JP2016172490A - Control device for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a hybrid vehicle capable of achieving both a suppression of a slip-in shock and a prevention of an engine stall, at the time of deceleration when a slip-in control of a friction clutch is performed.SOLUTION: There is provided a driving system including a second clutch between a motor generator and a right and a left front wheels. In this FF hybrid vehicle, a hybrid control module is provided which starts a CL2 slip-in control for causing the second clutch to be in a slip coupling state by a decrease in a clutch torque capacity and an increase in a motor torque, during a deceleration time of opening the second clutch, when a vehicle speed becomes a slip-in vehicle speed due to a decrease of vehicle speed. The hybrid control module, during the CL2 slip-in control, causes an increase inclination of the motor torque to be a climb gradient with a slow torque increase in a former half region from a control start, and when a latter half region starts, causes to be a climb gradient with a rapid torque increase than the climb gradient in the former half region.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control apparatus for a hybrid vehicle that performs slip-in control of a friction clutch interposed between a motor and a drive wheel during deceleration when the friction clutch is released.

  Conventionally, an engine start control device for a hybrid vehicle that performs CL2 slip-in control for starting slip of the second clutch CL2 by increasing motor torque when an engine start request is made is known (see, for example, Patent Document 1).

JP 2007-69817 A

  However, the conventional apparatus gives a constant gradient as the motor torque increase gradient, and starts CL2 slip-in control. For this reason, if a steep gradient angle is given as the rising gradient of the motor torque during deceleration when the second clutch CL2 is released, a slip-in shock occurs due to a sudden torque change in the slip start region where the clutch plate in the engaged state is peeled off. There was a problem that there was. On the other hand, if a gentle gradient angle is given as the rising gradient of the motor torque, the occurrence of differential rotation in the second clutch CL2 will be delayed, and this delay may reduce the engine speed and cause engine stall. There was a problem.

  The present invention has been made paying attention to the above problem, and provides a hybrid vehicle control device that achieves both slip-in shock suppression and engine stall prevention during deceleration when slip-in control of a friction clutch is performed. With the goal.

In order to achieve the above object, the present invention includes a drive system having an engine and a motor as a drive source, and a friction clutch interposed between the motor and the drive wheel.
In this hybrid vehicle, at the time of deceleration to release the friction clutch, when the slip-in vehicle speed is reached due to a decrease in the vehicle speed, a controller that starts slip-in control to bring the friction clutch into a slip-engaged state due to a decrease in clutch torque capacity and an increase in motor torque Is provided.
During the slip-in control, the controller makes the motor torque rise to a gentle gradient in which the torque rises in the first half from the start of the control, and when entering the second half, the torque rises more rapidly than the gradient in the first half. To do.

Therefore, during the slip-in control, the motor torque rises to a gentler slope in the first half of the period from the start of control, and when entering the second half, the torque rises to a steeper slope than that of the first half. Is done.
That is, the torque increase is made a gentle gradient in the first half region from the start of the slip-in control, so that a sudden torque change is suppressed in the slip start region where the clutch plate in the engaged state is peeled off. And if it enters into the latter half area of slip-in control, a torque rise will be made into a steep rising gradient, and a friction clutch will transfer to a slip state rapidly, and the fall of an engine speed is suppressed.
As a result, it is possible to achieve both suppression of slip-in shock and prevention of engine stall during deceleration when slip-in control of the friction clutch is performed.

1 is an overall system diagram illustrating an FF hybrid vehicle to which a control device according to a first embodiment is applied. It is a flowchart which shows the flow of the CL2 slip-in control process performed at the time of deceleration in the hybrid control module of Example 1. FIG. 4 is a motor torque gradient characteristic diagram showing a relationship between a CL2 open motor torque gradient and a transmission input rotation speed (vehicle speed) used in the motor torque ascending gradient switching in step S04 in the CL2 slip-in control process of FIG. 2; FIG. 4 is a block diagram showing that the CL2 open motor torque gradient used in the step S04 for increasing the torque gradient of the motor torque in the CL2 slip-in control process of FIG. 2 is determined by selecting the gradient with respect to the transmission input rotational speed and the gradient with respect to the vehicle speed. . FIG. 6 is a block diagram showing a switching process in EV mode / HEV mode / D range / R range used in the calculation of motor torque during CL2 release in step S05 in the CL2 slip-in control process of FIG. 2; Slip-in request determination, CL2 slip determination, CL2 torque capacity command, actual CL2 torque capacity, motor torque command, motor rotation speed, target motor rotation when CL2 slip-in control of the first embodiment is performed during deceleration in the driving scene 3 is a time chart showing characteristics of a number, transmission input rotation speed, vehicle speed, and ATF oil temperature. It is a comparative characteristic figure which shows the vehicle speed field expansion effect of cooperative regeneration control by performing CL2 slip-in control of Example 1 at the time of brake depression in a coast running scene.

  Hereinafter, the best mode for realizing a control device for a hybrid vehicle of the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
The control device in the first embodiment is applied to an FF hybrid vehicle (an example of a hybrid vehicle) in which left and right front wheels are drive wheels and a belt type continuously variable transmission is mounted as a transmission. Hereinafter, the configuration of the control device for the FF hybrid vehicle according to the first embodiment will be described by being divided into an “overall system configuration” and a “CL2 slip-in control processing configuration”.

[Overall system configuration]
FIG. 1 shows an overall system of an FF hybrid vehicle to which the control device of the first embodiment is applied. Hereinafter, the overall system configuration of the FF hybrid vehicle will be described with reference to FIG.

  As shown in FIG. 1, the drive system of the FF hybrid vehicle includes a horizontally placed engine 2, a first clutch 3 (abbreviated “CL1”), a motor generator 4 (abbreviated “MG”), and a second clutch 5 (abbreviated). "CL2") and a belt type continuously variable transmission 6 (abbreviated as "CVT"). The output shaft of the belt type continuously variable transmission 6 is drivingly connected to the left and right front wheels 10R and 10L via a final reduction gear train 7, a differential gear 8, and left and right drive shafts 9R and 9L. The left and right rear wheels 11R and 11L are driven wheels.

  The horizontal engine 2 is an engine disposed in a front room with a starter motor 1 and a crankshaft direction as a vehicle width direction, an electric water pump 12, and a crankshaft rotation sensor 13 for detecting reverse rotation of the horizontal engine 2. Have. This horizontal engine 2 has an “MG start mode” in which cranking is performed by the motor generator 4 while the first clutch 3 is slidingly engaged, and a starter motor 1 which is powered by the 12V battery 22 as an engine starting method. Starter start mode ". The “starter start mode” is selected only when a limited condition such as a cryogenic temperature condition is satisfied.

  The motor generator 4 is a three-phase AC permanent magnet synchronous motor connected to the transverse engine 2 via the first clutch 3. The motor generator 4 uses a high-power battery 21 described later as a power source, and an inverter 26 that converts direct current to three-phase alternating current during power running and converts three-phase alternating current to direct current during regeneration is connected to the stator coil via an AC harness 27. Connected. The first clutch 3 interposed between the horizontal engine 2 and the motor generator 4 is a dry or wet multi-plate clutch operated by hydraulic operation, and complete engagement / slip engagement / release is controlled by the first clutch hydraulic pressure. Is done.

  The second clutch 5 is a hydraulically operated wet multi-plate friction clutch interposed between the motor generator 4 and the left and right front wheels 10R and 10L as drive wheels, and is fully engaged / slip engaged by the second clutch hydraulic pressure. / Open is controlled. The second clutch 5 in the first embodiment uses a forward clutch 5a and a reverse brake 5b provided in a forward / reverse switching mechanism using a planetary gear. That is, the forward clutch 5 a is the second clutch 5 during forward travel, and the reverse brake 5 b is the second clutch 5 during reverse travel.

  The belt-type continuously variable transmission 6 includes a primary pulley 6a, a secondary pulley 6b, and a belt 6c that spans the pulleys 6a and 6b. And it is a transmission which obtains a stepless gear ratio by changing the winding diameter of belt 6c with the primary pressure and secondary pressure supplied to a primary oil chamber and a secondary oil chamber. The belt type continuously variable transmission 6 includes a main oil pump 14 (mechanical drive) that is rotated by a motor shaft (= transmission input shaft) of a motor generator 4 as a hydraulic pressure source, and a sub oil pump used as an auxiliary pump. 15 (motor drive). And the control which produces the primary pressure and the secondary pressure of the 1st clutch pressure, the 2nd clutch pressure, and the belt-type continuously variable transmission 6 from the line pressure PL produced | generated by adjusting the pump discharge pressure from a hydraulic power source as a source pressure. A valve unit 6d is provided.

  The first clutch 3, the motor generator 4 and the second clutch 5 constitute a hybrid drive system called a one-motor / two-clutch. The main drive modes are "EV mode", "HEV mode", "WSC mode" Have The “EV mode” is an electric vehicle mode in which the first clutch 3 is disengaged and the second clutch 5 is engaged and only the motor generator 4 is used as a drive source, and traveling in the “EV mode” is referred to as “EV traveling”. The “HEV mode” is a hybrid vehicle mode in which both the clutches 3 and 5 are engaged and the transverse engine 2 and the motor generator 4 are used as driving sources, and traveling in the “HEV mode” is referred to as “HEV traveling”. The “WSC mode” is a CL2 slip engagement mode in which the second clutch 5 is slip-engaged in the “HEV mode” or the “EV mode”. The “WSC mode” is a mode that is set by not having a rotation difference absorbing element such as a torque converter in the hybrid drive system. In particular, in the “HEV mode” in which the lowest engine speed is the engine idle engine speed, the differential clutch between the engine engine speed and the transmission input engine speed is absorbed by slip-engaging the second clutch 5 in the start and stop areas. .

  As shown in FIG. 1, the braking system of the FF hybrid vehicle includes a brake operation unit 16, a brake fluid pressure control unit 17, left and right front wheel brake units 18R and 18L, and left and right rear wheel brake units 19R and 19L. ing. In this braking system, when regeneration is performed by the motor generator 4 at the time of brake operation, cooperative regenerative control in which the hydraulic braking force shares the amount obtained by subtracting the regenerative braking force from the requested braking force with respect to the requested braking force based on the pedal operation. Done.

  The brake operation unit 16 includes a brake pedal 16a, a negative pressure booster 16b that uses the intake negative pressure of the horizontal engine 2, a master cylinder 16c, and the like. The cooperative regenerative brake unit 16 generates a predetermined master cylinder pressure in accordance with the brake depression force applied from the driver to the brake pedal 16a, and is a unit having a simple configuration that does not use an electric booster.

  Although not shown, the brake fluid pressure control unit 17 includes an electric oil pump, a pressure increasing solenoid valve, a pressure reducing solenoid valve, an oil path switching valve, and the like. Control of the brake fluid pressure control unit 17 by the brake control unit 85 exhibits a function of generating wheel cylinder fluid pressure when the brake is not operated and a function of adjusting wheel cylinder fluid pressure when the brake is operated. Control using the hydraulic pressure generation function when the brake is not operated includes traction control (TCS control), vehicle behavior control (VDC control), emergency brake control (automatic brake control), and the like. Control using the hydraulic pressure adjustment function at the time of brake operation includes cooperative regeneration control, anti-lock brake control (ABS control), and the like.

  The left and right front wheel brake units 18R and 18L are provided on the left and right front wheels 10R and 10L, respectively, and the left and right rear wheel brake units 19R and 19L are provided on the left and right rear wheels 11R and 11L, respectively. Give. These brake units 18R, 18L, 19R and 19L have wheel cylinders (not shown) to which the brake fluid pressure generated by the brake fluid pressure control unit 17 is supplied.

  As shown in FIG. 1, the power supply system of the FF hybrid vehicle includes a high-power battery 21 as a power supply for the motor generator 4 and a 12V battery 22 as a power supply for a 12V system load.

  The high-power battery 21 is a secondary battery mounted as a power source for the motor generator 4. For example, a lithium ion battery in which a cell module constituted by a large number of cells is set in a battery pack case is used. The high-power battery 21 has a built-in junction box in which relay circuits for supplying / cutting off / distributing high-power are integrated, and further includes a cooling fan unit 24 having a battery cooling function, a battery charging capacity (battery SOC) and a battery. And a lithium battery controller 86 for monitoring the temperature.

  The high-power battery 21 and the motor generator 4 are connected via a DC harness 25, an inverter 26, and an AC harness 27. The inverter 26 is provided with a motor controller 83 that performs power running / regenerative control. That is, the inverter 26 converts the direct current from the DC harness 25 into the three-phase alternating current to the AC harness 27 during power running that drives the motor generator 4 by discharging the high-power battery 21. Further, the three-phase alternating current from the AC harness 27 is converted into direct current to the DC harness 25 during regeneration in which the high-power battery 21 is charged by power generation by the motor generator 4.

  The 12V battery 22 is a secondary battery mounted as a power source for a starter motor 1 and a 12V system load that is an auxiliary machine. For example, a lead battery mounted in an engine vehicle or the like is used. The high voltage battery 21 and the 12V battery 22 are connected via a DC branch harness 25a, a DC / DC converter 37, and a battery harness 38. The DC / DC converter 37 converts a voltage of several hundred volts from the high-power battery 21 into 12V, and the charge amount of the 12V battery 22 is controlled by controlling the DC / DC converter 37 by the hybrid control module 81. The configuration is to be managed.

  As shown in FIG. 1, the electronic control system of the FF hybrid vehicle includes a hybrid control module 81 (abbreviation: “HCM”) as an electronic control unit having an integrated control function for appropriately managing energy consumption of the entire vehicle. Yes. Other electronic control units include an engine control module 82 (abbreviation: “ECM”), a motor controller 83 (abbreviation: “MC”), and a CVT control unit 84 (abbreviation: “CVTCU”). Furthermore, it has a brake control unit 85 (abbreviation: “BCU”) and a lithium battery controller 86 (abbreviation: “LBC”). These electronic control units 81, 82, 83, 84, 85, 86 are connected via a CAN communication line 90 (CAN is an abbreviation for “Controller Area Network”) so that bidirectional information can be exchanged, and share information with each other.

  The hybrid control module 81 inputs information from other electronic control units 82, 83, 84, 85, 86, an ignition switch 91, and the like. And various integrated control is performed based on these input information.

  The engine control module 82 inputs information from the hybrid control module 81, the engine speed sensor 92, and the like. Then, based on the input information, start control, fuel injection control, ignition control, fuel cut control, engine idle rotation control, and the like of the horizontal engine 2 are performed.

  The motor controller 83 inputs information from the hybrid control module 81, the motor rotation speed sensor 93, and the like. Based on the input information, power running control, regenerative control, motor creep control, motor idle control, and the like of the motor generator 4 are performed by a control command to the inverter 26.

  The CVT control unit 84 inputs information from the hybrid control module 81, the accelerator opening sensor 94, the vehicle speed sensor 95, the inhibitor switch 96, the ATF oil temperature sensor 97, the transmission input rotation speed sensor 102, and the like. Based on the input information, a control command is output to the control valve unit 6d, and the engagement hydraulic pressure control of the first clutch 3, the engagement hydraulic pressure control of the second clutch 5, the primary pressure and the secondary pressure of the belt-type continuously variable transmission 6 are output. Shifting hydraulic pressure control by pressure is performed.

  The brake control unit 85 inputs information from the hybrid control module 81, the brake switch 98, the brake stroke sensor 99, and the like. And based on these input information, a control command is output to the brake fluid pressure control unit 17, and TCS control, VDC control, automatic brake control, cooperative regeneration control, ABS control, etc. are performed.

  The lithium battery controller 86 manages the battery SOC, battery temperature, and the like of the high-power battery 21 based on input information from the battery voltage sensor 100, the battery temperature sensor 101, and the like.

[CL2 slip-in control processing configuration]
FIG. 2 shows the flow of the CL2 slip-in control process executed during deceleration by the hybrid control module 81 (controller) of the first embodiment. In the following, each step of FIG. 2 representing the CL2 slip-in control processing configuration for starting control by CL2 slip request determination and ending control by CL2 slip determination during deceleration will be described.

In step S01, processing is started at the time of deceleration, necessary data is received from each electronic control unit 82, 83, 84, 85, 86 (each ECU) via the CAN communication line 90, and the process proceeds to step S2.
Here, “necessary data” refers to data from the accelerator opening sensor 94, the brake switch 98, the vehicle speed sensor 95, the transmission input rotation speed sensor 102, the inhibitor switch 96, the ATF oil temperature sensor 97, and the like. That is, accelerator opening information, brake operation information, vehicle speed information, transmission input rotation speed information, range position information, ATF oil temperature information, and the like are necessary information. The hybrid control module 81 has mode information of “HEV mode” and “EV mode”.

In step S02, it is determined whether there is a slip-in request following the reception of data in step S01 or the determination that there is no CL2 slip determination in step S07. If YES (if there is a slip-in request) The process proceeds to step S03, and if NO (no slip-in request), the process proceeds to the end.
Here, “slip-in request” is determined as “no slip-in request” when the vehicle speed exceeds the CL2 slip-in vehicle speed during deceleration, and “slip-in request” occurs when the vehicle speed falls below the CL2 slip-in vehicle speed. It is determined.
This `` CL2 slip-in vehicle speed '' is the vehicle speed before the gear rattle filling control ends when performing cooperative regeneration control → gear rattle filling control → CL2 slip-in control in order as the vehicle speed decreases when the brake is depressed in the coasting scene. Set to. The “slip-in vehicle speed” is set to a lower vehicle speed when decelerating in the “EV mode” accompanied by the coordinated regenerative control than when decelerating in the “HEV mode” accompanied by the coordinated regenerative control.

In step S03, following the determination that there is a slip-in request in step S02, the CL2 torque capacity command to the second clutch CL2 is decreased so as to decrease the hydraulic pressure of the second clutch CL2, and the process proceeds to step S04.
Here, the “CL2 torque capacity command” is reduced from a command to give a capacity higher than the motor torque so that the second clutch CL2 does not slip to a command lower than the motor torque to a capacity to slide the second clutch CL2.

In step S04, following the CL2 oil pressure reduction in step S03, the motor torque rising gradient (= CL2 open motor torque gradient) is switched according to the transmission input speed, vehicle speed, ATF oil temperature, etc., and the process proceeds to step S05.
Here, switching of the motor torque inclination during CL2 opening will be described with reference to FIGS.
As shown in FIG. 3, the motor torque gradient during CL2 release is the CL2 open motor torque gradient in which the torque rises slowly in the first half of the period from the start of control. Set the motor torque gradient while CL2 is open with a sharp torque rise.
That is, as the deceleration stop information indicating the transition from deceleration to stop, the transmission input rotation speed and the vehicle speed are used, and as shown in FIG. 3, the ascending gradient α1 is made constant in the first half region of the CL2 slip-in control. In the second half of the CL2 slip-in control, the gradient angle gradually increases as it approaches the stop (α2 → α3 → α4, α1 <α2 <α3 <α4). Then, as shown by the broken line characteristics in FIG. 3, the CL2 opening motor torque gradient in the second half of the slip-in control is changed to a CL2 opening motor torque gradient with a steeper gradient angle as the ATF oil temperature is lower.
Further, as shown in FIG. 4, the motor torque gradient during CL2 release is determined based on the transmission input speed and the ATF oil temperature (block B1), and the motor torque gradient during CL2 release is determined based on the vehicle speed and the ATF oil temperature (block B2). Then, the larger one of the two determined inclinations is selected as the final CL2 releasing motor torque inclination (block B3).

In step S05, following the switching of the motor torque rising gradient in step S04, the CL2 open motor torque is calculated based on the CL2 open motor torque slope determined in step S04 and the previous value of the motor torque value. The process proceeds to step S06.
Here, as shown in FIG. 5, the “CL2 open motor torque” is switched by four state determinations (EV D range, HEV D range, EV R range, HEV R range), and the final CL2 open motor Torque is calculated.
That is, it has a D range / R range determination block B4, an EV / HEV determination block B5, and a state determination block B6, and issues a switching command from the state determination block B6. In the motor torque calculation block B7, the motor torque during opening of the EV D range CL2 is calculated, and in the motor torque calculation block B8, the motor torque during opening of the HEV D range CL2 is calculated. Further, the motor torque calculation block B9 calculates the motor torque during the opening of the EV R range CL2, and the motor torque calculation block B10 calculates the motor torque during the opening of the HEV R range CL2. In the switching block B11, one of the motor torque calculation blocks B7 to B10 is selected based on the switching command from the state determination block B6, and the final CL2 opening motor torque is calculated.

  In step S06, following the CL2 opening motor torque calculation in step S05, a command for obtaining the CL2 opening motor torque calculated in step S05 is output to the inverter 26 via the motor controller 83, and the process proceeds to step S07.

In step S07, it is determined whether or not the slip determination of the second clutch CL2 has been made following the output of the motor torque during CL2 release in step S06. If YES (CL2 slip determination is present), the process proceeds to the end. If NO (CL2 slip determination is not present), the process returns to step S02.
Here, “CL2 slip determination” monitors the slip amount of the second clutch CL2, and determines that the CL2 slip determination is present when the slip amount is equal to or greater than the slip determination threshold.

Next, the operation will be described.
The operation of the control device for the FF hybrid vehicle of the first embodiment will be described separately for “CL2 slip-in control processing operation”, “CL2 slip-in control operation”, and “characteristic operation of CL2 slip-in control”.

[CL2 slip-in control processing action]
Hereinafter, the operation of the CL2 slip-in control process will be described based on the flowchart of FIG.

  At the time of deceleration, when the slip-in vehicle speed is reached due to a decrease in the vehicle speed, the flow proceeds to step S01 → step S02 → step S03 → step S04 → step S05 → step S06 → step S07 in the flowchart of FIG. Then, while it is determined in step S07 that there is no CL2 slip determination, the flow of step S02 → step S03 → step S04 → step S05 → step S06 → step S07 is repeated. If it is determined in step S07 that the CL2 slip determination is present, the process proceeds from step S07 to the end.

  That is, in step S02, it is determined whether or not there is a slip-in request. In the next step S03, the CL2 torque capacity command to the second clutch CL2 is lowered so as to lower the hydraulic pressure of the second clutch CL2. In the next step S04, the motor torque gradient during CL2 release, which is the rising gradient of the motor torque, is switched according to the transmission input rotation speed, the vehicle speed, the ATF oil temperature, and the like. In the next step S05, the CL2 open motor torque is calculated based on the CL2 open motor torque gradient determined in step S04 and the previous value of the motor torque value. In the next step S06, a command for obtaining the calculated CL2 opening motor torque is output to the inverter 26 via the motor controller 83.

  Therefore, in the first half of the CL2 slip-in control from the slip-in vehicle speed until the transmission input rotational speed (vehicle speed) decreases to the predetermined rotational speed (predetermined vehicle speed), as shown in FIG. The ascending gradient α1. In the second half of the CL2 slip-in control after the transmission input rotational speed (vehicle speed) has decreased to a predetermined rotational speed (predetermined vehicle speed), the gradient angles gradually increase as α2, α3, and α4 increase as the vehicle approaches the stop. .

[CL2 slip-in control action]
Hereinafter, the CL2 slip-in control action of Example 1 is referred to as “CL2 slip-in control action when decelerating in the driving scene (FIG. 6)”, “CL2 slip-in control action when depressing the brake in the coasting scene ( FIG. 7) ”.

(CL2 slip-in control action during deceleration in a driving scene)
FIG. 6 is a time chart when the CL2 slip-in control according to the first embodiment is performed at the time of deceleration in the drive travel scene.
In FIG. 6, time t1 is the CL2 slip-in control start time, time t2 is the CL2 slip start time, time t3 is the motor torque slope sudden rise start time, time t4 is the motor torque slope upward slope increase time, and time t5 is the CL2 slip. This is the in-control end time.

  For example, when the vehicle decelerates while slowly returning the accelerator depression amount at a signal stop or the like, the motor torque command remains constant until the CL2 slip-in control start time t1, and the CL2 torque capacity command decreases according to the accelerator return operation. Then, at time t1 when the CL2 slip-in vehicle speed is reached due to the decrease in the vehicle speed, CL2 slip-in control is started based on the slip-in request determination, and the CL2 torque capacity command is rapidly reduced. The motor torque command starts to rise with a gentle slope with a constant rising gradient α1 from time t1, and the rising gradient α1 is maintained until time t3.

  After that, when the second clutch CL2 in the engaged state exceeds the actual CL2 torque capacity decreased at the time t2, and the clutch plate is peeled off and starts to slip, the motor speed is increased after the time t2. Gradually decreases. Then, at time t3, when the motor torque gradient starts to rise sharply, the slip progress of the second clutch CL2 is prompted. Thereafter, when the motor torque gradient increases the rising gradient at time t4, the differential rotation of the second clutch CL2 becomes equal to or greater than the slip determination threshold at time t5, CL2 slip determination is made, and CL2 slip-in control ends. Therefore, after time t5, the second clutch CL2 is in a non-engaged state, and the motor rotation speed is increased to the target motor rotation speed by allowing the second clutch CL2 to perform differential rotation.

  As described above, during deceleration in the drive travel scene, the torque increase is made to be a gentle upward gradient in the first half region (time t1 to time t3) from the start of the CL2 slip-in control. For this reason, the sudden torque change is suppressed in the slip start region where the clutch plate of the engaged second clutch CL2 is peeled off. Then, when entering the second half of the CL2 slip-in control (time t3 to t5), the torque increase is made a steep increase gradient, so that the second clutch CL2 quickly shifts to the slip state, so that the engine speed is increased. Can be prevented from decreasing.

(CL2 slip-in control action when braking and decelerating in coastal driving scenes)
FIG. 7 is a comparative characteristic diagram showing an expansion effect of the cooperative regeneration control region by performing the CL2 slip-in control of the first embodiment at the time of brake depression in a coasting scene. The vehicle speed relationship is V1 <V2 <V3 <V4 <V5.

First, in the comparative example (the broken line characteristic in FIG. 7), when the CL2 slip-in control is started, the motor torque is set to a constant gradient due to a steep rising slope, and the second clutch CL2 is brought into the slip engagement state. When the brake is depressed and decelerated in a coastal driving scene, when performing cooperative regeneration control → gear backlash control → CL2 slip-in control in order as the vehicle speed decreases, CL2 slip-in control starts after the gear backlash control ends. And
In the case of this comparative example, the cooperative regeneration end vehicle speed V5 in which the coast driving force is switched from negative to positive is the cooperative regeneration control section, and the cooperative regeneration end vehicle speed V5 to the gear rattling control end vehicle speed V3 is the gear backlash control section. The CL2 slip-in control section is from the gear rattling control end vehicle speed V3 (= CL2 slip-in vehicle speed) to the CL2 slip determination vehicle speed V1.

On the other hand, in the first embodiment, when the CL2 slip-in control is started, the motor torque in the first half area is set to a rising gradient due to a gentle slope, and the motor torque in the second half area is set to a rising gradient due to a steep slope. When the vehicle is decelerated by accelerator-off / brake-on, the CL2 slip-in vehicle speed is set to the vehicle speed before the gear rattle-packing control ends when performing cooperative regeneration control → gear rattle-packing control → CL2 slip-in control as the vehicle speed decreases. doing.
Therefore, in the case of the first embodiment, the cooperative regeneration end vehicle speed V4 (<vehicle speed V5) where the coast driving force is switched from negative to positive is the cooperative regeneration control section, and the gear regeneration is from the cooperative regeneration end vehicle speed V4 to the CL2 slip-in vehicle speed V3. It becomes a filling control section. And the CL2 slip-in vehicle speed V3 to the first half-end end vehicle speed V2 is the combined section of the gear backlash control and CL2 slip-in control, and the first half-end end vehicle speed V2 to the CL2 slip determination vehicle speed V1 is the CL2 slip-in control section. Become.
As described above, when the brake is depressed and decelerated in the coasting scene, in the first embodiment, the motor torque is set to a rising gradient with a gentle slope in the first half of the CL2 slip-in control. The first half of the control shares part of the gear backlash control that prevents the gear backlash shock. Therefore, when the CL2 slip-in vehicle speed V3 is set to the same vehicle speed in the comparative example and the example 1, the cooperative regeneration end vehicle speed V5 (comparative example) decreases to the cooperative regeneration end vehicle speed V4 (example 1). The amount of regeneration is increased, and fuel efficiency is improved.
The “gear rattling shock” means that when the drive system transmission torque is switched from a negative torque to a positive torque, the differential gear 8 moves so as to eliminate the gear gap close to the negative torque side at once, and the tooth surface contact is reduced. This refers to the shock that occurs. When CL2 slip-in control is performed in a coasting scene, the drive system transmission torque is switched from negative torque to positive torque.

[Characteristic action of CL2 slip-in control]
In the first embodiment, during the CL2 slip-in control, the motor torque increase slope is set to a gentle increase gradient in the first half from the start of the control, and when entering the second half area, the torque increase is steeper than the increase gradient in the first half area. It was set as the structure which made an ascending gradient.
That is, the torque increase is gradually increased in the first half region from the start of the CL2 slip-in control, so that a sudden torque change is suppressed in the slip start region where the clutch plate of the engaged second clutch CL2 is peeled off. Then, when entering the latter half of the CL2 slip-in control, the torque rises to a steep gradient, and the second clutch CL2 quickly shifts to the slip state, thereby suppressing a decrease in the engine speed.
As a result, at the time of deceleration when the CL2 slip-in control of the second clutch CL2 is performed, both slip-in shock suppression and engine stall prevention can be achieved.

In the first embodiment, the transmission input rotational speed or the vehicle speed is used as deceleration stop information indicating a transition from deceleration to stop for switching the rising gradient of the motor torque. In the first half of the CL2 slip-in control, the ascending gradient α1 is constant, and in the second half, the ascending gradient (α2, α3, α4) is gradually increased as the vehicle approaches the stop.
That is, in the second half of the CL2 slip-in control, the slope angle gradually increases as the vehicle approaches the stop (α2, α3, α4), so that the CL2 slip determination zone is entered early after the second half is started. .
Therefore, even if the switching vehicle speed that enters the rising gradient (α2, α3, α4) in the second half of the CL2 slip-in control is set to the low speed side, engine stall is reliably prevented.

In the first embodiment, the transmission input rotational speed and the vehicle speed are used as the deceleration stop information, and a larger upward slope is selected from the upward slope determined by the transmission input rotational speed and the upward slope determined by the vehicle speed. did.
That is, the transmission input rotational speed becomes rotational speed information obtained by amplifying the vehicle speed (= transmission output rotational speed) based on the low speed ratio of the belt type continuously variable transmission 6. On the other hand, the vehicle speed (= transmission output rotational speed) becomes rotational speed information that immediately decreases when the left and right front wheels 10L, 10R, which are drive wheels, become brake-locked.
Therefore, accurate deceleration stop information can be obtained from the transmission input rotational speed when decelerating by brake non-operation, and decelerated stop information having good response can be obtained by vehicle speed when decelerating by brake operation.

In the first embodiment, the motor torque increase gradient in the second half of the CL2 slip-in control is configured to be steeper as the ATF oil temperature is lower.
That is, when the ATF oil temperature is low, the viscosity of the ATF hydraulic oil increases, and the decrease response of the actual CL2 torque capacity of the second clutch CL2 is delayed.
Therefore, when the ATF oil temperature is low, the response to the slip state of the second clutch CL2 is prevented by increasing the motor torque by a steep gradient angle.

In the first embodiment, when a transition is made in the order of cooperative regeneration control → gear backlash control → CL2 slip-in control in accordance with the decrease in vehicle speed, the slip-in vehicle speed is set to the vehicle speed before the end of the gear backlash control.
In other words, when the brake is depressed and decelerated in a coastal driving scene, the motor torque is increased by a gentle slope in the first half of the CL2 slip-in control, so that part of the gear backlash control that prevents gear backlash shock is shared. Is done. Then, the CL2 slip-in control is started before the gear rattle filling control is finished, so that the vehicle speed at which the cooperative regeneration control is finished is reduced as compared with the case where the gear rattle filling control is waited for.
Therefore, when the brake is depressed and decelerated in a coasting scene, the regeneration amount is increased and the fuel consumption is improved by reducing the vehicle speed that terminates the cooperative regeneration control while preventing a gear rattling shock.

In the first embodiment, the slip-in vehicle speed is set to a lower vehicle speed at the time of deceleration in the “EV mode” with cooperative regeneration control than at the time of deceleration in the “HEV mode” with cooperative regeneration control.
That is, when the “EV mode” in which the horizontally mounted engine 2 is stopped is selected, the engine is not stalled, so that the timing for releasing the second clutch CL2 can be made later than when the “HEV mode” is selected.
Therefore, when the vehicle is decelerated in the “EV mode” with cooperative regeneration control, the regeneration amount is further increased by reducing the slip-in vehicle speed.

Next, the effect will be described.
In the control apparatus for the FF hybrid vehicle of the first embodiment, the following effects can be obtained.

(1) The drive source has an engine (horizontal engine 2) and a motor (motor generator 4), and a friction clutch (second motor) is provided between the motor (motor generator 4) and the drive wheels (left and right front wheels 10R, 10L). In a hybrid vehicle (FF hybrid vehicle) having a drive system with a clutch CL2) interposed,
At the time of deceleration when the friction clutch (second clutch CL2) is released, when the slip-in vehicle speed is reached due to a decrease in vehicle speed, CL2 brings the friction clutch (second clutch CL2) into a slip engagement state due to a decrease in clutch torque capacity and an increase in motor torque. A controller (hybrid control module 81) for starting slip-in control is provided,
During the CL2 slip-in control, the controller (hybrid control module 81) sets the motor torque increase gradient to a gentle increase gradient in the first half from the start of control, and when entering the second half, the torque is higher than the increase gradient in the first half. Use a steep climb.
For this reason, at the time of deceleration in which CL2 slip-in control of the friction clutch (second clutch CL2) is performed, it is possible to achieve both suppression of slip-in shock and prevention of engine stall.

(2) The controller (hybrid control module 81) uses the deceleration stop information (transmission input rotation speed or vehicle speed) indicating the transition from deceleration to stop for switching the rising gradient of the motor torque, and performs CL2 slip-in control. In the first half region, the ascending gradient α1 is made constant, and in the second half region, the ascending gradient (α2, α3, α4) is gradually increased as the vehicle approaches the stop.
For this reason, in addition to the effect of (1), engine stall can be reliably prevented even when the switching vehicle speed that enters the rising gradient (α2, α3, α4) in the latter half of the CL2 slip-in control is set to the low speed side.

(3) A transmission (belt type continuously variable transmission 6) is provided between the motor (motor generator 4) and the drive wheels (left and right front wheels 10L, 10R).
The controller (hybrid control module 81) uses the transmission input rotation speed (transmission input rotation speed) and the vehicle speed as the deceleration stop information, and the ascending gradient determined by the transmission input rotation speed (transmission input rotation speed) and the vehicle speed. A larger ascending gradient is selected from the determined ascending gradients.
For this reason, in addition to the effect of (2), accurate deceleration stop information can be obtained from the transmission input rotation speed (transmission input rotation speed) at the time of deceleration by brake non-operation, and at the time of deceleration by brake operation, the vehicle speed Accordingly, it is possible to obtain deceleration stop information with good response.

(4) The friction clutch (second clutch CL2) is a hydraulic clutch that engages / releases hydraulically,
The controller (hybrid control module 81) makes the motor torque increase gradient in the latter half of the CL2 slip-in control a steeper angle as the clutch operating oil temperature (ATF oil temperature) is lower.
Therefore, in addition to the effects of (1) to (3), when the clutch operating oil temperature (ATF oil temperature) is low, slipping the friction clutch (second clutch CL2) by increasing the motor torque with a steep gradient angle Response delay to the state can be prevented.

(5) The controller (hybrid control module 81) changes the slip-in vehicle speed to the vehicle speed before ending the gear backlash control when transitioning from cooperative regeneration control to gear backlash control to CL2 slip-in control in order as the vehicle speed decreases. Set.
For this reason, in addition to the effects of (1) to (4), at the time of brake depression in a coasting scene, the regenerative amount is increased by reducing the vehicle speed that terminates cooperative regenerative control while preventing gear backlash shock and preventing fuel backlash. Improvements can be made.

(6) The hybrid vehicle (FF hybrid vehicle) drives “EV mode” using only the motor (motor generator 4) as the drive source, and drives the engine (horizontal engine 2) and motor (motor generator 4) as drive modes. "HEV mode" as a source,
The controller (hybrid control module 81) sets the slip-in vehicle speed to a lower vehicle speed when decelerating in the “EV mode” with cooperative regeneration control than when decelerating in the “HEV mode” with cooperative regeneration control.
For this reason, in addition to the effect of (5), when the vehicle is decelerated in the “EV mode” accompanied by the coordinated regenerative control, the slip-in vehicle speed can be reduced to further increase the regeneration amount.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the first embodiment, an example in which a belt type continuously variable transmission 6 in which a belt 6c is stretched between the primary pulley 6a and the secondary pulley 6b and the primary pulley pressure Ppri and the secondary pulley pressure Psec are used as the transmission hydraulic pressure is used as the transmission. . However, as an example of a transmission, an automatic transmission called step AT, an AMT that automatically shifts with a manual transmission structure, a DCT that has two clutches and that automatically shifts with a manual transmission structure, and the like may be used. good.

  In the first embodiment, the climb gradient α1 is made constant in the first half of the CL2 slip-in control, and the climb gradient (α2, α3, α4) in which the gradient angle gradually increases as the vehicle approaches the stop in the second half. However, it may be an example of a two-step gradient in which the first half region of the CL2 slip-in control has a gentle constant rising gradient and the second half region has a steep constant rising gradient. Further, the curve characteristic such as a quadratic function characteristic may be given from the first half to the second half of the CL2 slip-in control.

  In the first embodiment, the transmission input rotation speed and the vehicle speed are used as deceleration stop information, and a larger increase gradient is selected from the increase gradient determined by the transmission input rotation speed and the increase gradient determined by the vehicle speed. Indicated. However, an example of determining the ascending gradient using only the transmission input rotation speed as the deceleration stop information may be used, or an example of determining the ascending gradient using only the vehicle speed as the deceleration stop information. Further, vehicle deceleration information may be added to these pieces of information, and an ascending gradient may be determined so as to achieve slip transition earlier as the vehicle deceleration increases.

  In the first embodiment, an example in which the control device of the present invention is applied to an FF hybrid vehicle with a drive format of 1 motor and 2 clutches is shown. However, the control device of the present invention can also be applied to an FR hybrid vehicle or a hybrid vehicle other than the one motor / two clutch drive type. In short, the present invention can be applied to a hybrid vehicle having an engine and a motor as a drive source and having a drive system in which a friction clutch is interposed between the motor and drive wheels.

2 Horizontal engine (engine)
3 First clutch 4 Motor generator (motor)
5 Second clutch (friction clutch)
6 Belt type continuously variable transmission (transmission)
8 Differential gears 10L, 10R Left and right front wheels (drive wheels)
14 Main oil pump 81 Hybrid control module (controller)
82 Engine control module 83 Motor controller 84 CVT control unit 85 Brake control unit 86 Lithium battery controller

Claims (6)

In a hybrid vehicle having an engine and a motor as a drive source and having a drive system in which a friction clutch is interposed between the motor and the drive wheel,
At the time of deceleration for releasing the friction clutch, a controller is provided for starting slip-in control to bring the friction clutch into a slip engagement state by lowering the clutch torque capacity and increasing the motor torque when the slip-in vehicle speed is reached due to a decrease in vehicle speed.
During the slip-in control, the controller sets the increase gradient of the motor torque to a gentle increase gradient in the first half from the start of the control, and when entering the second half, the torque increase is steeper than the increase gradient in the first half. A control device for a hybrid vehicle, characterized by having an ascending slope. In the hybrid vehicle control device according to claim 1,
The controller uses deceleration stop information indicating a transition from deceleration to stop for switching the increase gradient of the motor torque, makes the increase gradient constant in the first half of the slip-in control, and the gradient angle becomes closer to the stop in the second half. A control apparatus for a hybrid vehicle, characterized in that the slope gradually increases. In the hybrid vehicle control device according to claim 2,
A transmission is provided between the motor and the drive wheel,
The controller uses a transmission input rotational speed and a vehicle speed as deceleration stop information, and selects a larger upward slope from an upward slope determined by the transmission input rotational speed and an upward slope determined by the vehicle speed. A hybrid vehicle control device. In the control apparatus of the hybrid vehicle as described in any one of Claim 1- Claim 3,
The friction clutch is a hydraulic clutch that engages / releases hydraulically,
The controller is configured to control the increase gradient of the motor torque in the second half of the slip-in control to a steeper gradient angle as the clutch hydraulic oil temperature is lower. In the control apparatus of the hybrid vehicle as described in any one of Claim 1- Claim 4,
The controller sets the slip-in vehicle speed to the vehicle speed before ending the gear rattling control when the controller sequentially changes from cooperative regeneration control to gear rattling control to slip-in control in accordance with a decrease in vehicle speed. Control device for hybrid vehicle. In the hybrid vehicle control device according to claim 5,
The hybrid vehicle has, as drive modes, an EV mode using only the motor as a drive source, and an HEV mode using the engine and the motor as a drive source,
The controller controls the hybrid vehicle, wherein the slip-in vehicle speed is set to a lower vehicle speed at the time of deceleration in the EV mode with cooperative regeneration control than at the time of deceleration in the HEV mode with cooperative regeneration control. apparatus.