WO2018096604A1

WO2018096604A1 - Control method and control device for hybrid vehicle

Info

Publication number: WO2018096604A1
Application number: PCT/JP2016/084695
Authority: WO
Inventors: 充彦松本; 崇荻野
Original assignee: 日産自動車株式会社; ルノーエス．ア．エス．
Priority date: 2016-11-24
Filing date: 2016-11-24
Publication date: 2018-05-31

Abstract

The present invention secures the required hydraulic pressure for a driver acceleration request and reduces the load on a friction clutch for an engine start request. A first clutch (2) and a belt-type continuously variable transmission (6) are configured to operate by hydraulic pressure, and as a hydraulic pressure source therefor, an oil pump (10) that is rotationally driven by a motor generator (3) is provided. In an operation mode in which the motor generator (3) serves as a drive source, the first clutch (2) is fastened once an engine start request is established. In a control method of this FF hybrid vehicle, in the operation mode in which the motor generator (3) serves as a drive source, the rotation speed of the motor generator (3) is raised to a CL1 fastening motor rotation speed for a high-acceleration request in a rotation speed zone exceeding a CL1 fastening motor rotation speed for normal acceleration that is permitted by the first clutch (2). Once an engine start request is established during the rising of the rotation speed of the motor generator (3), the rotation speed of the motor generator (3) is lowered.

Description

Control method and control apparatus for hybrid vehicle

The present disclosure relates to a control method and a control apparatus for a hybrid vehicle that includes an oil pump that is rotationally driven by a motor, and that has a friction clutch that operates hydraulically using the oil pump as a hydraulic source and a transmission in a drive system.

Conventionally, this is a one-motor / two-clutch hybrid system in which an engine, a first clutch, a motor, a second clutch, and a belt-type continuously variable transmission are mounted in a drive system from a drive source to a drive wheel. In this hybrid system, the first clutch, the second clutch, and the belt-type continuously variable transmission are hydraulically operated, and an oil pump that is rotationally driven by a motor is provided as a hydraulic pressure source. In the EV mode, when an engine start request is established, a device is known in which a first clutch is engaged and the engine is cranked and started using the motor as a start motor (see, for example, Patent Document 1).

JP 2016-43892 A

However, in the conventional device, when the driver acceleration request by the accelerator depressing operation or the like is high at the time of starting, the hydraulic pressure that can be generated is insufficient with respect to the required hydraulic pressure. This is because if the demand for driver acceleration is high, the torque transmitted to the drive wheels increases, and even in the belt type continuously variable transmission, the belt slip must be suppressed against the high transmission torque. For this reason, the pulley hydraulic pressure needs to be high so as to ensure a high belt clamping force. On the other hand, since the rotational speed of the motor that rotates the oil pump is the differential rotational speed of the first clutch that is engaged when the engine is started, the motor rotational speed is kept low so that the differential rotational speed does not increase. For this reason, there is a limit to the oil pressure that can be generated from the oil pump. As a result, when the driver acceleration request is high, the hydraulic pressure that can be generated is insufficient with respect to the required hydraulic pressure.

In response to this, there is a plan to adopt an oil pump with increased hydraulic pressure supply capability. However, there is a trade-off that the cost and fuel consumption deteriorate as the rebound. Further, there is a countermeasure for setting the oil pump rotation speed (∝motor rotation speed) to a high rotation speed in advance and keeping the oil pressure that can be generated high. However, as a bounce, there is a problem that the differential rotational speed between the engine and the motor is increased, the load on the first clutch that is fastened when the engine is started is increased, and measures such as heat and wear are required.

This disclosure has been made by paying attention to the above-described problem, and aims to achieve both of ensuring the required hydraulic pressure for the driver acceleration request and reducing the burden on the friction clutch for the engine start request.

In order to achieve the above object, according to the present disclosure, a friction clutch and a transmission are hydraulically operated, and an oil pump that is rotationally driven by a motor is provided as the hydraulic pressure source. When the engine start request is established in the operation mode using the motor as a drive source, the friction clutch is engaged, and the engine is cranked and started using the motor as the start motor.
In this hybrid vehicle control method, in the operation mode using a motor as a drive source, the motor speed is increased to a target speed in a speed range that exceeds the allowable rotational speed allowed by the friction clutch.
If the engine start request is established while the motor speed is increased, the motor speed is decreased.

In this way, the motor rotation speed is increased in preparation for the driver acceleration request, and when the friction clutch is predicted to be engaged, the motor rotation speed is decreased to ensure the necessary hydraulic pressure for the driver acceleration request and the engine start request. It is possible to achieve both reduction of the load on the friction clutch.

1 is an overall system diagram illustrating a drive system and a control system of an FF hybrid vehicle to which a control method and a control device of Example 1 are applied. FIG. 2 is a hydraulic control system configuration diagram illustrating a hydraulic control system configuration of a belt-type continuously variable transmission CVT, a first clutch CL1, and a second clutch CL2 included in the drive system of the FF hybrid vehicle of the first embodiment. 4 is a flowchart showing a flow of a start-up motor rotation speed control process executed by the integrated controller of the first embodiment. In the comparative example, the motor speed, engine speed, motor torque, engine torque, transmission input shaft torque, possible hydraulic pressure, and required hydraulic pressure when the hydraulic pressure that can be generated at the start when the driver acceleration request is high are insufficient It is a time chart which shows each characteristic. 4 is a time chart showing brake, accelerator opening (APO), motor rotation speed, engine rotation speed, and hydraulic pressure characteristics for explaining the motor rotation speed control operation at the start when the driver acceleration request of Example 1 is high. . It is a time chart which shows each characteristic of motor number of rotations, input possible torque, and target torque for explaining the target torque rate which can be realized at the time of a start with high driver acceleration demand in a comparative example. 4 is a time chart showing characteristics of a motor rotation speed, an inputable torque, and a target torque for explaining a target torque rate that can be realized at the time of starting with a high driver acceleration request in the first embodiment.

Hereinafter, the best mode for realizing the hybrid vehicle control method and control device of the present disclosure will be described based on Example 1 shown in the drawings.

First, the configuration will be described.
The control method and the control device in the first embodiment are applied to an FF hybrid vehicle having a parallel hybrid drive system called a one-motor / two-clutch and equipped with a belt type continuously variable transmission as a transmission. Hereinafter, the configuration of the first embodiment will be described by dividing it into “the overall system configuration”, “CVT / CL1 / CL2 hydraulic control system configuration”, and “starting motor speed control processing configuration”.

[Overall system configuration]
FIG. 1 shows a drive system and a control system of an FF hybrid vehicle (an example of a hybrid vehicle) to which the control method and the control device of the first embodiment are applied. Hereinafter, based on FIG. 1, the whole system configuration by the drive system and control system of FF hybrid vehicle is demonstrated.

As shown in FIG. 1, the drive system of the FF hybrid vehicle includes an engine 1, a first clutch 2, a motor generator 3, a second clutch 4, a transmission input shaft 5, and a belt type continuously variable transmission 6. And a transmission output shaft 7, a final gear 8, and left and

right drive wheels

9, 9. The operation mode of the parallel hybrid drive system includes an electric vehicle mode (hereinafter referred to as “EV mode”), a hybrid vehicle mode (hereinafter referred to as “HEV mode”), and a drive torque control start mode (hereinafter referred to as “WSC”). Mode ")) and the like.

“EV mode” is a mode in which the first clutch 2 is disengaged and the vehicle is driven only by the power of the motor generator 3. The “HEV mode” is a mode in which the first clutch 2 is engaged and the vehicle travels in any of the motor assist mode, the traveling power generation mode, and the engine mode. The “WSC mode” maintains the slip engagement state of the second clutch 4 by controlling the number of revolutions of the motor generator 3 at the time of P, N → D selection start from the “EV mode” or “HEV mode”. The driving force transmitted to the left and

right drive wheels

9, 9 via the belt-type continuously variable transmission 6 or the like as the engagement capacity of the second clutch 4 is determined by the accelerator opening APO and the vehicle speed VSP. It is a mode to start while controlling to be equivalent to power. “WSC” is an abbreviation of “Wet Start clutch”.

Engine 1 (Eng) is capable of lean combustion, and is controlled so that the engine torque matches the command value by controlling the intake air amount by the throttle actuator, the fuel injection amount by the injector, and the ignition timing by the spark plug. . The engine 1 is set to “MG start” in which the motor generator 3 is used as a starter motor, the second clutch 4 is in a slip engagement state, and the engine 1 is cranked while increasing the engagement torque of the first clutch 2.

The first clutch 2 (CL1) is interposed at a position between the engine 1 and the motor generator 3, and is set to “EV mode” when released and “HEV mode” when engaged. As the first clutch 2, for example, a normally open dry multi-plate clutch or the like is used, and fastening / slip fastening / release is performed by hydraulic control.

The motor generator 3 (MG) has an AC synchronous motor structure, and performs torque control and rotation speed control by demonstrating a motor function when starting or running. During braking or deceleration, the generator function is performed to convert vehicle kinetic energy from the left and

right drive wheels

9 and 9 into electric energy, and regenerative control is performed to charge the battery 12 via the inverter 11.

The second clutch 4 (CL2) is a normally open wet multi-plate clutch or wet multi-plate brake provided in the forward / reverse switching mechanism, and generates clutch transmission torque with CL2 engagement torque by hydraulic control as an upper limit torque. The second clutch 4 sends torque output from the drive source to the left and

right drive wheels

9 and 9 via the transmission input shaft 5, the belt type continuously variable transmission 6, the transmission output shaft 7, and the final gear 8. Communicate. As shown in FIG. 1, the second clutch 2 is set at a position between the motor generator 3 and the belt-type continuously variable transmission 6, and the belt-type continuously variable transmission 6 and the left and

right drive wheels

9, 9 are set. You may set to the position between.

The belt-type continuously variable transmission 6 (CVT) includes a primary pulley 61 connected to the transmission input shaft 5, a secondary pulley 62 connected to the transmission output shaft 7, and the primary pulley 61 and the secondary pulley 62. And a passed pulley belt 63. A stepless transmission ratio is obtained according to the winding diameter of the pulley belt 63 around the primary pulley 61 and the secondary pulley 62. That is, when the belt clamping width of the primary pulley 61 is widened and the belt clamping width of the secondary pulley 62 is narrowed, the gear ratio changes to the low gear ratio side. Further, as the belt clamping width of the primary pulley 61 becomes narrower and the belt clamping width of the secondary pulley 62 becomes wider, the gear ratio changes to the High gear ratio side.

As shown in FIG. 1, the control system of the FF hybrid vehicle includes an integrated controller 14, a transmission controller 15, a clutch controller 16, an engine controller 17, a motor controller 18, and a battery controller 19. . The engine speed sensor 21, the motor speed sensor 22, the transmission input speed sensor 23, the CVT oil temperature sensor 24, the accelerator opening sensor 25, the G sensor 26, the brake sensor 27, and the wheels A speed sensor 28 and an inhibitor switch 29 are provided.

The integrated controller 14 is a controller that manages the parallel hybrid drive system in an integrated manner, and calculates a target driving force, a target state, and the like from the battery SOC state, accelerator opening APO, vehicle speed VSP, hydraulic oil temperature, and the like. Then, based on the calculation result, command values for the actuators (engine 1, first clutch 2, motor generator 3, second clutch 4, belt type continuously variable transmission 6) are calculated, via CAN communication line 20. To each of the

controllers

15, 16, 17, 18, and 19.

The transmission controller 15 performs shift control by controlling the pulley hydraulic pressure supplied to the primary pulley 61 and the secondary pulley 62 of the belt-type continuously variable transmission 6 so as to achieve the shift command from the integrated controller 14.

The clutch controller 16 inputs sensor information from the engine speed sensor 21, the motor speed sensor 22, the transmission input speed sensor 23, and the like, and also inputs a command from the integrated controller 14. Then, a CL1 hydraulic pressure command value to the first clutch 2 is output according to the selected operation mode and the like. Further, a CL2 hydraulic pressure command value to the second clutch 4 is output in response to a CL2 slip request or the like.

The engine controller 17 inputs sensor information from the engine speed sensor 21 and performs torque control and speed control of the engine 1 so as to achieve the engine torque command value and the engine speed command value from the integrated controller 14. Do. The engine controller 17 outputs a fuel injection command and an ignition command when the cranking rotational speed reaches a predetermined rotational speed when the engine is started.

The motor controller 18 outputs a control command to the inverter 8 so as to achieve the motor torque command value and the motor rotation speed command value from the integrated controller 14, and performs torque control and rotation speed control of the motor generator 3. The inverter 11 performs DC / AC mutual conversion, and converts the discharge current from the battery 12 into the drive current of the motor generator 3 during power running. Further, during regeneration, the generated current from the motor generator 3 is converted into a charging current for the battery 12.

The battery controller 19 manages the charge capacity (battery SOC) of the battery 9 and the battery temperature, and transmits battery information to the integrated controller 14 and the engine controller 17.

[Hydraulic control system configuration of CVT / CL1 / CL2]
FIG. 2 shows a hydraulic control system configuration of the belt-type continuously variable transmission CVT, the first clutch CL1, and the second clutch CL2 included in the drive system of the FF hybrid vehicle of the first embodiment. Hereinafter, the hydraulic control system configuration of the belt type continuously variable transmission CVT / first clutch CL1 / second clutch CL2 will be described with reference to FIG.

As shown in FIG. 2, an oil pump 10 and a control valve unit 11 are provided as a hydraulic control system for CVT / CL1 / CL2. The hydraulic control system of CVT / CL1 / CL2 is characterized by the fact that the oil pump 10 that is rotationally driven by the motor generator 3 (MG) is the only hydraulic source, and the belt type continuously variable transmission 6 (CVT) that is hydraulically operated The point is that all the hydraulic pressure to the first clutch 2 (CL1) and the second clutch 4 (CL2) is covered.

The control valve unit 11 is attached to the belt type continuously variable transmission CVT, and includes a hydraulic control valve and a hydraulic control circuit. The control valve unit 11 includes a line pressure control valve 111 having a solenoid valve structure, a primary pressure control valve 112, a secondary pressure control valve 113, a first clutch pressure control valve 114, a second clutch pressure control valve 115, Have Each of the

hydraulic control valves

111, 112, 113, 114, and 115 has a configuration in which the control pressure output with the minimum command current is maximized and the control pressure output with the maximum command current is minimum.

The line pressure control valve 111 uses the pump discharge pressure from the oil pump 10 as a source pressure, and the line pressure PL (the highest hydraulic pressure as the transmission pressure or the engagement pressure based on the command current from the transmission controller 15 to the solenoid 111a. = Adjustable oil pressure). In the pressure regulation control of the line pressure PL, first, the target line pressure PL ^* is determined by the magnitude of the accelerator opening APO. When the target line pressure PL ^* is determined, the actual line pressure is controlled to match the target line pressure PL ^* .

The primary pressure control valve 112 uses the line pressure PL as an original pressure, and based on the instruction current from the transmission controller 15 to the solenoid 112a, the primary pressure Ppri that leads to the primary pressure chamber of the belt type continuously variable transmission 6 (CVT). Adjust pressure.

The secondary pressure control valve 113 uses the line pressure PL as the original pressure, and based on the instruction current from the transmission controller 15 to the solenoid 113a, the secondary pressure Psec that leads to the secondary pressure chamber of the belt type continuously variable transmission 6 (CVT). Adjust pressure.

Here, in the transmission hydraulic pressure control of the belt type continuously variable transmission 6 (CVT), first, the target primary rotational speed Npri ^* corresponding to the target speed ratio is determined by the vehicle speed VSP and the accelerator opening APO. When the target primary rotation speed Npri ^* is determined, the differential pressure between the primary pressure Ppri and the secondary pressure Psec is feedback-controlled so as to eliminate the deviation from the actual primary rotation speed Npri.

The first clutch pressure control valve 114 uses the line pressure PL as a source pressure, and based on the command current from the clutch controller 16 to the solenoid 114a, the first clutch pressure PCL1 that leads to the clutch oil chamber of the first clutch 2 (CL1). Adjust pressure. For example, when an engine start request is made, the engagement capacity of the first clutch 2 (CL1) is gradually increased, and the engine 1 (Eng) is cranked and started using the motor generator 3 as a starter motor.

The second clutch pressure control valve 115 uses the line pressure PL as a source pressure, and based on the instruction current from the clutch controller 16 to the solenoid 115a, the second clutch pressure PCL2 that leads to the clutch oil chamber of the second clutch 4 (CL2). Adjust pressure. For example, when “WSC mode” is selected, the driving force transmitted to the left and

right drive wheels

9 and 9 via the belt-type continuously variable transmission 6 (CVT) or the like is set as the target when the second clutch pressure PCL2 is engaged. It is controlled so as to be equivalent to the driving force.

[Starting motor speed control processing configuration]
FIG. 3 shows a start-up motor rotation speed control process executed by the integrated controller 14 according to the first embodiment. Hereinafter, each step of FIG. 3 showing the configuration of the motor speed control process at the time of start will be described. This flowchart starts with the brake stopped in the “EV mode” and ends when the engagement of the first clutch 2 (CL1) is completed.

In step S1, it is determined whether or not brake ON → OFF (brake release operation) has been detected. If YES (brake ON → OFF), the process proceeds to step S2. If NO (brake ON), the determination in step S1 is repeated.
Here, “brake ON → OFF (brake release operation)” is detected by a signal from the brake sensor 27 or the brake switch.

In step S2, following the determination that the brake is ON → OFF in step S1, it is determined whether or not accelerator OFF → ON (accelerator depression operation) is detected. If YES (accelerator OFF → ON), the process proceeds to step S3. If NO (accelerator OFF), the determination in step S2 is repeated.
Here, “accelerator OFF → ON (accelerator depression operation)” is acquired when the sensor signal from the accelerator opening sensor 25 switches from the signal indicating the accelerator opening APO = 0 to the accelerator opening APO> 0.

In step S3, following the detection of accelerator OFF → ON in step S2, the oil temperature of the belt type continuously variable transmission 6 (CVT) is detected, and the process proceeds to step S4.
Here, the “oil temperature” information is obtained from a sensor signal from the CVT oil temperature sensor 24.

In step S4, following the oil temperature detection in step S3, B and A stepping times from the brake operation to the accelerator operation are calculated, and the process proceeds to step S5.
Here, “B, A stepping time” is the time for determining the acceleration request from the state without creep torque, the time when the brake ON → OFF is detected in step S1 and the accelerator OFF → ON in step S2. Calculation is performed based on the time difference from the detected time.

In step S5, following the calculation of the B and A changeover times in step S4, an accelerator opening deviation that is a change amount of the accelerator opening APO per predetermined time is calculated, and the process proceeds to step S6.
Here, the “accelerator opening deviation” is calculated by obtaining an accelerator opening differential value (accelerator opening changing speed) which is a change amount per unit time of the accelerator opening APO from the accelerator opening sensor 25. The

In step S6, following the calculation of the accelerator opening deviation in step S5, whether or not B, A stepping time ≦ predetermined time, or accelerator opening deviation ≧ predetermined value, and oil temperature ≧ predetermined value. Determine whether. If YES (high acceleration requirement condition and oil temperature condition are satisfied), the process proceeds to step S8. If NO (high acceleration requirement condition or oil temperature condition is not satisfied), the process proceeds to step S7.
Here, the condition “B, A stepping time ≦ predetermined time or accelerator opening deviation ≧ predetermined value” is a high acceleration requirement condition indicating that the driver acceleration requirement is higher than the normal acceleration requirement. Therefore, the “predetermined time” and the “predetermined value” are set as thresholds for determining that there is a possibility that the generated hydraulic pressure may be insufficient with respect to the required hydraulic pressure when the driver acceleration request is higher than the normal acceleration request. The condition “oil temperature ≧ predetermined value” is an oil temperature condition indicating that the oil pressure response delay is in a stable oil temperature region. Therefore, the “predetermined value” is set to the lower limit threshold value of the oil temperature region where the hydraulic response delay is stable.

In step S7, following the determination that the high acceleration requirement condition or the oil temperature condition is not satisfied in step S6, the rotational speed of the motor generator 3 (MG) is increased to the normal acceleration CL1 engagement motor rotational speed. Proceed to S10.
Here, the “normally accelerating CL1 engagement motor rotational speed” is a tolerance that is secured as a differential rotational speed of the first clutch 2 (CL1) that is engaged when starting the engine while securing a necessary hydraulic pressure up to the normal acceleration range. The number of revolutions is set (for example, about 1000 rpm).

In step S8, following the determination that the high acceleration requirement condition and the oil temperature condition are satisfied in step S6, the “hydraulic pressure immediate securing flag” is rewritten from the immediately hydraulic pressure securing flag = 0 to the immediate hydraulic pressure securing flag = 1. The process proceeds to step S9.
Here, the “hydraulic oil immediately secure flag” means that when the high acceleration requirement condition and the oil temperature condition are satisfied, the rotation speed of the motor generator 3 (MG) is increased to a rotation speed higher than the rotation speed of the normal acceleration CL1 engagement motor. The flag indicates that the oil pressure that can be generated from the oil pump 10 is secured.

In step S9, following the rewriting to the immediate oil pressure securing flag = 1 in step S8, the rotation speed of the motor generator 3 (MG) is increased to the high acceleration request CL1 engagement motor rotation speed, and the process proceeds to step S10.
Here, the “high acceleration request CL1 engagement motor rotation speed” is higher than the normal acceleration CL1 engagement motor rotation speed, and the required hydraulic pressure for the high acceleration request can be realized by the oil pressure that can be generated by the oil pump 10. It is set to the target rotational speed (for example, about 1500 rpm) when a high acceleration is requested.
The "high acceleration request CL1 engagement motor speed" is a variable value as shown below according to the values of "B, A stepping time" and "accelerator opening deviation" that determine the high acceleration request condition. Given.
(a) The higher the motor speed for high acceleration request is set to a higher speed as the time for stepping B and A is shorter.
(b) The higher the accelerator opening deviation, the higher the high acceleration requesting CL1 engagement motor rotational speed is set.
For (a) and (b), the motor rotation speed reference value when the high acceleration request condition and the oil temperature condition are satisfied is determined, and the high rotation request CL1 is calculated by correcting the motor rotation speed reference value. The fastening motor speed may be set. Further, the CL1 engagement motor rotational speed for high acceleration request may be set by map search using a B, A stepping time map or an accelerator opening deviation map.

In step S10, the second clutch 4 (CL2) is slipped following the increase to the normal acceleration CL1 engagement motor rotation speed in step S7 or the increase to the high acceleration request CL1 engagement motor rotation speed in step S9. The fastening operation is performed, and the process proceeds to step S11.
Here, by controlling the rotation speed of the motor generator 3 (MG), the rotation speed of the second clutch 4 (CL2) is increased to the normal acceleration CL1 engagement motor rotation speed or the high acceleration request CL1 engagement motor rotation speed. In order to absorb the rotational difference between the input side and the output side, a slip fastening operation is performed.

In step S11, following the CL2 operation in step S10, the engagement capacity of the second clutch 4 (CL2) is set to a capacity capable of obtaining the target driving force, the WSC start is made by selecting the “WSC mode”, and the process proceeds to step S12.
Here, the engagement capacity of the second clutch 4 (CL2) is such that the driving force transmitted to the left and

right drive wheels

9, 9 via the belt-type continuously variable transmission 6 (CVT) or the like is the accelerator opening APO. It is controlled so as to be equivalent to the target driving force required by the vehicle speed VSP.

In step S12, following the WSC start in step S11, it is determined whether an engine start request is satisfied. If YES (engine start request is established), the process proceeds to step S13. If NO (engine start request is not established), the determination in step S12 is repeated.
Here, “establishment of the engine start request” calculates, for example, the maximum motor torque based on the rotation speed of the motor generator 3 (MG) and the battery output. Then, while the motor torque margin obtained by subtracting the actual motor torque from the maximum motor torque exceeds the cranking required torque of the engine 1, it is determined that the engine start request is not established. However, when the motor torque margin reaches the cranking required torque of the engine 1, it is determined that the engine start request is established.

In step S13, following the determination that the engine start request is established in step S12, when the rotational speed of the motor generator 3 (MG) is increased to the high acceleration request CL1 engagement motor rotational speed, The speed is decreased to the CL1 fastening motor speed, and the process proceeds to step S14.
Here, when the engine speed is the normal acceleration CL1 engagement motor rotation speed when the engine start request is established, the normal acceleration CL1 engagement motor rotation speed is maintained as it is.

In step S14, following the decrease to the normal acceleration CL1 engagement motor rotation speed in step S13, the "hydraulic pressure immediately secure flag" is rewritten from the immediately hydraulic pressure secure flag = 1 to the immediate hydraulic pressure secure flag = 0, and the process proceeds to step S15. move on.
Here, when the immediate hydraulic pressure securing flag = 0, the immediate hydraulic pressure securing flag = 0 is maintained.

In step S15, in order to start the cranking of the engine 1 (Eng) following the rewriting to the immediate hydraulic pressure securing flag = 0 in step S14 or the determination that the CL1 engagement is not completed in step S16. Engagement control of 1 clutch 2 (CL1) is performed and it progresses to step S16.
Here, “Cranking start of engine 1 (Eng)” starts engagement of first clutch 2 (CL1) that is released when WSC starts in “EV mode”. Then, the cranking torque of the motor torque from the motor generator 3 (MG) is transmitted to the engine 1 (Eng) via the first clutch 2 (CL1).

In step S16, following the CL1 engagement control in step S15, it is determined whether or not the engagement of the first clutch 2 (CL1) has been completed. If YES (CL1 fastening is complete), the process proceeds to the end. If NO (CL1 fastening is not complete), the process returns to step S15.
Here, “CL1 engagement completion” is determined, for example, when the engine rotational speed≈the motor rotational speed. When the engagement of the first clutch 2 (CL1) is completed, the operation mode is changed to the “HEV mode”.

Next, the operation will be described.
The operation of the first embodiment is changed to “starting motor rotation speed control processing operation”, “starting motor rotation speed control operation”, “starting torque rate realization operation”, and “starting motor rotation speed control operation”. Separately described.

[Starting motor speed control processing action]
Hereinafter, based on the flowchart shown in FIG.

When starting, a brake / accelerator switching operation is detected, but if the high acceleration requirement condition or the oil temperature condition is not established, step S1, step S2, step S3, step S4, step S5, step S6, step Proceed to S7. Therefore, in step S7, control is performed to increase the rotation speed of the motor generator 3 (MG) to the normal acceleration CL1 engagement motor rotation speed.

On the other hand, at the time of departure, when the operation of switching between the brake and the accelerator is detected and the high acceleration requirement condition and the oil temperature condition are satisfied, step S1, step S2, step S3, step S4, step S5, step S6, step S8. → Proceed to step S9. Therefore, in step S8, the “immediate hydraulic pressure securing flag” is rewritten from the immediate hydraulic pressure securing flag = 0 to the immediate hydraulic pressure securing flag = 1. In step S9, control is performed to increase the rotation speed of the motor generator 3 (MG) to the high acceleration request CL1 engagement motor rotation speed (> the normal acceleration CL1 engagement motor rotation speed).

Then, the process proceeds from step S10 to step S11 to step S12, and while it is determined in step S12 that the engine start request is not established, the rotational speed of the motor generator 3 (MG) is the CL1 engagement motor rotational speed for high acceleration request. Maintained. Thereafter, when it is determined in step S12 that the engine start request is established, the process proceeds from step S12 to step S13. In step S13, the rotation speed of the motor generator 3 (MG) is determined from the high acceleration request CL1 engagement motor rotation speed. Control is normally performed to reduce the rotational speed of the CL1 fastening motor for acceleration.

When the rotational speed of the motor generator 3 (MG) decreases to the normal acceleration CL1 engagement motor rotational speed, the process proceeds from step S13 to step S14 → step S15 → step S16. While it is determined that the CL1 engagement is not completed in step S16, the flow from step S15 to step S16 is repeated. In step S14, the “hydraulic oil immediately secure flag” is rewritten from the immediately oil pressure secure flag = 1 to the immediately oil pressure secure flag = 0. In step S15, engagement control of the first clutch 2 (CL1) is performed to start cranking the engine 1 (Eng). If it is determined in step S16 that the engagement of the first clutch 2 (CL1) has been completed, the process proceeds from step S16 to the end, and the operation mode is changed to the “HEV mode”.

As described above, at the time of departure, the brake / accelerator switching operation is detected, and only when the high acceleration requirement condition and the oil temperature condition are satisfied, the rotational speed of the motor generator 3 (MG) is set to the high acceleration request CL1. Control is performed to increase the speed to the fastening motor speed (> CL1 fastening motor speed for normal acceleration). In other words, at the time of starting, a brake / accelerator switching operation is detected, but when the high acceleration requirement condition or the oil temperature condition is not satisfied, the rotation speed of the motor generator 3 (MG) is normally accelerated as before. Control to increase the rotational speed of the CL1 fastening motor is performed. In this way, the motor rotation speed increase control is performed only when the condition is satisfied, and the motor rotation speed increase control is not performed when the condition is not satisfied, so that the CL1 engagement motor rotation speed for high acceleration request (> CL1 engagement motor rotation speed for normal acceleration) ) Is reduced in frequency.

Then, when the rotational speed of the motor generator 3 (MG) is increased to the high acceleration request CL1 engagement motor rotation speed at the determination timing of the satisfaction of the condition, the high acceleration request CL1 engagement motor rotation is performed while the engine start request is not satisfied. Keep the number. Thereafter, when the engine start request is established, control is performed to reduce the high acceleration request CL1 engagement motor rotation speed to the normal acceleration CL1 engagement motor rotation speed. Thus, the first clutch 2 (CL1) that is engaged when the engine 1 (Eng) is started is reduced by reducing the rotational speed of the motor generator 3 (MG) prior to the engagement control of the first clutch 2 (CL1). ) To reduce the burden of expanding the differential rotation speed.

[Motor speed control at start-up]
FIG. 4 is a time chart showing each characteristic when the hydraulic pressure that can be generated at the time of start when the driver acceleration request is high in the comparative example is insufficient with respect to the required hydraulic pressure. Hereinafter, based on FIG. 4, a description will be given of an operation in which the hydraulic pressure that can be generated at the time of start when the driver acceleration request is high is insufficient with respect to the required hydraulic pressure in the comparative example.

In the case of the comparative example, when a start start operation with a high driver acceleration request is started at time t1 due to a sudden accelerator stepping operation or the like, the motor rotation speed is set to a preset rotation speed (for example, CL1 engagement motor rotation speed for normal acceleration) To rise. Then, it is assumed that the hydraulic engagement of the first clutch CL1 is started at time t2, and the hydraulic engagement of the first clutch CL1 is completed at time t3. At this time, as shown in the hydraulic characteristic surrounded by the arrow C in FIG. 4, the necessary hydraulic characteristic is generated in the region shifted in the time axis direction due to the hydraulic response delay with respect to the engagement region of the first clutch CL1. Therefore, the hydraulic pressure that can be generated (actual PL) is insufficient for the required hydraulic pressure (target PL). The portion indicated by hatching in the hydraulic characteristics of FIG.

The reason for this is that the transmission torque to the drive wheels increases due to high driver acceleration demands, and accordingly, it is necessary to keep the pulley pressures Ppri and Psec at high hydraulic pressure to prevent belt slip in the belt type continuously variable transmission CVT. . If the first clutch CL1 is hydraulically engaged due to the establishment of the engine start request in this state, the required hydraulic pressure is set to the pulley pressures Ppri and Psec to the belt-type continuously variable transmission CVT and the first clutch pressure to the first clutch CL1. PCL1 is added.

On the other hand, since the motor rotational speed for rotating the oil pump O / P is the differential rotational speed of the first clutch CL1 when the engine is started, the motor rotational speed is kept low so as to suppress the differential rotational speed (for example, Normal CL1 fastening motor speed for acceleration). For this reason, there is a limit to the oil pressure that can be generated (actual PL) using the oil pump O / P as the oil pressure source. As a result, the hydraulic pressure that can be generated (actual PL) is insufficient with respect to the increasing required hydraulic pressure (target PL).

On the other hand, there is a countermeasure to adopt a large-capacity oil pump with an increased hydraulic pressure supply capacity, but as a bounce, a trade-off occurs that cost and fuel consumption deteriorate. In addition, there is a countermeasure to uniformly increase the oil pump rotation speed (回転 motor rotation speed) when starting, regardless of whether the driver acceleration request is high or low. However, as the rebound, the frequency of increasing the oil pump rotational speed increases, and the differential rotational speed between the engine Eng and the motor MG at the time of starting the engine increases. For this reason, if the oil pump rotation speed (回転 motor rotation speed) is kept increased, the burden at the time of engaging the first clutch CL1 with respect to the engine start request becomes large, and measures such as heat and wear are required. .

FIG. 5 is a time chart showing characteristics for explaining the motor speed control operation at the time of start when the driver acceleration request of Example 1 is high. Hereinafter, based on FIG. 5, the motor speed control operation at the time of start when the driver acceleration request of the first embodiment is high will be described.

When the brake ON → OFF operation is performed at time t0, control is performed to increase the rotation speed of the motor generator 3 (MG) to the normal acceleration CL1 engagement motor rotation speed at time t1 immediately thereafter. Subsequently, when an accelerator OFF → ON operation is performed at time t2, the high acceleration requirement condition and the oil temperature condition are satisfied at time t2 of the start start operation. Therefore, at the timing at time t2 immediately after the start start operation, control is performed to increase the rotation speed of the motor generator 3 (MG) from the normal acceleration CL1 engagement motor rotation speed to the high acceleration request CL1 engagement motor rotation speed. Is called.

From the time t4 when the high acceleration request CL1 engagement motor rotation speed is reached until the engine start request establishment time t6, the rotation speed of the motor generator 3 (MG) is maintained at the high acceleration request CL1 engagement motor rotation speed. The When the engine start request establishment time t6 is reached, the rotation speed of the motor generator 3 (MG) is decreased from the high acceleration request CL1 engagement motor rotation speed and reaches the normal acceleration CL1 engagement motor rotation speed at time t7. . Engagement of the first clutch 2 (CL1) is started at time t7, and engagement of the first clutch 2 (CL1) is completed at time t8.

Thus, in Example 1, as shown in hatching region D in FIG. 5, the motor rotation speed (∝ oil pump rotation speed) is increased from time t3 to time t7 as compared with the comparative example. As the rotational speed of the oil pump 10 increases, the pump discharge pressure increases, and as shown in the hatched region E of FIG. 5, the hydraulic pressure (actual PL) that can be generated is higher than that of the comparative example from time t5 to time t8. As described above, the region E in which the hydraulic pressure rises with a delay from the region D in which the motor rotational speed rises has a time delay according to the amount of hydraulic oil leakage even if the motor rotational speed is reduced at time t7. This is because the oil pressure drops in the state where As a result, even after time t7 when the engagement of the first clutch 2 (CL1) is started, the hydraulic pressure characteristics that can be generated become characteristics higher than the required hydraulic pressure characteristics, and can be generated for the increased required hydraulic pressure (target PL). The shortage of hydraulic pressure (actual PL) is resolved.

[Achieving torque rate when starting]
FIG. 6 is a time chart showing characteristics for explaining a target torque rate that can be realized at the time of start when the driver acceleration request is high in the comparative example. Hereinafter, based on FIG. 6, a description will be given of an effect of realizing the torque rate at the start when the driver acceleration request is high in the comparative example.

As described above, in the case of the comparative example, if the start start operation with a high driver acceleration request is performed by an accelerator sudden depression operation or the like, the available hydraulic pressure (actual PL) is insufficient with respect to the required hydraulic pressure (target PL). Since the possible hydraulic pressure (actual PL) is insufficient in this way, the torque that can be input to the belt type continuously variable transmission CVT is kept low, and the target torque climb gradient (target torque rate) that can be achieved is also kept low. It is done. For this reason, in the case of the comparative example, the torque transmitted to the drive wheels via the belt type continuously variable transmission CVT is lower than the torque that realizes the target drive force according to the accelerator operation.

FIG. 7 is a time chart showing characteristics for explaining a target torque rate that can be realized at the time of start when the driver acceleration request is high in the first embodiment. Hereinafter, based on FIG. 7, an explanation will be given of the torque rate realization operation at the time of start with a high driver acceleration request in the first embodiment.

As described above, in the case of Example 1, when the start start operation with a high driver acceleration request is performed by the accelerator sudden depression operation, the shortage of the available hydraulic pressure (actual PL) to the required hydraulic pressure (target PL) is solved. Is done. In this way, since the shortage of the possible hydraulic pressure (actual PL) is resolved, the torque that can be input to the belt type continuously variable transmission CVT is not limited, and the input torque characteristics are surrounded by the arrow F in FIG. As shown in the characteristic, the torque increases at a larger gradient angle than the input possible torque characteristic of the comparative example. Along with this, the target torque increase gradient (target torque rate) that can be realized also increases. For this reason, in the case of Example 1, the torque transmitted to the

drive wheels

9 and 9 via the belt-type continuously variable transmission 6 (CVT) becomes the torque that realizes the target drive force according to the accelerator operation.

Thus, in the case of Example 1, the target torque rate that determines the acceleration responsiveness to the driver operation at the time of start is improved as compared with the target torque rate of the comparative example. Incidentally, according to the experimental example conducted by the inventor, the target torque rate is about 200 Nm / sec in the comparative example, whereas the target torque rate is about 400 Nm / sec in the first embodiment. It was. From this experimental result, it has been found that a significant improvement in target torque rate can be expected compared to the comparative example.

[Characteristics of motor speed control at start-up]
In the first embodiment, in the operation mode using the motor generator 3 as a drive source, the high speed request for the high speed range of the motor generator 3 exceeding the normal acceleration CL1 engagement motor rotational speed allowed by the first clutch 2 is required. Increase to CL1 fastening motor speed. If the engine start request is established while the rotational speed of the motor generator 3 is being increased, the rotational speed of the motor generator 3 is decreased.

That is, in the operation mode using the motor generator 3 as a drive source, the motor rotational speed is increased in preparation for a driver acceleration request. In this way, by increasing the rotational speed of the motor generator 3 that rotationally drives the oil pump 10, the required hydraulic pressure is ensured when there is a driver acceleration request.
When the engagement of the first clutch 2 is predicted due to the establishment of the engine start request, the motor speed is decreased. Thus, by reducing the motor rotation speed at the timing before starting the engagement of the first clutch 2, the burden on the first clutch 2 due to the differential rotation speed between the engine 1 and the motor generator 3 is reduced. Is done.
Here, while it is necessary to ensure the hydraulic pressure for engaging the first clutch 2 when the engine is started, the motor rotation speed is reduced at a timing before the first clutch 2 is started to be engaged. However, the discharge hydraulic pressure characteristic of the oil pump 10 has a response delay with respect to the increase or decrease of the pump rotation speed (∝motor rotation speed). The oil pressure is gradually decreasing. For this reason, even if the motor rotational speed is reduced before starting the engagement of the first clutch 2, the hydraulic pressure necessary for engaging the first clutch 2 is ensured by the residual hydraulic pressure when the motor rotational speed is high.
Therefore, it is possible to achieve both of ensuring the required oil pressure for the driver acceleration request and reducing the burden on the first clutch 2 for the engine start request.

In the first embodiment, in the operation mode using the motor generator 3 as a drive source, it is determined whether or not the driver acceleration request by the driver operation is higher than the normal acceleration request. When it is determined that the driver acceleration request is equal to or less than the normal acceleration request, the rotation speed of the motor generator 3 is set to the normal acceleration CL1 engagement motor rotation speed allowed by the first clutch 2. On the other hand, if it is determined that the driver acceleration request is higher than the normal acceleration request, the rotational speed of the motor generator 3 is increased to the high acceleration request CL1 engagement motor rotational speed.

That is, whether or not the required hydraulic pressure is high is predicted based on whether or not the driver acceleration request is higher than the normal acceleration request. When it is determined that the driver acceleration request is equal to or less than the normal acceleration request, the increase in the rotational speed of the motor generator 3 is suppressed. On the other hand, when it is determined that the driver acceleration request is higher than the normal acceleration request, the rotational speed of the motor generator 3 that rotationally drives the oil pump 10 is increased. In this way, the opportunity for increasing the motor speed is limited to when the driver acceleration request is higher than the normal acceleration request, that is, when the required hydraulic pressure is predicted to be high, so that the frequency of the motor rotation speed increases. Be lowered.
Therefore, the burden on the first clutch 2 with respect to the engine start request is further reduced by reducing the frequency of increase in the motor rotation speed.

In Example 1, it is determined that the driver acceleration request is higher than the normal acceleration request when the accelerator opening deviation, which is a change amount of the accelerator opening APO per predetermined time due to the driver's accelerator depression operation, is equal to or greater than a predetermined value. If it is determined that the driver acceleration request is higher than the normal acceleration request, the higher the accelerator opening degree deviation, the higher the high acceleration request CL1 engagement motor rotational speed is set.

That is, the high acceleration requirement condition is established in the start acceleration scene or the intermediate acceleration scene due to the sudden depression of the accelerator, and the possible hydraulic pressure using the oil pump 10 as the hydraulic source is increased by increasing the motor rotation speed. Then, as the accelerator depression speed increases, the required oil pressure is ensured regardless of the accelerator depression speed by increasing the increase in the motor rotation speed as the required oil pressure increases. Therefore, in the start acceleration scene and the intermediate acceleration scene, the required hydraulic pressure is ensured regardless of the accelerator depression speed.

In Example 1, it is determined that the driver acceleration request is higher than the normal acceleration request when the switching time from the brake operation of the driver to the accelerator operation is equal to or shorter than a predetermined time. If it is determined that the driver acceleration request is higher than the normal acceleration request, the higher the rotation speed is set to the higher acceleration request CL1 fastening motor rotation speed, the shorter the stepping time is.

That is, during the brake operation, since there is no creep torque by the motor generator 3, the switching from the brake operation state to the accelerator operation is performed in a short time. The high acceleration requirement condition is satisfied in a scene where the switching from the brake operation to the accelerator operation is performed quickly, and by increasing the motor rotation speed, the possible hydraulic pressure using the oil pump 10 as a hydraulic source is increased. And the shorter the changeover time, the greater the required oil pressure increases so as to prevent the vehicle from slipping down. Hydraulic pressure is secured. Therefore, in a scene where the stepping from the brake operation to the accelerator operation is performed quickly, the necessary hydraulic pressure is ensured regardless of the length of the stepping time.

In the first embodiment, when it is determined that the driver acceleration request is higher than the normal acceleration request, and the oil temperature of the belt-type continuously variable transmission 6 is equal to or higher than a predetermined value, the rotational speed of the motor generator 3 is set for high acceleration request. Increase to CL1 fastening motor speed.

That is, when the oil temperature of the belt-type continuously variable transmission 6 is less than a predetermined value, the viscosity of the hydraulic oil is high, and the required hydraulic pressure may not be ensured even if the motor speed is increased. Therefore, when the motor speed is increased, by adding the oil temperature condition to the high acceleration requirement condition, the frequency of increasing the motor speed is reduced, and the burden on the first clutch 2 is further reduced.

In the first embodiment, when it is determined that the driver acceleration request is higher than the normal acceleration request during the start operation using the motor generator 3 as a drive source, the rotation speed of the motor generator 3 is set to the high acceleration request CL1 engagement motor rotation speed. To rise. Start up in “WSC mode” in which the increase in the rotational speed of the motor generator 3 is absorbed by sliding engagement of the second clutch 4 and the transmission torque to the

drive wheels

9 and 9 is equivalent to the target driving force by the engagement capacity control of the second clutch 4 To do.

That is, in the start acceleration scene, a necessary hydraulic pressure that can realize an inputable torque that is higher than the target torque is secured, and the target torque rate is improved as compared with the comparative example. Therefore, in the start acceleration scene, the start acceleration response with the target torque rate corresponding to the driver's accelerator operation is realized.

Next, the effect will be described.
In the control method and control apparatus for the FF hybrid vehicle in the first embodiment, the effects listed below can be obtained.

(1) An engine 1, a friction clutch (first clutch 2), a motor (motor generator 3), and a transmission (belt type continuously variable transmission 6) are mounted on a drive system from the drive source to the

drive wheels

9, 9. The
The friction clutch (first clutch 2) and the transmission (belt type continuously variable transmission 6) are hydraulically operated, and an oil pump 10 that is rotationally driven by a motor (motor generator 3) is provided as a hydraulic source of these.
When the engine start request is established in the operation mode using the motor (motor generator 3) as a drive source, the friction clutch (first clutch 2) is engaged, and the engine 1 is cranked using the motor (motor generator 3) as a start motor. Start.
In this hybrid vehicle (FF hybrid vehicle) control method, the friction clutch (first clutch 2) allows the rotational speed of the motor (motor generator 3) in the operation mode using the motor (motor generator 3) as a drive source. To the target rotational speed (CL1 fastening motor rotational speed for high acceleration request) in the rotational speed range that exceeds the allowable rotational speed (normal acceleration CL1 fastening motor rotational speed).
If the engine start request is established while the rotational speed of the motor (motor generator 3) is being increased, the rotational speed of the motor (motor generator 3) is decreased (FIG. 5).
For this reason, it is possible to provide a control method for a hybrid vehicle (FF hybrid vehicle) that achieves both securing of the required hydraulic pressure for a driver acceleration request and reducing the burden on the friction clutch (first clutch 2) for an engine start request. it can.

(2) In the operation mode using the motor (motor generator 3) as a drive source, it is determined whether or not the driver acceleration request by the driver operation is higher than the normal acceleration request (S6 in FIG. 3).
When it is determined that the driver acceleration request is equal to or less than the normal acceleration request, the allowable rotational speed (the normal acceleration CL1 engagement motor rotational speed) at which the friction clutch (first clutch 2) allows the rotational speed of the motor (motor generator 3). (S6 → S7 in FIG. 3).
If it is determined that the driver acceleration request is higher than the normal acceleration request, the rotational speed of the motor (motor generator 3) is increased to the target rotational speed (CL1 engagement motor rotational speed for high acceleration request) (S6 → S8 in FIG. 3). → S9).
For this reason, in addition to the effect of (1), the burden on the friction clutch (first clutch 2) with respect to the engine start request can be further reduced by reducing the frequency of increase in the motor rotation speed.

(3) When the accelerator opening deviation, which is the amount of change in the accelerator opening APO per predetermined time due to the driver's accelerator depression operation, is greater than or equal to a predetermined value, it is determined that the driver acceleration request is higher than the normal acceleration request.
When it is determined that the driver acceleration request is higher than the normal acceleration request, the target rotation speed (CL1 engagement motor rotation speed for high acceleration request) is set to a higher rotation speed as the accelerator opening degree deviation becomes larger (Fig. 3 S6 → S8 → S9).
For this reason, in addition to the effect of (2), the required hydraulic pressure can be secured regardless of the accelerator depression speed in the start acceleration scene and the intermediate acceleration scene.

(4) When the time required for the driver to switch from the brake operation to the accelerator operation is less than or equal to the predetermined time, it is determined that the driver acceleration request is higher than the normal acceleration request.
When it is determined that the driver acceleration request is higher than the normal acceleration request, the target rotation speed (CL1 engagement motor rotation speed for high acceleration request) is set to a higher rotation speed as the time required for switching is shorter (FIG. 3). S6 → S8 → S9).
For this reason, in addition to the effect of (2) or (3), in the scene where the stepping from the brake operation to the accelerator operation is performed quickly, the necessary hydraulic pressure can be ensured regardless of the length of the stepping time.

(5) When it is determined that the driver acceleration request is higher than the normal acceleration request and the oil temperature of the transmission (belt type continuously variable transmission 6) is equal to or higher than a predetermined value, the rotational speed of the motor (motor generator 3) Is increased to a target rotational speed (CL1 engagement motor rotational speed for high acceleration request) (S6 → S8 → S9 in FIG. 3).
For this reason, in addition to the effects (2) to (4), when increasing the motor speed, adding the oil temperature condition to the high acceleration requirement condition reduces the frequency of increasing the motor speed, and the friction clutch (first The burden on 1 clutch 2) can be further reduced.

(6) When the friction clutch interposed between the engine 1 and the motor (motor generator 3) is referred to as the first clutch 2, the second clutch 4 is interposed between the motor (motor generator 3) and the

drive wheels

9, 9. Disguise.
During a start operation using the motor (motor generator 3) as a drive source, if it is determined that the driver acceleration request is higher than the normal acceleration request, the rotation speed of the motor (motor generator 3) is changed to the target rotation speed (for high acceleration request). Increase to CL1 fastening motor speed).
Drive torque control that absorbs the increase in the rotational speed of the motor (motor generator 3) by sliding engagement of the second clutch 4, and makes the transmission torque to the

drive wheels

9, 9 equivalent to the target driving force by the engagement capacity control of the second clutch 4. Start in the start mode (WSC mode) (Figure 3).
Therefore, in addition to the effects (2) to (5), it is possible to realize start acceleration response at a target torque rate according to the driver's accelerator operation in the start acceleration scene.

(7) The engine 1, the friction clutch (first clutch 2), the motor (motor generator 3), and the transmission (belt type continuously variable transmission 6) are mounted on the drive system from the drive source to the

drive wheels

9, 9. The
The friction clutch (first clutch 2) and the transmission (belt type continuously variable transmission 6) are hydraulically operated, and an oil pump 10 that is rotationally driven by a motor (motor generator 3) is provided as a hydraulic source of these.
When the engine start request is established in the operation mode using the motor (motor generator 3) as a drive source, the friction clutch (first clutch 2) is engaged, and the engine 1 is cranked using the motor (motor generator 3) as a start motor. A controller (integrated controller 14) for starting is provided.
In this hybrid vehicle (FF hybrid vehicle) control device, the controller (integrated controller 14) determines the rotational speed of the motor (motor generator 3) as a friction clutch in the operation mode using the motor (motor generator 3) as a drive source. The rotation speed is increased to a target rotation speed (CL1 engagement motor rotation speed for high acceleration request) exceeding the allowable rotation speed (normal acceleration CL1 engagement motor rotation speed) allowed by (first clutch 2).
If the engine start request is satisfied while the rotational speed of the motor (motor generator 3) is being increased, a process of decreasing the rotational speed of the motor (motor generator 3) is executed (FIG. 3).
For this reason, it is possible to provide a control device for a hybrid vehicle (FF hybrid vehicle) that achieves both securing of a required hydraulic pressure for a driver acceleration request and reducing a burden on a friction clutch (first clutch 2) for an engine start request. it can.

The hybrid vehicle control method and control device of the present disclosure have been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and design changes and additions are permitted without departing from the gist of the invention according to each claim of the claims.

In the first embodiment, when the rotation speed of the motor generator 3 is increased to the high acceleration request CL1 engagement motor rotation speed and the engine start request is satisfied, the rotation speed of the motor generator 3 is changed to the normal acceleration CL1 engagement motor rotation speed. An example of lowering is shown. However, if the engine start request is established, the rotation that does not reach the normal acceleration CL1 engagement motor rotation speed is possible if the CL1 engagement motor rotation speed for high acceleration request is decreased toward the normal acceleration CL1 engagement motor rotation speed. It may be an example where the number is reduced to a number. In addition, when the engine start request is established, the high acceleration request CL1 engagement motor rotational speed may be reduced to a rotational speed exceeding the normal acceleration CL1 engagement motor rotational speed.

In the first embodiment, the driver acceleration request is high when the accelerator opening deviation due to the driver's accelerator depression operation is greater than or equal to a predetermined value, or when the time from the driver's brake operation to the accelerator operation is less than the predetermined time. An example of judging is given. However, it may be an example in which it is determined that the driver acceleration request is high when the accelerator opening degree by the driver's accelerator depression operation becomes equal to or greater than a predetermined opening degree. Furthermore, it is good also as an example which judges that a driver acceleration request | requirement is high combining an accelerator opening deviation and an accelerator opening.

Example 1 shows an example in which control is performed to increase the motor speed when it is determined that the driver acceleration request is high in the start scene. However, in an intermediate acceleration scene in which the accelerator is depressed during low-speed traveling in the “EV mode”, if it is determined that the driver acceleration request is high, control for increasing the motor rotation speed may be performed.

In the first embodiment, an example in which the control method and the control device of the present disclosure are applied to an FF hybrid vehicle having a parallel hybrid drive system called a one-motor / two-clutch and having a belt type continuously variable transmission as a transmission. Indicated. However, the control method and the control device of the present disclosure are also applicable to a hybrid vehicle equipped with a hydraulic stepped transmission that increases the hydraulic pressure to the frictional engagement element for shifting that is hydraulically engaged when acceleration is requested. Can do. Furthermore, the present invention can also be applied to a hybrid vehicle that does not have the second clutch that absorbs the rotation difference by sliding engagement but absorbs the rotation difference by a fluid coupling or the like.

Claims

The drive system from the drive source to the drive wheels is equipped with an engine, friction clutch, motor, and transmission,
The friction clutch and the transmission are hydraulically operated, and an oil pump that is rotationally driven by the motor is provided as a hydraulic source of these,
In an operation mode using the motor as a drive source, when an engine start request is established, the friction clutch is engaged, and the engine is cranked and started using the motor as a start motor.
When in the operation mode using the motor as a drive source, the rotational speed of the motor is increased to a target rotational speed in a rotational speed range exceeding the allowable rotational speed allowed by the friction clutch,
The method of controlling a hybrid vehicle, wherein when the engine start request is satisfied while the rotational speed of the motor is increased, the rotational speed of the motor is decreased.
The hybrid vehicle control method according to claim 1, wherein:
When the operation mode using the motor as a drive source, it is determined whether the driver acceleration request by the driver operation is higher than the normal acceleration request,
When it is determined that the driver acceleration request is equal to or less than the normal acceleration request, the rotation speed of the motor is set as a permissible rotation speed allowed by the friction clutch,
When it is determined that the driver acceleration request is higher than the normal acceleration request, the rotational speed of the motor is increased to the target rotational speed.
In the control method of the hybrid vehicle described in Claim 2,
When the accelerator opening deviation, which is the amount of change in the accelerator opening per predetermined time due to the driver's accelerator depressing operation, is greater than or equal to a predetermined value, it is determined that the driver acceleration request is higher than the normal acceleration request,
When it is determined that the driver acceleration request is higher than the normal acceleration request, the target rotational speed is set to a higher rotational speed as the accelerator opening deviation is larger. .
In the control method of the hybrid vehicle according to claim 2 or claim 3,
When the time for the driver to switch from the brake operation to the accelerator operation is less than the predetermined time, the driver acceleration request is determined to be higher than the normal acceleration request,
When it is determined that the driver acceleration request is higher than the normal acceleration request, the target rotational speed is set to a higher rotational speed as the changeover time is shorter.
In the control method of the hybrid vehicle as described in any one of Claim 2 to Claim 4,
A hybrid vehicle characterized in that when the driver acceleration request is determined to be higher than the normal acceleration request and the oil temperature of the transmission is equal to or higher than a predetermined value, the rotational speed of the motor is increased to the target rotational speed. Control method.
In the control method of the hybrid vehicle as described in any one of Claim 2-5,
When the friction clutch interposed between the engine and the motor is referred to as a first clutch, a second clutch is interposed between the motor and the driving wheel,
During a start operation using the motor as a drive source, if it is determined that the driver acceleration request is higher than the normal acceleration request, the rotational speed of the motor is increased to the target rotational speed,
Starting up in a drive torque control start mode in which the increase in the rotational speed of the motor is absorbed by slip engagement of the second clutch, and the transmission torque to the drive wheels is equivalent to the target drive force by the engagement capacity control of the second clutch. A control method of a hybrid vehicle characterized by the above.
The drive system from the drive source to the drive wheels is equipped with an engine, friction clutch, motor, and transmission,
The friction clutch and the transmission are hydraulically operated, and an oil pump that is rotationally driven by the motor is provided as a hydraulic source of these,
In an operation mode using the motor as a drive source, when an engine start request is established, the friction clutch is engaged, and the hybrid vehicle control device includes a controller that starts cranking the engine using the motor as a start motor.
The controller is
When in the operation mode using the motor as a drive source, increase to a target rotational speed in a rotational speed range exceeding the allowable rotational speed allowed by the friction clutch,
A control apparatus for a hybrid vehicle, wherein when the engine start request is satisfied while increasing the rotation speed of the motor, a process of decreasing the rotation speed of the motor is executed.