JP2021031036A - Hybrid vehicle - Google Patents

Abstract

To suppress the deterioration of drivability by suppressing the slowness of a rise of an engine rotation number when raising the engine rotation number toward a rotation number after a downshift of a simulation gear change stage in parallel with a downshift of a gear change stage of a stepped transmission accompanied by an increase of an accelerator opening.SOLUTION: When raising an engine rotation number toward a rotation number after a downshift of a simulation gear change stage in parallel with a downshift of a gear change stage of a stepped transmission accompanied by an increase of an accelerator operation amount, a control device limits an accumulator-power compensation compared with the case that an output is not limited to an engine when the output is limited to the engine.SELECTED DRAWING: Figure 15

Description

The present invention relates to a hybrid vehicle.

Conventionally, as a hybrid vehicle of this type, a first motor is connected to the sun gear of the planetary gear, an engine is connected to the carrier, a transmission member is connected to the ring gear, a second motor is connected to the transmission member, and a drive shaft connected to the transmission member and the axle. A stepped transmission is attached between the motor and the motor, and a battery is connected to the first motor and the second motor via a power line (see, for example, Patent Document 1). In this hybrid vehicle, the required driving force required for the drive shaft is set based on the accelerator opening and the vehicle speed, and a virtual gear is set as the gear of the stepped transmission based on the accelerator opening and the vehicle speed. A simulated shift is set from the added shifts, a target shift of the stepped transmission is set, and the engine drive speed is set based on the vehicle speed and the shift. Next, the upper limit power of the engine when the engine is operated at the driving speed is set, the upper limit driving force of the drive shaft when the upper power is output from the engine is set, and the engine is operated at the driving speed. The engine, the first motor, the second motor, and the stepped transmission so that the shift stage of the stepped transmission becomes the target shift stage and the smaller of the required driving force and the upper limit driving force is output to the drive shaft. And control. With such control, even when the driver depresses the accelerator pedal, the engine speed becomes the number of revolutions according to the vehicle speed, so the engine speed increases sharply prior to the increase in vehicle speed. It is possible to give a person a better driving feeling. Further, when the shift stage is changed, the engine speed changes, so that the driver can be given a feeling of shift.

JP-A-2017-159732

In the above-mentioned hybrid vehicle, when the accelerator opening increases and the required driving force becomes larger than the upper limit driving force, the power of the battery is used to output the driving force larger than the upper limit driving force to the drive shaft. Therefore, it is conceivable to perform predetermined control to increase the torque output from the second motor to the drive shaft. In addition, when the engine speed is increased toward the drive speed after the downshift of the simulated gear in parallel with the downshift of the gear of the stepped transmission due to the increase in the accelerator opening, the engine is used. On the other hand, when the output is limited, it is necessary to increase the engine speed by the first motor. If an attempt is made to increase the engine speed by the first motor while performing the above-mentioned predetermined control, a large torque cannot be output from the first motor, the engine speed increases slowly, and drivability deteriorates. there's a possibility that.

In the hybrid vehicle of the present invention, when the engine speed is increased toward the speed after the downshift of the simulated gear in parallel with the downshift of the gear of the stepped transmission as the accelerator opening is increased. The main purpose is to suppress the sluggishness of the engine speed increase and to suppress the deterioration of the hybrid.

The hybrid vehicle of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The hybrid vehicle of the present invention
An engine, a first motor, a planetary gear in which three rotating elements are connected to the engine, the first motor, and a transmission member, and a drive shaft connected to the transmission member and an axle. A speed transmission, a second motor capable of inputting / outputting power to the transmission member or the drive shaft, a power storage device for exchanging power with the first motor and the second motor, and a control device are provided.
The control device is
The required driving force required for the drive shaft is set based on the accelerator operation amount and the vehicle speed.
Based on the accelerator operation amount and the vehicle speed, a simulated shift stage is set from the shift stage of the stepped transmission or a shift stage in which a virtual shift stage is added to the shift stage of the stepped transmission, and the simulated shift stage is set. Set the target speed of the stepped transmission,
The target rotation speed of the engine is set based on the vehicle speed and the simulated shift stage, and the target rotation speed is set.
The upper limit power of the engine when operating the engine at the target rotation speed is set, and the upper limit power of the engine is set.
The first upper limit driving force of the drive shaft when the upper limit power is output from the engine is set.
The target driving force of the driving shaft is set based on the magnitude relationship between the required driving force and the first upper limit driving force.
The engine, the first motor, and the second motor so that the engine is operated at the target speed and the shift stage of the stepped transmission becomes the target shift stage and travels based on the target driving force. Controlling the stepped transmission,
It ’s a hybrid vehicle,
The control device is
When the required driving force is equal to or less than the first upper limit driving force, the required driving force is set as the target driving force.
When the required driving force is larger than the first upper limit driving force,
The target supplementary power of the power storage device is set based on the difference between the required driving force and the first upper limit driving force.
The second upper limit driving force of the drive shaft is set when the upper limit power is output from the engine and the power storage device is charged and discharged with the power based on the target compensation power.
The smaller of the required driving force and the second upper limit driving force is set as the target driving force.
Further, the control device directs the engine speed to the speed after the downshift of the simulated gear in parallel with the downshift of the gear of the stepped transmission as the accelerator operation amount increases. When the output is limited to the engine when the engine is raised, the power supply of the power storage device is limited as compared with the case where the output is not limited to the engine.
The gist is that.

In the hybrid vehicle of the present invention, when the required driving force is equal to or less than the first upper limit driving force, the control device sets the required driving force as the target driving force. On the other hand, when the required driving force is larger than the first upper limit driving force, the control device sets the target supplementary power of the power storage device based on the difference between the required driving force and the first upper limit driving force, and sets the upper limit power from the engine. Set the second upper limit driving force of the drive shaft when outputting and charging / discharging the power storage device with the power based on the target compensation power, and the smaller of the required driving force and the second upper limit driving force. Is set as the target driving force. Further, the control device increases the engine speed toward the speed after the downshift of the simulated gear in parallel with the downshift of the gear of the stepped transmission due to the increase in the accelerator operation amount. When the output limit is applied to the engine, the power supply of the power storage device is limited as compared with the case where the output limit is not applied to the engine. As a result, a large torque can be output from the first motor in order to increase the engine speed, as compared with the one that does not limit the power supply of the power storage device. Deterioration of drivability can be suppressed.

Here, the "shift stage in which a virtual shift stage is added to the shift stage of the stepped transmission" means a shift stage in which the shift stage of the stepped transmission and the virtual shift stage are combined. For example, if one virtual gear is provided for each gear of a two-speed stepped transmission, a total of four gears is obtained. Further, if two virtual gears are provided for each of the first to third gears of the four-speed stepped transmission, a total of 10 gears is obtained. In this way, a desired number of gears can be used.

Further, as "when the output is limited to the engine", for example, when the input allowable power of the battery is equal to or less than the threshold value can be mentioned. When the input allowable power of the battery is equal to or less than the threshold value, the generated power of the first motor, that is, the torque in the direction of suppressing the number of revolutions of the engine that may be output from the first motor is limited to a relatively small value. If the output is not limited to the engine, the engine speed will be changed to the speed after the downshift of the simulated gear in parallel with the downshift of the gear of the stepped transmission due to the increase in the accelerator operation amount. There is a possibility that the engine speed will rise (overshoot) with respect to the speed after the downshift of the simulated shift stage. In order to suppress the increase in the number of revolutions of the engine, when the allowable input power of the battery is equal to or less than the threshold value, the output is generally limited to the engine.

In such a hybrid vehicle of the present invention, when setting the first upper limit driving force, the control device is based on the upper limit power and the storage ratio of the power storage device, and the discharge side is positive. The driving force when the sum power of the one required charge / discharge power is output to the drive shaft is set as the first upper limit driving force, and when the second upper limit driving force is set, the upper limit power is set. When the sum of the first required charge / discharge power and the second required charge / discharge power of the power storage device based on the target compensation power and the discharge side is positive is output to the drive shaft. The force may be set as the second upper limit driving force. In this way, the first upper limit driving force and the second upper limit driving force can be set more appropriately.

In this case, when the required driving force is equal to or less than the first upper limit driving force, the control device calculates the power obtained by subtracting the required charge / discharge power from the power for outputting the target driving force to the drive shaft. When the required driving force is larger than the first upper limit driving force, the power for outputting the target driving force to the driving shaft is used to obtain the first required charge / discharge power and the second required driving force. A power obtained by subtracting the sum of the charge / discharge power may be set as the target power of the engine, and the engine may be controlled so that the target power is output from the engine. In this way, the target power of the engine can be set more appropriately.

It is a block diagram which shows the outline of the structure of the hybrid vehicle 20 as an Example of this invention. It is a block diagram which shows the outline of the structure of the engine 22, the planetary gear 30, the motors MG1 and MG2, and the stepped transmission 60. It is an operation table which shows the relationship between each shift stage of a stepped transmission 60 and the state of clutches C1, C2 and brakes B1, B2, B3. It is a collinear diagram which shows the relationship of the rotation speed of each rotating element of a planetary gear 30 and a stepped transmission 60. It is a flowchart (first half part) which shows an example of a drive priority control routine. It is a flowchart (the latter half part) which shows an example of a drive priority control routine. It is explanatory drawing which shows an example of the required driving force setting map. It is explanatory drawing which shows an example of the shift line diagram. It is explanatory drawing which shows an example of the rotation speed setting map for driving. It is explanatory drawing which shows an example of the map for setting the upper limit power. It is explanatory drawing which shows an example of the required charge / discharge power setting map. It is explanatory drawing which shows an example of the map for setting the replenishable power. It is explanatory drawing which shows an example of the map for rate value setting. Accelerator opening Acc, vehicle speed V, simulated shift stage Gsv, engine 22 target speed Ne * and actual speed Ne, engine 22 target power Pe * and actual output power Pe, required driving force Tdusr, upper limit driving force It is explanatory drawing which shows an example of the state of the required charge / discharge power Pb1 *, Pb2 * of Tdlim1, the battery 50, the actual charge / discharge power Pb, the target driving force Td *, and the output driving force Td. It is a flowchart which shows an example of the power-on-downshift processing routine executed by HVECU 70. It is a collinear diagram which shows the relationship between the rotation speed and torque of each rotating element of a planetary gear 30 when traveling while running the engine 22 with a steady load. When the absolute value of the input limit Win of the battery 50 is equal to or less than the threshold Wref and the rotation speed Ne of the engine 22 is increased toward the rotation speed after shifting in parallel with the power on / down shift, the accelerator opening Acc and the target shifting stage Explanatory drawing showing an example of Gsat *, the rotation speed Nin of the input shaft 61 of the stepped transmission 60, the required charge / discharge power Pb2 * and the charge / discharge power Pb of the battery 50, and the output power Pe and the rotation speed Ne of the engine 22. Is.

Next, a mode for carrying out the present invention will be described with reference to examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. FIG. 2 is a configuration diagram showing an outline of the configuration of the engine 22, the planetary gear 30, the motors MG1 and MG2, and the stepped transmission 60. As shown in FIGS. 1 and 2, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50 as a power storage device, and a stepped transmission. It includes 60 and an electronic control unit for hybrid (hereinafter referred to as “HVECU”) 70.

The engine 22 is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel. The engine 22 is operated and controlled by an electronic control unit for an engine (hereinafter, referred to as "engine ECU") 24.

The engine ECU 24 includes a microcomputer having a CPU, a ROM, a RAM, an input / output port, and a communication port. Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 from the input port. Examples of the signal input to the engine ECU 24 include the crank angle θcr of the crankshaft 23 from the crank position sensor 23a that detects the rotational position of the crankshaft 23 of the engine 22. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via the output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23a.

The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The planetary gear 30 rotates (rotates) and revolves around a sun gear 30s, which is an external gear, a ring gear 30r, which is an internal gear, a plurality of pinion gears 30p that mesh with the sun gear 30s and the ring gear 30r, respectively, and a plurality of pinion gears 30p. Has a carrier 30c and a support for the. The sun gear 30s is connected to the rotor of the motor MG1. The ring gear 30r is connected to the rotor of the motor MG2 and the input shaft 61 of the stepped transmission 60 via the transmission member 32. The carrier 30c is connected to the crankshaft 23 of the engine 22 via a damper 28.

The motors MG1 and MG2 are both configured as, for example, synchronous generator motors. As described above, the rotor of the motor MG1 is connected to the sun gear 30s of the planetary gear 30. As described above, the rotor of the motor MG2 is connected to the ring gear 30r of the planetary gear 30 and the input shaft 61 of the stepped transmission 60 via the transmission member 32. The inverters 41 and 42 are used to drive the motors MG1 and MG2 and are connected to the battery 50 via the power line 54. The motors MG1 and MG2 are rotationally driven by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by an electronic control unit for a motor (hereinafter referred to as "motor ECU") 40.

The motor ECU 40 includes a microcomputer having a CPU, ROM, RAM, input / output ports, and communication ports. Signals from various sensors necessary for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input port. The signals input to the motor ECU 40 include, for example, the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotation position sensors 43 and 44 that detect the rotation positions of the rotors of the motors MG1 and MG2, and the motor MG1. , Iu1, Iv1, Iu2, Iv2 of the phase currents of each phase of the motors MG1 and MG2 from the current sensor that detects the phase current flowing in each phase of MG2. From the motor ECU 40, switching control signals and the like to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the electric angles θe1, θe2 and the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotation position sensors 43 and 44.

The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery. As described above, the battery 50 is connected to the inverters 41 and 42 via the power line 54. The battery 50 is managed by an electronic control unit for batteries (hereinafter, referred to as "battery ECU") 52.

The battery ECU 52 includes a microcomputer having a CPU, ROM, RAM, input / output ports, and communication ports. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. The signals input to the battery ECU 52 include, for example, the voltage Vb of the battery 50 from the voltage sensor 51a attached between the terminals of the battery 50 and the battery 50 from the current sensor 51b attached to the output terminal of the battery 50. Examples include the current Ib and the temperature Tb of the battery 50 from the temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC of the battery 50 based on the integrated value of the current Ib of the battery 50 from the current sensor 51b. The storage ratio SOC is the ratio of the capacity of electric power that can be discharged from the battery 50 to the total capacity of the battery 50. Further, the battery ECU 52 calculates the input / output restriction Win and Wout of the battery 50 based on the storage ratio SOC of the battery 50 and the temperature Tb of the battery 50 from the temperature sensor 51c. The input limit Win is the maximum permissible power (negative value) that may charge the battery 50, and the output limit Wout is the maximum permissible power (positive value) that may be discharged from the battery 50.

The stepped transmission 60 is configured as a four-speed stepped transmission. The stepped transmission 60 includes an input shaft 61, an output shaft 62, planetary gears 63, 64, 65, clutches C1, C2, and brakes B1, B2, B3. As described above, the input shaft 61 is connected to the ring gear 30r of the planetary gear 30 and the motor MG2 via the transmission member 32. The output shaft 62 is connected to a drive shaft 36 connected to the drive wheels 39a and 39b via a differential gear 38.

The planetary gear 63 is configured as a single pinion type planetary gear mechanism. The planetary gear 63 rotates (rotates) and revolves around a sun gear 63s, which is an external gear, a ring gear 63r, which is an internal gear, a plurality of pinion gears 63p that mesh with the sun gear 63s and the ring gear 63r, respectively, and a plurality of pinion gears 63p. Has a carrier 63c and a support for the tooth.

The planetary gear 64 is configured as a single pinion type planetary gear mechanism. The planetary gear 64 rotates (rotates) and revolves around a sun gear 64s, which is an external gear, a ring gear 64r, which is an internal gear, a plurality of pinion gears 64p that mesh with the sun gear 64s and the ring gear 64r, respectively, and a plurality of pinion gears 64p. Has a carrier 64c and a support for the.

The planetary gear 65 is configured as a single pinion type planetary gear mechanism. The planetary gear 65 rotates (rotates) and revolves around a sun gear 65s, which is an external gear, a ring gear 65r, which is an internal gear, a plurality of pinion gears 65p that mesh with the sun gear 65s and the ring gear 65r, respectively, and a plurality of pinion gears 65p. It has a carrier 65c and a support for the carrier 65c.

The sun gear 63s of the planetary gear 63 and the sun gear 64s of the planetary gear 64 are connected (fixed) to each other. The ring gear 63r of the planetary gear 63, the carrier 64c of the planetary gear 64, and the carrier 65c of the planetary gear 65 are connected to each other. The ring gear 64r of the planetary gear 64 and the sun gear 65s of the planetary gear 65 are connected to each other. Therefore, the planetary gears 63, 64, 65 are the sun gear 63s of the planetary gear 63 and the sun gear 64s of the planetary gear 64, the carrier 63c of the planetary gear 63, the ring gear 65r of the planetary gear 65, the ring gear 63r of the planetary gear 63 and the carrier 64c of the planetary gear 64, and the carrier of the planetary gear 65. The 65c, the ring gear 64r of the planetary gear 64, and the sun gear 65s of the planetary gear 65 function as a five-element type mechanism having five rotating elements. Further, the ring gear 63r of the planetary gear 63, the carrier 64c of the planetary gear 64, and the carrier 65c of the planetary gear 65 are connected to the output shaft 62.

The clutch C1 connects the input shaft 61, the ring gear 64r of the planetary gear 64, and the sun gear 65s of the planetary gear 65 to each other, and disconnects the two. The clutch C2 connects the input shaft 61, the sun gear 63s of the planetary gear 63, and the sun gear 64s of the planetary gear 64 to each other, and disconnects the two.

The brake B1 rotatably fixes (connects) the sun gear 63s of the planetary gear 63 and the sun gear 64s of the planetary gear 64 to the transmission case 69, and rotatably releases the sun gear 63s and the sun gear 64s to the transmission case 69. The brake B2 rotatably fixes (connects) the carrier 63c of the planetary gear 63 to the transmission case 69 and releases the carrier 63c to the transmission case 69 rotatably. The brake B3 rotatably fixes (connects) the ring gear 65r of the planetary gear 65 to the transmission case 69 and releases the ring gear 65r to the transmission case 69 rotatably.

The clutches C1 and C2 are respectively configured as, for example, a hydraulically driven multi-plate clutch. The brake B1 is configured as, for example, a hydraulically driven band brake. The brakes B2 and B3 are respectively configured as, for example, a hydraulically driven multi-plate brake. The clutches C1 and C2 and the brakes B1, B2 and B3 operate by supplying and discharging hydraulic oil by a hydraulic control device (not shown). The hydraulic control device is controlled by the HVECU 70.

FIG. 3 is an operation table showing the relationship between each shift stage of the stepped transmission 60 and the states of the clutches C1 and C2 and the brakes B1, B2 and B3. FIG. 4 is a collinear diagram showing the relationship between the rotation speeds of each rotating element of the planetary gear 30 and the stepped transmission 60. In FIG. 4, “ρ0” is the gear ratio of the planetary gear 30 (the number of teeth of the sun gear 30s / the number of teeth of the ring gear 30r). “Ρ1” is the gear ratio of the planetary gear 63 (the number of teeth of the sun gear 63s / the number of teeth of the ring gear 63r). “Ρ2” is the gear ratio of the planetary gear 64 (the number of teeth of the sun gear 64s / the number of teeth of the ring gear 64r). “Ρ3” is the gear ratio of the planetary gear 65 (the number of teeth of the sun gear 65s / the number of teeth of the ring gear 65r).

Further, in FIG. 4, the left side is a collinear diagram of the planetary gear 30, and the right side is a collinear diagram of the stepped transmission 60. In the co-line diagram of the planetary gear 30, the 30s axis indicates the rotation speed of the sun gear 30s, which is the rotation speed Nm1 of the motor MG1, the 30c axis indicates the rotation speed of the carrier 30c, which is the rotation speed Ne of the engine 22, and the 30r axis indicates the rotation speed. , The rotation speed Nm2 of the motor MG2, the rotation speed of the transmission member 32, and the rotation speed of the ring gear 30r, which is the rotation speed of the input shaft 61, are shown. In the joint diagram of the stepped transmission 60, the 63s and 64s axes indicate the rotation speeds of the sun gear 63s of the planetary gear 63 and the sun gear 64s of the planetary gear 64, and the 63c axis indicates the rotation speed of the carrier 63c of the planetary gear 63. The shaft indicates the rotation speed of the ring gear 65r of the planetary gear 65, and 63r, 64c, 65c are the rotation speed Nd of the drive shaft 36 (the rotation speed of the output shaft 62), the ring gear 63r of the planetary gear 63, and the carrier 64c of the planetary gear 64. The rotation speed of the planetary gear 65 with the carrier 65c is shown, and the 64r and 65s axes show the rotation speed of the ring gear 64r of the planetary gear 64 and the sun gear 65s of the planetary gear 65.

In the stepped transmission 60, the clutches C1 and C2 and the brakes B1, B2 and B3 are engaged or disengaged as shown in FIG. Will be done. Specifically, the first forward speed is formed by engaging the clutch C1 and the brake B3 and releasing the clutch C2 and the brakes B1 and B2. The second forward speed is formed by engaging the clutch C1 and the brake B2 and releasing the clutch C2 and the brakes B1 and B3. The third forward speed is formed by engaging the clutch C1 and the brake B1 and releasing the clutch C2 and the brakes B2 and B3. The fourth forward speed is formed by engaging the clutches C1 and C2 and releasing the brakes B1, B2 and B3. The reverse stage is formed by engaging the clutch C2 and the brake B3 and releasing the clutch C1 and the brakes B1 and B2.

The HVECU 70 includes a microcomputer having a CPU, a ROM, a RAM, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via input ports. The signals input to the HVECU 70 include, for example, the rotation speed Nd of the drive shaft 36 from the rotation speed sensor 36a that detects the rotation speed of the drive shaft 36, the ignition signal from the ignition switch 80, and the operation position of the shift lever 81. The shift position SP from the shift position sensor 82 to be detected can be mentioned. Examples include the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83, and the brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85. The vehicle speed V from the vehicle speed sensor 88, the road surface gradient θrd from the gradient sensor 89 (a positive value on the climbing side), and the mode signal from the mode switch 90 can also be mentioned. Various control signals are output from the HVECU 70 via the output port. Examples of the signal output from the HVECU 70 include a control signal to the stepped transmission 60 (flood control device). As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via a communication port.

Here, as the shift position SP, a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), and the like are prepared.

The mode switch 90 is executed from a plurality of driving modes including a normal mode in which the driver prioritizes fuel efficiency and a driving priority mode in which the driver's driving feeling (drivability and drive feeling) is prioritized over fuel efficiency. It is a switch for selecting a driving mode. When the normal mode is selected as the running mode for execution, the engine 22 and the motors MG1 and MG2 are driven and controlled so that the engine 22 runs while being efficiently operated when the shift position SP is in the D position. When the drive priority mode is selected as the driving mode for execution, when the shift position SP is in the D position, the engine 22 goes through a virtual stepped transmission (hereinafter referred to as "simulated transmission") with 10 speeds. The engine 22 and the motors MG1 and MG2 are driven and controlled so as to travel while being operated so as to be connected to the drive shaft 36. Here, each of the 10-speed simulated transmissions is provided with two virtual gears for each of the first to third gears of the four-speed stepped transmission 60. It is composed of.

The hybrid vehicle 20 of the embodiment configured in this way performs hybrid traveling (HV traveling) traveling with the operation of the engine 22 and electric traveling (EV traveling) traveling without the operation of the engine 22.

Next, the operation of the hybrid vehicle 20 configured in this way, particularly the operation when the drive priority mode is selected as the execution driving mode by the mode switch 90 and the shift position SP performs HV traveling in the D position will be described. 5 and 6 are flowcharts showing an example of a drive priority control routine executed by the HVECU 70. This routine is repeatedly executed when the drive priority mode is selected as the execution mode by the mode switch 90 and the shift position SP performs HV travel in the D position.

When the drive priority control routines of FIGS. 5 and 6 are executed, the HVECU 70 first determines the accelerator opening degree Acc, the vehicle speed V, the rotation speed Nd of the drive shaft 36, the rotation speed Ne of the engine 22, and the motors MG1 and MG2. Data such as the rotation speeds Nm1 and Nm2, the storage ratio SOC of the battery 50, and the output limit Wout are input (step S100). Here, a value detected by the accelerator pedal position sensor 84 is input to the accelerator opening degree Acc. A value detected by the vehicle speed sensor 88 is input as the vehicle speed V. A value detected by the rotation speed sensor 36a is input to the rotation speed Nd of the drive shaft 36. A value calculated by the engine ECU 24 is input to the rotation speed Ne of the engine 22. The values calculated by the motor ECU 40 are input to the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2. The values calculated by the battery ECU 52 are input to the storage ratio SOC of the battery 50 and the output limit Wout.

When the data is input in this way, the HVECU 70 sets the required driving force Tdusrr required for traveling (required for the drive shaft 36) by using the accelerator opening degree Acc, the vehicle speed V, and the required driving force setting map. (Step S110). Here, the required driving force setting map is preset as a relationship between the accelerator opening degree Acc, the vehicle speed V, and the required driving force Tdusrr, and is stored in a ROM (not shown). FIG. 7 is an explanatory diagram showing an example of a required driving force setting map.

Subsequently, the HVECU 70 sets the simulated shift stage Gsv and the target shift stage Gsat * using the accelerator opening degree Acc, the vehicle speed V, and the shift diagram (step S120). Here, the simulated shift stage Gsv is the shift stage of the simulated transmission with 10 speeds, and the target shift stage Gsat * is the target shift stage of the stepped transmission 60 with 4 speeds. The shift diagram is predetermined as the relationship between the accelerator opening Acc, the vehicle speed V, the simulated shift stage Gsv, and the target shift stage Gsat *.

FIG. 8 is an explanatory diagram showing an example of a transmission line diagram. In the figure, the solid line (thin solid line and thick solid line) is the shift line for upshifting, and the one-dot chain line (thin one-dot chain line and thin one-dot chain line broken line) is the shift line for downshifting. The simulated shift stage Gsv is set based on all the shift lines shown in FIG. 8 depending on which of the 10 shift stages corresponds to. The target shift stage Gsat * is set based on which of the four gears corresponds to each of the four gears based on the thick solid line and the thick broken line in FIG.

When the target shift stage Gsat * is obtained in this way, the HVECU 70 controls the stepped transmission 60 using the target shift stage Gsat * (step S130). In the stepped transmission 60, when the gear Gsat matches the target gear Gsat *, the gear Gsat is held, and when the gear Gsat is different from the target gear Gsat *, the gear Gsat is the target gear Gsat *. The shift stage Gsat is changed so as to be. The control of the stepped transmission 60 is also performed when the normal mode is selected as the execution mode and HV travel is performed, or when EV travel is performed. Further, it takes a longer time than the execution cycle of this routine to change the shift stage Gsat.

The shift gear Gsat is changed, for example, as follows. First, the first stage release control is executed for the release side element of the clutches C1, C2 and the brakes B1, B2, B3 of the stepped transmission 60 that switches from the engaged state to the release state according to the change of the shift stage Gsat. At the same time, stroke control is executed for the engaging side element that switches from the released state to the engaged state. The first stage release control is a control in which the oil pressure is lowered by one step to slip-engage the release side element. Stroke control is a control that closes the gap between the piston of the engaging side element and the friction engaging plate (strokes the piston), and then performs low-pressure standby that holds the flood control at a relatively low standby pressure. ..

Subsequently, the second stage release control is executed for the release side element, and the torque phase control is executed for the engagement side element. In the second stage release control and torque phase control, the oil pressure of the release side element is gradually reduced and the oil pressure of the engagement side element is gradually increased, and the torque transmission is changed from the transmission by the transmission stage before the change to the change. It is a control that changes to transmission by a gear.

Then, the third stage release control is executed for the release side element, and the inertia phase control and the final control are executed in order for the engagement side element. The third stage release control is a control that further lowers the oil pressure of the release side element. The inertia phase control is a control in which the oil pressure of the engaging side element is gradually increased to bring the rotation speed Nin of the input shaft 61 of the stepped transmission 60 closer to the rotation speed corresponding to the target transmission speed Gsat *. Telophase control is a control that further raises the oil pressure of the engaging side element.

Further, when the simulated shift speed Gsv is obtained in step S120, the HVECU 70 sets the drive rotation speed Nedrv of the engine 22 by using the vehicle speed V, the simulated shift speed Gsv, and the drive rotation speed setting map (step S140). ), The set engine 22 drive rotation speed Nedrv is set as the engine 22 target rotation speed Ne * (step S150). Here, the drive rotation speed setting map is preset as a relationship between the vehicle speed V, the simulated shift stage Gsv, and the drive rotation speed Nedrv of the engine 22, and is stored in a ROM (not shown).

FIG. 9 is an explanatory diagram showing an example of a map for setting the rotation speed for driving. As shown in the figure, the rotation speed Nedrv for driving of the engine 22 is linearly increased as the vehicle speed V is larger in each simulated shift stage Gsv of the simulated transmission with 10 speeds, and the simulated shift stage Gsv is larger. It is set so that the inclination with respect to the vehicle speed V becomes smaller. As a result, when the engine 22 is operated at the rotation speed Nedrv for driving, the rotation speed Ne of the engine 22 increases as the vehicle speed V increases at each simulated shift stage Gsv of the simulated transmission with 10 speeds, and the simulated shift is performed. The rotation speed Ne of the engine 22 decreases when the gear Gsv shifts up, and the rotation speed Ne of the engine 22 increases when the simulated shift gear Gsv shifts down. As a result, the behavior of the rotation speed Ne of the engine 22 can be made closer to that of an automobile equipped with an actual stepped transmission having 10 speeds.

When the target rotation speed Ne * of the engine 22 is obtained in this way, the HVECU 70 sets the upper limit power Perim of the engine 22 using the target rotation speed Ne * of the engine 22 and the upper limit power setting map (step S160). Here, the upper limit power Perim of the engine 22 means the upper limit of the power that can be output from the engine 22 when the engine 22 is operated at the target rotation speed Ne * (rotational speed Nedrv for driving). The upper limit power setting map is preset as the relationship between the target rotation speed Ne * of the engine 22 and the upper limit power Perim, and is stored in a ROM (not shown). FIG. 10 is an explanatory diagram showing an example of an upper limit power setting map. As shown in the figure, the upper limit power Perim of the engine 22 is set so as to increase as the target rotation speed Ne * of the engine 22 increases.

Subsequently, the HVECU 70 uses the storage ratio SOC of the battery 50 and the required charge / discharge power setting map so that the storage ratio SOC of the battery 50 approaches the target ratio SOC * so that the required charge / discharge power Pb1 * of the battery 50 ( Set (a positive value when discharging from the battery 50) (step S170). Here, the required charge / discharge power setting map is preset as the relationship between the storage ratio SOC of the battery 50 and the required charge / discharge power Pb1 *, and is stored in a ROM (not shown).

FIG. 11 is an explanatory diagram showing an example of a required charge / discharge power setting map. As shown in the figure, the required charge / discharge power Pb1 * of the battery 50 is set to a value 0 when the storage ratio SOC of the battery 50 is equal to the target ratio SOC *. Further, when the storage ratio SOC is larger than the target ratio SOC *, the required charge / discharge power Pb1 * increases from a value of 0 toward the predetermined power Pdi1 for discharge (positive) as the storage ratio SOC increases. It is set to be constant in Pdi1. Further, when the storage ratio SOC is smaller than the target ratio SOC *, the required charge / discharge power Pb1 * decreases from a value of 0 toward the predetermined charging (negative) power Pch1 as the storage ratio SOC becomes smaller. It is set to be constant at Pch1.

Then, as shown in the equation (1), the HVECU 70 divides the sum of the upper limit power Perim of the engine 22 and the required charge / discharge power Pb1 * of the battery 50 by the rotation speed Nd of the drive shaft 36 to obtain the upper limit driving force Tdlim1. Calculate (step S180). Here, the upper limit driving force Tdlim1 outputs the upper limit power Perim from the engine 22 along with the operation at the target rotation speed Ne * (rotational speed Nedrv for driving) of the engine 22, and the battery 50 has the required charge / discharge power Pb1 *. It means the upper limit of the driving force that can be output to the driving shaft 36 when charging / discharging. In the formula (1), adding the required charge / discharge power Pb1 * of the battery 50 to the upper limit power Perim of the engine 22 changes the power output from the engine 22 when the battery 50 is charged / discharged with the required charge / discharge power Pb1 *. This is to prevent it from being discharged.

Tdlim1 = (Pelim + Pb1 *) / Nd (1)

Next, the HVECU 70 compares the required driving force Tdusr with the upper limit driving force Tdlim1 (step S190). This process is a process of determining whether or not the required driving force Tdusr can be output to the drive shaft 36 with the charging / discharging of the battery 50 with the required charging / discharging power Pb1 *.

When the required driving force Tdusr is equal to or less than the upper limit driving force Tdlim1, the HVECU 70 determines that the required driving force Tdusrr can be output to the drive shaft 36 with the charging / discharging of the battery 50 with the required charging / discharging power Pb1 *. A value 0 is set to the required charge / discharge power Pb2 * (a positive value when discharging from the battery 50) of the battery 50 (step S200), and the required driving force Tdusr should be output to the drive shaft 36 as the target driving force Td *. (Step S210). Here, the details of the required charge / discharge power Pb2 * of the battery 50 will be described later.

Subsequently, as shown in the equation (2), the HVECU 70 subtracts the required charge / discharge power Pb1 * of the battery 50 from the product of the target driving force Td * and the rotation speed Nd of the drive shaft 36, and outputs the power from the engine 22. The target power Pe * to be calculated is calculated (step S220). Here, in the equation (2), the product of the target driving force Td * and the rotation speed Nd of the drive shaft 36 means the target power Pd * to be output to the drive shaft 36. Further, the target power Pe * of the engine 22 obtained by the equation (2) is required to output the target driving force Td * to the drive shaft 36 with the charging / discharging of the battery 50 at the required charge / discharge power Pb1 *. It means the power of the engine 22. Further, since the case where the required driving force Tdusr is equal to or less than the upper limit driving force Tdlim1 is considered, it can be seen that the target power Pe * of the engine 22 is equal to or less than the upper limit power Pelim based on the equations (1) and (2). ..

Pe * = Td * ・ Nd-Pb1 * (2)

When the target power Pe * and the target rotation speed Ne * of the engine 22 are obtained in this way, the HVECU 70 uses the rotation speed Ne of the engine 22, the target rotation speed Ne *, the target power Pe *, and the gear ratio ρ0 of the planetary gear 30. , The torque command Tm1 * of the motor MG1 is calculated by the equation (3) (step S320). Here, the equation (3) is a relational expression of feedback control for rotating the engine 22 at the target rotation speed Ne *. In the equation (3), the first term on the right side is a feedforward term, the second term on the right side is a proportional term of the feedback term, and the third term on the right side is an integral term of the feedback term. The first term on the right side is a torque for the motor MG1 to receive the torque output from the engine 22 and acting on the rotating shaft of the motor MG1 via the planetary gear 30. The second term “kp” on the right side is the gain of the proportional term, and the “ki” of the third term on the right side is the gain of the integral term.

Tm1 * =-(Pe * / Ne *) ・ {ρ0 / (1 + ρ0)} + kp ・ (Ne * -Ne) + ki ・ ∫ (Ne * -Ne) dt (3)

Next, the HVECU 70 divides the target driving force Td * by the gear ratio Grat of the stepped transmission 60 to calculate the target driving force Tin * to be output to the input shaft 61 of the stepped transmission 60 (step S330). ). Here, the gear ratio Grat of the stepped transmission 60 is obtained by dividing, for example, the rotation speed Nm2 of the motor MG2 (the rotation speed of the input shaft 61 of the stepped transmission 60) by the rotation speed Nd of the drive shaft 36. The value to be used is used.

Subsequently, as shown in the equation (4), the HVECU 70 calculates a temporary torque Tm2tp, which is a temporary value of the torque command Tm2 * of the motor MG2, by subtracting the torque (-Tm1 * / ρ) from the target driving force Tin *. (Step S340). Here, in the equation (4), the torque (-Tm1 * / ρ) is the torque that is output from the motor MG1 when the motor MG1 is driven by the torque command Tm1 * and acts on the drive shaft 36 via the planetary gear 30. means.

Tm2tmp = Td * / Grat + Tm1 * / ρ0 (4)

Subsequently, as shown in the equation (5), the HVECU 70 subtracts the product of the torque command Tm1 * of the motor MG1 and the rotation speed Nm1 from the output limit Wout of the battery 50 and divides this by the rotation speed Nm2 of the motor MG2. Then, the torque limit Tm2max of the motor MG2 is calculated (step S350). Here, in the equation (5), the product of the torque command Tm1 * of the motor MG1 and the rotation speed Nm1 means the electric power of the motor MG1 (a positive value when the motor MG1 is driven by power running). Then, as shown in the equation (6), the smaller of the temporary torque Tm2tp and the torque limit Tm2max of the motor MG2 is set as the torque command Tm2 * of the motor MG2 (step S360).

Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (5)
Tm2 * = min (Tm2tmp, Tm2max) (6)

When the target power Pe * and the target rotation speed Ne * of the engine 22 and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are obtained in this way, the HVECU 70 uses the target power Pe * and the target rotation speed Ne * of the engine 22 as the engine. Along with transmitting to the ECU 24, torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S370) to end this routine.

When the engine ECU 24 receives the target power Pe * and the target rotation speed Ne * of the engine 22, the operation control of the engine 22 (for example, the operation control of the engine 22 so that the engine 22 is operated based on the target power Pe * and the target rotation speed Ne *) (for example, Intake air amount control, fuel injection control, ignition control, etc.) are performed. When the motor ECU 40 receives the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2, the motor ECU 40 controls switching of a plurality of switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. To do.

By such control, when the required driving force Tdusrr is equal to or less than the upper limit driving force Tdlim1, the engine 22 is operated at the target rotation speed Ne * (driving rotation speed Nedrv) and the required driving force Tdusur is set as the target driving force Td *. Will control the engine 22 and the motors MG1 and MG2 so that the engine 22 is output to the drive shaft 36 within the output limit Wout of the battery 50.

When the required driving force Tdusr is larger than the upper limit driving force Tdlim1 in step S190, the HVECU 70 cannot output the required driving force Tdusrr to the drive shaft 36 with charging / discharging of the battery 50 with the required charging / discharging power Pb1 *. Judge. At this time, the HVECU 70 determines that battery power supplementation is required. Here, the battery power compensation increases the driving force that can be output to the drive shaft 36 by charging / discharging the battery 50 with a power larger (smaller on the charging side) on the discharging side than the required charging / discharging power Pb1 * from the upper limit driving force Tdlim1. Also means to increase.

Subsequently, as shown in the equation (7), the HVECU 70 calculates the required supplementary power Pcoreq of the battery 50 by subtracting the upper limit driving force Tdlim1 from the required driving force Tdusrr and multiplying this by the rotation speed Nd of the drive shaft 36 ( Step S230). Subsequently, the replenishable power Pcolim is set within the range below the output limit Wout of the battery 50 by using the storage ratio SOC of the battery 50 and the replenishable power setting map (step S240). Here, the replenishable power setting map is preset as the relationship between the storage ratio SOC of the battery 50 and the replenishable power Pcolim, and is stored in a ROM (not shown).

Pcoreq = (Tdusr-Tdlim1) ・ Nd (7)

FIG. 12 is an explanatory diagram showing an example of a map for setting the replenishable power. As shown in the figure, the replenishable power Pcolim of the battery 50 is a predetermined power Pdi2 for discharging that is sufficiently larger than the above-mentioned predetermined power Pdi1 when the storage ratio SOC of the battery 50 is a threshold value Slo1 or more smaller than the target ratio SOC *. Is set. Further, the replenishable power Pcolim is set so that when the storage ratio SOC is smaller than the threshold Slo1 and larger than the threshold Slo2 smaller than the threshold Slo1, the smaller the storage ratio SOC is, the smaller the predetermined power Pdi2 toward the value 0. Will be done. Further, the replenishable power Pcolim is set to a value 0 when the storage ratio SOC is equal to or less than the threshold value Slo2.

When the required supplementary power Pcoreq and the replenishable power Pcolim of the battery 50 are obtained in this way, the HVECU 70 determines the smaller of the required replenishment power Pcoreq and the replenishable power Pcolim of the battery 50 as shown in the equation (8). It is set as the target compensation power Pcotag of (step S250).

Pcotag = min (Pcoreq, Pcolim) (8)

Subsequently, the HVECU 70 compares the previous required driving force (previous Tdusr) with the previous first upper limit driving force (previous Tdlim1) (step S260). This process is a process for determining whether or not the required driving force Tdusrr has immediately become larger than the upper limit driving force Tdlim1, that is, immediately after the request for battery power supplementation has been started.

When the previous required driving force (previous Tdusr) is equal to or less than the previous first upper limit driving force (previous Tdlim1) in step S260, the HVECU 70 determines that the request for battery power supplementation has just started, and determines that the battery 50 has just started. The rate value α is set using the required compensation power Pcoreq and the rate value setting map (step S270). Here, the rate value α is used when increasing the required charge / discharge power Pb2 * of the battery 50 toward the target supplement power Pcotag. The rate value setting map is preset as the relationship between the required compensation power Pcoreq and the rate value α, and is stored in a ROM (not shown). FIG. 13 is an explanatory diagram showing an example of a rate value setting map. As shown in the figure, the rate value α is set so as to increase as the required compensation power Pcoreq increases. The reason for this will be described later.

When the previous required driving force (previous Tdusr) is larger than the previous first upper limit driving force (previous Tdlim1) in step S260, the HVECU 70 is not immediately after the request for battery power replenishment is started (this request is ongoing). Yes), and the process of step S270 is not executed.

Subsequently, as shown in the equation (9), the HVECU 70 is the smaller of the value obtained by adding the rate value α to the execution supplement power (previous Pb2 *) of the previous battery 50 and the target supplement power Pcotag of the battery 50. This is set as the required charge / discharge power Pb2 * of the battery 50 (step S280). The process of step S280 is a process of applying a rate process using the rate value α to the target supplementary power Pcotag of the battery 50 to calculate the required charge / discharge power Pb2 * of the battery 50.

Pb2 * = min (previous Pb2 * + α, Pcotag) (9)

Therefore, the HVECU 70 gradually increases the required charge / discharge power Pb2 * of the battery 50 toward the target replenishment power Pcotag of the battery 50 when the request for battery power replenishment continues by repeatedly executing this routine. Will let you. Further, after the required charge / discharge power Pb2 * of the battery 50 reaches the target compensation power Pcotag, the difference between the required driving force Tdusr and the upper limit driving force Tdlim1 and thus the target compensation power Pcotag gradually decreases (approaches the value 0). As a result, the required charge / discharge power Pb2 * of the battery 50 is gradually reduced (approaching the value 0).

When the required charge / discharge power Pb2 * of the battery 50 is obtained in this way, the HVECU 70 sums the upper limit power Perim of the engine 22 and the required charge / discharge powers Pb1 * and Pb2 * of the battery 50 as shown in the equation (10). The upper limit driving force Tdlim2 is calculated by dividing by the rotation speed Nd of the drive shaft 36 (step S290).

Tdlim2 = (Pelim + (Pb1 * + Pb2 *)) / Nd (10)

Here, the upper limit driving force Tdlim2 outputs the upper limit power Perim from the engine 22 along with the operation at the target rotation speed Ne * (rotational speed Nedrv for driving) of the engine 22, and the battery 50 requires the required charge / discharge power Pb1 *, It means the upper limit of the driving force that can be output to the driving shaft 36 when charging / discharging with the sum power of Pb2 *. This upper limit driving force Tdlim2 is different from the above-mentioned upper limit driving force Tdlim1 in that the required charge / discharge power Pb2 * of the battery 50 is taken into consideration. In the formula (10), the sum of the required charge / discharge powers Pb1 * and Pb2 * of the battery 50 is added to the upper limit power Perim of the engine 22 by the battery 50 being charged by the sum of the required charge / discharge powers Pb1 * and Pb2 *. This is because the power output from the engine 22 does not change when discharging.

When the upper limit driving force Tdlim2 is obtained in this way, the HVECU 70 sets the smaller of the required driving force Tdusr and the upper limit driving force Tdlim2 as the target driving force Td * as shown in the equation (11) (step S300). Subsequently, as shown in the equation (12), the sum of the required charge / discharge powers Pb1 * and Pb2 * of the battery 50 is subtracted from the product of the target driving force Td * and the rotation speed Nd of the drive shaft 36 to target the engine 22. The power Pe * is calculated (step S310), the processes of steps S320 to S370 are executed, and this routine is terminated.

Td * = min (Tdusr, Tdlim2) (11)
Pe * = Td * ・ Nd- (Pb1 * + Pb2 *) (12)

Here, the target power Pe * of the engine 22 obtained by the equation (12) drives the target driving force Td * with the charging / discharging of the battery 50 with the sum of the required charge / discharge powers Pb1 * and Pb2 *. It means the power of the engine 22 required to output to 36. Further, since the smaller of the required driving force Tdusr and the upper limit driving force Tdlim2 is set as the target driving force Td *, the target power Pe * of the engine 22 is the upper limit power based on the equations (10) and (12). It can be seen that it is less than or equal to Pelim. Further, from the processing of steps S290, S300, S330 to S360, the required charge / discharge power Pb2 * of the battery 50 becomes the upper limit driving force Tdlim2, the target driving force Td *, the target driving force Tin *, and the torque command Tm2 * of the motor MG2. It can be seen that it is reflected and is reflected in the driving force output to the drive shaft 36.

By such control, when the required driving force Tdusr is larger than the upper limit driving force Tdlim1, the upper limit driving force Tdlim2 is set based on the sum of the upper limit power Perim of the engine 22 and the required charge / discharge powers Pb1 * and Pb2 * of the battery 50. , The engine 22 is operated at the target rotation speed Ne * (driving speed Nedrv), and the target driving force Td * set as the smaller of the required driving force Tdusr and the upper limit driving force Tdlim2 limits the output of the battery 50. The engine 22 and the motors MG1 and MG2 are controlled so as to be output to the drive shaft 36 within the range of Wout. At this time, by charging / discharging the battery 50 with the sum of the required charge / discharge powers Pb1 * and Pb2 *, it is possible to output a driving force larger than the upper limit driving force Tdlim1 to the drive shaft 36. That is, battery power is replenished. As a result, when the upper limit driving force Tdlim1 becomes smaller than the required driving force Tdusrr due to the decrease in the upper limit driving force Tdlim1 due to the upshift of the simulated shift stage Gsv, the driving force output to the drive shaft 36 is suppressed from dropping. can do. As a result, deterioration of the driver's driving sensation can be suppressed.

Moreover, when the required driving force Tdusr is larger than the upper limit driving force Tdlim1, the larger the required compensation power Pcoreq immediately after the required driving force Tdusur becomes larger than the upper limit driving force Tdlim1 (the request for battery power compensation is started). The increased rate value α is used to increase the required charge / discharge power Pb2 * of the battery 50 toward the required supplement power Pcoreq. When the target rotation speed Ne * (rotation speed Nedrv for driving) of the engine 22 decreases with the upshift of the simulated shift stage Gsv, the rotation speed Ne of the engine 22 and the output power Pe follow this (with a response delay). Decreases. The decrease speed (decrease amount per unit time) of the rotation speed Ne and the output power Pe of the engine 22 generally increases as the difference between the required driving force Tdusr and the upper limit driving force Tdlim1 increases. Therefore, by setting the rate value α as described above, when the upper limit driving force Tdlim1 becomes smaller than the target driving force Td * due to this upshift, the driving force output to the drive shaft 36 drops. Can be suppressed more appropriately. The relationship between the required compensation power Pcoreq and the rate value α is determined in advance by experiments and analysis so that the decrease rate of the output power Pe of the engine 22 and the increase rate of the required charge / discharge power Pb2 * of the battery 50 are substantially synchronized. It is more preferable to create a map for setting the rate value.

FIG. 14 shows the accelerator opening Acc, the vehicle speed V, the simulated shift stage Gsv, the target rotation speed Ne * and the actual rotation speed Ne * of the engine 22, the target power Pe * and the actual output power Pe * of the engine 22, and the required driving force Tdusr. , Upper limit driving force Tdlim1, required charge / discharge power Pb1 *, Pb2 * of battery 50, actual charge / discharge power Pb, target driving force Td *, actual driving force (output driving force Td) output to the drive shaft 36. It is explanatory drawing which shows an example of the situation. In the figure, for the column of the required charge / discharge power Pb2 * of the battery 50, the target supplement power Pcotag of the battery 50 is also shown for reference. Further, in the figure, with respect to the required charge / discharge power Pb2 *, charge / discharge power Pb, target driving force Td *, and output driving force Td of the battery 50, the solid line shows the state of the embodiment, and the alternate long and short dash line shows the state of the comparative example. .. As a comparative example, when the required charge / discharge power Pb2 * of the battery 50 is not taken into consideration, that is, the required charge / discharge power Pb2 * of the battery 50 has a value of 0 regardless of the magnitude relationship between the required driving force Tdusr and the upper limit driving force Tdlim1. Was set to consider the case where the upper limit driving forces Tdlim1 and Tdlim2 have the same value.

As shown in the figure, in the comparative example, the upper limit driving force Tdlim1 becomes smaller than the required driving force Tdusrr due to the decrease of the upper limit driving force Tdlim1 due to the upshift of the simulated shift stage Gsv, and then the required driving force Tdusur becomes the upper limit driving force. There is a drop in the output driving force Td with respect to the required driving force Tdusrr until it reaches Tdlim1 or higher (time t11 to t12).

On the other hand, in the embodiment, when the upper limit driving force Tdlim1 becomes smaller than the required driving force Tdusrr due to the decrease of the upper limit driving force Tdlim1 due to the upshift of the simulated shift stage Gsv (time t11), the required charge / discharge power of the battery 50 By increasing Pb2 * and thus the charge / discharge power Pb toward the target compensation power Pcotag and matching the target compensation power Pcotag, the target driving force Td * and thus the output driving force Td are larger than the upper limit driving force Tdlim1 ( Times t11 to t12). In this way, the drop of the output driving force Td with respect to the required driving force Tdusr is suppressed. Moreover, in the example of FIG. 14, when the upper limit driving force Tdlim1 becomes smaller than the required driving force Tdusr (time t11), the required charge / discharge power Pb2 * of the battery 50 and thus the battery 50 so as to be substantially synchronized with the decrease in the output power Pe of the engine 22. By increasing the charge / discharge power Pb, the drop of the output driving force Td with respect to the required driving force Tdusrr is suppressed more appropriately.

Next, in parallel with the power-on downshift, which is the downshift of the stepped transmission 60 with the increase in the accelerator opening Acc, the rotation speed Ne of the engine 22 is simulated. (Hereinafter, the process of increasing the number of revolutions after shifting) will be described. FIG. 15 is a flowchart showing an example of a power-on / downshift processing routine executed by the HVECU 70. In this routine, when the accelerator opening Acc is increased and the power-on downshift and the rotation speed Ne of the engine 22 are increased across the downshift line of the stepped transmission 60 (and the downshift line of the simulated transmission). When it is determined, execution is started. Further, this routine is a routine for giving necessary instructions to the drive priority control routines of FIGS. 5 and 6.

When the power-on-downshift processing routine of FIG. 15 is executed, the HVECU 70 first inputs the input limit Win of the battery 50 calculated by the battery ECU 52 by communication (step S400), and inputs the input battery 50. The absolute value of the limiting Win is compared with the threshold Wref (step S410). Here, the threshold value Wref is a threshold value used for determining whether or not the absolute value of the input limit Win of the battery 50 is relatively small.

FIG. 16 is a collinear diagram showing the relationship between the rotation speed and torque of each rotating element of the planetary gear 30 when the engine 22 is driven while operating under a steady load. As shown in the figure, when the engine 22 is operated under a steady load, it is accompanied by an output of torque (see the downward arrow on the 30s axis in the figure) in the direction of suppressing the rotation speed Ne of the engine 22 from the motor MG1, that is, the motor MG1. The torque of the engine 22 is output to the ring gear 30r (transmission member 32) of the planetary gear 30 with the regenerative drive of the above. The smaller the absolute value of the input limit Win of the battery 50, the more the generated power (torque of regenerative drive) of the motor MG1 is limited. Therefore, the absolute value of the input limit Win of the battery 50 is small and the simulated shift stage Gsv and the target shift stage. When Gsat * is changed to the downshift side and the engine 22 speed Ne is increased toward the speed after shifting while outputting a large amount of power from the engine 22, sufficient regenerative drive torque cannot be output from the motor MG1. In addition, there is a possibility that the rotation speed Ne of the engine 22 will rise with respect to the rotation speed after shifting. The process of step S410 is a process of determining the presence or absence of such a possibility.

When the absolute value of the input limit Win of the battery 50 is larger than the threshold value Wref in step S410, the HVECU 70 may increase the rotation speed Ne of the engine 22 toward the rotation speed after shifting while outputting a large power from the engine 22. , It is judged that the rotation speed Ne of the engine 22 is unlikely to rise with respect to the rotation speed after shifting, and this routine is terminated without giving any instruction to the drive priority control routines of FIGS. 5 and 6. ..

When the absolute value of the input limit Win of the battery 50 is equal to or less than the threshold value Wref in step S410, the HVECU 70 increases the rotation speed Ne of the engine 22 toward the rotation speed after shifting while outputting a large power from the engine 22. Judging that there is a possibility that the rotation speed Ne of 22 may rise with respect to the rotation speed after shifting, the engine power limit instruction and the battery power compensation limit instruction are given to the drive priority control routines of FIGS. 5 and 6. (Step S420).

Upon receiving the instruction to limit the engine power, the HVECU 70 executes the engine power limiting process. In the engine power limiting process, for example, the target power Pe * of the engine 22 calculated in step S220 or step S310 after the process of step S360 of the drive priority control routine of FIGS. 5 and 6 and before the process of step S370. The target power Pe * of the engine 22 is reset by guarding the upper limit with the limit power Pemax, and the torque command Tm1 * of the motor MG1 is reset within the range of the output limit Wout of the battery 50 in the same manner as the processing in step S320. Set. Here, the limiting power Pemax is defined as a power capable of sufficiently suppressing the rotation speed Ne of the engine 22 from rising with respect to the rotation speed after shifting.

Further, upon receiving the battery power replenishment restriction instruction, the HVECU 70 executes the battery power replenishment restriction process. In the battery power compensation limiting process, for example, when the required driving force Tdusr is equal to or less than the upper limit driving force Tdlim1 in step S190 of the drive priority control routine of FIGS. 5 and 6 (when battery power compensation is not required), the step When the processing of S200 is executed and the required driving force Tdusr is larger than the upper limit driving force Tdlim1 in step S190 (when battery power supplementation is required), the equation (13) is replaced with the processing of steps S230 to S280. ), The larger of the value obtained by subtracting the rate value β from the previous supplementary power for execution of the battery 50 (previous Pb2 *) and the value 0 is set as the required charge / discharge power Pb2 * of the battery 50. .. Here, the rate value β is predetermined as a value for lowering the required charge / discharge power Pb2 * of the battery 50. That is, when the required charge / discharge power Pb2 * of the battery 50 is a positive value, the required charge / discharge power Pb2 * is lowered toward the value 0, and when the required charge / discharge power Pb2 * is a value 0, it is retained.

Pb2 * = max (previous Pb2 * -β, 0) (13)

When increasing the rotation speed Ne of the engine 22 toward the rotation speed after shifting, when the engine power limiting process is being executed, the increase in the rotation speed Ne due to the power of the engine 22 may cause a stagnation. Therefore, the motor MG1 It is necessary to increase the rotation speed Ne of the engine 22 by the torque of the power running drive. In the embodiment, at this time, by executing the battery power compensation limiting process, it is possible to suppress the increase in the power consumption of the motor MG2 as compared with the one not executing the battery power compensation limiting process. The power of the minute can be used to increase the rotation speed of the engine 22 by the motor MG1. As a result, when the rotation speed Ne of the engine 22 is increased toward the rotation speed after shifting, it is possible to suppress the sluggishness of the increase in the rotation speed Ne of the engine 22 and suppress the deterioration of drivability.

Then, the HVECU 70 waits for the downshift of the shift stage Gsat of the stepped transmission 60 to be completed and the rotation speed Ne of the engine 22 to reach the rotation speed after the shift (steps S430 and S440), and then the engine power limitation is released. An instruction and a return instruction for battery power replenishment are given to the drive priority control routines of FIGS. 5 and 6 (step S450), and this routine is terminated. Upon receiving the engine power limit release instruction and the battery power compensation return instruction, the HVECU 70 ends the engine power limit process and the battery power compensation limit process described above. That is, the drive priority control routines of FIGS. 5 and 6 are repeatedly executed.

FIG. 17 shows the accelerator opening Acc. When the absolute value of the input limit Win of the battery 50 is equal to or less than the threshold value Wref and the rotation speed Ne of the engine 22 is increased toward the rotation speed after shifting in parallel with the power on / down shift. An example of the state of the target shift stage Gsat *, the rotation speed Nin of the input shaft 61 of the stepped transmission 60, the required charge / discharge power Pb2 * and charge / discharge power Pb of the battery 50, the output power Pe and the rotation speed Ne of the engine 22. It is explanatory drawing which shows. In the figure, with respect to the required charge / discharge power Pb2 * of the battery 50, the charge / discharge power Pb, and the rotation speed Ne of the engine 22, the solid line shows the state of the embodiment, and the alternate long and short dash line shows the state of the comparative example. As a comparative example, when the absolute value of the input limit Win of the battery 50 is equal to or less than the threshold value Wref and the rotation speed Ne of the engine 22 is increased toward the rotation speed after shifting in parallel with the power on / down shift, the battery power is supplemented. The case where is not restricted is considered.

As shown in the figure, in the comparative example, when it is determined that the shift stage Gsat of the stepped transmission 60 is downshifted (time t21), the engine power limiting process is executed, but the battery power replenishment process is not executed. Therefore, when increasing the rotation speed Ne of the engine 22 in parallel with the inertia phase in the downshift of the shift stage Gsat (time t22 ~), sufficient torque is applied from the motor MG1 to increase the rotation speed Ne of the engine 22. The engine 22's rotation speed Ne is rising slowly because it cannot output. Then, when the downshift of the stepped transmission 60 is completed (time t24) and the rotation speed Ne of the engine 22 reaches the rotation speed after the shift (time t25), the engine power limiting process is terminated.

On the other hand, in the embodiment, when it is determined that the shift stage Gsat of the stepped transmission 60 is downshifted (time t21), the engine power limiting process and the battery power compensation limiting process are executed. Therefore, when increasing the rotation speed Ne of the engine 22 in parallel with the inertia phase in the downshift of the shift stage Gsat (time t22 ~), sufficient torque is applied from the motor MG1 to increase the rotation speed Ne of the engine 22. It is possible to output, and it is possible to suppress the sluggish increase in the rotation speed Ne of the engine 22. Then, when the rotation speed Ne of the engine 22 reaches the rotation speed after shifting (time t23) and the downshift of the stepped transmission 60 is completed, the engine power limiting process and the battery power compensation limiting process are completed.

In the hybrid vehicle 20 of the above-described embodiment, when the engine power limiting process is executed when the engine speed Ne is increased toward the engine speed after the shift in parallel with the power-on-downshift, the battery power is supplemented. Execute restriction processing. As a result, sufficient torque can be output from the motor MG1 to increase the rotation speed Ne of the engine 22 as compared with the case where the battery power compensation limiting process is not executed, and the increase of the rotation speed Ne of the engine 22 can be achieved. It is possible to suppress sluggishness and suppress deterioration of drivability.

In the hybrid vehicle 20 of the embodiment, the HVECU 70 applies rate processing using the rate value α based on the required supplementary power Pcoreq of the battery 50 to the target supplementary power Pcotag of the battery 50 to calculate the required charge / discharge power Pb2 * of the battery 50. I decided to do it. However, the rate value α is not limited to this, and a value based on the gears before and after the upshift of the simulated gear Gsv may be used, or a uniform value may be used. It may be a thing.

In the hybrid vehicle 20 of the embodiment, the HVECU 70 applies rate processing using the rate value α to the target supplement power Pcotag of the battery 50 to calculate the required charge / discharge power Pb2 * of the battery 50. However, the HVECU 70 may calculate the required charge / discharge power Pb2 * of the battery 50 by applying the annealing process using the time constant τ to the target supplement power Pcotag of the battery 50. Here, as the time constant τ, a value based on the required supplementary power Pcoreq of the battery 50 may be used, or a value based on the shift stage before and after the upshift of the simulated shift stage Gsv is used. Or a uniform value may be used.

In the hybrid vehicle 20 of the embodiment, the mode switch 90 is provided, the drive priority mode is selected as the execution travel mode by the mode switch 90, and when the shift position SP performs HV travel in the D position, the HVECU 70 is shown in FIG. It is assumed that the hybrid priority control routine of FIG. 6 and the power-on / downshift processing routine of FIG. 15 are executed. However, when the shift position SP performs HV travel in the D position in the normal mode without the mode switch 90, the HVECU 70 performs the hybrid priority control routine of FIGS. 5 and 6 and the power-on-downshift process of FIG. It may be the one that executes the routine.

In the hybrid vehicle 20 of the embodiment, the simulated transmission with 10 speeds has two virtual speeds for each of the first to third speeds of the four-speed stepped transmission 60. It was assumed that it was provided and configured. However, the stepped transmission 60 is not limited to the 4-speed shift, and may be a 2-speed shift, a 3-speed shift, or a 5-speed shift or higher. Further, the virtual gears may be provided in a desired number of gears such as one or two gears for at least one gear of the stepped transmission 60. In this case, the desired number of gears may be different for each gear of the stepped transmission 60. Further, the virtual shift stage may not be provided.

In the hybrid vehicle 20 of the embodiment, the motor MG2 is assumed to be directly connected to the input shaft 61 of the stepped transmission 60. However, the motor MG2 may be connected to the input shaft 61 of the stepped transmission 60 via a speed reducer or the like. Further, the motor MG2 may be directly connected to the output shaft 62 of the stepped transmission 60. Further, the motor MG2 may be connected to the output shaft 62 of the stepped transmission 60 via a speed reducer or the like.

In the hybrid vehicle 20 of the embodiment, the battery 50 is assumed to be used as the power storage device. However, a capacitor may be used as the power storage device.

The hybrid vehicle 20 of the embodiment includes an engine ECU 24, a motor ECU 40, a battery ECU 52, a brake ECU 96, and an HVE ECU 70. However, at least two of these may be configured as a single electronic control unit.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the engine 22 corresponds to the "engine", the motor MG1 corresponds to the "first motor", the planetary gear 30 corresponds to the "planetary gear", the motor MG2 corresponds to the "second motor", and the battery 50. Corresponds to the "storage device", and the engine ECU 24, the motor ECU 40, and the HVECU 70 correspond to the "control device".

Regarding the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of the means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

The present invention can be used in the manufacturing industry of hybrid vehicles and the like.

20 hybrid vehicle, 22 engine, 23 crankshaft, 23a crank position sensor, 24 engine ECU, 28 damper, 30, 63, 64, 65 planetary gear, 30c, 63c, 64c, 65c carrier, 30p, 63p, 64p, 65p pinion gear, 30r, 63r, 64r, 65r ring gear, 30s, 63s, 64s, 65s sun gear, 32 transmission member, 36 drive shaft, 36a rotation speed sensor, 38 differential gear, 39a, 39b drive wheel, 40 motor ECU, 41,42 inverter, 43,44 rotation position sensor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 battery ECU, 54 power line, 60 stepped transmission, 61 input shaft, 62 output shaft, 69 transmission case, 70 HVECU , 80 Ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 89 gradient sensor, 90 mode switch, 96 brake ECU, B1, B2, B3 brakes, C1, C2 clutches, MG1, MG2 motors.

Claims (1)

An engine, a first motor, a planetary gear in which three rotating elements are connected to the engine, the first motor, and a transmission member, and a drive shaft connected to the transmission member and an axle. A speed transmission, a second motor capable of inputting / outputting power to the transmission member or the drive shaft, a power storage device for exchanging power with the first motor and the second motor, and a control device are provided.
The control device is
The required driving force required for the drive shaft is set based on the accelerator operation amount and the vehicle speed.
Based on the accelerator operation amount and the vehicle speed, a simulated shift stage is set from the shift stage of the stepped transmission or a shift stage in which a virtual shift stage is added to the shift stage of the stepped transmission, and the simulated shift stage is set. Set the target speed of the stepped transmission,
The target rotation speed of the engine is set based on the vehicle speed and the simulated shift stage, and the target rotation speed is set.
The upper limit power of the engine when operating the engine at the target rotation speed is set, and the upper limit power of the engine is set.
The first upper limit driving force of the drive shaft when the upper limit power is output from the engine is set.
The target driving force of the driving shaft is set based on the magnitude relationship between the required driving force and the first upper limit driving force.
The engine, the first motor, and the second motor so that the engine is operated at the target speed and the shift stage of the stepped transmission becomes the target shift stage and travels based on the target driving force. Controlling the stepped transmission,
It ’s a hybrid vehicle,
The control device is
When the required driving force is equal to or less than the first upper limit driving force, the required driving force is set as the target driving force.
When the required driving force is larger than the first upper limit driving force,
The target supplementary power of the power storage device is set based on the difference between the required driving force and the first upper limit driving force.
The second upper limit driving force of the drive shaft is set when the upper limit power is output from the engine and the power storage device is charged and discharged with the power based on the target compensation power.
The smaller of the required driving force and the second upper limit driving force is set as the target driving force.
Further, the control device directs the engine speed to the speed after the downshift of the simulated gear in parallel with the downshift of the gear of the stepped transmission as the accelerator operation amount increases. When the output is limited to the engine when the engine is raised, the power supply of the power storage device is limited as compared with the case where the output is not limited to the engine.
Hybrid vehicle.

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