JP5417926B2 - Mode switching control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a traveling mode switching control technique in a hybrid vehicle in which a traveling mode can be switched between an EV mode that travels with a driving force of only a motor and an HEV mode that travels by driving a motor and an engine.

As a conventional mode switching control device for a hybrid vehicle, a technique for switching a traveling mode based on an accelerator opening is known from Patent Document 1 and the like.
This prior art checks whether the accelerator opening speed ΔAPO is less than the set speed ΔAPOa (weak acceleration intention I) or whether the standard or strong acceleration intention II or III with ΔAPO ≧ ΔAPOa. In the case of weak acceleration intention I, the driving force control based on the control input accelerator opening cAPO having a small delay characteristic with respect to the actual accelerator opening APO is performed, and this control input accelerator opening cAPO is the basic set accelerator opening. It was checked whether it was less than APOa (accelerator operation form I-2) or above (accelerator operation form I-1). Further, in the case of the accelerator operation mode I-1, the vehicle is driven in the HEV mode by the mode switching control based on the comparison between the small control input accelerator opening cAPO and the set accelerator opening APOa. In the case of the accelerator operation mode I-2, The vehicle was traveling in the EV mode by mode switching based on a comparison between the small control input accelerator opening cAPO and the set accelerator opening APOa.

JP 2008-126901 A

  However, the conventional mode change control device for a hybrid vehicle only changes the accelerator opening characteristic, and when the vehicle is running in the HEV mode, the accelerator is returned to a vehicle state balanced with the driving load, and the accelerator opening becomes the engine start. There is a possibility that the vehicle will continue to run in the HEV mode when it stays within the hysteresis of the accelerator opening of the line and the engine stop line.

  The present invention has been made paying attention to the above problem, and an object thereof is to provide a mode switching control device for a hybrid vehicle that can increase the traveling frequency of the EV mode.

  To achieve the above object, the hybrid vehicle mode switching control apparatus of the present invention sets the HEV mode when the accelerator opening exceeds the engine start line, and sets the EV mode when the accelerator opening falls below the engine stop line. A mode switching control device for a hybrid vehicle including a travel mode control means, wherein the travel mode control means is configured such that the accelerator opening is between the engine start line and the engine stop line while traveling in the HEV mode. A hybrid vehicle mode switching control device that executes EV time transition processing for transitioning to the EV mode when the transition time set in advance exceeds a preset transition setting time. .

In the mode switching control device of the present invention, during the HEV mode, even if the accelerator opening is a value higher than the engine stop line, the transition set time is set in the hysteresis region between the engine start line and the engine stop line. When it has exceeded, it is made to shift to EV mode based on EV time transition processing.
Therefore, the hysteresis is set between the engine start line and the engine stop line to suppress the occurrence of control chattering, and the mode is shifted to the EV mode only when the accelerator opening is lower than the engine stop line. Compared with, the frequency of EV mode increases and fuel consumption can be reduced.

1 is an overall system diagram illustrating an FR hybrid vehicle (an example of a vehicle) by rear wheel drive to which a hybrid vehicle mode switching control device according to a first embodiment is applied. FIG. 3 is a control block diagram illustrating a calculation process executed by the integrated controller 10 according to the first embodiment. FIG. 2 is a characteristic diagram for explaining characteristics used to determine a target steady torque and a motor assist torque in the integrated controller 10 according to the first embodiment, where (a) is a target steady torque characteristic diagram, and (b) is a motor assist torque map. is there. FIG. 6 is a mode characteristic diagram illustrating an EV-HEV selection map used when mode selection processing is performed by the integrated controller 10 according to the first embodiment. It is a charge / discharge amount characteristic diagram showing a target charge / discharge amount map used when the battery charge control is performed by the target charge / discharge calculation unit 300 of the integrated controller 10 in the first embodiment. FIG. 5 is an engine output characteristic diagram used to calculate an output required to increase the engine torque to the best fuel consumption line in the target charge / discharge calculation unit 300 of the integrated controller 10 in the first embodiment. 3 is a flowchart showing a flow of processing until a command value executed by the integrated controller 10 according to the first embodiment is output. 3 is a flowchart showing a flow of a determination process for executing a start sequence executed by the integrated controller 10 according to the first embodiment. 3 is a flowchart illustrating a flow of determination processing for executing a stop sequence executed by the integrated controller 10 according to the first embodiment. 6 is a flowchart illustrating a flow of EV time transition permission flag determination processing according to the first embodiment. 6 is a time chart illustrating an operation example of a comparative example in a case where the EV time transition process of Example 1 is not executed. 3 is a time chart illustrating an example of an operation according to the first exemplary embodiment. It is a flowchart which shows the flow of EV time transfer permission flag determination processing in Example 2. 6 is a time chart illustrating an example of an operation according to the second embodiment. 14 is a flowchart illustrating a part of a determination process of an EV time transition permission flag according to the fourth embodiment. It is a flowchart which shows the remaining part of the flow of the determination process of the EV time transfer permission flag of Example 4. 10 is a time chart illustrating a first operation example of Embodiment 4. 10 is a time chart illustrating a second operation example of the fourth embodiment. 12 is a time chart illustrating a third operation example of the fourth embodiment. It is a flowchart which shows the principal part of the determination process of the EV time transfer permission flag of Example 5.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The mode switching control device for a hybrid vehicle according to an embodiment of the present invention can transmit a driving force to the driving wheels (RL, RR) side and a driving force to the motor (MG). An engine (Eng) provided in the engine, a clutch (CL1) which is interposed between the engine (Eng) and the motor (MG) and can change a transmission torque, and controls a transmission torque capacity of the clutch (CL1) Clutch torque control means (5) for controlling, motor control means (2) for controlling output torque of the motor (MG), accelerator opening degree detecting means (16) for detecting accelerator opening degree, and vehicle speed for detecting vehicle speed The vehicle travel mode is determined based on the detection means (17) and the accelerator opening, and when the accelerator opening exceeds an engine start line set in accordance with the vehicle speed, the And the rotation of the motor (MG) is transmitted to the engine (Eng), the engine (Eng) is started and the engine (Eng) and the motor (MG) are driven to travel. When the accelerator opening falls below an engine stop line set to a value lower than the engine start line, the clutch (CL1) is released and the engine (Eng) is stopped to stop the motor (MG). ) Driving mode control means (10) for driving only by driving the EV mode), and the traveling mode control means (10) is configured such that the accelerator opening is set to the engine while traveling in the HEV mode. When the preset transition set time is exceeded in the hysteresis area between the start line and the engine stop line, A mode changeover control device for a hybrid vehicle and executes the EV time migration process to migrate to the EV mode.

  A hybrid vehicle mode switching control apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

First, the configuration of the first embodiment will be described.
FIG. 1 is an overall system diagram illustrating a rear-wheel drive hybrid vehicle (an example of a hybrid vehicle) to which an engine start control device for a hybrid vehicle according to a first embodiment is applied. Based on this diagram, a drive system and a control system are illustrated. The structure of will be described.

(Configuration of drive system)
First, the configuration of the drive system will be described.
The drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a flywheel FW, a first clutch (clutch) CL1, a motor generator (motor) MG, a second clutch CL2, an automatic transmission AT, It has a propeller shaft PS, a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel (drive wheel) RL, and a right rear wheel (drive wheel) RR. Note that FL is the left front wheel and FR is the right front wheel.

  The engine Eng and the motor generator MG are provided as drive sources that apply drive force to the left and right rear wheels RL and RR as drive wheels, and are provided in series with the propeller shaft PS.

  The engine Eng is a gasoline engine or a diesel engine. Based on an engine control command from the engine controller 1, engine start control, engine stop control, throttle valve opening control, fuel cut control, and the like are performed. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine Eng and the motor generator MG, and is generated by the first clutch hydraulic unit 6 based on a first clutch control command from the first clutch controller 5. The first clutch control hydraulic pressure controls engagement / slip engagement (half-clutch state) / release. As the first clutch CL1, for example, a normally closed dry type in which a complete engagement is maintained by an urging force of a diaphragm spring and a stroke control using a hydraulic actuator 14 having a piston 14a is used to control from slip engagement to complete release. A single plate clutch is used.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and a three-phase alternating current generated by an inverter 3 is applied based on a control command from the motor controller 2. It is controlled by doing. The motor generator MG can operate as an electric motor that is driven to rotate by receiving electric power from the battery 4 (hereinafter, this operation state is referred to as “powering”), and the rotor rotates from the engine Eng or the driving wheel. When receiving energy, the battery 4 can be charged by functioning as a generator that generates electromotive force at both ends of the stator coil (hereinafter, this operation state is referred to as “regeneration”). The rotor of motor generator MG is connected to the transmission input shaft of automatic transmission AT via a damper.

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL, RR, and based on a second clutch control command from the AT controller 7, the second clutch hydraulic unit 8 The fastening / slip fastening / release is controlled by the control hydraulic pressure generated by the above. As the second clutch CL2, for example, a normally open wet multi-plate clutch or a wet multi-plate brake capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used. The first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are built in an AT hydraulic control valve unit CVU attached to the automatic transmission AT.

  The automatic transmission AT is, for example, a stepped transmission that automatically switches stepped speeds such as forward 7 speed / reverse 1 speed according to vehicle speed, accelerator opening, etc., and the second clutch CL2 However, it is not newly added as a dedicated clutch, but the most suitable clutch or brake arranged in the torque transmission path is selected from among a plurality of friction engagement elements that are engaged at each gear stage of the automatic transmission AT. . The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR.

  The hybrid drive system of the first embodiment includes an electric vehicle travel mode (hereinafter referred to as “EV mode”), a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), and a drive torque control travel mode (hereinafter referred to as “ It has a travel mode such as “WSC mode”.

  The “EV mode” is a mode in which the first clutch CL1 is disengaged and the vehicle travels only with the power of the motor generator MG. The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle travels in any of the motor assist travel mode, travel power generation mode, and engine travel mode. The “WSC mode” is the second by controlling the rotation speed of the motor generator MG at the time of P, N → D select start from the “HEV mode”, or at the start of the D range from the “EV mode” or “HEV mode”. In this mode, the clutch CL2 is maintained in the slip engagement state, and the clutch transmission torque that passes through the second clutch CL2 starts while controlling the clutch torque capacity so that the required driving torque is determined according to the vehicle state and the driver operation. . “WSC” is an abbreviation for “Wet Start Clutch”.

(Control system configuration)
Next, the control system of the hybrid vehicle will be described.
As shown in FIG. 1, the control system of the FR hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller (motor control means) 2, an inverter 3, a battery 4, and a first clutch controller (clutch torque control). Means) 5, first clutch hydraulic unit 6, AT controller 7, second clutch hydraulic unit 8, brake controller 9, and integrated controller 10 (travel mode control means). . The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, and the integrated controller 10 are connected via a CAN communication line 11 that can mutually exchange information. ing.

  The engine controller 1 inputs engine speed information from the engine speed sensor 12, a target engine torque (tTe) command from the integrated controller 10, and other necessary information. Then, a command for controlling the engine operating point (Ne, Te) is output to the throttle valve actuator or the like of the engine Eng.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor generator MG, a target motor torque command and a target motor rotational speed command from the integrated controller 10, and other necessary information. Then, a command (tNm, tTm) for controlling the motor operating point (Nm, Tm) of motor generator MG is output to inverter 3. The motor controller 2 monitors the battery charge / discharge amount SOC indicating the charge capacity of the battery 4, and this battery charge / discharge amount SOC information is used for control information of the motor generator MG and is connected to the CAN communication line 11. To the integrated controller 10.

  The first clutch controller 5 includes sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, a target first clutch torque capacity command from the integrated controller 10, and other necessary information. Enter. Then, a command for controlling engagement / slip engagement / release of the first clutch CL1 is output to the first clutch hydraulic unit 6 in the AT hydraulic control valve unit CVU.

  The AT controller 7 includes information from an accelerator opening sensor (accelerator opening detecting means) 16, a vehicle speed sensor (vehicle speed detecting means) 17, and other sensors 18 (transmission input rotation speed sensor, inhibitor switch, etc.). Enter. Then, when traveling with the D range selected, a control command for retrieving the optimum gear position by searching for the position where the operating point determined by the accelerator opening APO and the vehicle speed VSP exists on the shift map is obtained. Output to AT hydraulic control valve unit CVU. The shift map is a map in which an upshift line and a downshift line are written according to the accelerator opening APO and the vehicle speed VSP. In addition to the automatic shift control, when a target second clutch torque capacity command is input from the integrated controller 10, a command for controlling the slip engagement of the second clutch CL2 is sent to the second clutch hydraulic unit 8 in the AT hydraulic control valve unit CVU. 2nd clutch control which outputs to is performed.

  The brake controller 9 inputs a wheel speed sensor 19 for detecting the wheel speeds of the four wheels, sensor information from the brake stroke sensor 20, a regenerative cooperative control command from the integrated controller 10, and other necessary information. And, for example, at the time of brake depression, if the regenerative braking force is insufficient for the required braking force obtained from the brake stroke BS, the shortage is compensated by the mechanical braking force (hydraulic braking force or motor braking force) Perform regenerative cooperative brake control.

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The motor rotation number sensor 21 for detecting the motor rotation number Nm and other sensors / switches 22 are used. Necessary information and information via the CAN communication line 11 are input. Then, a target engine torque (tTe) command to the engine controller 1, a target motor torque (tTm) command and a target motor rotational speed (tNm) command to the motor controller 2, and a target first clutch torque capacity (tTc1) to the first clutch controller 5 The command, the target second clutch torque capacity (tTc2) command to the AT controller 7 and the regeneration cooperative control command to the brake controller 9 are output.

(Calculation processing executed by the integrated controller 10)
FIG. 2 is a control block diagram illustrating arithmetic processing executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. FIG. 3 is a characteristic diagram used for determining the target steady torque and the motor assist torque by the integrated controller 10. FIG. 4 is a diagram showing an EV-HEV selection map used when mode selection processing is performed in the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. FIG. 5 is a diagram illustrating a target charge / discharge amount map used when battery charge control is performed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. Hereinafter, based on FIGS. 2-5, the arithmetic processing performed in the integrated controller 10 of Example 1 is demonstrated.

  As shown in FIG. 2, the integrated controller 10 includes a target drive torque calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, an operating point command unit 400, and a shift control unit 500.

  The target drive torque calculation unit 100 calculates the target steady drive torque and the motor assist torque from the accelerator opening APO and the vehicle speed VSP using the target steady drive torque map and the motor assist torque map shown in FIG.

  The operation mode (HEV traveling, EV traveling) is calculated using the mode selection unit 200 and the engine start / stop line map shown in FIG. However, if the battery charge / discharge amount SOC is equal to or less than the predetermined value, the “HEV mode” is forcibly set as the target travel mode. Further, at the time of P, N → D select start from the “HEV mode”, the “WSC mode” is selected as the target travel mode until the vehicle speed VSP becomes the first set vehicle speed VSP1.

  The target charge / discharge calculation unit 300 calculates the target charge / discharge power tP from the battery charge / discharge amount SOC using the running power generation request output map shown in FIG. Further, an output necessary for increasing the engine torque from the current operating point to the best fuel consumption line shown in FIG. 6 is calculated, and an output smaller than the target charge / discharge power tP is added to the engine output as a required output. .

  The operating point command unit 400 uses the accelerator opening APO, the target steady torque and the motor assist torque, the target mode, the vehicle speed VSP, and the target charge / discharge power tP as a target for reaching the operating point. The engine torque tTe, the target motor torque tTm, the target second clutch torque capacity tTc2, the target gear ratio, and the target first clutch torque capacity tTc1 (first clutch solenoid current command) are calculated. Then, the operating point command unit outputs a signal for commanding each target value to each of the controllers 1, 2, 5, 7 via the CAN communication line 11.

  The shift control unit 500 outputs a command value for driving and controlling the solenoid valve in the automatic transmission AT so as to achieve these from the target second clutch torque capacity tTc2 and the target gear ratio.

(Processing flow in the integrated controller 10)
Next, the flow of processing executed by the integrated controller 10 of the first embodiment will be described based on the flowchart of FIG.
First, in step S1, a steady target drive torque tFo0 is calculated from the accelerator opening APO and the vehicle speed VSP using a preset target drive torque map, and the process proceeds to the next step S2.

  In step S2, the target shift speed SHIFT is calculated from the accelerator opening APO and the vehicle speed VSP based on a preset shift map, and the process proceeds to the next step S3.

  In step S3, a target operation mode (EV mode, HEV mode, WSC mode) is determined from the accelerator opening APO and the vehicle speed VSP using a preset target operation mode region map (see FIG. 3). The process proceeds to step S4. In step S3, as shown in FIG. 3, normally, the HEV mode is set at a high load (large accelerator opening) and a high vehicle speed, and the EV mode is set at a low load and a low vehicle speed.

In step S4, an operation mode transition calculation is performed by comparing the current operation mode with the target operation mode, and the process proceeds to the next step S5.
In step S4, if the current operation mode matches the target operation mode, the current operation mode is maintained. Further, if the current operation mode is the EV mode and the target operation mode is the HEV mode, a command to switch the mode from the EV mode to the HEV mode is issued. On the other hand, if the current operation mode is the HEV mode and the target operation mode is the EV mode, the mode switching from the HEV mode to the EV mode is instructed.

  In step S5, a transient target drive torque tFo required to shift from the current drive force to the target drive torque tFo0 obtained in step S1 with a response having a predetermined seasoning is calculated, and the process proceeds to step S6. In the calculation of step S5, for example, an output obtained by passing the target drive torque tFo0 through a low-pass filter having a predetermined time constant can be set as the transient target drive torque tFo.

In step S6, the target engine torque tTe required to achieve the transient target drive torque tFo is obtained in cooperation with the motor generator MG or alone, and the process proceeds to step S7.
The target engine torque tTe depends on the operation mode (EV mode, HEV mode) and mode switching, the transient target drive torque tFo, the tire effective radius Rt of the left and right rear wheels RL and RR, and the final gear ratio if. From the gear ratio iG of the automatic transmission AT determined by the currently selected shift speed, the input rotational speed Ni of the automatic transmission AT, the engine rotational speed Ne, and the target charge / discharge power tP corresponding to the battery charge / discharge amount SOC Ask.

  In step S7, the target first clutch torque capacity tTc1 and the target second clutch necessary for achieving the transient target drive torque tFo or necessary for executing the mode transition according to the operation mode and the mode transition. The torque capacity tTc2 is calculated, and the process proceeds to the next step S8.

  In step S8, the target motor torque tTm necessary for achieving the transient target drive torque tFo, or the target motor rotation speed tNm as required, is obtained in cooperation with the engine Eng or alone, and the process proceeds to the next step S9. move on. Note that the target motor torque tTm depends on the transient target drive torque tFo, the effective tire radius Rt of the left and right rear wheels RL and RR, the final gear ratio if, and the currently selected shift speed, depending on the operation mode and mode switching. It is determined from the determined gear ratio iG of the automatic transmission AT, the input rotational speed Ni of the automatic transmission AT, the engine rotational speed Ne, and the target charge / discharge power tP according to the battery charge / discharge amount SOC. Further, the target motor rotation speed tNm is calculated in place of the target motor torque tTm at the time of engine start described later.

  In step S9, the command values for achieving the target gear stage SHIFT, the operation mode holding or switching command, the target engine torque tTe, the both clutch torque capacities tTc1 and tTc2, the target motor torque tTm, and the target motor rotation speed tNm are obtained. , 2, 5 and 7.

(Start sequence and stop sequence)
In the integrated controller 10 of the first embodiment, a start sequence and a stop sequence for controlling start and stop of the engine Eng are executed in accordance with the processing by the operation mode transition calculation in step S4.

  The start sequence is a sequence for shifting to the HEV mode when the accelerator opening APO exceeds the engine start line shown in FIG. 4 in the EV mode. Specifically, first, the target second clutch torque capacity tTc2 is controlled so as to cause the second clutch CL2 to slip into the half-clutch state, and then, after determining that the second clutch CL2 has started to slip, the first clutch CL1 Start the conclusion of. When the first clutch CL1 is engaged and the motor rotation is transmitted to the engine Eng and the engine rotation speed Ne reaches a rotation speed at which the initial explosion is possible, the engine Eng is started, and the motor rotation speed Nm and the engine rotation speed Ne are started. The first clutch CL1 is completely engaged, and then the second clutch CL2 is locked up to shift to the HEV mode.

  The stop sequence is a sequence for transitioning to the EV mode when the accelerator opening APO falls below the engine stop line shown in FIG. 4 in the HEV mode. Specifically, first, the target first clutch torque capacity tTc1 is controlled to release the first clutch CL1, and at the same time, the engine torque Te is decreased to 0 and the motor torque Tm is increased. Thereafter, when the difference between the motor rotation speed Nm and the engine rotation speed Ne is sufficiently generated, the engine Eng is fuel-cut and stopped to shift to the EV mode.

Next, the flow of the start sequence execution start and stop determination process and the stop sequence execution start and stop determination process described above will be described with reference to the flowcharts of FIGS.
(Start sequence start / stop judgment)
The flow of processing for determining the start and stop of the start sequence will be described based on the flowchart of FIG.
In step S101, it is determined whether or not the current travel mode is the EV mode. If the current mode is the EV mode, the process proceeds to step S102. If not, the one-time process is terminated.

  In step S102, it is determined whether or not the accelerator opening APO exceeds the engine start line. If the accelerator opening APO exceeds the engine start line, the process proceeds to step S103 to shift to the HEV mode, and if the accelerator opening APO does not exceed the engine start line, EV. In order to maintain the mode, one process is terminated.

In step S103, it is determined that the engine is requested to start, and the process proceeds to the next step S104.
In step S104, an engine start sequence is started, and the process proceeds to next step S105.
In step S105, the start cancellation timer starts counting, and the process proceeds to the next step S106.

  In step S106, it is determined whether or not the count of the start stop timer is less than the start stop set time testartth. If it is less than the start stop set time teststatth, the process proceeds to step S107, and if the start stop set time testartth is exceeded, step S111 is performed. Proceed to Note that the start stop set time testartth is slightly shorter than the time required for the first clutch CL1 to start torque transmission and to increase the engine speed Ne to the startable speed after starting the engine start sequence. Set to time.

  In step S107, it is determined whether or not the accelerator opening APO has fallen below the engine stop line. If the accelerator opening APO has fallen below, the process proceeds to step S108 to stop the start, and if not, the process proceeds to step S111.

In step S108, a start sequence cancel request is output, and the process proceeds to the next step S109.
In step S109, it is determined whether or not the start sequence cancel process has been completed. If completed, the process proceeds to step S110, where the start stop timer is reset to zero. If the start sequence cancel process has not been completed, one process is terminated.

In step S111 that proceeds during the measurement of the timer, the start sequence is continued, and the process proceeds to the next step S112.
In step S112, it is determined whether or not the start of the engine Eng is completed. When the start is completed, the process proceeds to step S113, the start stop timer is reset to 0, one process is ended, and the start is not completed. One process is completed.

(Stop sequence start / stop determination)
Next, the flow of processing for determining the start and stop of the stop sequence will be described based on the flowchart of FIG.
First, in step S201, it is determined whether or not the current travel mode is the HEV mode. If the current travel mode is the HEV mode, the process proceeds to step S202. If the current travel mode is not the HEV mode, one process is terminated.

  In step S202, it is determined whether or not the accelerator opening APO is below the engine stop line. If the accelerator opening APO is below, the process proceeds to step S203, and if not, the process proceeds to step S214.

In step S203, it determines with an engine stop request | requirement, and progresses to the following step S204.
In step S204, the engine stop sequence described above is started, and the process proceeds to next step S205.
In step S205, the stop cancellation timer starts counting, and the process proceeds to the next step S206.

  In step S206, it is determined whether or not the count of the stop cancellation timer is less than the stop cancellation set time testth. If it is less than the stop stop set time testth, the process proceeds to step S207. The process proceeds to S211. The stop cancellation set time testtop is set to a time slightly shorter than the time required from the start of the engine stop sequence until the engine Eng actually stops.

In step S207, it is determined whether or not the accelerator opening APO exceeds the engine stop line. If the accelerator opening APO exceeds the engine stop line, the process proceeds to step S208.
In step S208, it is determined as a stop sequence cancel request, and the process proceeds to step S209 to determine whether or not the stop sequence cancel process is completed. If the stop sequence cancel process is completed, the process proceeds to step S210 and the stop sequence cancel process is performed. If not completed, one process is terminated.
In step S210, the stop cancellation timer is reset to 0, and one process is terminated.

  In step S206, the stop sequence process is continued in step S211, which proceeds when the count of the timer exceeds the stop set time tset2, and the process proceeds to step S212.

In step S212, it is determined whether or not the disengagement of the first clutch CL1 is finished. If the disengagement is finished, the process proceeds to step S213.
In step S213, the count of the stop cancellation timer is reset to 0, and when the engine stop line is raised in step S215, which will be described later, a return process for returning the engine stop line to the original position is performed and one process is performed. Exit.
The engine stop line return process may be executed in step S113 after the transition to the HEV mode described with reference to FIG. 8 is completed.

In step S214 that proceeds when NO is determined in step S202, it is determined whether or not the EV time transition permission flag Fev = 1, the process proceeds to step S215 if Fev = 1, and once if Fev ≠ 1. Terminate the process. The EV time transition permission flag Fev permits the engine Eng to stop and shift from the HEV mode to the EV mode if the preset condition is satisfied even when the accelerator opening APO is larger than the engine stop line. Details of the flag will be described later.
In the next step S215, while the EV time transition permission flag Fev = 1, the process of raising the engine stop line to just before the engine start line (for example, before 1 seg) is performed, and then one process is finished. To do.

(Set EV time transition permission flag Fev)
Next, the EV time shift permission flag Fev setting process will be described with reference to the flowchart of FIG.
This EV time transition permission flag Fev is used to permit the transition to the EV mode even when the accelerator opening APO exceeds the engine stop line. As described above, the EV time transition permission flag Fev With this setting, the engine stop line is raised to just before the engine start line, so that the EV mode is entered.

  The EV time shift permission flag Fev is determined when the accelerator opening APO is lower than the engine start line in the HEV mode, and is executed every preset control cycle.

  First, in step S301, the EV time transition permission flag Fev, the EV time transition permission timer flag Ftim, and the EV time transition permission SOC flag Fsoc are set to 0, respectively, and the process proceeds to step S302.

  In step S302, it is determined whether or not the accelerator opening APO exists in a hysteresis region that is a region between the engine stop line and the engine start line. If the accelerator opening APO exists in this hysteresis region, step S303 is performed. If it does not exist in this hysteresis region, one process is terminated.

In step S303, counting of the EV time transition permission timer tkyoka is started, and the process proceeds to step S304.
In step S304, it is determined whether or not the count of the EV time transition permission timer tkyoka has exceeded a preset first transition setting time tth1, and if it exceeds the first transition setting time tth1, the process proceeds to step S305 and does not exceed it. In this case, one process is finished.
In step S305, the EV time transition permission timer flag Ftim is set to 1, and the process proceeds to the next step S306. The first transition set time tth1 is a length of time (about 2 to 3 seconds) in which the accelerator opening APO stays in the above-described region and the driver can be regarded as neither accelerating nor stopping. Is set to several seconds).

In step S306, it is determined whether or not the battery charge / discharge amount SOC is greater than or equal to a preset SOC threshold SOCth. If greater than or equal to the SOC threshold SOCth, the process proceeds to step S307. If less than the SOC threshold SOCth, one process is performed. finish.
In step S307, the EV time transition permission SOC flag Fsoc is set to 1.
Note that the SOC threshold SOCth is set to a battery charge / discharge amount SOC that can output an output possible upper limit value of the battery 4 and does not enter the forced charge mode when traveling in the EV mode.

  In step S308, it is determined whether or not both the EV time transition permission timer flag Ftim and the EV time transition permission SOC flag Fsoc are set to 1. If both are set to 1, the process proceeds to step S309 and either or either of them is set. If one is not set to 1, one process is terminated.

  Therefore, the accelerator opening APO remains between the engine stop line and the engine start line for exceeding the first transition set time tth1, and the battery charge / discharge amount SOC is a value sufficient to travel in the EV mode. In this case, the EV time transition permission flag Fev is set to 1. In this case, the engine stop line is raised to the position of the engine start line by the process of steps S214 → S215 described above.

(Operation of Example 1)
Next, the operation of the first embodiment will be described.
In describing the operation of the first embodiment, first, the operation of the comparative example when the EV time transition process of the first embodiment is not executed will be described based on the time chart of FIG.

  FIG. 11 shows that after depressing the accelerator and accelerating, the vehicle state reaches a desired vehicle speed VSP, and further, the accelerator is loosened in a stable state balanced with the traveling load. A state in which the opening degree is within a hysteresis region between the start line and the engine stop line is shown.

  In such a running state, at time t01, when the accelerator opening APO exceeds the engine start line, the HEV mode is determined, the start sequence is executed, and the engine is started.

  Thereafter, at time t02, the accelerator opening APO falls below the engine start line, but hysteresis is set between the engine stop line and the HEV mode is maintained. Thus, even if the vehicle is in a stable state and the accelerator is loosened, the EV mode is not entered unless the accelerator opening APO is below the engine stop line.

  Therefore, in such a case, if the driver wants to shift to the EV mode, it is necessary to loosen the accelerator. In the illustrated example, the accelerator is loosened from the time t03, and the EV mode is transitioned to the time t04 when the accelerator opening APO falls below the engine stop line. In this case, since the accelerator is loosened, the vehicle speed VSP may decrease, and the driver's intention may not be met.

FIG. 12 shows an operation example of the first embodiment under the same traveling conditions as the comparative example of FIG.
Similarly to the comparative example of FIG. 11, in the operation example of FIG. 12, after depressing the accelerator and accelerating, the vehicle state becomes a stable state balanced with the traveling load, the accelerator is loosened, and the accelerator opening APO becomes the engine start line. It shows a state in which the opening is within a hysteresis region between the engine stop line and the engine stop line.

  In this case, since the accelerator opening APO exceeds the engine start line at time t11, the engine Eng is started and the engine start sequence is started based on the processing of steps S102 → S103. In the case of this example, the accelerator opening APO does not immediately fall below the engine start line, and the start sequence is continued, and the engine Eng is started at time t12.

Thereafter, at time t13, the accelerator opening APO becomes a value in the hysteresis region between the engine stop line and the engine start line, and therefore, EV time transition permission flag determination processing in steps S301 to S309 is executed. In this EV time transition permission flag, when the elapsed time after the accelerator opening APO falls below the engine start line and stays between the engine stop line exceeds the first transition set time tth1, the EV time transition permission timer The flag Ftim is set to 1. The EV time transition permission SOC flag Fsoc is also set to 1 because it exceeds the SOC threshold SOCth. Therefore, the EV time transition permission flag Fev is set to 1 from time t14, and the engine stop sequence is executed.
Therefore, after passing through the WSC mode in which the second clutch CL2 is slipped, the mode is shifted to the EV mode at time t15.

  As described above, in the first embodiment, even if the accelerator opening APO is not below the engine stop line, it is determined that the driver does not intend to accelerate, and the battery charge / discharge amount SOC can be shifted to the EV mode. If it is a value, the EV mode is entered. Thus, compared to the comparative example, the frequency of traveling in the EV mode can be increased, which is advantageous for fuel consumption.

  In addition, when performing the determination to the EV mode, the EV transition set time is counted up, and when the accelerator opening APO does not exceed the engine start line during the count, the EV mode is shifted. Therefore, frequent mode transitions can be performed to prevent the driver from feeling uncomfortable, such as lack of acceleration.

(Effect of Example 1)
In the first embodiment described above, the effects listed below can be obtained. A) The accelerator opening APO remains in the hysteresis region between the engine start line and the engine stop line when traveling in the HEV mode. In this case, if a predetermined condition is satisfied, the EV time shift permission flag Fev is set to shift to the EV mode. For this reason, hysteresis is set between the engine start line and the engine stop line to suppress frequent mode transitions between the EV mode and the HEV mode, and the driver feels uncomfortable due to frequent mode transitions. While avoiding this, it is possible to increase the frequency of traveling in the EV mode and perform traveling that is advantageous in terms of fuel consumption.

b) As a predetermined condition in the above a), the accelerator opening APO is between the engine start line and the engine stop line until the count value of the EV time transition permission timer tkyoka exceeds the first transition set time tth1. It was assumed that it remained in a certain hysteresis region.
Accordingly, hunting occurs in the HEV mode and the EV mode even when the driver depresses the accelerator after the accelerator opening APO stays in the hysteresis region between the engine start line and the engine stop line for a short time. Can be suppressed.

c) As a predetermined condition in the above a), the battery charge / discharge amount SOC exceeds the SOC threshold SOCth. The SOC threshold SOCth is set to the battery charge / discharge amount SOC that can output the upper limit of the output of the battery 4 and that does not enter the forced charge mode when the vehicle travels in the EV mode.
Therefore, when the engine stop line is raised to shift to the EV mode, immediately after that, the battery charge / discharge amount is insufficient and the shift to the HEV mode can be suppressed, and the occurrence of control hunting can be prevented.

d) After running in the HEV mode, including an increase in the engine stop line based on the setting of the EV time transition permission flag Fev in a) above, after the accelerator opening APO is below the engine stop line and the engine stop sequence is started However, the engine stop sequence is canceled if the accelerator opening APO exceeds the engine start line within a predetermined time.
Therefore, it is possible to prevent hunting from occurring between the HEV mode and the EV mode when the driver depresses the accelerator.

e) The engine stop line raised in step S215 is restored to the original state when the transition to the EV mode is completed (step S213).
As described above, since the previous EV time transition permission condition has been cleared, the next time the accelerator opening falls below the engine start line and stays within the hysteresis region, the engine start line and the engine stop line are correctly Hysteresis can be set between them.

(Other examples)
Other embodiments will be described below. Since these other embodiments are modifications of the first embodiment, only the differences will be described, and the configuration common to the first embodiment or the other embodiments will be described. The description is omitted by giving a common reference numeral.

The second embodiment is a modification of the first embodiment, and the setting condition of the EV time transition permission flag Fev is different from the first embodiment.
In the second embodiment, as a condition for setting the EV time transition permission flag Fev, the accelerator opening speed ΔAPO, which is a change angle per time of the accelerator opening APO, is negative (opening speed threshold ΔAPOth = 0 deg / sec). Added.

That is, as shown in the flowchart of FIG. 13, in step S401, in addition to the flags Ftim and Fsoc in step S301 of the first embodiment, the EV time transition permission APO flag Fapo is set to 0.
Then, in step S402 following step S307, it is determined whether or not the accelerator opening speed ΔAPO is negative. If negative, the process proceeds to step S403.

In the next step S403, the EV time transition permission APO flag Fapo is set to 1, and the process proceeds to the next step S404.
In step S404, it is determined whether or not all of the EV time transition permission timer flag Ftim, the EV time transition permission SOC flag Fsoc, and the EV time transition permission APO flag Fapo are set to 1, and when all of these are set. In step S309, the EV time shift permission flag Fev is set to 1.

(Operation of Example 2)
The operation of the second embodiment will be described based on the time chart of FIG.
The operation from time t11 to time t13 is the same as that in the first embodiment.
The EV time transition permission timer flag Ftim is set to 1 at time t14 when the elapsed time after the accelerator opening APO falls below the engine start line and stays in the hysteresis region exceeds the first transition set time tth1. However, since the accelerator opening speed ΔAPO is positive at this time, the EV time transition permission APO flag Fapo = 0, and at this time, the EV time transition permission APO flag Fapo is not set.

  Thereafter, at time t15 when the accelerator opening speed ΔAPO becomes negative and the probability that the driver performs the operation of depressing the accelerator becomes low, all the flags Ftim, Fsoc, and Fapo are set to 1, and at that time, the engine is stopped. Since the line is raised to the height of the engine start line and the accelerator opening APO is below the engine stop line, the engine stop sequence is executed and the EV mode is entered.

(Effect of Example 2)
In the second embodiment, the accelerator opening speed ΔAPO is negative as a condition for setting the EV time transition permission flag Fev and shifting to the EV mode.
Accordingly, since the accelerator opening APO is shifted to the EV mode from the hysteresis region where the accelerator opening APO is between the engine start line and the engine stop line, the EV mode is shifted to the EV mode. It is possible to further suppress the deterioration of drivability and response caused by hunting between the two.

  The third embodiment is a modification of the second embodiment. In the third embodiment, the first transition set time tth1 and the EV time transition permission APO flag Fapo, which are threshold values for determining the set of the EV time transition permission timer tkyoka, are set. The opening speed threshold value ΔAPOth for determination is variable.

That is, in the third embodiment, the first transition set time tth1 and the opening speed threshold ΔAPOth are changed according to the traveling state.
Thus, in the third embodiment, the integrated controller 10 is connected to a traveling state detection unit (not shown) so that it can be determined whether the traveling state is a normal traveling state or an active traveling state. The active running state is a state in which the accelerator ON / OFF switching frequency, the accelerator opening / closing speed, and the vehicle speed are high. For example, when driving on a winding road where there are many changes in curves, uphills and downhills, For example, the transmission mode of the transmission AT is switched from “normal” to “sports”.

  When the traveling state detecting means determines that the active traveling state is present, the first transition set time tth1 is changed to a longer value and the opening speed threshold ΔAPOth is changed to a larger value than when the normal traveling state is determined.

  As an example, the first transition set time tth1 is set to tth1 = 4 sec during normal driving, and tth1 == 8 sec during active driving. Further, the opening speed threshold value ΔAPOth is set to ΔAPOth = −20 ° during normal driving, and ΔAPOth = −10 ° in the active driving state.

(Operation of Example 3)
In the third embodiment, in the active running state, the first transition set time tth1 is increased and the opening speed threshold value ΔAPOth is increased as compared with the normal running state, so that the EV time transition permission timer flag Ftim and the EV time transition permission. It becomes difficult to set the APO flag Fapo.

(Effect of Example 3)
Therefore, in the normal driving state, as in the first and second embodiments described above, when the driving frequency of the EV mode is increased to improve fuel efficiency, but the driver is actively driving, Compared to the driving state, when the accelerator opening APO remains in the hysteresis region, the frequency of transition from the HEV mode to the EV mode is reduced, driving performance and response are deteriorated, and the driver feels uncomfortable. Giving can be suppressed.

  The fourth embodiment is an example in which a first engine stop line and a second engine stop line (see FIG. 17) having a lower value are set as the engine stop line. Therefore, in the fourth embodiment, as the hysteresis region between the engine start line and the engine stop line, the basic hysteresis region between the first engine stop line and the engine start line, the first engine stop line, and the second engine It is assumed that there is an erroneous stop prevention area between the stop line and the stop line.

The flow of the EV time shift permission flag determination process according to the fourth embodiment will be described below based on the flowcharts of FIGS. 15 and 16.
In step S501, the EV time transition permission flag Fev = 0, the EV time transition permission timer flag Ftim = 0, the EV time transition permission SOC flag Fsoc = 1, and the EV time transition permission APO flag Fapo = 0 are reset, and the process proceeds to step S502. .

  In step S502, it is determined whether or not the accelerator opening APO exists in the basic hysteresis region between the engine start line and the first engine stop line. If the accelerator opening APO exists in this basic hysteresis region, the process proceeds to step S503. If it does not exist in the basic hysteresis region, the process proceeds to step S510.

In step S503, the second EV time transition permission timer tkoka2 is reset, and the process proceeds to step S504.
In step S504, the first EV time transition permission timer tkoka1 starts counting up, and the process proceeds to step S505.
The first EV time transition permission timer tkoka1 is a timer that counts the time during which the accelerator opening APO remains in the basic hysteresis region, and the second EV time transition permission timer tkoka2 is the time during which the accelerator opening remains in the erroneous stop prevention region. It is a timer to count.

  In step S505, when the count value of the first EV time transition permission timer tkoka1 exceeds the preset first transition setting time tth1, the EV time transition permission timer flag Ftim = 1 is set, and the process proceeds to step S506. .

  In step S506, when the battery charge / discharge amount SOC is equal to or greater than the SOC threshold SOCth, the EV time transition permission SOC flag Fsoc = 1 is set, and the process proceeds to step S507. In step S507, when the accelerator opening speed ΔAPO is equal to or less than 0 deg / sec which is the opening speed threshold value ΔAPOth, the EV time transition permission APO flag Fapo = 1 is set, and the process proceeds to step S508.

In step S508, it is determined whether the EV time transition permission timer flag Ftim, the EV time transition permission SOC flag Fsoc, and the EV time transition permission APO flag Fapo are all set, and all the flags Ftim, Fsoc, and Fapo are set. If YES in step S509, the flow advances to step S509. If one of the values is not set, one process ends.
In step S509, the EV time transition permission flag Fev = 1 is set.

  In step S502, when the accelerator opening APO does not exist in the basic hysteresis region between the engine start line and the first engine stop line, the process proceeds to step S510, where the accelerator opening APO has the first engine stop line and the second engine stop line. It is determined whether or not it exists in the erroneous stop prevention area between the line and if it exists in this erroneous stop prevention area, the process proceeds to step S511, and if not present in the erroneous stop prevention area, the process proceeds to step S518.

  In step S511, the first EV time transition permission timer tkoka1 is reset, the process proceeds to step S512, the second EV time transition permission timer tkoka2 is counted up, and the process proceeds to step S513.

  In step S513, it is determined whether or not the count value of the second EV time transition permission timer tkoka2 has exceeded the second transition setting time tth2, and if so, the EV time transition permission timer flag Ftim is set, and the process proceeds to step S514. The second transition set time tth2 is set to a time shorter than the first transition set time tth1 (for example, about 1.5 sec).

In step S514, it is determined whether or not the accelerator opening speed ΔAPO when the accelerator opening APO falls below the first engine stop line is equal to or less than a preset second opening speed threshold value ΔAPOth2, and the second opening speed threshold value ΔAPOth2 is determined. In the following cases, the process proceeds to step S517, and when larger than the second opening speed threshold value ΔAPOth2, the process proceeds to step S515.
In step S515, if the current accelerator opening speed ΔAPO is equal to or less than 0 deg / sec (opening speed threshold value ΔAPOth), the EV time transition permission APO flag Fapo = 1 is set, and the process proceeds to step S516. Note that the second opening speed threshold value ΔAPOth2 is set to a value smaller than 0 deg / sec (for example, a value within a range of −10 to −20 deg / sec, and in this embodiment 4, −20 deg / sec). Has been.

In step S516, it is determined whether the EV time transition permission timer flag Ftim and the EV time transition permission APO flag Fapo are set to 1. If both the flags Ftim and Fapo are set, the process proceeds to step S517. If either or both are not set, one process is finished as it is.
In step S517, the EV time transition permission flag Fev = 1 is set, and one process is completed.

  In step S510, if the accelerator opening APO does not exist in the erroneous stop prevention region between both engine stop lines, that is, if it does not exist between the engine start line and the second engine stop line, step S518 proceeds. It is determined whether or not the accelerator opening APO is below the second engine stop line. If the accelerator opening APO is below the second engine stop line, the process proceeds to step S519; otherwise, the process proceeds to step S521.

In step S519, the EV time transition permission flag Fev = 1 is set, and the process proceeds to step S520.
In step S520, the first EV time transition permission timer tkoka1 and the second EV time transition permission timer tkoka2 are reset, and one process is completed.
Also in step S521, the first EV time transition permission timer tkoka1 and the second EV time transition permission timer tkoka2 are reset, and one process is completed.

  When the EV time transition permission flag Fev is set, both engine stop lines are raised to just before the engine start line (for example, before 1 deg) as in the first embodiment (the processing of steps S214 → S251). Based).

(Operation of Example 4)
An operation example of the fourth embodiment will be described based on the time charts of FIGS.

  FIG. 17 shows that after the accelerator opening APO once exceeds the engine start line and the engine is started by shifting from the EV mode to the HEV mode, the accelerator opening APO has the first engine stop line and the second engine stop line. The case where it falls in the false stop prevention area | region between is shown.

  In this case, at the time t41 when the accelerator opening APO falls below the engine start line, the count of the first EV time transition permission timer tkoka1 is started, and further, at the time t42 when it falls below the engine stop line and reaches the erroneous stop prevention region. Thus, the count of the second EV time transition permission timer tkoka2 is started. Here, in the example of FIG. 17, the accelerator opening speed ΔAPO at the time when the accelerator opening APO enters the erroneous stop prevention region is larger than the opening speed threshold ΔAPOth and larger than 0 deg / sec. The EV time transition permission flag Fev is not set until the permission timer tkoka2 reaches the second transition set time tth2.

  Thereafter, at time t43 before the second EV time transition permission timer tkoka2 reaches the second transition set time tth2, the accelerator opening APO has moved to the basic hysteresis region between the first engine stop line and the engine start line. The second EV time transition permission timer tkoka2 is reset, and the count of the first EV time transition permission timer tkoka1 is started.

  Thereafter, the count value of the first EV time transition permission timer tkoka1 has reached the first transition setting time tth1 at time t44. At this time, since the EV time transition permission APO flag Fapo is not set, the EV time transition The permission flag Fev is not set.

Thereafter, at time t45, since the accelerator opening speed ΔAPO has fallen below 0 deg / sec, YES is determined in step S508, and the EV time transition permission flag Fev is set.
Therefore, the EV mode is shifted from this point.

  FIG. 18 shows a case where the accelerator opening APO has decreased from the second engine stop line after the accelerator opening APO has once exceeded the engine start line, the EV mode has been shifted to the HEV mode, and the engine has been started. ing.

In this case, the count of the first EV time transition permission timer tkoka1 is started at the time t51 when the accelerator opening APO falls below the engine start line, and further the second EV time transition permission at the time t52 when it falls below the first engine stop line. The timer tkoka2 starts counting. Thereafter, at time t53 when the accelerator opening APO falls below the second engine stop line, the EV time transition permission flag Fev = 1 is set based on the processing of steps S502 → S510 → S517 → S518, and both engine stop lines are set. Is raised to just before the engine start line, and the mode is shifted to the EV mode.
Thereafter, since the accelerator opening APO does not exceed the engine start line, it is maintained in the EV mode.

  In the example shown in the time chart of FIG. 19, after the accelerator opening APO once exceeds the engine start line and the engine is started by shifting from the EV mode to the HEV mode, the accelerator opening APO is set to the first engine stop line. The case where it falls to the false stop prevention area | region between the 2nd engine stop line is shown. In this example, the accelerator opening APO is suddenly returned, and the accelerator opening speed ΔAPO when it falls below the first engine stop line is set to a value lower than the opening speed threshold ΔAPOth2.

  In this case, the processing of steps S510 to S515 is performed, and the count of the second EV time transition permission timer tkyoka2 is started from the time t62 when the accelerator opening APO falls below the first engine stop line, and this count value is shifted to the second transition. At time t63 when the set time tth2 is exceeded, the EV time transition permission flag Fev = 1 is set, and the EV mode is entered. This EV mode is maintained until the accelerator opening APO exceeds the engine start line.

(Effect of Example 4)
As described above, in the fourth embodiment, when the second engine stop line is set below the first engine stop line, and the accelerator opening APO remains in the erroneous stop prevention region between both engine stop lines, Whether or not to set the EV time transition permission flag Fev is determined based on the remaining time and the accelerator opening speed ΔAPO. Even if the accelerator opening APO falls below the first engine stop line, the second engine is stopped. When it exceeds the line, it is determined not to immediately shift to the EV mode.

  Therefore, there is a possibility that the accelerator opening APO returns to the first engine stop line before the second transition set time tth2 elapses, or the accelerator opening speed ΔAPO is slowly returned, so that the intention to accelerate again occurs. If the engine is large, maintaining the HEV mode without stopping the engine Eng increases the frequency of switching between the EV mode and the HEV mode, thereby further suppressing deterioration of drivability and response. it can. Therefore, it is possible to prevent hunting in the EV mode and HEV mode that are not intended by the driver.

Furthermore, in the fourth embodiment, counting is performed for setting the EV time transition permission timer flag Ftim depending on whether the accelerator opening APO exists in the basic hysteresis region or in the erroneous stop prevention region. The first and second transition setting times tth1 and tth2 are made different, and the latter sets the flag in a shorter time than the former.
That is, when the accelerator opening APO exists in the basic hysteresis region, it is more likely that the accelerator will be depressed again than when the accelerator opening APO exists in the erroneous stop prevention region. Thus, by setting the count time according to the driver's operation intention, it is possible to prevent hunting in the EV mode and the HEV mode not intended by the driver, and to ensure drivability and acceleration. be able to.

  In the fourth embodiment, when the accelerator opening APO is high in the return speed of the accelerator opening speed ΔAPO when entering the erroneous stop prevention region, the EV time transition permission flag Fev is immediately set. Therefore, the stop timing of the engine Eng can be determined at a position where the accelerator opening APO is high, the engine stop according to the driver's intention can be achieved, the stop timing is advanced, and fuel consumption can be improved.

  Further, in the fourth embodiment, when the accelerator opening APO further falls below the second engine stop line from the erroneous stop prevention region, the engine Eng is immediately stopped. Therefore, switching from the HEV mode to the EV mode according to the driver's intention can be performed, and efficient traveling is possible.

The fifth embodiment is a modification of the fourth embodiment. As shown in the flowchart of FIG. 20, a process (step S601) for setting the second transition set time tth2 between steps S512 and S513 of the fourth embodiment is performed. This is an added example.
The setting of this second transition set time tth2 is determined by the accelerator opening speed ΔAPO when the accelerator opening APO crosses the first engine stop line and enters the erroneous stop determination region, and this accelerator opening speed ΔAPO is determined by the opening speed threshold. When it is larger than ΔAPOth (for example, −10 deg / sec), tth2 = ta, and when smaller than the opening speed threshold ΔAPOth, tth2 = tb. If ta> tb and the accelerator opening speed ΔAPO is small, the second transition setting time tth2 is short.

(Effect of Example 5)
Thus, in the fifth embodiment, in the HEV mode running state, when the accelerator opening APO enters the erroneous stop prevention region between the first engine stop line and the second engine stop line, the accelerator opening speed ΔAPO is set. Accordingly, the time for shifting to the EV mode is changed.
Therefore, engine stop according to the driver's operation intention can be realized.

  As mentioned above, although the clutch control apparatus of this invention has been demonstrated based on Embodiment and Example 1, it is not restricted to these Embodiment and Example about specific structure, Claims Modifications and additions of the design are permitted without departing from the spirit of the invention according to the claims.

  For example, in the first embodiment, the application example to the FR hybrid vehicle is shown, but it can be applied to a front-wheel drive or four-wheel drive type hybrid vehicle. A manual transmission, a mechanical automatic transmission, or the like can also be applied as the transmission.

  In the first embodiment, the motor generator MG capable of regeneration is shown as the motor. However, the present invention is not limited to this, and a motor capable of only power running may be used.

  For example, in the fourth embodiment, the accelerator position is shifted to the EV mode when the set time remains in both the basic hysteresis area and the erroneous stop prevention area. However, the present invention is not limited to this. Only when staying in the erroneous stop prevention area, the mode may be shifted to the EV mode.

  Although the engine stop line is raised until it substantially matches the engine start line, a predetermined interval may be maintained between them.

2 Motor controller (motor control means)
5 First clutch controller (clutch torque control means)
10 Integrated controller (mode switching control means)
APO accelerator opening CL1 1st clutch (clutch)
Eng Engine MG Motor generator (motor)
RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)
tth1 first transition set time tth2 second transition set time ΔAPO accelerator opening speed ΔAPOth opening speed threshold ΔAPOth2 second opening speed threshold

Claims (5)

A motor capable of transmitting driving force to the driving wheel side;
An engine provided to transmit the driving force with the motor;
A clutch that is interposed between the engine and the motor and can change the transmission torque;
Clutch torque control means for controlling the transmission torque capacity of the clutch;
Motor control means for controlling the output torque of the motor;
An accelerator opening detecting means for detecting the accelerator opening;
Vehicle speed detection means for detecting the vehicle speed;
The vehicle travel mode is determined based on the accelerator opening, and when the accelerator opening exceeds an engine start line set in accordance with the vehicle speed, the clutch is engaged to rotate the motor to the engine. When the HEV mode that travels by driving the engine and the motor by driving the engine and driving, and the accelerator opening is below the engine stop line set to a value lower than the engine start line, A travel mode control means for releasing the clutch and stopping the engine and driving only the motor to set the EV mode;
With
The travel mode control means includes
During traveling in the HEV mode, the accelerator opening, the hysteresis region between the engine start line and the engine stop line, when in Tsu Tomah beyond preset migrated set time, the Execute EV time transition processing to transition to EV mode ,
Furthermore, a relatively high value first engine stop line and a relatively low value second engine stop line are set as the engine stop line, and the engine start line and the first engine stop line are A basic hysteresis region is set between the first engine stop line and the second engine stop line, and an erroneous stop prevention region is set.
In the EV time transition process, the second transition setting time that is the transition setting time in the erroneous stop prevention region is set shorter than the first transition setting time that is the transition setting time in the basic hysteresis region. A mode switching control device for a hybrid vehicle. A motor capable of transmitting driving force to the driving wheel side;
An engine provided to transmit the driving force with the motor;
A clutch that is interposed between the engine and the motor and can change the transmission torque;
Clutch torque control means for controlling the transmission torque capacity of the clutch;
Motor control means for controlling the output torque of the motor;
An accelerator opening detecting means for detecting the accelerator opening;
Vehicle speed detection means for detecting the vehicle speed;
The vehicle travel mode is determined based on the accelerator opening, and when the accelerator opening exceeds an engine start line set in accordance with the vehicle speed, the clutch is engaged to rotate the motor to the engine. When the HEV mode that travels by driving the engine and the motor by driving the engine and driving, and the accelerator opening is below the engine stop line set to a value lower than the engine start line, A travel mode control means for releasing the clutch and stopping the engine and driving only the motor to set the EV mode;
With
The travel mode control means includes
While traveling in the HEV mode, when the accelerator opening remains in the hysteresis region between the engine start line and the engine stop line for more than a preset transition setting time, the EV mode Execute EV time transition processing to shift to
Furthermore, as the engine stop line, a first engine stop line having a relatively high value and a second engine stop line having a relatively low value are set, and in the EV time transition process, the accelerator opening is In the hysteresis region, at least when the elapsed time from the time of entering the erroneous stop prevention region between the first engine stop line and the second engine stop line exceeds the transition set time, the EV mode is entered. Migrate,
The transition set time is greater than when the accelerator opening speed when the accelerator opening is in the erroneous stop prevention region is smaller than a preset negative opening speed threshold, than when the accelerator opening speed is larger than the opening speed threshold. A mode switching control device for a hybrid vehicle, characterized in that the mode switching control device is also set short . The travel mode control means shifts to the EV mode when the accelerator opening is less than the second engine stop line in the EV time transition process. The hybrid vehicle mode switching control device. The travel mode control means executes a hysteresis changing process for bringing the engine stop line closer to the engine start line when a condition for shifting to the EV mode is satisfied in the EV time transition process. The mode switching control device for a hybrid vehicle according to any one of claims 3 to 4 . The travel mode control means executes a hysteresis return process for returning the engine stop line brought closer to the engine start line side by the hysteresis change process to the original value when the hysteresis return condition is satisfied, and the hysteresis return condition 5. The mode switching of the hybrid vehicle according to claim 4, wherein the accelerator opening exceeds one of the engine start line and the transition to the EV mode is completed. Control device.