection and disconnection of the K0 clutch 20, and four shift solenoid valves SL1 to SL4 for controlling the shifting of the automatic transmission 24 (hereinafter, referred to as "shift solenoid valves SL" unless otherwise specified). These K0 solenoid valves SC and shift solenoid valves SL are, for example, well-known linear solenoid valves, and include an electromagnetic part that converts electrical energy into driving force by supplying a driving current to a solenoid, and a pressure regulating part that regulates the pressure of the hydraulic oil OIL by driving the electromagnetic part to generate hydraulic oil pressure.

By controlling the drive current of the K0 solenoid valve SC, the hydraulic pressure supplied to the hydraulic actuator that controls the connected/disconnected state of the K0 clutch 20 is adjusted to control the connected/disconnected state of the K0 clutch 20. For example, by turning off the drive current of the K0 solenoid valve SC (a state in which no drive current flows), the K0 clutch 20 is put into a released state, and by turning on the drive current of the K0 solenoid valve SC (a state in which drive current flows), the K0 clutch 20 is put into an engaged state.

By controlling the on/off combination of each drive current of the shift solenoid valve SL, the hydraulic pressure supplied to each hydraulic actuator that controls the engagement and disengagement state of the shift engagement device CB provided in the automatic transmission 24 is adjusted. This allows the automatic transmission 24 to be placed in neutral or to form the desired gear ratio γat. The shift engagement device CB is, for example, a wet-type multi-plate hydraulic friction engagement device such as a brake or clutch.

In the power transmission device 16, when the K0 clutch 20 is engaged, the power output from the engine 12 is transmitted from the engine connecting shaft 34 to the drive wheels 14 via the K0 clutch 20, the electric motor connecting shaft 36, the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in that order. Regardless of the control state of the K0 clutch 20, the power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the drive wheels 14 via the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in that order.

The vehicle 10 is equipped with a MOP 58, which is a mechanical oil pump, an EOP 60, which is an electric oil pump, a pump motor 62, and the like. The MOP 58 is connected to the pump impeller 22a, and is rotated and driven by the driving power source for traveling (the engine 12, the electric motor MG) to discharge hydraulic oil OIL used in the power transmission device 16. The pump motor 62 is a motor dedicated to the EOP for rotating and driving the EOP 60. The EOP 60 is rotated and driven by the pump motor 62 to discharge hydraulic oil OIL. The hydraulic oil OIL discharged by the MOP 58 and the EOP 60 is supplied to the hydraulic control circuit 56. The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, and the like, which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and/or the EOP 60.

The vehicle 10 is equipped with an electronic control device 90. The electronic control device 90 is configured to include a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input/output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing according to a program previously stored in the ROM while utilizing the temporary storage function of the RAM. The electronic control device 90 is configured to include computers for engine control, electric motor control, hydraulic control, etc. as necessary. The electronic control device 90 corresponds to the "control device" in this invention.

The electronic control device 90 receives various signals based on the detection values of various sensors (e.g., engine speed sensor 70, turbine speed sensor 72, output speed sensor 74, motor speed sensor 76, accelerator opening sensor 78, throttle valve opening sensor 80, battery sensor 84, etc.) provided in the vehicle 10 (e.g., engine speed Ne [rpm], which is the rotation speed of the engine 12; turbine speed Nt, which is the same value as AT input speed Ni; AT output speed No, which corresponds to the vehicle speed V; motor speed Nm [rpm], which is the rotation speed of the motor MG; accelerator opening θacc [%], which is the driver's accelerator operation amount indicating the magnitude of the driver's acceleration operation; throttle valve opening θth [%], which is the opening of the electronic throttle valve; battery temperature THbat [°C] of the battery 54, battery charge/discharge current Ibat [A], battery voltage Vbat [V], etc.).

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

The electronic control device 90 functionally comprises a hybrid control means, i.e., a hybrid control unit 92, a clutch control means, i.e., a clutch control unit 94, and a gear shift control means, i.e., a gear shift control unit 96.

The hybrid control unit 92 functionally comprises an engine control means, i.e., an engine control unit 92a, that controls the operation of the engine 12, and an electric motor control means, i.e., an electric motor control unit 92b, that controls the operation of the electric motor MG via the inverter 52, and executes hybrid drive control using the engine 12 and the electric motor MG, etc., by using these control functions.

The hybrid control unit 92 calculates the drive demand amount of the vehicle 10 by the driver, for example, by applying the accelerator opening θacc and the vehicle speed V to a drive demand amount map. The drive demand amount map is a map in which the relationship between the accelerator opening θacc and the vehicle speed V and the drive demand amount is determined in advance experimentally or by design and stored. The drive demand amount is, for example, the required drive torque Trdem [Nm] at 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. The drive demand amount can also be the required drive force Frdem [N] at the drive wheels 14, the required AT output torque at the transmission output shaft 26, etc. In calculating the drive demand amount, the AT output rotation speed No, etc. may be used instead of the vehicle speed V.

The hybrid control unit 92 outputs an engine control signal Se for controlling the engine 12 and an electric motor control signal Sm for controlling the electric motor MG so as to realize the required driving power Prdem, taking into consideration the transmission loss, the auxiliary load, the gear ratio γat of the automatic transmission 24, the chargeable electric power Win [W] and the dischargeable electric power Wout [W] of the battery 54, etc. The engine control signal Se is, for example, a command value for 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, which specifies the limit on the input power of the battery 54, and indicates the input limit of the battery 54. The dischargeable power Wout of the battery 54 is the maximum power that can be output, which specifies the limit on the output power of the battery 54, and indicates the output limit of the battery 54. The chargeable power Win and dischargeable power Wout of the battery 54 are calculated by the electronic control unit 90 based on, for example, the battery temperature THbat and the charge state value (the ratio of the actual charge amount to a predetermined full charge capacity) SOC [%] of the battery 54.

When the required drive torque Trdem can be met only by the output of the electric motor MG, the hybrid control unit 92 sets the driving mode to the motor driving (=EV driving) mode. In the EV driving mode, the hybrid control unit 92 performs EV driving by outputting the driving force only from the electric motor MG among the driving force sources (engine 12, electric motor MG) when the K0 clutch 20 is in the disengaged state. On the other hand, when the required drive torque Trdem cannot be met without using at least the output of the engine 12, the hybrid control unit 92 sets the driving mode to the engine driving mode, i.e., hybrid driving (=HV driving) mode. In the HV driving mode, the hybrid control unit 92 performs engine driving, i.e., HV driving, by outputting the driving force from at least the engine 12 among the driving force sources (engine 12, electric motor MG) when the K0 clutch 20 is in the engaged state. On the other hand, even if the required drive torque Trdem can be satisfied only by the output of the electric motor MG, the hybrid control unit 92 establishes the HV driving mode when the state of charge value SOC of the battery 54 is less than a predetermined engine start threshold value or when warming up of the engine 12, etc. is required. The engine start threshold value is a predetermined threshold value for determining that the state of charge value SOC is such that the engine 12 needs to be forcibly started to charge the battery 54. In this way, the hybrid control unit 92 switches between the EV driving mode and the HV driving mode by automatically stopping the engine 12 during HV driving and restarting the engine 12 after the engine has stopped, starting the engine 12 during EV driving, automatically stopping the engine 12 while the vehicle is stopped and restarting the engine 12 after the engine has stopped, based on the required drive torque Trdem, etc.

The engine control unit 92a controls the engine torque Te to realize the drive demand for the vehicle 10. The motor control unit 92b controls the motor torque Tm to realize the drive demand for the vehicle 10. Specifically, in the EV driving mode, the motor control unit 92b controls the motor torque Tm to realize the required drive torque Trdem. In the HV driving mode, the engine control unit 92a controls the engine torque Te to realize all or part of the required drive torque Trdem, and the motor control unit 92b controls the motor torque Tm to compensate for the torque that is insufficient in the engine torque Te for the required drive torque Trdem.

The hybrid control unit 92 further includes functionally a start determination means, i.e., a start determination unit 92c, that determines whether the engine 12 should be started, and a start control means, i.e., a start control unit 92d, that executes start control of the engine 12.

The start determination unit 92c determines whether or not a start of the engine 12 has been requested. In other words, the start determination unit 92c determines whether or not there is a request to start the engine 12. For example, in the EV driving mode, the start determination unit 92c determines that there is a request to start the engine 12 if (a) the required drive torque Trdem has increased beyond the range that can be covered by the output of the electric motor MG alone, (b) warming up of the engine 12, etc. is required, or (c) the state of charge value SOC of the battery 54 is less than the engine start threshold.

When the start determination unit 92c determines that the start of the engine 12 is requested, the clutch control unit 94 controls the K0 clutch 20 to execute start control of the engine 12. For example, the clutch control unit 94 outputs a K0 hydraulic control signal Sk0 to the hydraulic control circuit 56 to control the K0 clutch 20 from a released state toward an engaged state so as to obtain a K0 torque Tk0 for transmitting the cranking torque Tcr, which is a torque that increases the engine rotation speed Ne, to the engine 12 side. The clutch control unit 94 outputs a K0 hydraulic control signal Sk0 to the hydraulic control circuit 56 to control the actuator to switch the control state of the K0 clutch 20 from a released state to an engaged state when the engine 12 is started.

When the start determination unit 92c determines that the start of the engine 12 is requested, the start control unit 92d controls the engine 12 and the electric motor MG to execute start control of the engine 12. For example, the start control unit 92d outputs to the inverter 52 an electric motor control signal Sm for causing the electric motor MG to output the cranking torque Tcr in accordance with the switching of the K0 clutch 20 to the engaged state by the clutch control unit 94. In other words, when starting the engine 12, the start control unit 92d outputs to the inverter 52 an electric motor control signal Sm for controlling the electric motor MG to output the cranking torque Tcr.

When the start determination unit 92c determines that the start of the engine 12 has been requested, the start control unit 92d outputs an engine control signal Se to the engine control device 50 to start fuel supply, ignition, and the like, in conjunction with cranking of the engine 12 by the K0 clutch 20 and the electric motor MG. In other words, when starting the engine 12, the start control unit 92d outputs an engine control signal Se to the engine control device 50 to control the engine 12 so that the engine 12 starts operating. In this way, 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 has been requested.

When starting the engine 12 during EV driving, the start control unit 92d causes the electric motor MG to output an electric motor torque Tm equivalent to the cranking torque Tcr in addition to the electric motor torque Tm for EV driving, i.e., the electric motor torque Tm that generates the drive torque Tr.

The shift control unit 96 uses, for example, a shift map, which is a predetermined relationship, to determine whether to shift the automatic transmission 24, and outputs a CB hydraulic control signal Scb to the hydraulic control circuit 56 to execute shift control of the automatic transmission 24 as necessary. The shift map is a predetermined relationship having a shift line for determining whether to shift the automatic transmission 24 on a two-dimensional coordinate system with, for example, vehicle speed V and required driving torque Trdem as variables. In the shift map, the AT output rotation speed No may be used instead of the vehicle speed V, and the required driving force Frdem, accelerator opening θacc, throttle valve opening θth, etc. may be used instead of the required driving torque Trdem.

The shift phases of the automatic transmission 24 include a shift preparation phase, a torque phase, and an inertia phase. In the shift preparation phase, for example, prior to the torque phase, the lock-up clutch 40 is switched from an engaged state to a released state to suppress shift shock. The torque phase is a phase during the shift period of the automatic transmission 24 (the period from the start of shift control to the end of shift control) during which the output torque of the automatic transmission 24 is changing. The inertia phase is a phase during which the turbine rotation speed Nt, which is equal to the rotation speed of the transmission input shaft 38, which is the input rotating member of the automatic transmission 24, changes from the theoretical pre-shift turbine rotation speed Nt_pre (theoretical turbine rotation speed Nt calculated from the gear ratio γat in the gear stage before the shift and the vehicle speed V) to the theoretical post-shift turbine rotation speed Nt_post (theoretical turbine rotation speed Nt calculated from the gear ratio γat in the gear stage after the shift and the vehicle speed V). The torque phase is also a period during which the transmission torque capacity of the engaging side engaging device CBcon and the disengaging side engaging device CBdis changes.

If a request to start the engine 12 occurs during a period when the automatic transmission 24 is not being controlled by the start control unit 92d, the start control unit 92d executes the start control unit 12 as described above. Also, if the automatic transmission 24 is controlled by the start control unit 92d during a period when the engine 12 is not being controlled by the start control unit 92d, the shift control unit 96 executes the shift control unit 96 as described above.

However, a request to start the engine 12 may occur during shift control of the automatic transmission 24 (while shift control is being executed) during EV driving.

When the start determination unit 92c determines that the start of the engine 12 is requested, the progress determination unit 98 determines whether the torque phase progress degree α [%] at the time when the start request of the engine 12 is generated is within a predetermined range. The torque phase progress degree α is the progress degree of the torque phase in the shift phase. For example, the torque phase progress degree α is expressed as the ratio of the transmission torque capacity Tcb_con to the sum of the transmission torque capacity Tcb_dis of the release side engagement device CBdis and the transmission torque capacity Tcb_con of the engagement side engagement device CBcon {= Tcb_con / (Tcb_dis + Tcb_con)}. The transmission torque capacity Tcb_dis can be calculated based on a map in which the relationship between the release side hydraulic pressure Pdis and the transmission torque capacity Tcb_dis is experimentally or design-predetermined, and the transmission torque capacity Tcb_con can be calculated based on a map in which the relationship between the engagement side hydraulic pressure Pcon and the transmission torque capacity Tcb_con is experimentally or design-predetermined. When the shift phase is in the shift preparation stage, the torque phase progress degree α is 0 [%], and when the shift phase is the inertia phase, the torque phase progress degree α is 100 [%]. The predetermined range is a range of the torque phase progress degree α that is predetermined for determining that the progress of the torque phase, which is the shift phase, is to be delayed, and is, for example, a range that is predetermined for each gear stage before and after the shift in the automatic transmission 24. For example, the lower limit value and the upper limit value of the predetermined range are set so that even if the cranking of the engine 12 is started after the determination by the progress degree determination unit 98, the fluctuation of the input torque of the automatic transmission 24 at the start of the inertia phase is small and the delay in the shift completion is within an acceptable range. For example, compared to when the gear stages before and after the shift are on the low-speed side with a large gear ratio γat, when the gear stages before and after the shift are on the high-speed side with a small gear ratio γat, the shift period is short, and therefore the effect on hesitation, which causes the shift completion to be delayed, is small. Therefore, the higher the speed, the narrower the predetermined range is set, i.e., the lower the upper limit of the predetermined range is set, and the higher the lower limit of the predetermined range is set. In this embodiment, the lower limit of the predetermined range is set to a value equal to or greater than 0% and the upper limit of the predetermined range is set to a value slightly lower than 100% (see FIG. 3). "Progression of the torque phase" means that shift control is advanced in the torque phase, i.e., the torque phase progression degree is increased. Note that the torque phase progression degree α corresponds to the "progression degree of the torque phase" in this invention.

If the progress determination unit 98 determines that the torque phase progress degree α at the time when the start request of the engine 12 is generated is within a predetermined range, the shift control unit 96 delays the progress of the torque phase, and the start control unit 92d starts cranking the engine 12. Specifically, the shift control unit 96 interrupts and returns the progress of the torque phase once started in the automatic transmission 24, that is, returns the shift phase to the state at the start of the torque phase. The shift control unit 96 sets the release time of the delay of the torque phase progress based on a map that is predetermined experimentally or by design, for example, between the torque phase progress degree α at the delay start time when the delay of the torque phase progress starts, the gear stages before and after the shift in the automatic transmission 24, and the release time (= delay start time + delay period) at which the delay of the torque phase progress is released. The delay start time corresponds to the "start time when the delay of the torque phase progress starts" in this invention. When the time has passed when the delay in the progression of the torque phase is released, the gear shift control unit 96 releases the delay in the progression of the torque phase, advances the torque phase, and resumes gear shift control.

If the progress determination unit 98 determines that the torque phase progress degree α at the time when a request to start the engine 12 is generated is not within a predetermined range, the gear shift control unit 96 continues gear shift control, such as advancing the torque phase, and the start control unit 92d starts cranking the engine 12.

Figure 2 is an example of a flowchart that explains the control operation of the electronic control device 90 shown in Figure 1. The flowchart in Figure 2 is repeatedly executed during shift control of the automatic transmission 24 during EV driving.

First, in step S10 (hereinafter, step will be omitted) corresponding to the function of the start determination unit 92c, it is determined whether a request to start the engine 12 has occurred. If the determination in S10 is positive, then in S20, corresponding to the function of the progress determination unit 98, it is determined whether the torque phase progress degree α at the time when the request to start the engine 12 has occurred is within a predetermined range. If the determination in S10 is negative, then in S30, corresponding to the function of the shift control unit 96, shift control of the automatic transmission 24 continues, and then the process returns.

If the determination in S20 is positive, in S40, which corresponds to the functions of the shift control unit 96 and the start control unit 92d, the torque phase is delayed while cranking of the engine 12 is started, and then S50 is executed. In S50, which corresponds to the function of the shift control unit 96, the delay in the torque phase is released, shift control is executed, and then the process returns. If the determination in S20 is negative, in S60, which corresponds to the functions of the shift control unit 96 and the start control unit 92d, shift control of the automatic transmission 24 is continued and cranking of the engine 12 is started, and then the process returns.

Figure 3 is an example of a time chart in which the flowchart in Figure 2 is executed during shift control of a power-on upshift of the automatic transmission 24 during EV driving. The horizontal axis in Figure 3 represents time t [ms]. A power-on upshift is an upshift that is executed when the accelerator opening θacc is increased by the driver's accelerator operation (e.g., depressing the accelerator pedal).

In FIG. 3, the engine operation signal is a signal that controls the operating state of the engine 12, and ON is a control signal that puts the engine 12 in an operating state, and OFF is a control signal that puts the engine 12 in a stopped state. In FIG. 3, the delay period setting signal is a signal that indicates the start point of the delay in the progression of the torque phase when it switches from OFF to ON, and indicates the release point of the delay in the progression of the torque phase when it switches from OFF to ON. In FIG. 3, the start setting signal is a "signal that indicates the start point of the set torque phase," and the timing that it switches from OFF to ON indicates the start point of the torque phase, and the end setting signal is a "signal that indicates the end point of the set torque phase," and the timing that it switches from OFF to ON indicates the end point of the torque phase.

In the torque phase progression degree α, motor rotation speed Nm, turbine rotation speed Nt, and engagement side hydraulic pressure Pcon and release side hydraulic pressure Pdis shown in FIG. 3, the present embodiment in which the torque phase progression is delayed is shown by a solid line, and the comparative example in which the torque phase progression is not delayed is shown by a dashed line.

The time chart for this embodiment is explained below.

Before time t1, the lock-up clutch 40 is engaged during EV driving, and the motor rotation speed Nm is increasing due to the driver's accelerator operation. At time t1, the gear shift preparation stage in the power-on upshift gear shift control begins. As part of the gear shift preparation stage, the lock-up clutch 40 is switched from an engaged state to a released state. By switching the lock-up clutch 40 to the released state, the motor connecting shaft 36 and the transmission input shaft 38 are connected via a fluid, and at time t2 (>t1), the motor rotation speed Nm of the electric motor MG, which is the driving force source for driving, begins to become higher than the turbine rotation speed Nt.

At time t3 (>t2) after the lock-up clutch 40 has been switched to the released state, the start setting signal is switched from OFF to ON. In accordance with the timing of this switching of the start setting signal from OFF to ON, a decrease control is started to decrease the release side hydraulic pressure Pdis, and an increase control is started to increase the engagement side hydraulic pressure Pcon, starting the torque phase in the shift control. As a result, the torque phase progression degree α gradually increases from time t3.

At time t4 (>t3), a request to start the engine 12 is generated, the engine operation signal is switched from OFF (stopped) to ON (operating), and cranking of the engine 12 is started. At time t4, when the request to start the engine 12 is generated, the torque phase progression degree α is within a predetermined range. Therefore, at time t4, the delay period setting signal is switched from OFF to ON, and the delay of the torque phase progression begins. Time t4 is the start time of the delay. Specifically, the release side hydraulic pressure Pdis is quickly returned to the hydraulic pressure at the start of the decrease control at a predetermined rate, and the engagement side hydraulic pressure Pcon is quickly returned to the hydraulic pressure at the start of the increase control at a predetermined rate, i.e., the progression of the torque phase is delayed and the shift phase is returned to the state at the start of the torque phase.

At time t6 (>t4), the delay period setting signal is switched from on to off, the delay in the progression of the torque phase is released, and the torque phase is advanced. Time t6 corresponds to the "release time point for releasing the delay in the progression of the torque phase" in the present invention. At time t7 (>t6), the end setting signal is switched from off to on. In accordance with the timing of the end setting signal switching from off to on, the decrease control of the release side hydraulic pressure Pdis is terminated and the increase control of the engagement side hydraulic pressure Pcon is terminated, and the torque phase in the shift control is terminated. In the period from time t6 to time t7 (>t6), the torque phase is advanced and the torque phase advancement degree α changes from 0 [%] to 100 [%]. The inertia phase begins at time t7, and in the period from time t7 to time t9 (>t7), the turbine rotation speed Nt corresponding to the vehicle speed V decreases from the theoretical pre-shift turbine rotation speed Nt_pre to the theoretical post-shift turbine rotation speed Nt_post, and the inertia phase ends at time t9.

During the period from time t9 to time t10 (>t9), the lock-up clutch 40 is switched from a released state to an engaged state, causing the turbine rotation speed Nt to increase toward the motor rotation speed Nm of the electric motor MG, which is the driving force source for traveling.

In this way, the cranking of the engine 12 starts before time t7 when the inertia phase starts, and preferably the cranking of the engine 12 also ends before time t7 when the inertia phase starts. If the cranking of the engine 12 ends before time t7 when the inertia phase starts, the input torque of the automatic transmission 24 is prevented from fluctuating due to the cranking of the engine 12, including the start of the cranking of the engine 12, at the start of the inertia phase, so that delays in the end of the gear shift are suppressed.

The following is a description of the time chart of the comparative example. The time chart of this comparative example is substantially the same as the time chart of the embodiment described above, but differs in that the torque phase progression is not delayed even if the torque phase progression degree α at time t4, when the start request for the engine 12 is generated, is within a predetermined range. Therefore, the following description will focus on the parts that differ from the embodiment, and parts that are substantially the same as the embodiment will be given the same reference numerals and descriptions thereof will be omitted as appropriate.

In the comparative example, at time t4, the release side hydraulic pressure Pdis continues to be decreased and the engagement side hydraulic pressure Pcon continues to be increased, i.e., the progression of the torque phase is not delayed. As a result, in the period from time t4 to time t5 (>t4), the torque phase is advanced and the torque phase progression degree α changes from 0 [%] to 100 [%]. The inertia phase begins at time t5, and in the period from time t5 to time t8 (>t5), the turbine rotation speed Nt corresponding to the vehicle speed V decreases from the theoretical pre-shift turbine rotation speed Nt_pre to the theoretical post-shift turbine rotation speed Nt_post, and the inertia phase ends at time t8.

In this comparative example, the end time of cranking of the engine 12 is after time t5 when the inertia phase starts. Therefore, cranking of the engine 12 starts at time t5. In FIG. 3, the input torque of the automatic transmission 24 fluctuates with the start of cranking of the engine 12 (start of starting the engine 12) at the start of the inertia phase, and hesitation, for example, in which the end of gear shifting is delayed, is not shown, but there is a risk of hesitation occurring.

According to this embodiment, if a request to start the engine 12 occurs before the automatic transmission 24 ends the torque phase of the shift phase, the torque phase is delayed and cranking of the engine 12 is started, and then the delay in the torque phase is released and the torque phase is allowed to proceed. In this way, the torque phase in the shift control of the automatic transmission 24 is delayed while the start of cranking of the engine 12 is prioritized, so that the deterioration of the start responsiveness of the engine 12 is suppressed. In addition, since the start of the inertia phase of the shift control is after the start of cranking of the engine 12, the input torque of the automatic transmission 24 is suppressed from fluctuating with the start of cranking of the engine 12, and a delay in the end of the shift is suppressed. In this way, both the start responsiveness and the shift performance of the engine 12 are achieved.

According to this embodiment, if the torque phase is in progress when a start request for the engine 12 is generated, the progress of the torque phase is interrupted and the shift phase is returned to the state at the start of the torque phase, thereby delaying the progress of the torque phase. In this way, if the torque phase is in progress when a start request for the engine 12 is generated, the progress of the torque phase is interrupted and the shift phase is returned to the state at the start of the torque phase, thereby achieving both suppression of deterioration in the start responsiveness of the engine 12 and suppression of delays in the completion of shifting.

According to this embodiment, if the torque phase progression degree α at the time when a request to start the engine 12 is generated is within a predetermined range that is determined in advance for each gear stage before and after the shift in the automatic transmission 24, the progression of the torque phase is delayed. In this way, if the torque phase progression degree α at the time when a request to start the engine 12 is generated is within a predetermined range that is determined in advance for each gear stage before and after the shift in the automatic transmission 24, the progression of the torque phase is delayed while the start of cranking of the engine 12 is prioritized. Whether or not to delay the progression of the torque phase is determined according to the torque phase progression degree α at the time when a request to start the engine 12 is generated, it is easy to achieve both the starting responsiveness and the shifting performance of the engine 12.

According to this embodiment, the release time point for releasing the delay in the torque phase progression is set based on the torque phase progression degree α at the start time point when the delay in the torque phase progression is started and the gear stages before and after the shift in the automatic transmission 24. In this way, since the release time point for releasing the delay in the torque phase progression is set based on the torque phase progression degree α at the start time point when the delay in the torque phase progression is started and the gear stages before and after the shift in the automatic transmission 24, it is possible to control the release time point so that it is not too late.

According to this embodiment, if a request to start the engine 12 occurs during the gear shift preparation stage before the start of the torque phase, the start of the torque phase is delayed, thereby slowing down the progress of the torque phase. In this way, if a request to start the engine 12 occurs during the progress of the torque phase, the start of the torque phase is delayed, thereby achieving both prevention of deterioration of the start responsiveness of the engine 12 and prevention of delays in the completion of gear shifting.

The above describes in detail an embodiment of the present invention based on the drawings, but the present invention can also be applied in other aspects.

In the above embodiment, a case where a request to start the engine 12 occurs while the automatic transmission 24 is in the torque phase in the time chart of FIG. 3 is illustrated, but the present invention is not limited to this example. For example, the present invention can also be applied to a case where a request to start the engine 12 occurs while the automatic transmission 24 is in the shift preparation stage. In this case, even if the shift preparation stage ends, the start of the torque phase is delayed and the cranking of the engine 12 is started, and then the torque phase is advanced. In this way, the "delay" of the progression of the torque phase in the present invention includes both a case where the progression of a torque phase that has once started is interrupted and returned to its original state, and a case where the start of a torque phase that has not yet started is delayed.

In the above embodiment, the progression of the torque phase is delayed when the torque phase progression degree α at the time when the start request of the engine 12 is generated is within a predetermined range that is set in advance for each gear stage before and after the shift in the automatic transmission 24, but the present invention is not limited to this embodiment. For example, a predetermined range may not be set, and the progression of the torque phase may be delayed when the start request of the engine 12 is generated while the torque phase is in progress. Even in such an embodiment, the progression of the torque phase in the shift control of the automatic transmission 24 is delayed while the start of cranking of the engine 12 is prioritized, so that the deterioration of the start responsiveness of the engine 12 is suppressed. In addition, the input torque of the automatic transmission 24 is suppressed from fluctuating with the engine start at the start of the inertia phase of the shift control, so that the delay in the end of the shift is suppressed. In this way, both the start responsiveness and the shift performance of the engine 12 are achieved.

In the above embodiment, the release time for releasing the delay in the torque phase progression is set based on the torque phase progression degree α at the start time when the delay in the torque phase progression is started and the gear stages before and after the shift in the automatic transmission 24, but the present invention is not limited to this aspect. For example, the release time may be determined in advance experimentally or by design, regardless of the torque phase progression degree α at the start time when the delay in the torque phase progression is started and the gear stages before and after the shift in the automatic transmission 24, as long as it is set so that cranking of the engine 12 is not started at the start time of the inertia phase.

In the above embodiment, the automatic transmission 24 was a planetary gear type, but the automatic transmission in the present invention may be a stepped transmission of other configurations, such as a constant mesh parallel shaft type.

In the above-described embodiment, the time chart in FIG. 3 is for a case where a request to start the engine 12 occurs during the power-on upshift shift control of the automatic transmission 24, but the present invention is also applicable to cases where a request to start the engine 12 occurs during other shift control, not limited to the power-on upshift.

In the above embodiment, a torque converter 22 is used as the fluid transmission device, but the present invention is not limited to this embodiment. For example, instead of the torque converter 22, other fluid transmission devices that do not have a torque amplifying effect, such as a fluid coupling, may be used as the fluid transmission device. Also, the fluid transmission device does not necessarily have to be provided, and may be replaced with, for example, a clutch for starting.

The above is merely an example of the present invention, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the invention.

10: Vehicle 12: Engine 14: Drive wheels 20: K0 clutch (clutch)
24: Automatic transmission 90: Electronic control device (control device)
MG: Electric motor α: Torque phase progress (progression of torque phase)

Claims (3)

A control device for a vehicle including an engine and an electric motor as a driving force source for driving the vehicle, a clutch disposed between the engine and the electric motor, and an automatic transmission disposed between the driving force source for driving the vehicle and a driving wheel,
When a request to start the engine occurs before a torque phase of a shift phase of the automatic transmission ends, the engine cranking is started while delaying the progression of the torque phase, and then the delay of the progression of the torque phase is released to advance the torque phase ;
When the engine start request occurs while the torque phase is in progress, the progress of the torque phase is interrupted and the shift phase is returned to a state at the start of the torque phase, thereby delaying the progress of the torque phase;
a control device for a vehicle, characterized in that, when a progress of the torque phase at a time when a request to start the engine is generated is within a predetermined range that is determined in advance for each gear stage before and after a shift in the automatic transmission, the control device delays the progress of the torque phase . The vehicle control device according to claim 1, further comprising: a torque phase delay control unit that determines a timing at which the torque phase delay is released based on the degree of progress of the torque phase at a start point when the delay of the torque phase progress is started and the gear stages before and after the shift in the automatic transmission. 2. The vehicle control device according to claim 1, wherein, when the engine start request occurs during a shift preparation stage before a torque phase starts, the start of the torque phase is delayed to delay the progress of the torque phase.

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