JP7663053B2 - Hybrid vehicles - Google Patents

Description

The present invention relates to a hybrid vehicle.

A conventional hybrid vehicle of this type includes an engine and a motor connected to a power transmission system that transmits engine power to the drive shaft of the wheels (see, for example, Patent Document 1). In this hybrid vehicle, when a request to drive the vehicle occurs while the vehicle is decelerating and the engine combustion is stopped, the motor generates torque based on a torque command value obtained after filtering a backlash-eliminating torque command value for changing the torque of the drive shaft from negative to positive. This suppresses the occurrence of shock caused by gear teeth striking the power transmission system when the torque of the drive shaft is changed from negative to positive by the backlash-eliminating torque of the motor. Then, after the torque of the drive shaft is changed from negative to positive by the backlash-eliminating torque of the motor, engine combustion is permitted.

JP 2015-89735 A

In such hybrid vehicles, the engine and motor may be connected via a first connecting part such as a dual mass flywheel. In this case, it is difficult to use the motor's backlash-eliminating torque to eliminate backlash in the first connecting part in the power transmission system and the second connecting part that is closer to the drive shaft than the motor. For this reason, it is possible to use the engine's backlash-eliminating torque to eliminate backlash in the first connecting part and the second connecting part in the power transmission system in that order, but this may result in a longer time required to complete backlash elimination in the entire power transmission system, and a longer time until positive torque is applied to the drive shaft. In light of this, there is a demand for improving vehicle responsiveness.

The main purpose of the hybrid vehicle of the present invention is to improve vehicle responsiveness.

The hybrid vehicle of the present invention employs the following means to achieve the above-mentioned main objective.

The hybrid vehicle of the present invention is
The engine,
a motor connected to the engine via a first connection portion and connected to a driving wheel via a second connection portion;
A control device;
A hybrid vehicle comprising:
the control device controls the engine and the motor so that, at a predetermined time when the accelerator is turned on to apply a driving force to the drive wheels with the return of fuel injection of the engine from a state in which a braking force is applied to the drive wheels with fuel cut of the engine with the accelerator being turned off, the engine and the motor are controlled so that the backlash of the second connection portion is eliminated using the torque of the motor and the backlash of the first connection portion is eliminated using the torque of the engine in parallel.
The gist of the present invention is as follows.

In the hybrid vehicle of the present invention, when the accelerator is turned on to apply a driving force to the drive wheels with the engine fuel cut off due to the accelerator being turned off, the engine and motor are controlled so that the clearance of the second connection part using the motor torque and the clearance of the first connection part using the engine torque are performed in parallel at a predetermined time when the driving force is applied to the drive wheels with the engine fuel injection being restored after the accelerator is turned on. This makes it possible to shorten the time required from turning on the accelerator until clearance of the second connection part is completed, i.e., the time until the driving force is applied to the drive wheels, compared to when clearance of the first connection part and the second connection part are performed in this order using the engine torque without using the motor torque. As a result, it is possible to improve the vehicle responsiveness.

In the hybrid vehicle of the present invention, the control device may, at the predetermined time, perform a first slow-change processing on the required torque of the input shaft of the second connection to set a processed required torque of the input shaft, perform a second slow-change processing on the required torque or the processed required torque to set and control the engine, and set and control the motor torque command based on the processed required torque, and the first slow-change processing may be a processing for slowing the change in the processed required torque when the backlash elimination of the second connection is not completed compared to when the backlash elimination of the second connection is completed, and the second slow-change processing may be a processing for slowing the change in the target torque when the backlash elimination of the first connection is not completed compared to when the backlash elimination of the first connection is completed. In this way, the generation of abnormal noise when backlash elimination of the first connection or the second connection can be more appropriately suppressed.

In this case, the control device may set the post-processing required torque to the torque command when the removal of backlash in the first connecting portion is not complete, and set the torque command to the torque difference between the post-processing required torque and the target torque when the removal of backlash in the first connecting portion is complete. In this way, a torque equivalent to the post-processing required torque can be output to the input shaft of the second connecting portion.

In the hybrid vehicle of the present invention, the first connecting part may be a dual mass flywheel, and the second connecting part may have a transmission and a differential gear.

1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention; 4 is a flowchart showing an example of a control routine executed by an HVECU 70. 1 is a time chart showing an example of the accelerator opening Acc, the required torque Tdtg and actual torque Td of the drive wheels 49, the required torque Titg and processed required torque Tism of the input shaft 41 of the transmission 40, the required torque Tetg and target torque Te* of the engine 22, and the torque command Tm* of the motor 30 in an embodiment and a comparative example.

Next, we will explain how to implement the present invention using examples.

FIG. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 according to an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 according to the embodiment includes an engine 22, an engine electronic control unit (hereinafter referred to as "engine ECU") 24, a dual mass flywheel (hereinafter referred to as "DMF (Dual-Mass Flywheel)") 23, a motor 30, an inverter 32, a motor electronic control unit (hereinafter referred to as "motor ECU") 34, a clutch K0, a clutch WSC, a transmission 40, a hydraulic control device 44, a transmission electronic control unit (hereinafter referred to as "transmission ECU") 46, a battery 50 as an electricity storage device, a battery electronic control unit (hereinafter referred to as "battery ECU") 52, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

The engine 22 is configured as an internal combustion engine that outputs power using fuel such as gasoline or diesel from a fuel tank. The crankshaft 23 of the engine 22 is connected to the primary side (input side) of the DMF 26. The DMF 26 has a primary flywheel connected to the crankshaft 23 of the engine 22, a secondary flywheel connected to the rotating shaft 31 of the motor 30 via the clutch K0, and multiple coil springs for damping torsional vibration between the primary flywheel and the secondary flywheel.

Although not shown, the engine ECU 24 is equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. Signals from various sensors are input to the engine ECU 24 via the input port. Examples of signals input to the engine ECU 24 include the crank angle θcr from the crank position sensor 23a that detects the rotational position of the crankshaft 23 of the engine 22, the cooling water temperature Tw from the water temperature sensor that detects the temperature of the cooling water of the engine 22, and the intake air amount Qa from the air flow meter that detects the intake air amount of the engine 22. Various control signals are output from the engine ECU 24 via the output port. Examples of signals output from the engine ECU 24 include a control signal to a throttle valve, a control signal to a fuel injection valve, and a control signal to an ignition plug. 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 of the crankshaft 23 from the crank position sensor 23a.

The motor 30 is configured as a synchronous generator motor, and has a rotor with a permanent magnet embedded in the rotor core, and a stator with a three-phase coil wound around the stator core. The rotating shaft 31 to which the rotor of the motor 30 is fixed is connected to the crankshaft 23 of the engine 22 via the clutch K0, and is also connected to the input shaft 41 of the transmission 40 via the clutch WSC. The inverter 32 is used to drive the motor 30, and is connected to the battery 50 via the power line 54. The motor 30 is rotated and driven by switching of multiple switching elements of the inverter 32.

Although not shown, the motor ECU 34 is equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. Signals from various sensors are input to the motor ECU 34 via the input port. Examples of signals input to the motor ECU 34 include the rotational position θm from the rotational position sensor 30a that detects the rotational position of the rotor (rotating shaft 31) of the motor 30, and the phase currents Iu and Iv from the current sensors that detect the currents of each phase of the motor 30. The motor ECU 34 outputs control signals to the inverter 32 and the like via the output port. The motor ECU 34 is connected to the HVECU 70 via a communication port. The motor ECU 34 calculates the rotation speed Nm of the motor 30 based on the rotational position θm of the rotor (rotating shaft 31) of the motor 30 from the rotational position sensor 30a.

Clutch K0 is configured, for example, as a hydraulically driven friction clutch, and connects and disconnects the crankshaft 23 of the engine 22 and the rotating shaft 31 of the motor 30 via the DMF 26. Clutch WSC is configured, for example, as a hydraulically driven friction clutch, and connects and disconnects the rotating shaft 31 of the motor 30 and the input shaft 41 of the transmission 40. Both clutch K0 and clutch WSC have a hydraulic servo consisting of a piston, multiple friction engagement plates (friction plates and separator plates), an oil chamber to which hydraulic oil is supplied, and the like.

The transmission 40 is configured as an automatic transmission with 4, 6, 8, or 10 speeds, and has an input shaft 41, an output shaft 42, multiple planetary gears, and multiple hydraulically driven frictional engagement elements (clutches and brakes). The input shaft 41 is connected to the rotor of the motor 30 via a clutch WSC, and the output shaft 42 is connected to the drive wheels 49 via a differential gear 48. Each of the multiple frictional engagement elements has a hydraulic servo consisting of a piston, multiple frictional engagement plates (friction plates and separator plates), and an oil chamber to which hydraulic oil is supplied. The transmission 40 forms a forward gear or reverse gear for each gear by engaging or disengaging the multiple frictional engagement elements, and connects the input shaft 41 and the output shaft 42 (transmits power between them) or disconnects the input shaft 41 and the output shaft 42.

The hydraulic control device 44 has a valve body with multiple oil passages, multiple regulator valves, multiple linear solenoid valves, etc. This hydraulic control device 44 regulates the hydraulic pressure of the hydraulic oil from the mechanical oil pump or the electric oil pump and supplies it to the clutch K0, the clutch WSC, the multiple friction engagement elements of the transmission 40, etc.

Although not shown, the transmission ECU 46 is equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. Signals from various sensors are input to the transmission ECU 46 via the input ports. Examples of signals input to the transmission ECU 46 include the rotation speed Ni from the rotation speed sensor 41a that detects the rotation speed of the input shaft 41 of the transmission 40, the rotation speed No from the rotation speed sensor 42a that detects the rotation speed of the output shaft 42 of the transmission 40, and the oil temperature Tho of the hydraulic oil of the hydraulic control device 44. Control signals to the hydraulic control device 44 are output from the transmission ECU 46 via the output ports. The transmission ECU 46 is connected to the HVECU 70 via the communication port.

The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the inverter 32 via the power line 54 as described above. The battery ECU 52 includes a microcomputer having a CPU, ROM, RAM, flash memory, input/output ports, and a communication port, although not shown. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include a voltage Vb from a voltage sensor that detects the voltage of the battery 50, a current Ib (positive value when discharging) from a current sensor that detects the current of the battery 50, and a temperature Tb from a temperature sensor that detects the temperature of the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the battery 50's power storage ratio SOC based on the integrated value of the battery 50's current Ib from the current sensor, and calculates the output limit Wout of the battery 50 based on the calculated power storage ratio SOC and the battery 50's temperature Tb from the temperature sensor. The power storage ratio SOC is the ratio of the amount of power that can be discharged from the battery 50 to the total capacity of the battery 50, and the output limit Wout is the allowable output power that can be discharged from the battery 50.

Although not shown, the HVECU 70 is equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. Signals from various sensors are input to the HVECU 70 via the input ports. Examples of signals input to the HVECU 70 include a start signal from a start switch 80 and a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81. Examples of signals input to the HVECU 70 include an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, and a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85. Examples of signals input to the HVECU 70 include a vehicle speed V from a vehicle speed sensor 87 and a vehicle acceleration α from an acceleration sensor 88. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 34, the transmission ECU 46, and the battery ECU 52 via communication ports.

The hybrid vehicle 20 of the embodiment thus configured runs in hybrid driving (HV driving) mode or electric driving (EV driving) mode through cooperative control between the HVECU 70, engine ECU 24, motor ECU 34, and transmission ECU 46. The HV driving mode is a driving mode in which the clutches K0 and WSC are engaged and the engine 22 rotates. The EV driving mode is a driving mode in which the clutch K0 is released and the clutch WSC is engaged and the engine 22 does not rotate. The engagement state of the clutches K0 and WSC includes not only a fully engaged state but also a slipping engaged state.

Next, the operation of the hybrid vehicle 20 of the embodiment thus configured will be described. In particular, the operation will be described when, in the HV driving mode, the accelerator is turned on from a state in which a braking torque (braking force) is applied to the drive wheels 49 with fuel cut of the engine 22 due to the accelerator being off, and a driving torque (driving force) is applied to the drive wheels 49 with fuel injection of the engine 22 being restored. FIG. 2 is a flowchart showing an example of a control routine executed by the HVECU 70. This routine is repeatedly executed when, in the HV driving mode, the accelerator is turned on from a state in which a braking force is applied to the drive wheels 49 with fuel cut of the engine 22 due to the accelerator being off. When a braking force is applied to the drive wheels 49 with the fuel cut of the engine 22, the primary flywheel and coil spring, and the coil spring and secondary flywheel in the DMF 26 (first connection part), and the two meshing gears in the power transmission part (second connection part) including the transmission 40 and the differential gear 48 are eliminated on the braking side of the vehicle.

2 is executed, the HVECU 70 first inputs data such as the accelerator opening Acc, vehicle speed V, and gear ratio Gt of the transmission 40 (step S100). Here, the accelerator opening Acc is input with a value detected by the accelerator pedal position sensor 84. The vehicle speed V is input with a value detected by the vehicle speed sensor 87. The gear ratio Gt of the transmission 40 is input with a value corresponding to the gear stage M of the transmission 40. Note that the gear ratio Gt of the transmission 40 may be input with a value obtained by dividing the rotation speed Ni of the input shaft 41 of the transmission 40 from the rotation speed sensor 41a by the rotation speed No of the output shaft 42 of the transmission 40 from the rotation speed sensor 42a.

When the data is input in this manner, the required torque Tdtg of the drive wheels 49 (for driving) is set based on the accelerator opening Acc and the vehicle speed V (step S110), and the required torque Tdtg of the drive wheels 49 is divided by the product of the gear ratio Gt of the transmission 40 and the gear ratio Gd of the differential gear 48 as shown in equation (1) and set as the required torque Ti* of the input shaft 41 of the transmission 40 (step S120). Here, the processing of step S100 can be performed by applying the accelerator opening Acc and the vehicle speed V to a predetermined relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tdtg of the drive wheels 49 to set the required torque Tdtg of the drive wheels 49.

Titg＝Tdtg/(Gt・Gd) (1)

Next, it is determined whether or not the backlash elimination from the vehicle's braking side to the driving side in the power transmission section has been completed (step S130). In this embodiment, this determination process is performed by determining whether or not a predetermined time T1 has elapsed since the accelerator was turned on (since the repeated execution of this routine began). Here, the predetermined time T1 is the time required for this backlash elimination to be completed, and details thereof will be described later. Note that the torque of the input shaft 41 is not transmitted to the driving wheels 49 when this backlash elimination in the power transmission section has not been completed, and is transmitted to the driving wheels 49 when this backlash elimination has been completed.

When it is determined in step S130 that backlash elimination from the vehicle's braking side to the driving side in the power transmission unit has not been completed, a relatively small value Tirt1 is set to the rate value Tirt (step S140). On the other hand, when it is determined that this backlash elimination has been completed, a value Tirt2 greater than the value Tirt1 is set to the rate value Tirt (step S150). Then, a rate process using the rate value Tirt is performed on the required torque Titg of the input shaft 41 of the transmission 40 to set the processed required torque Tism of the input shaft 41 (step S160). This process can be performed by setting the processed required torque Tism by upper limiting the value obtained by adding the rate value Tirt to the previous processed required torque (previous Tism) with the required torque Titg, as shown in equation (2).

Tism＝min(previous Tism＋Tirt, Titg) (2)

In this way, when backlash elimination from the vehicle's braking side to the driving side in the power transmission section is not complete, the rate value Tirt (value Tirt1) smaller than when backlash elimination is complete is used to gently change the processed required torque Tism of the input shaft 41 toward the required torque Titg. The value Tirt is set as a value that can suppress the generation of abnormal noise when backlash elimination is performed in the power transmission section. The above-mentioned predetermined time T1 is set as the time required for the backlash elimination in the power transmission section to be completed when the processed required torque Tism of the input shaft 41 of the transmission 40 is increased using the rate value Tirt of value Tirt1.

Then, the required torque Titg of the input shaft 41 of the transmission 40 is set to the required torque Tetg of the engine 22 (step S170). Then, it is determined whether or not the combustion restoration in the engine 22 is completed (step S180). If it is determined that the combustion restoration in the engine 22 is not completed, the fuel injection control and ignition control are resumed if they have not been resumed (step S190), and the target torque Te* of the engine 22 is set to a negative torque Te0 for the combustion restoration (step S200).

When it is determined in step S180 that the combustion return in the engine 22 is complete, it is determined whether or not the clearance from the braking side to the driving side of the vehicle in the DMF 26 is complete (step S210). In this embodiment, this determination process is performed by determining whether or not a predetermined time T2 has elapsed since the combustion return in the engine 22 is complete. Here, the predetermined time T2 is the time required for this clearance to be completed, and details thereof will be described later. Note that the torque of the engine 22 is not transmitted to the rotating shaft 31 of the motor 30 when the clearance in the DMF 26 is not completed, and is transmitted to the rotating shaft 31 of the motor 30 when this clearance is completed.

When it is determined in step S210 that the backlash elimination from the braking side to the driving side of the vehicle in the DMF 26 has not been completed, a relatively small value Tert1 is set to the rate value Tert (step S220). On the other hand, when it is determined that the backlash elimination has been completed, a value Tert2 larger than the value Tert1 is set to the rate value Tert (step S230). Then, a rate process using the rate value Tert is performed on the required torque Tetg of the engine 22 to set the target torque Te* of the engine 22 (step S240). This process can be performed by setting the target torque Te* by upper limiting the value obtained by adding the rate value Tert to the previous target torque (previous Te*) with the required torque Tetg, as shown in equation (3).

Tesm = min (previous Tesm + Tert, Tetg) (3)

In this way, when the backlash elimination from the vehicle's braking side to the driving side in the DMF 26 is not complete, the target torque Te* of the engine 22 is gradually changed toward the required torque Tetg by using a rate value Tert (value Tert1) smaller than when the backlash elimination is complete. The value Tert is set as a value that can suppress the generation of abnormal noise when the backlash elimination is performed in the DMF 26. The above-mentioned predetermined time T2 is set as the time when the backlash elimination in the DMF 26 is completed (the target torque Te* reaches the backlash elimination completion torque Te1) when the target torque Te* of the engine 22 is increased using the rate value Tert of value Reirt1.

When the target torque Te* of the engine 22 is set in this manner, it is determined whether or not the clearance elimination from the braking side to the driving side of the vehicle in the DMF 26 is completed, similar to the processing of step S210 (step S250). Then, when it is determined that the clearance elimination is not completed (the torque of the engine 22 is not transmitted to the rotating shaft 31 of the motor 30), the processed required torque Tism of the input shaft 41 of the transmission 40 is set as the torque command Tm* of the motor 30 (step S260). On the other hand, when it is determined that the clearance elimination is completed (the torque of the engine 22 is transmitted to the rotating shaft 31 of the motor 30), the torque obtained by subtracting the target torque Te* of the engine 22 from the processed required torque Tism of the input shaft 41 of the transmission 40 is set as the torque command Tm* of the motor 30 (step S270).

Then, the target torque Te* of the engine 22 is sent to the engine ECU 24, and the torque command Tm* of the motor 30 is sent to the motor ECU 34 (step S280), and this routine ends. When the engine ECU 24 receives the target torque Te* of the engine 22, it performs operation control of the engine 22 (intake air amount control, fuel injection control, ignition control) so that the engine 22 is operated at the target torque Te*. When the motor ECU 34 receives the torque command Tm* of the motor 30, it performs switching control of multiple switching elements of the inverter 32 so that the motor 30 is driven at the torque command Tm*.

This control allows the torque of the motor 30 to be used to eliminate backlash in the power transmission section, and the torque of the engine 22 to be used to eliminate backlash in the DMF 26, to be performed in parallel. This shortens the time required to complete the elimination of backlash in the power transmission section, i.e., the time required for torque (driving force) for driving to be output to the drive wheels 49, compared to when the torque of the engine 22 is used to eliminate backlash in the DMF 26 and power transmission section in this order, without using the torque of the motor 30. As a result, the vehicle responsiveness can be improved.

When backlash elimination from the vehicle's braking side to the driving side in the power transmission section is not complete, the processed required torque Tism of the input shaft 41 is gradually increased toward the required torque Titg using a rate value Tirt (value Tirt1) smaller than when backlash elimination is complete, and the torque command Tm* of the motor 30 (inverter 32) is set based on this processed required torque Tism to control the motor 30, thereby suppressing the generation of abnormal noise when this backlash elimination is performed. When backlash elimination from the vehicle's braking side to the driving side in the DMF 26 is not complete, the target torque Te* of the engine 22 is gradually increased toward the required torque Tetg using a rate value Tert (value Tert1) smaller than when backlash elimination is complete to control the engine 22, thereby suppressing the generation of abnormal noise when this backlash elimination is performed.

Furthermore, when backlash elimination from the vehicle's braking side to the driving side in the DMF 26 has not been completed, the processed required torque Tism of the input shaft 41 of the transmission 40 is set as the torque command Tm* of the motor 30 to control the motor 30, and when this backlash elimination has been completed, the torque obtained by subtracting the target torque Te* of the engine 22 from the processed required torque Tism is set as the torque command Tm* of the motor 30 to control the motor 30, thereby making it possible to output a torque equivalent to the processed required torque Tism to the input shaft 41 of the transmission 40 regardless of whether this backlash elimination has been completed.

3 is a time chart showing an example of the accelerator opening Acc, the required torque Tdtg and actual torque Td of the drive wheels 49, the required torque Titg and processed required torque Tism of the input shaft 41 of the transmission 40, the required torque Tetg and target torque Te* of the engine 22, and the torque command Tm* of the motor 30 in the embodiment and the comparative example. In the figure, torque Ti1 is the processed required torque Tism when the processed required torque Tism is increased using the rate value Tirt of the value Tirt1 over a predetermined time T1 (times t1 to t3) after the accelerator is turned on in the embodiment (when backlash removal of the power transmission section is completed using the torque of the motor 30). The torque Te1 is the target torque Te* when the target torque Te* is increased using the rate value Tert of the value Tert1 for a predetermined time T2 (time t2 to t4) after the combustion return in the engine 22 is completed in the embodiment (when the backlash elimination of the DMF 26 is completed using the torque of the engine 22). The torque (Ti1·Gt·Gd) is a converted value obtained by converting the torque Ti1 into the torque of the drive wheels 49. In the comparative example, the backlash elimination of the DMF 26 and the backlash elimination of the power transmission unit are performed in this order using the torque of the engine 22. For this reason, in the comparative example, instead of the processing of steps S130 and S210 of the control routine in FIG. 2, it is determined whether the backlash elimination of the DMF 26 and the power transmission unit is completed, and instead of the processing of steps S250 to S270, the torque command Tm* of the motor 30 is set to a value of 0. In addition, the determination of whether the removal of backlash in the DMF 26 and the power transmission section has been completed is made by determining whether the sum of the predetermined time T2 and the predetermined time T1 has elapsed since the completion of the return of combustion in the engine 22.

As shown in the figure, in the embodiment and comparative example, when the accelerator is turned on from off (time t1), the torque required for the drive wheels 49 Tdtg, the torque required for the input shaft 41 of the transmission 40, and the torque required for the engine 22 Tetg are increased as the accelerator opening Acc increases, and the torque required for the input shaft 41 Titg is subjected to rate processing to increase the processed torque required for the input shaft 41 Tism. Also, when the accelerator is turned on (time t1), the fuel injection control and ignition control for the engine 22 are resumed, and when the combustion return is completed (time t2), the torque required for the engine 22 Tetg is subjected to rate processing to increase the target torque Te* for the engine 22.

In the comparative example, the torque command Tm* of the motor 30 is held at a value of 0, and the torque of the engine 22 is used to eliminate backlash in the DMF 26 (times t2 to t4), and then to eliminate backlash in the power transmission section (times t4 to t5). Then, when the elimination of backlash in the power transmission section is completed (time t5), the torque of the engine 22 is output to the drive wheels 49 as a torque (driving force) for driving. For this reason, the time from when the accelerator is turned on until the torque for driving is output to the drive wheels 49 is relatively long.

In contrast, in the embodiment, when the backlash elimination of the DMF 26 using the torque of the engine 22 is not completed (time t1 to t4), the torque of the motor 30 is used to eliminate the backlash of the power transmission section by setting the processed required torque Tism of the input shaft 41 of the transmission 40 to the torque command Tm* of the motor 30 (time t1 to t3). Then, when this backlash elimination is completed (time t3), the torque of the motor 30 is output to the drive wheels 49 as a torque (driving force) for driving. Therefore, compared to the comparative example, the time from when the accelerator is turned on to when the torque for driving is output to the drive wheels 49 can be shortened. As a result, the vehicle responsiveness can be improved. After that, when the backlash elimination of the DMF 26 using the torque of the engine 22 is completed, the torque of the engine 22 is also output to the drive wheels 49 as a torque for driving. Therefore, the torque command Tm* of the motor 30 decreases as the target torque Te* of the engine 22 increases.

In the hybrid vehicle 20 of the embodiment described above, when a driving force is applied to the drive wheels 49 with the return of fuel injection from the engine 22 after a braking force is applied to the drive wheels 49 with fuel cut of the engine 22 (a state in which the DMF 26 and the power transmission unit are filled on the braking side of the vehicle), the engine 22 and the motor 30 are controlled so that the filling of the drive side of the vehicle in the power transmission unit using the torque of the motor 30 and the filling of the drive side of the vehicle in the DMF 26 using the torque of the engine 22 are performed in parallel. As a result, the time required from when the accelerator is turned on until the filling of the power transmission unit is completed, that is, the time until the torque (driving force) for driving is output to the drive wheels 49, can be shortened compared to the case in which the DMF 26 and the power transmission unit are filled in this order using the torque of the engine 22 without using the torque of the motor 30. As a result, the vehicle responsiveness can be improved.

In the hybrid vehicle 20 of the embodiment, in the process of step S130 of the control routine of FIG. 2, by determining whether a predetermined time T1 has elapsed since the accelerator was turned on, it is determined whether the backlash elimination from the vehicle's braking side to the driving side in the power transmission section has been completed. However, instead of this, it may be determined whether the previous post-processing required torque (previous Tism) of the input shaft 41 of the transmission 40 is equal to or greater than the above-mentioned torque Ti1 to determine whether the backlash elimination has been completed.

In the hybrid vehicle 20 of the embodiment, in the process of step S170 of the control routine in FIG. 2, the required torque Titg of the input shaft 41 of the transmission 40 is set to the required torque Tetg of the engine 22. However, instead of this, the processed required torque Tism of the input shaft 41 of the transmission 40 may be set to the required torque Tetg of the engine 22.

In the hybrid vehicle 20 of the embodiment, in the processing of steps S210 and S250 of the control routine of FIG. 2, it is determined whether a predetermined time T2 has elapsed since the completion of the combustion return in the engine 22, thereby determining whether the backlash elimination from the braking side to the driving side of the vehicle in the DMF 26 has been completed. However, instead of this, it may be determined whether the backlash elimination has been completed by determining whether the previous target torque (previous Te*) of the engine 22 is equal to or greater than the above-mentioned torque Te1.

In the hybrid vehicle 20 of the embodiment, in the control routine of FIG. 2, the required torque Titg of the input shaft 41 of the transmission 40 is subjected to rate processing using the rate value Tirt to set the processed required torque Tism of the input shaft 41 of the transmission 40, and when the combustion return in the engine 22 is completed, the required torque Tetg of the engine 22 is subjected to rate processing using the rate value Tert to set the target torque Te* of the engine 22. However, instead of this, the required torque Titg may be subjected to smoothing processing using a time constant τi to set the processed required torque Tism, and when the combustion return in the engine 22 is completed, the required torque Tetg may be subjected to smoothing processing using a time constant τe to set the target torque Te*. In this case, when the elimination of backlash from the vehicle's braking side to the driving side in the power transmission unit is not complete, the change in the processed required torque Tism is made gentler by using a time constant τi larger than when this elimination is complete, and when the elimination of backlash from the vehicle's braking side to the driving side in the DMF 26 is not complete, the change in the target torque Te* is made gentler by using a time constant τe larger than when this elimination is complete.

In the hybrid vehicle 20 of the embodiment, the transmission 40 is configured as a stepped transmission. However, instead, the transmission 40 may be configured as a continuously variable transmission.

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

In the embodiment, the hybrid vehicle 20 includes an engine ECU 24, a motor ECU 34, a transmission ECU 46, a battery ECU 52, and an HVECU 70. However, at least two of these may be integrated into one unit.

The relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be explained. In the embodiment, the engine 22 corresponds to the "engine", the motor 30 corresponds to the "motor", and the HVECU 70, engine ECU 24, and motor ECU 34 correspond to the "control device". Additionally, the DMF 26 corresponds to the "first connecting part", and the transmission 40 and differential gear 48 correspond to the "second connecting part".

The correspondence between the main elements of the Examples and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the Examples are examples for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Means for Solving the Problem column.

The above describes the form for carrying out the present invention using examples, but the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the invention.

The present invention can be used in the hybrid vehicle manufacturing industry, etc.

20 Hybrid vehicle, 22 Engine, 23 Crankshaft, 23a Crank position sensor, 24 Engine ECU, 26 DMF, 30 Motor, 30a Rotational position sensor, 31 Rotating shaft, 32 Inverter, 34 Motor ECU, K0, WSC Clutch, 40 Transmission, 41 Input shaft, 41a RPM sensor, 42 Output shaft, 42a RPM sensor, 44 Hydraulic control device, 46 Transmission ECU, 48 Differential gear, 49 Drive wheels, 50 Battery, 52 Battery ECU, 54 Power line, 70 HV ECU, 80 Start switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 87 Vehicle speed sensor, 88 Acceleration sensor, 89 Gradient sensor.

Claims (3)

The engine,
a motor connected to the engine via a first connection portion and connected to a driving wheel via a second connection portion;
A control device;
A hybrid vehicle comprising:
the control device controls the engine and the motor so that, at a predetermined time when the accelerator is turned on to apply a driving force to the drive wheels with the return of fuel injection of the engine from a state in which a braking force is applied to the drive wheels with fuel cut in the engine with the accelerator being turned off, the engine and the motor are controlled so that the removal of backlash of the second connection portion using the torque of the motor and the removal of backlash of the first connection portion using the torque of the engine are performed in parallel ,
The control device, at the predetermined time,
a first slow-change processing is performed on the required torque of the input shaft of the second connection portion to set a processed required torque of the input shaft;
Regarding the engine, a second slow-change processing is performed on the required torque or the processed required torque to set a target torque of the engine and control the engine;
Regarding the motor, a torque command of the motor is set based on the processed required torque, and the motor is controlled;
the first change-reducing process is a process for making a change in the post-processing required torque more gradual when the removal of the backlash of the second connection portion has not been completed, compared to when the removal of the backlash of the second connection portion has been completed,
The second change-reducing process is a process for making the change in the target torque more gradual when the removal of the backlash of the first connection portion has not been completed, compared to when the removal of the backlash of the first connection portion has been completed.
Hybrid car. 2. The hybrid vehicle according to claim 1 ,
the control device sets the post-processing required torque as the torque command when the removal of the backlash of the first connecting portion has not been completed, and sets the torque command to a torque that is a difference between the post-processing required torque and the target torque when the removal of the backlash of the first connecting portion has been completed.
Hybrid car. 3. The hybrid vehicle according to claim 1 or 2 ,
the first connecting portion is a dual mass flywheel,
The second connection portion has a transmission and a differential gear.
Hybrid car.

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