Vehicle control device

Abstract

To appropriately maintain the charge residual amount of a battery while suppressing the occurrence of shock when charging while traveling.SOLUTION: In a case where a rotation speed of a transmission shaft is equal to or lower than a given rotation speed, with transmission shaft torque equal to or less than a given value, what is performed is charge-limiting control in which charging power is limited in charge control for increasing engine torque relative to engine torque that realizes a drive requirement amount so as to a required amount of charging power that charges the battery by a motor generating, whereas in a case where a rotation speed of the transmission shaft is exceeding the given rotation speed or where the transmission torque exceeds the given value, no charging control is performed, and therefore, an increase in engine torque relative to the required value of charging power is suppressed, and an influence of engine torque variation on the transmission shaft toque is suppressed. Thus, when charge control is performed while traveling, the charge residual amount of a battery can be appropriately maintained while suppressing the occurrence of shock.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle equipped with a power transmission device that transmits torque of a power source including an engine and an electric motor to drive wheels. [Background technology]

[0002] There is a well-known control device for a vehicle that includes a power source including an engine and an electric motor, a power transmission device having a transmission shaft to which the power source is connected so as to be capable of transmitting power, which transmits the torque of the power source input to the transmission shaft to a driving wheel, and an electric storage device that receives and supplies electric power to the electric motor. For example, a control device for a hybrid vehicle described in Patent Document 1 is such a device. Patent Document 1 discloses that the power transmission device includes an automatic transmission, that the electric storage device is charged using the power of the engine within a range of a charging limit value with respect to a required value of charging power to be charged to the electric storage device, that the charging limit value is set to a smaller value when the gear ratio of the automatic transmission is a high-speed side gear ratio than when it is a low-speed side gear ratio, and that this makes it possible to appropriately maintain the remaining charge of the electric storage device while suppressing vibrations and abnormal noises generated during driving. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-9635 A Summary of the Invention [Problem to be solved by the invention]

[0004] When performing charging control to charge the power storage device while the vehicle is traveling in a driving state, it is necessary to increase the engine torque by the amount of charging power with respect to the engine torque that realizes the driving demand amount. On the other hand, the higher the engine torque, the worse the estimation accuracy of the engine torque becomes, and the greater the deviation between the actual value and the estimated value of the engine torque tends to become. Therefore, for example, when controlling the torque of the electric motor in accordance with the estimated value of the engine torque, it becomes difficult to control the actual value of the engine torque to a target value, and there is a concern that a shock is likely to occur.

[0005] The present invention has been made against the background of the above circumstances, and its object is to provide a vehicle control device that can appropriately maintain the remaining charge of the storage device while suppressing the occurrence of shocks when performing charging control while driving. [Means for solving the problem]

[0006] The gist of a first aspect of the present invention is a control device for a vehicle including: (a) a power source including an engine and an electric motor; a power transmission device having a transmission shaft to which the power source is connected so as to be capable of transmitting power, the power transmission device transmitting torque of the power source input to the transmission shaft to drive wheels; and an electric storage device receiving and supplying electric power to the electric motor, the control device including: (b) a power source control unit that performs charging control to increase a torque of the engine with respect to a torque of the engine that realizes a required amount of driving so as to realize a required value of charging power to be charged to the electric storage device by power generation by the electric motor while the vehicle is traveling in a driving state; and (c) a charge limit control unit that performs charge limiting control to limit the charging power in the charging control when a rotation speed of the transmission shaft is equal to or lower than a predetermined rotation speed and a transmission shaft torque, which is a torque on the transmission shaft that is transmitted to the drive wheels among the torque of the power source, is equal to or lower than a predetermined torque, and that does not perform the charge limiting control when the rotation speed of the transmission shaft exceeds the predetermined rotation speed or the transmission shaft torque exceeds the predetermined torque. (d) the charge limit control unit performs the charge limit control when the vehicle speed is equal to or lower than a predetermined vehicle speed, and does not perform the charge limit control when the vehicle speed exceeds the predetermined vehicle speed; and (e) when performing the charge limit control, the charge limit control unit sets at least one of the predetermined rotation speed and the predetermined torque to a higher value as the vehicle speed becomes lower. The point is... The gist of a second invention is a control device for a vehicle including: (a) a power source including an engine and an electric motor; a power transmission device having a transmission shaft to which the power source is connected so as to be capable of transmitting power, the power transmission device transmitting torque of the power source input to the transmission shaft to drive wheels; and an electric storage device receiving and supplying electric power to the electric motor, (b) a power source control unit that performs charging control to increase the torque of the engine relative to the torque of the engine that realizes a required amount of drive so as to realize a required value of charging power to be charged to the electric storage device by power generation by the electric motor while the vehicle is traveling in a driving state; and (c) a power source control unit that performs charging control to increase the torque of the engine relative to the torque of the engine that realizes a required amount of drive so as to realize a required value of charging power to be charged to the electric storage device by power generation by the electric motor while the vehicle is traveling in a driving state, the power source control unit performing charging control to increase the torque of the engine relative to the torque of the engine that realizes a required amount of drive so as to realize a required value of charging power to be charged to the electric storage device by power generation by the electric motor, and (d) a control unit that performs charging control to increase the torque of the engine relative to the torque of the engine that realizes a required amount of drive so as to realize a required value of charging power to be charged to the electric storage device by power generation by the electric motor, the control unit performing ... and a charge limit control unit that performs charge limit control to limit the charging power in the charge control when the rotational speed of the transmission shaft exceeds the predetermined rotational speed or the transmission shaft torque exceeds the predetermined torque, but does not perform the charge limit control when the rotational speed of the transmission shaft exceeds the predetermined rotational speed or the transmission shaft torque exceeds the predetermined torque; (d) the charge limit control unit performs the charge limit control when the gear ratio of an automatic transmission provided in the power transmission device is a predetermined low-speed side gear ratio, but does not perform the charge limit control when the gear ratio is on the higher vehicle speed side than the predetermined low-speed side gear ratio; and (e) the charge limit control unit sets at least one of the predetermined rotational speed and the predetermined torque to a higher value as the gear ratio is on the lower vehicle speed side when performing the charge limit control.

[0007] Also, 3 The present invention relates to the 2 In the vehicle control device described in the invention, the charge limit control unit performs the charge limit control when the vehicle speed is equal to or lower than a predetermined vehicle speed, and does not perform the charge limit control when the vehicle speed exceeds the predetermined vehicle speed.

[0009] The fourth invention is the above-mentioned 1 In the vehicle control device described in the first or second invention, when performing the charge limiting control, the charge limiting control unit sets the upper limit value of the charge power when limiting the charge power to a smaller value the lower the vehicle speed.

[0010] The fifth invention is the first invention. Clearly In the described vehicle control device, the charge limit control unit performs the charge limit control when the gear ratio of the automatic transmission provided in the power transmission device is a predetermined low-speed side gear ratio, and does not perform the charge limit control when the gear ratio is on the higher vehicle speed side than the predetermined low-speed side gear ratio.

[0011] A sixth aspect of the present invention is that, in the vehicle control device according to the fifth aspect of the present invention, when performing the charge limiting control, the charge limiting control unit sets at least one of the specified rotational speed and the specified torque to a higher value as the gear ratio becomes lower.

[0012] The seventh invention is the above-mentioned Second invention, third invention, Fifth invention , and The sixth invention Any one of In the vehicle control device described in the above, when performing the charge limiting control, the charge limiting control unit sets the upper limit value of the charging power when limiting the charging power to a smaller value as the gear ratio is on the lower vehicle speed side.

[0013] Further, an eighth aspect of the present invention is that in the vehicle control device according to any one of the first to seventh aspects of the present invention, when performing the charge limiting control, the charge limiting control unit sets the upper limit value of the charge power when limiting the charge power to a smaller value the lower the rotation speed of the transmission shaft.

[0014] A ninth aspect of the present invention is that, in a vehicle control device according to any one of the first to eighth aspects of the present invention, when performing the charge limiting control, the charge limiting control unit sets the upper limit value of the charge power when limiting the charge power to a smaller value as the transmission shaft torque becomes lower. Effect of the Invention

[0015] The first invention Or the second invention According to the method, when the rotation speed of the transmission shaft is equal to or lower than a predetermined rotation speed and the transmission shaft torque is equal to or lower than a predetermined torque, a charge limiting control is performed to limit the charging power in the charging control, which increases the engine torque relative to the engine torque that realizes the drive demand amount so as to realize the demand value of the charging power to be charged to the power storage device by the power generation of the electric motor, whereas when the rotation speed of the transmission shaft exceeds the predetermined rotation speed or the transmission shaft torque exceeds the predetermined torque, the charge limiting control is not performed, so that the increase in the engine torque relative to the demand value of the charging power is suppressed and the effect of the variation in the engine torque on the transmission shaft torque is suppressed. Therefore, when the charging control is performed during driving, the occurrence of shocks can be suppressed and the remaining charge of the power storage device can be appropriately maintained.

[0016] In addition, 1 The invention Or the third invention According to the invention, when the vehicle speed is below a predetermined vehicle speed, charging limit control is performed, whereas when the vehicle speed exceeds the predetermined vehicle speed, charging limit control is not performed, so that charging limit control is performed in the low vehicle speed range where shock sensitivity is high, thereby suppressing the occurrence of shock.

[0017] In addition, 1According to the invention, when charge limit control is performed, the lower the vehicle speed, the higher the value at least one of the specified rotational speed and the specified torque is set to, so that the lower the vehicle speed, the higher the shock sensitivity, making it easier for charge limit control to be performed.

[0018] Furthermore, according to the fourth aspect of the present invention, when charge limiting control is performed, the lower the vehicle speed, the smaller the upper limit value of the charging power when limiting the charging power is set, so that the lower the vehicle speed is, the more the increase in engine torque is suppressed and the effects of engine torque variations are further suppressed.

[0019] In addition, Second invention or According to the fifth aspect of the present invention, when the gear ratio of the automatic transmission is a predetermined low-speed side gear ratio, charging limit control is performed, whereas when the gear ratio of the automatic transmission is a higher speed side than the predetermined low-speed side gear ratio, charging limit control is not performed. Therefore, charging limit control is performed at the low-speed side gear ratio, which has high shock sensitivity, thereby suppressing the occurrence of shock.

[0020] In addition, Second invention or According to the sixth aspect of the present invention, when charge limit control is performed, the lower the vehicle speed side of the gear ratio, the higher the value at least one of the specified rotation speed and the specified torque is set to, so that the lower the vehicle speed side of the gear ratio, the higher the shock sensitivity, the more likely it is that charge limit control will be performed.

[0021] Furthermore, according to the seventh aspect of the present invention, when charge limiting control is performed, the lower the vehicle speed side of the gear ratio, the smaller the upper limit value of the charging power when limiting the charging power is set to. Therefore, the lower the vehicle speed side of the gear ratio, which has high shock sensitivity, the more the increase in engine torque is suppressed and the effect of engine torque variations is further suppressed.

[0022] Furthermore, according to the eighth aspect of the present invention, when charge limiting control is performed, the lower the rotation speed of the transmission shaft, the smaller the upper limit value of the charging power when limiting the charging power is set to, so that the increase in engine torque is more suppressed at lower transmission shaft rotation speeds where engine torque is more likely to increase.

[0023] Furthermore, according to the ninth aspect of the present invention, when charging limiting control is performed, the lower the transmission shaft torque, the smaller the upper limit value of the charging power when limiting the charging power is set to, so that the lower the transmission shaft torque, which is more susceptible to the influence of engine torque variations, the more the influence of engine torque variations is suppressed. [Brief description of the drawings]

[0024] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and a control system for various controls in the vehicle. [Diagram 2] FIG. 13 is a diagram illustrating an example of an upper limit value map used for setting an upper limit charging power, the diagram illustrating an example of an upper limit value map that differs for each vehicle speed range. [Diagram 3] FIG. 13 is a diagram showing an example of an upper limit value map used for setting an upper limit charging power, and is a diagram illustrating an example of an upper limit value map that differs for each gear stage of an automatic transmission. [Figure 4] 1 is a flowchart illustrating the main control operations of the electronic control device, and is a flowchart illustrating the control operations for appropriately maintaining the remaining battery charge while suppressing the occurrence of shocks when performing charging control during driving. [Diagram 5] FIG. 2 is a diagram for explaining a schematic configuration of a vehicle to which the present invention is applied, showing an example of a vehicle different from the vehicle in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] In an embodiment of the present invention, the gear ratio in the automatic transmission is "rotation speed of the input rotating member / rotation speed of the output rotating member." The high side gear ratio of the automatic transmission is a high vehicle speed side gear ratio on the side where the gear ratio is small. The low side gear ratio of the automatic transmission is a low vehicle speed side gear ratio on the side where the gear ratio is large. For example, the lowest side gear ratio is the lowest vehicle speed side gear ratio on the lowest vehicle speed side, and is the maximum gear ratio at which the gear ratio is the largest value.

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0027] Fig. 1 is a diagram for explaining the schematic configuration of a vehicle 10 to which the present invention is applied, and is also a diagram for explaining the main parts of the control functions and control system for various controls in the vehicle 10. In Fig. 1, the vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG that function as a power source SP. The vehicle 10 also has drive wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14.

[0028] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, etc., provided in the vehicle 10 is controlled by an electronic control device 90 described later, whereby the engine torque Te of the engine 12 is controlled.

[0029] The electric motor MG is a rotating electric machine having a function as a motor that generates mechanical power from electric power and a function as a generator that generates electric power from mechanical power, and is a so-called motor generator. The electric motor MG is connected to a battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The battery 54 is an electricity storage device that supplies and receives electric power to the electric motor MG. The electric motor MG controls the MG torque Tm, which is the torque of the electric motor MG, 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 a positive rotation that is the same as the rotation direction when the engine 12 is in operation, the MG 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 driving force, torque, and force when there is no particular distinction.

[0030] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and the like, in a case 18 that is a non-rotating member attached to the vehicle body. The K0 clutch 20 is a clutch provided between the engine 12 and the electric motor MG in a power transmission path between the engine 12 and the drive wheels 14. The torque converter 22 is connected to the engine 12 via the K0 clutch 20. The automatic transmission 24 is connected to the torque converter 22 and is interposed in a power transmission path between the torque converter 22 and the drive wheels 14. The automatic transmission 24 is a transmission provided between the electric motor MG and the drive wheels 14 in a power transmission path between the engine 12 and the drive wheels 14. The power transmission device 16 also includes a propeller shaft 28 connected to a transmission output shaft 26 that is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, and the like. The power transmission device 16 also includes an engine connecting shaft 34 that connects the engine 12 and the K0 clutch 20, and an electric motor connecting shaft 36 that connects the K0 clutch 20 and the torque converter 22. The K0 clutch 20 is a clutch provided in a power transmission path between the engine 12 and the electric motor connecting shaft 36.

[0031] The electric motor MG is connected to the electric motor connecting shaft 36 in the case 18 so as to be capable of transmitting power. That is, the electric motor MG is connected to a power transmission path between the engine 12 and the drive wheels 14, in particular, to a power transmission path between the K0 clutch 20 and the torque converter 22. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 so as to be capable of transmitting power without passing through the K0 clutch 20.

[0032] The torque converter 22 includes a pump wheel 22a connected to the motor connecting shaft 36, and a turbine wheel 22b connected to a transmission input shaft 38 that is an input rotating member of the automatic transmission 24. The torque converter 22 is a fluid type power transmission device that transmits power from the power source SP from the motor connecting shaft 36 to the transmission input shaft 38 via fluid. The torque converter 22 includes an LU clutch 40 as a direct clutch that connects the pump wheel 22a and the turbine wheel 22b, that is, that connects the motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a known lock-up clutch.

[0033] The electric motor connecting shaft 36 is a transmission shaft to which the electric motor MG is connected so as to be capable of transmitting power, and to which the engine 12 is connected so as to be capable of transmitting power via the K0 clutch 20. The transmission input shaft 38 is a transmission shaft to which the electric motor MG is connected so as to be capable of transmitting power via the torque converter 22, and to which the engine 12 is connected so as to be capable of transmitting power via the K0 clutch 20 and the torque converter 22. In other words, the electric motor connecting shaft 36 and the transmission input shaft 38 each function as a transmission shaft to which the power source SP is connected so as to be capable of transmitting power.

[0034] The automatic transmission 24 is a known planetary gear type automatic transmission that includes, for example, one or more planetary gear devices (not shown) and an engagement device CB. The engagement device CB includes, for example, a plurality of hydraulic engagement devices, such as known friction engagement devices. The engagement devices CB are switched between operating states, i.e., control states, such as an engaged state, a slip state, a released state, etc., by changing the CB torque Tcb, which is the respective torque capacity, by the CB hydraulic pressure PRcb, which is the regulated hydraulic pressure supplied from a hydraulic control circuit 56 provided in the vehicle 10.

[0035] The automatic transmission 24 is a stepped transmission in which one of a plurality of gear stages (also called gear stages) with different speed ratios (also called gear ratios) γat (=AT input rotation speed Ni / AT output rotation speed No) is formed by engaging one of the engagement devices CB. The automatic transmission 24 switches the formed gear stages by switching the control state of the engagement devices CB involved in the shifting of the automatic transmission 24 according to the accelerator operation of the driver (=operator) and the vehicle speed V by an electronic control device 90 described later. The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38, and is the input rotation speed of the automatic transmission 24. The AT input rotation speed Ni is the same value as the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22. The AT input rotation speed Ni can be expressed by the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26, and is the output rotation speed of the automatic transmission 24.

[0036] The K0 clutch 20 is a hydraulic friction engagement device constituted by, for example, a multi-plate or single-plate clutch, and is a wet or dry type clutch. The K0 clutch 20 switches between control states such as an engaged state, a slip state, and a released state by changing the torque capacity of the K0 clutch 20, K0 torque Tk0, by the regulated hydraulic pressure K0 hydraulic pressure PRk0 supplied from the hydraulic control circuit 56.

[0037] In the vehicle 10, when the K0 clutch 20 is in an engaged state, the engine 12 and the torque converter 22 are connected to each other so as to transmit power. On the other hand, when the K0 clutch 20 is in a disengaged state, power transmission between the engine 12 and the torque converter 22 is interrupted. Since the electric motor MG is connected to the torque converter 22, the K0 clutch 20 functions as a clutch that connects and disconnects the engine 12 from the electric motor MG.

[0038] 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 motor connecting shaft 36, the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order. Moreover, the power output from the motor MG is transmitted from the 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 this order, regardless of the control state of the K0 clutch 20. The automatic transmission 24 transmits the power source torque Tsp, which is the torque of the power source SP input to the motor connecting shaft 36, to the drive wheels 14. The power source torque Tsp is the sum of the engine torque Te and the MG torque Tm. In this manner, the power transmission device 16 transmits the power source torque Tsp input to the motor connecting shaft 36 or the transmission input shaft 38 to the drive wheels 14 .

[0039] The vehicle 10 includes the MOP 58, which is a mechanical oil pump, the EOP 60, which is an electric oil pump, and a pump motor 62. The MOP 58 is connected to the pump impeller 22a, and is rotated by a power source SP to discharge hydraulic oil OIL used in the power transmission device 16. The pump motor 62 is a motor dedicated to the EOP 60 for rotating the EOP 60. The EOP 60 is rotated by the pump motor 62 to discharge hydraulic oil OIL. The hydraulic oil OIL discharged by the MOP 58 and the EOP 60 is supplied to a hydraulic control circuit 56. The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, and the like, which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and / or the EOP 60.

[0040] The vehicle 10 further includes an electronic control device 90 including a control device for the vehicle 10. The electronic control device 90 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, and the like, and the CPU executes various controls of the vehicle 10 by performing signal processing according to a program previously stored in the ROM while utilizing the temporary storage function of the RAM. The electronic control device 90 includes computers for engine control, electric motor control, clutch control, transmission control, and the like as necessary.

[0041] The electronic control device 90 is supplied with various signals based on detection values ​​by various sensors provided in the vehicle 10 (e.g., engine rotation speed sensor 70, turbine rotation speed sensor 72, output rotation speed sensor 74, MG rotation speed sensor 76, accelerator opening sensor 78, throttle valve opening sensor 80, brake switch 82, battery sensor 84, oil temperature sensor 86, etc.) (e.g., engine rotation speed Ne, which is the rotation speed of the engine 12, turbine rotation speed Nt, which is the same value as the AT input rotation speed Ni, AT output rotation speed No corresponding to the vehicle speed V, MG rotation speed Nm, which is the rotation speed of the electric motor MG, accelerator opening θacc, which is the amount of accelerator operation by the driver indicating the magnitude of the driver's acceleration operation, throttle valve opening θth, which is the opening of the electronic throttle valve, brake-on signal Bon, which is a signal indicating a state in which the brake pedal for operating the wheel brakes is being operated by the driver, battery temperature THbat, battery charge / discharge current Ibat, and battery voltage Vbat of the battery 54, and hydraulic oil temperature THoil, which is the temperature of the hydraulic oil OIL in the hydraulic control circuit 56).

[0042] The electronic control device 90 calculates the battery remaining charge SOC [%] based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat. The battery remaining charge SOC is the remaining charge of the battery 54, and is a value indicating the charging state of the battery 54, that is, a charging state value. The electronic control device 90 calculates the chargeable power Win [W] and the dischargeable power Wout [W] of the battery 54 based on, for example, the battery temperature THbat and the battery remaining charge SOC. The chargeable power Win of the battery 54 is the maximum chargeable power of the battery 54, which is determined in consideration of the durability of the battery 54, that is, the maximum power that is allowed to be input to the battery 54. The dischargeable power Wout of the battery 54 is the maximum dischargeable power of the battery 54, which is determined in consideration of the durability of the battery 54, that is, the maximum power that is allowed to be output from the battery 54.

[0043] The electronic control device 90 outputs various command signals (e.g., an engine control command signal Se for controlling the engine 12, an MG control command signal Sm for controlling the electric motor MG, a CB hydraulic control command signal Sbc for controlling the engagement device CB, a K0 hydraulic control command signal Sk0 for controlling the K0 clutch 20, an LU hydraulic control command signal Slu for controlling the LU clutch 40, an EOP control command signal Seop for controlling the EOP 60, etc.) to each device (e.g., the engine control device 50, the inverter 52, the hydraulic control circuit 56, the pump motor 62, etc.) provided in the vehicle 10.

[0044] In order to realize various controls in the vehicle 10, the electronic control unit 90 includes a power source control means, i.e., a power source control section 92, and a transmission control means, i.e., a transmission control section 94.

[0045] The power source control unit 92 includes a function as engine control means, i.e., engine control unit 92a, that controls the operation of the engine 12, and a function as electric motor control means, i.e., electric motor control unit 92b, that controls the operation of the electric motor MG via the inverter 52, and is a hybrid control means, i.e., a hybrid control unit, that performs hybrid drive control by the engine 12 and the electric motor MG using these control functions.

[0046] The power source control unit 92 calculates the amount of drive required by the driver for the vehicle 10, for example, by applying the accelerator opening θacc and the vehicle speed V to a drive demand map. The drive demand map is a relationship that is experimentally or design-wise determined and stored in advance, i.e., a predetermined relationship. The drive demand is, for example, a required drive torque Trdem at the drive wheels 14. In other words, the required drive torque Trdem [Nm] is the required drive power Prdem [W] at the vehicle speed V at that time. The drive demand can also be a required drive force Frdem [N] at the drive wheels 14, a required AT output torque at the transmission output shaft 26, or the like. In calculating the drive demand, an AT output rotation speed No, or the like, can be used instead of the vehicle speed V.

[0047] The power source control unit 92 calculates the required system shaft torque Tsysdem for realizing the required drive torque Trdem, taking into consideration the transmission loss, the speed ratio γat of the automatic transmission 24, and the like. The power source control unit 92 outputs an engine control command signal Se for controlling the engine 12 and an MG control command signal Sm for controlling the electric motor MG so as to obtain the power source torque Tsp for realizing the required system shaft torque Tsysdem. The required system shaft torque Tsysdem is a required value of the system shaft torque Tsys. The system shaft torque Tsys is a transmission shaft torque, which is a torque on a transmission shaft that is transmitted to the drive wheels 14, among the power source torque Tsp, that is, a torque used as the drive torque Tr. In this embodiment, the torque on the transmission input shaft 38 is exemplified as the system shaft torque Tsys. The difference between the torque on the transmission input shaft 38 and the torque on the electric motor connecting shaft 36 is a difference corresponding to the torque ratio (= turbine torque / pump torque) of the torque converter 22, and the torque on the electric motor connecting shaft 36 may be the system shaft torque Tsys. The torque ratio of the torque converter 22 is a function of the speed ratio (=turbine rotation speed Nt / pump rotation speed) of the torque converter 22, and is calculated by applying the actual speed ratio to a predetermined relationship between the speed ratio and the torque ratio. The pump rotation speed is equal to the MG rotation speed Nm.

[0048] When the required system shaft torque Tsysdem can be satisfied only by the output of the electric motor MG, the power source control unit 92 establishes the motor drive mode, i.e., the BEV drive mode, as the drive mode for driving the vehicle 10. The BEV drive mode is an electric drive mode that enables motor driving, i.e., electric driving (=BEV driving), in which the vehicle runs using only the electric motor MG as the power source SP with the K0 clutch 20 in a disengaged state and the operation of the engine 12 stopped. On the other hand, when the required system shaft torque Tsysdem cannot be satisfied without using at least the output of the engine 12, the power source control unit 92 establishes the engine drive mode, i.e., the HEV drive mode, as the drive mode. The HEV drive mode is a hybrid drive mode that enables engine driving, i.e., hybrid driving (=HEV driving), in which the vehicle runs using at least the engine 12 as the power source SP with the K0 clutch 20 in an engaged state. On the other hand, even if the required system shaft torque Tsysdem can be covered by the output of the electric motor MG alone, the power source control unit 92 establishes the HEV drive mode as the drive mode when it is necessary to charge the battery 54 or when it is necessary to warm up the engine 12, etc.

[0049] The battery 54 needs to be charged when, for example, the battery SOC needs to be maintained at a specified value, or when the battery SOC has fallen below a specified range, or when the battery SOC is within the specified range but charging the battery 54 would result in better energy efficiency.

[0050] The power source control unit 92 calculates a required charging power Wchgdem, which is a required value of the charging power Wchg [W] to be charged to the battery 54 by the power generation of the electric motor MG, based on, for example, the difference between the target value and the actual value of the battery remaining charge SOC. When the battery 54 needs to be charged while the vehicle 10 is traveling in a driving state, for example, the power source control unit 92 performs charging control CTchg to increase the engine torque Te with respect to the engine torque Te that realizes the required system shaft torque Tsysdem corresponding to the required driving torque Trdem, so as to realize the required charging power Wchgdem. When the battery 54 needs to be charged during HEV traveling, the engine torque Te is increased by the amount of charging. When the battery 54 needs to be charged during BEV traveling, the engine 12 is started, the system shaft torque Tsys is generated by the engine 12 instead of the electric motor MG, and the engine torque Te is increased by the amount of charging. The driving state of the vehicle 10 is a state in which the driving wheels 14 are rotated and driven by the power source torque Tsp. The driven state of the vehicle 10 is a state in which the power source SP is rotationally driven by torque input from the drive wheels 14.

[0051] The transmission control unit 94 performs a shift determination of the automatic transmission 24 using, for example, a shift map, which is a predetermined relationship, and outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 to execute shift control of the automatic transmission 24 as necessary, that is, according to the result of the shift determination. In the shift control of the automatic transmission 24, the transmission control unit 94 performs shifting of the automatic transmission 24, for example, by switching a disengagement side engagement device of the engagement devices CB to a disengaged state and switching an engagement side engagement device of the engagement devices CB to an engaged state. The shift map is a predetermined relationship having a shift line for determining a shift of the automatic transmission 24 on a two-dimensional coordinate system having, for example, the vehicle speed V and the 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, the accelerator opening θacc, the throttle valve opening θth, etc. may be used instead of the required driving torque Trdem.

[0052] Here, when the accelerator is released or nearly released while the vehicle 10 is traveling in a driving state, the vehicle 10 is switched from the driving state to the driven state so as to create a feeling of deceleration. When the vehicle 10 is switched from the driving state to the driven state, teeth striking occurs due to the direction in which backlash between rotating members in the power transmission device 16, for example, gear backlash, is eliminated is reversed. Therefore, a so-called tip-out shock, which is a backlash elimination shock, may occur due to teeth striking at the time of switching from the driving state to the driven state, i.e., at the time of tip-out. In response to this, the power source control unit 92 makes the change in the system shaft torque Tsys gentler in accordance with the tip-out of the vehicle 10 so as to suppress the tip-out shock.

[0053] Incidentally, when the charging control CTchg is performed while the vehicle 10 is traveling in a driving state, the engine torque Te is increased by the amount of charging. In a region where the engine torque Te is high, the calculation accuracy of the estimated engine torque Tee, which is an estimated value of the engine torque Te, is likely to deteriorate. That is, in a region where the engine torque Te is high, the deviation between the estimated engine torque Tee and the actual engine torque Ter, which is the actual value of the engine torque Te, is likely to become large. On the other hand, when the accelerator is released or the like while the charging control CTchg is being performed while the vehicle 10 is traveling in a driving state, the MG torque Tm is controlled in accordance with the decrease in the estimated engine torque Tee, and the vehicle 10 is switched from the driving state to the driven state. When the system shaft torque Tsys is changed gradually by controlling the MG torque Tm in accordance with the tip-out, if the calculation accuracy of the estimated engine torque Tee is poor, there is a possibility that the system shaft torque Tsys cannot smoothly pass through the zero value. That is, there is a possibility that the MG torque Tm for removing the backlash at the time of tip-out cannot be appropriately generated with respect to the actual engine torque Ter. In this case, there is a risk that the effect of suppressing the tip-out shock by the MG torque Tm cannot be adequately obtained. Note that the estimated engine torque Tee is calculated, for example, by applying the engine rotation speed Ne and the throttle valve opening θth to a predetermined engine torque map.

[0054] When the charging control CTchg is performed while the vehicle 10 is traveling in a driving state, if the engine rotation speed Ne is low, a high engine torque Te is required to obtain the engine power Pe, which is the power of the engine 12 for realizing the required charging power Wchgdem. In other words, when the charging control CTchg is performed, the engine torque Te is likely to be high in a region where the engine rotation speed Ne is low. Therefore, when the charging control CTchg is performed, in a region where the engine rotation speed Ne is low, the tip-out shock is difficult to suppress. Since the K0 clutch 20 is in an engaged state during HEV traveling, the engine rotation speed Ne and the MG rotation speed Nm have the same value. In addition, the difference between the MG rotation speed Nm and the turbine rotation speed Nt is the difference corresponding to the speed ratio of the torque converter 22, and both the MG rotation speed Nm and the turbine rotation speed Nt may be the rotation speed of the transmission shaft, i.e., the system shaft rotation speed Nsys. From the above, when the charging control CTchg is performed, in a region where the system shaft rotation speed Nsys is low, the tip-out shock is difficult to suppress.

[0055] Also, in a region where the required drive torque Trdem, i.e., the system shaft torque Tsys for realizing the required drive torque Trdem, is low, the degree of influence due to the deviation of the actual engine torque Ter from the estimated engine torque Tee tends to become large. Therefore, in a region where the required drive torque Trdem, i.e., the system shaft torque Tsys, is low when the charging control CTchg is executed, the tip-out shock is difficult to suppress. Or, from another point of view, in a region where the system shaft torque Tsys is low, the time for reducing the engine torque Te at the time of tip-out is shortened, so that the tip-out shock is difficult to suppress.

[0056] Therefore, the electronic control device 90 further includes a charge limit control means, that is, a charge limit control section 96 .

[0057] When the system shaft rotation speed Nsys is equal to or lower than a predetermined rotation speed Nsysf and the system shaft torque Tsys is equal to or lower than a predetermined torque Tsysf, the charge limit control unit 96 performs the charge limit control CTlimchg to limit the charging power Wchg in the charge control CTchg. On the other hand, when the system shaft rotation speed Nsys exceeds the predetermined rotation speed Nsysf or the system shaft torque Tsys exceeds the predetermined torque Tsysf, the charge limit control unit 96 does not perform the charge limit control CTlimchg. The predetermined rotation speed Nsysf and the predetermined rotation speed Nsysf are predetermined thresholds for determining the vehicle state when the charge control CTchg is being performed, in which the tip-out shock is difficult to suppress at the time of tip-out. Note that, as the system shaft torque Tsys when determining whether or not to perform the charge limit control CTlimchg, an actual value or a required system shaft torque Tsysdem may be used. In this embodiment, the required system shaft torque Tsysdem is used.

[0058] Specifically, the charge limit control unit 96 determines whether the system shaft rotation speed Nsys is equal to or less than a predetermined rotation speed Nsysf. Also, the charge limit control unit 96 determines whether the required system shaft torque Tsysdem is equal to or less than a predetermined torque Tsysf. When the charge limit control unit 96 determines that the system shaft rotation speed Nsys is equal to or less than the predetermined rotation speed Nsysf and that the required system shaft torque Tsysdem is equal to or less than the predetermined torque Tsysf, the charge limit control unit 96 performs the charge limit control CTlimchg. When the charge limit control unit 96 determines that the system shaft rotation speed Nsys exceeds the predetermined rotation speed Nsysf or determines that the required system shaft torque Tsysdem exceeds the predetermined torque Tsysf, the charge limit control unit 96 does not perform the charge limit control CTlimchg.

[0059] In a region where the vehicle speed V is low, the sensitivity of the tip-out shock to a calculation error of the estimated engine torque Tee is likely to be high. Therefore, the charge limit control unit 96 may perform the charge limit control CTlimchg when the vehicle speed V is in a relatively low vehicle speed region. For example, the charge limit control unit 96 performs the charge limit control CTlimchg when the vehicle speed V is equal to or lower than a predetermined vehicle speed Vf. On the other hand, the charge limit control unit 96 does not perform the charge limit control CTlimchg when the vehicle speed V exceeds the predetermined vehicle speed Vf. The predetermined vehicle speed Vf is, for example, a predetermined threshold value for determining whether to perform the charge limit control CTlimchg in consideration of the sensitivity of the tip-out shock.

[0060] When the gear stage of the automatic transmission 24 is a low-speed gear stage (= low gear stage), the sensitivity of the tip-out shock to the calculation error of the estimated engine torque Tee is likely to be high. Therefore, the charge limit control unit 96 may perform the charge limit control CTlimchg when the gear stage of the automatic transmission 24 is a low gear stage. For example, the charge limit control unit 96 performs the charge limit control CTlimchg when the gear ratio γat of the automatic transmission 24 is a predetermined low-speed gear ratio, that is, a predetermined low-side gear ratio γatf. On the other hand, the charge limit control unit 96 does not perform the charge limit control CTlimchg when the gear ratio γat is on the higher vehicle speed side (= high side) than the predetermined low-side gear ratio γatf. The predetermined low-side gear ratio γatf is, for example, a predetermined gear ratio γat for determining whether to perform the charge limit control CTlimchg in consideration of the sensitivity of the tip-out shock. For example, when the automatic transmission 24 is a 10-speed forward transmission, the predetermined low-side gear ratio γatf is the gear ratio γat corresponding to the first gear (1st) to fourth gear (4th).

[0061] The charge limit control unit 96 performs charge limit control CTlimchg by setting an upper limit charge power Wchgul, which is an upper limit value of the charge power Wchg when limiting the charge power Wchg, and suppressing the charge power Wchg to the upper limit charge power Wchgul with respect to the required charge power Wchgdem. Note that if the upper limit charge power Wchgul is equal to or greater than the required charge power Wchgdem, the required charge power Wchgdem can be achieved even if the charge limit control CTlimchg is performed.

[0062] The charge limit control unit 96 sets the upper limit charge power Wchgul by applying the system shaft rotation speed Nsys and the required system shaft torque Tsysdem to an upper limit value map, which is a predetermined relationship, for example.

[0063] Fig. 2 and Fig. 3 are diagrams showing examples of upper limit value maps used for setting the upper limit charging power Wchgul. Fig. 2 is a diagram explaining an example of an upper limit value map that differs for each region of the vehicle speed V, i.e., each vehicle speed range. Fig. 3 is a diagram explaining an example of an upper limit value map that differs for each gear stage of the automatic transmission 24. The upper limit value map in Fig. 2 and the upper limit value map in Fig. 3 each have a predetermined relationship in which regions having different values ​​of the upper limit charging power Wchgul are predefined on a two-dimensional coordinate system having variables, for example, the system shaft rotation speed Nsys and the required system shaft torque Tsysdem.

[0064] In FIG. 2, "Nsysfa" and "Nsysfb" each indicate a predetermined rotation speed Nsysf. "Tsysfa" and "Tsysfb" each indicate a predetermined torque Tsysf. "A1", "A2", "A3", "B1", "B2", and "B3" each indicate an upper limit charging power Wchgul. The predetermined rotation speed Nsysfa and the predetermined torque Tsysfa shown by the solid line BLa are thresholds when the vehicle speed V is in the low vehicle speed region A. The low vehicle speed region A is, for example, a vehicle speed region where the vehicle speed V exceeds the vehicle speed V1 and is equal to or lower than the vehicle speed V2. The predetermined rotation speed Nsysfb and the predetermined torque Tsysfb shown by the dashed line BLb are thresholds when the vehicle speed V is in the low vehicle speed region B. The low vehicle speed region B is, for example, a vehicle speed region where the vehicle speed V exceeds zero and is equal to or lower than the vehicle speed V1. The upper limit charging powers A1, A2, and A3 are the upper limit charging power Wchgul when the vehicle speed V is in the low vehicle speed region A. The upper limit charging power A1 is the upper limit charging power Wchgul set in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line La1. The upper limit charging power A2 is the upper limit charging power Wchgul set in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high with respect to the solid line La1, and in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line La2. The upper limit charging power A3 is the upper limit charging power Wchgul set in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high with respect to the solid line La2, and in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line BLa. The upper limit charging powers B1, B2, and B3 are the upper limit charging power Wchgul when the vehicle speed V is in the low vehicle speed region B. The upper limit charging power B1 is the upper limit charging power Wchgul that is set in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low, relative to the dashed line Lb1.The upper limit charging power B2 is the upper limit charging power Wchgul set in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high relative to the dashed line Lb1, and in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low relative to the dashed line Lb2. The upper limit charging power B3 is the upper limit charging power Wchgul set in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high relative to the dashed line Lb2, and in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low relative to the dashed line BLb.

[0065] In both the low vehicle speed region A and the low vehicle speed region B, the vehicle speed V is equal to or lower than a predetermined vehicle speed Vf, so that in the low vehicle speed region A and the low vehicle speed region B, the upper limit charging power Wchgul is set and the charging limit control CTlimchg is performed. Specifically, in the low vehicle speed region A, in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high with respect to the solid line BLa, the upper limit charging power Wchgul is not set and the charging limit control CTlimchg is not performed. In the low vehicle speed region A, in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line BLa, the upper limit charging power Wchgul is set and the charging limit control CTlimchg is performed. In the low vehicle speed region B, in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high with respect to the dashed line BLb, the upper limit charging power Wchgul is not set and the charging limit control CTlimchg is not performed. In the low vehicle speed region B, the upper limit charging power Wchgul is set and the charging limit control CTlimchg is performed in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the dashed line BLb. On the other hand, when the vehicle speed V is in a high vehicle speed region exceeding the predetermined vehicle speed Vf, the upper limit charging power Wchgul is not set and the charging limit control CTlimchg is not performed.

[0066] The lower the vehicle speed V, the higher the sensitivity of the tip-out shock is. Therefore, the lower the vehicle speed V, the higher the system shaft rotation speed Nsys and / or the higher the required system shaft torque Tsysdem may be the charge limit control CTlimchg. The low vehicle speed region B is a vehicle speed region that is lower than the low vehicle speed region A. Therefore, the predetermined rotation speed Nsysfb is set to a value higher than the predetermined rotation speed Nsysfa. The predetermined torque Tsysfb is set to a value higher than the predetermined torque Tsysfa. In this way, when the charge limit control unit 96 performs the charge limit control CTlimchg, the lower the vehicle speed V, the higher the predetermined rotation speed Nsysf and / or the predetermined torque Tsysf are set.

[0067] The lower the system shaft rotation speed Nsys and / or the lower the required system shaft torque Tsysdem, the more difficult it is to suppress the tip-out shock at the time of tip-out. Therefore, the lower the system shaft rotation speed Nsys and / or the lower the required system shaft torque Tsysdem, the smaller the upper limit charging power Wchgul may be set to. Therefore, in the low vehicle speed region A, the upper limit charging power A1 is set to a value smaller than the upper limit charging power A2, and the upper limit charging power A2 is set to a value smaller than the upper limit charging power A3. In the low vehicle speed region B, the upper limit charging power B1 is set to a value smaller than the upper limit charging power B2, and the upper limit charging power B2 is set to a value smaller than the upper limit charging power B3. As a result, in a part of the region where the upper limit charging power A2 is set in the case of the low vehicle speed region A, the upper limit charging power B1 is set in the case of the low vehicle speed region B. In a part of the region where the upper limit charging power A3 is set in the case of the low vehicle speed region A, the upper limit charging power B2 is set in the case of the low vehicle speed region B. In this embodiment, the upper limit charging power A1 and the upper limit charging power B1 are set to the same value, the upper limit charging power A2 and the upper limit charging power B2 are set to the same value, and the upper limit charging power A3 and the upper limit charging power B3 are set to the same value. Therefore, the lower the vehicle speed V, the smaller the upper limit charging power Wchgul is set to. In this way, when performing the charging limit control CTlimchg, the charging limit control unit 96 sets the upper limit charging power Wchgul to a smaller value as the vehicle speed V is lower.

[0068] In FIG. 3, "Nsysfc" and "Nsysfd" each indicate a predetermined rotation speed Nsysf. "Tsysfc" and "Tsysfd" each indicate a predetermined torque Tsysf. "C1", "C2", "C3", "D1", "D2", and "D3" each indicate an upper limit charging power Wchgul. The predetermined rotation speed Nsysfc and the predetermined torque Tsysfc shown by the solid line BLc are thresholds when the gear stage of the automatic transmission 24 is in the C-th gear stage. The C-th gear stage is, for example, the second gear stage (2nd). The predetermined rotation speed Nsysfd and the predetermined torque Tsysfd shown by the dashed line BLd are thresholds when the gear stage of the automatic transmission 24 is in the D-th gear stage. The D-th gear stage is, for example, the first gear stage (1st). The upper limit charging powers C1, C2, and C3 are the upper limit charging power Wchgul when the gear stage of the automatic transmission 24 is in the C-th gear stage. The upper limit charging power C1 is the upper limit charging power Wchgul set in a region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line Lc1. The upper limit charging power C2 is the upper limit charging power Wchgul set in a region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high with respect to the solid line Lc1, and in a region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line Lc2. The upper limit charging power C3 is the upper limit charging power Wchgul set in a region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high with respect to the solid line Lc2, and in a region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line BLc. The upper limit charging powers D1, D2, and D3 are the upper limit charging powers Wchgul when the automatic transmission 24 is in the D-th gear. The upper limit charging power D1 is the upper limit charging power Wchgul that is set in a region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low, relative to the dashed line Ld1.The upper limit charging power D2 is the upper limit charging power Wchgul set in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high relative to the dashed line Ld1, and in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low relative to the dashed line Ld2. The upper limit charging power D3 is the upper limit charging power Wchgul set in the region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high relative to the dashed line Ld2, and in the region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low relative to the dashed line BLd.

[0069] Since both the C-th gear and the D-th gear are low gears in which the gear ratio γat of the automatic transmission 24 is a predetermined low-side gear ratio γatf, the upper limit charging power Wchgul is set and the charging limit control CTlimchg is performed in the C-th gear and the D-th gear. Specifically, in the C-th gear, in a region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high with respect to the solid line BLc, the upper limit charging power Wchgul is not set and the charging limit control CTlimchg is not performed. In the C-th gear, in a region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low with respect to the solid line BLc, the upper limit charging power Wchgul is set and the charging limit control CTlimchg is performed. In the D-th gear, in a region where the system shaft rotation speed Nsys is high or the required system shaft torque Tsysdem is high relative to the dashed line BLd, the upper limit charging power Wchgul is not set and the charging limit control CTlimchg is not performed. In the D-th gear, in a region where the system shaft rotation speed Nsys is low and the required system shaft torque Tsysdem is low relative to the dashed line BLd, the upper limit charging power Wchgul is set and the charging limit control CTlimchg is performed. On the other hand, in a high vehicle speed gear (= high gear) where the gear ratio γat of the automatic transmission 24 is higher than the predetermined low-side gear ratio γatf, the upper limit charging power Wchgul is not set and the charging limit control CTlimchg is not performed.

[0070] The lower the speed ratio γat of the automatic transmission 24 is (=low side), the higher the sensitivity of the tip-out shock is. Therefore, the lower the speed ratio γat is, the higher the system shaft rotation speed Nsys is and / or the higher the required system shaft torque Tsysdem is. The D-th gear is a lower gear than the C-th gear. Therefore, the predetermined rotation speed Nsysfd is set to a higher value than the predetermined rotation speed Nsysfc. The predetermined torque Tsysfd is set to a higher value than the predetermined torque Tsysfc. In this way, when the charge limit control unit 96 performs the charge limit control CTlimchg, the lower the speed ratio γat is, the higher the predetermined rotation speed Nsysf and / or the predetermined torque Tsysf is set to.

[0071] The lower the system shaft rotation speed Nsys and / or the lower the required system shaft torque Tsysdem, the more difficult it is to suppress the tip-out shock at the time of tip-out. Therefore, the lower the system shaft rotation speed Nsys and / or the lower the required system shaft torque Tsysdem, the smaller the upper limit charging power Wchgul may be set to. Therefore, in the Cth gear, the upper limit charging power C1 is set to a value smaller than the upper limit charging power C2, and the upper limit charging power C2 is set to a value smaller than the upper limit charging power C3. In the Dth gear, the upper limit charging power D1 is set to a value smaller than the upper limit charging power D2, and the upper limit charging power D2 is set to a value smaller than the upper limit charging power D3. As a result, in a part of the region where the upper limit charging power C2 is set in the Cth gear, the upper limit charging power D1 is set in the Dth gear. In a part of the region where the upper limit charging power C3 is set in the Cth gear, the upper limit charging power D2 is set in the Dth gear. In this embodiment, the upper limit charging power C1 and the upper limit charging power D1 are set to the same value, the upper limit charging power C2 and the upper limit charging power D2 are set to the same value, and the upper limit charging power C3 and the upper limit charging power D3 are set to the same value. Therefore, the lower the gear ratio γat of the automatic transmission 24, the smaller the upper limit charging power Wchgul is set to. In this way, when performing the charge limit control CTlimchg, the charge limit control unit 96 sets the upper limit charging power Wchgul to a smaller value as the gear ratio γat of the automatic transmission 24 is on the lower side.

[0072] 2 and 3, when the charge limit control CTlimchg is performed, the charge limit control unit 96 sets the upper limit charge power Wchgul to a smaller value as the system shaft rotation speed Nsys is lower. When the charge limit control CTlimchg is performed, the charge limit control unit 96 sets the upper limit charge power Wchgul to a smaller value as the required system shaft torque Tsysdem is lower.

[0073] FIG. 4 is a flowchart illustrating the main control operations of the electronic control device 90, which are performed to appropriately maintain the battery state of charge SOC while suppressing the occurrence of shocks when performing charging control CTchg while driving, and is executed, for example, repeatedly.

[0074] In FIG. 4, each step of the flowchart corresponds to the function of the charge limit control unit 96. In step (hereinafter, step is omitted) S10, it is determined whether the system shaft rotation speed Nsys is equal to or lower than a predetermined rotation speed Nsysf. If the determination in S10 is positive, it is determined in S20 whether the required system shaft torque Tsysdem is equal to or lower than a predetermined torque Tsysf. If the determination in S20 is positive, the charge limit control CTlimchg is performed in S30. For example, an upper limit charging power Wchgul is set, and the charging power Wchg is limited to the upper limit charging power Wchgul with respect to the required charging power Wchgdem. On the other hand, if the determination in S10 is negative, or if the determination in S20 is negative, the charge limit control CTlimchg is not performed in S40. For example, the charging power Wchg is not limited with respect to the required charging power Wchgdem.

[0075] As described above, according to this embodiment, when the system shaft rotation speed Nsys is equal to or lower than the predetermined rotation speed Nsysf and the system shaft torque Tsys is equal to or lower than the predetermined torque Tsysf, the charge limit control CTlimchg is performed, whereas when the system shaft rotation speed Nsys exceeds the predetermined rotation speed Nsysf or the system shaft torque Tsys exceeds the predetermined torque Tsysf, the charge limit control CTlimchg is not performed, so that the increase in the engine torque Te relative to the required charging power Wchgdem is suppressed and the influence of the variation in the engine torque Te on the system shaft torque Tsys is suppressed. Therefore, when the charge control CTchg is performed during driving, the occurrence of shocks can be suppressed and the battery remaining charge SOC can be appropriately maintained.

[0076] Furthermore, according to this embodiment, when the vehicle speed V is equal to or lower than a predetermined vehicle speed Vf, the charge limit control CTlimchg is performed, whereas when the vehicle speed V exceeds the predetermined vehicle speed Vf, the charge limit control CTlimchg is not performed. Therefore, in the low vehicle speed range where shock sensitivity is high, the charge limit control CTlimchg is performed to suppress the occurrence of shock.

[0077] In addition, according to this embodiment, when the charging limit control CTlimchg is performed, the lower the vehicle speed V, the higher the value at which at least one of the specified rotational speed Nsysf and the specified torque Tsysf is set, so that the charging limit control CTlimchg is more likely to be performed at lower vehicle speeds where the shock sensitivity is higher.

[0078] Furthermore, according to this embodiment, when the charge limit control CTlimchg is performed, the lower the vehicle speed V, the smaller the value to which the upper limit charging power Wchgul is set. Therefore, at lower vehicle speeds where shock sensitivity is higher, the increase in engine torque Te is more suppressed and the effects of variations in engine torque Te are more suppressed.

[0079] Furthermore, according to this embodiment, when the gear ratio γat of the automatic transmission 24 is a predetermined low-side gear ratio γatf, the charge limit control CTlimchg is performed, whereas when the gear ratio γat is higher than the predetermined low-side gear ratio γatf, the charge limit control CTlimchg is not performed. Therefore, the charge limit control CTlimchg is performed at the low-side gear ratio which has high shock sensitivity, thereby suppressing the occurrence of shock.

[0080] In addition, according to this embodiment, when the charging limit control CTlimchg is performed, the lower the gear ratio γat is, the higher the value at least one of the specified rotational speed Nsysf and the specified torque Tsysf is set to, so that the lower the gear ratio is, the more likely it is that the charging limit control CTlimchg will be performed.

[0081] Furthermore, according to this embodiment, when the charge limiting control CTlimchg is performed, the lower the gear ratio γat of the automatic transmission 24, the smaller the upper limit charging power Wchgul is set to, so that the lower the gear ratio is, the higher the shock sensitivity is, and the greater the suppression of the increase in engine torque Te and the greater the suppression of the effects of variations in engine torque Te.

[0082] Furthermore, according to this embodiment, when the charging limit control CTlimchg is performed, the lower the system shaft rotation speed Nsys, the smaller the value to which the upper limit charging power Wchgul is set, so that the increase in engine torque Te is more suppressed at lower system shaft rotation speeds Nsys, at which the engine torque Te is more likely to increase.

[0083] Furthermore, according to this embodiment, when the charge limit control CTlimchg is performed, the lower the system shaft torque Tsys, the smaller the value to which the upper limit charge power Wchgul is set. Therefore, the lower the system shaft torque Tsys, which is more susceptible to the influence of variations in the engine torque Te, the more the influence of variations in the engine torque Te is suppressed.

[0084] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the present invention can be applied to other embodiments.

[0085] For example, the present invention can be applied to a vehicle 100 that does not include the K0 clutch 20, as shown in Fig. 5, instead of the vehicle 10 in the above-described embodiment. In a power transmission device 102 included in the vehicle 100, the engine 12 is connected to the motor connecting shaft 36 so as to be capable of transmitting power without passing through the K0 clutch 20.

[0086] In the above embodiment, a planetary gear type automatic transmission is exemplified as the automatic transmission 24, but the present invention is not limited to this. For example, the automatic transmission 24 may be a synchronous mesh type parallel two-shaft automatic transmission including a known DCT (Dual Clutch Transmission), a known belt type continuously variable transmission, or the like. Alternatively, the automatic transmission 24 does not necessarily have to be provided. In this case, an upper limit value map that differs for each gear stage of the automatic transmission 24 as shown in FIG. 3 is not used.

[0087] In addition, in the above-described embodiment, the torque converter 22 is used as the fluid-type power transmission device, but the present invention is not limited to this. For example, instead of the torque converter 22, another fluid-type power transmission device, such as a fluid coupling that does not amplify torque, may be used as the fluid-type power transmission device. Alternatively, the fluid-type power transmission device does not necessarily have to be provided, and may be replaced with, for example, a clutch for starting. In short, the present invention can be applied to any vehicle that includes a power source including an engine and an electric motor, a power transmission device having a transmission shaft to which the power source is connected so as to be capable of transmitting power, which transmits the torque of the power source input to the transmission shaft to the drive wheels, and an electricity storage device that supplies and receives electric power to the electric motor.

[0088] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0089] 10, 100: Vehicle 12: Engine 14: Drive wheel 16, 102: Power transmission device 24: Automatic transmission 36: Motor connecting shaft (transmission shaft) 38: Transmission input shaft (transmission shaft) 54: Battery (energy storage device) 90: Electronic control device (control device) 92: Power source control unit 96: Charging limit control unit MG: Electric motor SP: Power source

Claims

1. A control device for a vehicle including a power source including an engine and an electric motor, a power transmission device having a transmission shaft to which the power source is connected so as to be capable of transmitting power, the power transmission device transmitting torque of the power source input to the transmission shaft to driving wheels, and an electricity storage device supplying and receiving electric power to and from the electric motor, a power source control unit that performs charging control to increase the torque of the engine relative to a torque of the engine that realizes a required amount of driving power so as to realize a required value of charging power to be charged to the power storage device by power generation of the electric motor while the vehicle is traveling in a driving state; and a charge limit control unit that performs charge limit control to limit the charging power in the charging control when the rotation speed of the transmission shaft is equal to or lower than a predetermined rotation speed and when a transmission shaft torque, which is a torque on the transmission shaft transmitted to the drive wheels among the torque of the power source, is equal to or lower than a predetermined torque, and does not perform the charge limit control when the rotation speed of the transmission shaft exceeds the predetermined rotation speed or the transmission shaft torque exceeds the predetermined torque; and the charge limit control unit performs the charge limit control when the vehicle speed is equal to or lower than a predetermined vehicle speed, and does not perform the charge limit control when the vehicle speed exceeds the predetermined vehicle speed, A vehicle control device characterized in that, when performing the charge limit control, the charge limit control unit sets at least one of the predetermined rotation speed and the predetermined torque to a higher value as the vehicle speed is lower.

2. A control device for a vehicle equipped with a power source including an engine and an electric motor, a power transmission device having a transmission shaft to which the power source is connected so as to be capable of transmitting power, the power transmission device transmitting the torque of the power source input to the transmission shaft to a drive wheel, and an electricity storage device supplying and receiving electric power to and from the electric motor, a power source control unit that performs charging control to increase the torque of the engine relative to a torque of the engine that realizes a required amount of driving power so as to realize a required value of charging power to be charged to the power storage device by power generation of the electric motor while the vehicle is traveling in a driving state; and a charge limit control unit that performs charge limit control to limit the charging power in the charging control when the rotation speed of the transmission shaft is equal to or lower than a predetermined rotation speed and when a transmission shaft torque, which is a torque on the transmission shaft transmitted to the drive wheels among the torque of the power source, is equal to or lower than a predetermined torque, and does not perform the charge limit control when the rotation speed of the transmission shaft exceeds the predetermined rotation speed or the transmission shaft torque exceeds the predetermined torque; and the charge limit control unit performs the charge limit control when a gear ratio of an automatic transmission included in the power transmission device is a predetermined low-speed gear ratio, and does not perform the charge limit control when the gear ratio is a higher speed side than the predetermined low-speed gear ratio, The vehicle control device is characterized in that, when performing the charge limit control, the charge limit control unit sets at least one of the specified rotation speed and the specified torque to a higher value as the gear ratio becomes lower.

3. 3. The vehicle control device according to claim 2, wherein the charge limit control unit performs the charge limit control when the vehicle speed is equal to or lower than a predetermined vehicle speed, and does not perform the charge limit control when the vehicle speed exceeds the predetermined vehicle speed.

4. 4. The vehicle control device according to claim 1, wherein, when performing the charge limit control, the charge limit control unit sets the upper limit value of the charge power when limiting the charge power to a smaller value as the vehicle speed becomes lower.

5. 2. The vehicle control device according to claim 1, wherein the charge limit control unit performs the charge limit control when a gear ratio of an automatic transmission provided in the power transmission device is a predetermined low-speed gear ratio, but does not perform the charge limit control when the gear ratio is a higher speed side than the predetermined low-speed gear ratio.

6. 6. The vehicle control device according to claim 5, wherein, when performing the charge limiting control, the charge limiting control unit sets at least one of the predetermined rotation speed and the predetermined torque to a higher value as the gear ratio becomes lower.

7. 7. The vehicle control device according to claim 2, wherein, when performing the charge limiting control, the charge limiting control unit sets the upper limit value of the charge power when limiting the charge power to a smaller value as the gear ratio becomes lower.

8. 8. The vehicle control device according to claim 1, wherein, when performing the charge limiting control, the charge limiting control unit sets the upper limit value of the charging power when limiting the charging power to a smaller value as the rotation speed of the transmission shaft becomes lower.

9. 9. The vehicle control device according to claim 1, wherein, when performing the charge limiting control, the charge limiting control unit sets the upper limit value of the charge power when limiting the charge power to a smaller value as the transmission shaft torque becomes lower.

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