Hybrid vehicle control device

Abstract

To provide a control device for a hybrid vehicle, capable of reproducing behavior upon the occurrence of an engine stall which is similar to that of a conventional manual transmission-mounted vehicle.SOLUTION: There is provided a control device for a hybrid vehicle including: an engine; a manual transmission; a clutch to be switched to a coupled state where power is transmitted between the engine and the manual transmission, or to a released state where the power is not transmitted; and a motor generator connected so as to be capable of transmitting power to a driving wheel. In the hybrid vehicle, a shift stage is switched in response to the operation of a clutch pedal and a shift lever by a driver. The control device includes an ECU which has an EV mode as a travel mode, and which executes pseudo engine stall control to reduce motor torque in a case where a motor rotational speed falls below an MG_idle rotational speed in the EV mode. When the pseudo engine stall control is executed, the ECU executes rotation suppression control to suppress the rotation of the driving wheel.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a control device for a hybrid vehicle. [Background technology]

[0002] Patent Document 1 discloses a motor torque control device for a hybrid vehicle in which an engine and a motor generator are connected via an automatic clutch, and the motor generator and a manual transmission are connected via a manual clutch, the device having driving modes including an EV mode in which the automatic clutch is released and the vehicle runs on power from the motor generator, and an HEV mode in which the automatic clutch is engaged and the vehicle runs on power from the engine, or the engine and the motor generator, and the device is equipped with an ECU for switching the driving modes.

[0003] In this motor torque control device for a hybrid vehicle, in order to prevent the driver from confusing the driving operation due to the different starting operations for each driving mode, when starting the hybrid vehicle, the ECU reduces the MG torque so that starting becomes difficult when the MG rotation speed is in the low rotation range equivalent to or below the engine idle rotation speed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-104614 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional motor torque control device for a hybrid vehicle, the MG torque is controlled so that the behavior of the driving force output from the driving force source at start-off is the same in EV mode and HEV mode. However, this does not yet reproduce the behavior of a vehicle equipped with a conventional manual transmission and powered by an internal combustion engine when an engine stall occurs, and there is still room for improvement.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a motor torque control device for a hybrid vehicle that can reproduce the behavior when an engine stall occurs in the same manner as in a vehicle equipped with a conventional manual transmission. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a vehicle engine, a transmission that changes the rotation of the engine at a speed ratio corresponding to a gear stage and outputs the rotation to a drive wheel, The clutch lever is provided in a power transmission path between the engine and the transmission, and is operated in conjunction with the operation of a clutch pedal by a driver. a clutch that can be switched between an engaged state in which power is transmitted between the engine and the transmission and a released state in which the power is not transmitted; The clutch is provided in a power transmission path between the transmission and the drive wheels, and the power transmission is not performed through the transmission or the clutch. a motor connected to the drive wheels so as to be capable of transmitting power thereto; The above A control device for a hybrid vehicle in which the gear stage of the transmission is changed in response to an operation of a clutch pedal and a shift lever, the control device having an EV mode as a driving mode in which the clutch is released and the vehicle runs on power from the motor, and a torque of the motor is reduced when the motor rotation speed in the EV mode falls below a rotation speed corresponding to an idle rotation speed of the engine. Regulation Execute the command and executing a rotation suppression control for suppressing the rotation of the drive wheels while the control is being executed. Equipped with a control unit El It has a configuration. Effect of the Invention

[0008] According to the present invention, it is possible to provide a control device for a hybrid vehicle that can reproduce the behavior when an engine stall occurs similar to that of a vehicle equipped with a conventional manual transmission. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a hybrid vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a flowchart showing a flow of processing executed by an ECU mounted on a hybrid vehicle according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic configuration diagram of a hybrid vehicle according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A control device for a hybrid vehicle according to one embodiment of the present invention includes an engine, a transmission that changes the speed of the engine at a gear ratio corresponding to a gear position and outputs the engine rotation to drive wheels, a clutch that can be switched between an engaged state in which power is transmitted between the engine and the transmission or a disengaged state in which power is not transmitted, and a motor connected to the drive wheels so that the gear position of the transmission can be changed in response to an operation of a clutch pedal and a shift lever by a driver, the control device has an EV mode in which the clutch is disengaged and the vehicle travels using power from the motor, and includes a control unit that executes pseudo engine stall control to reduce the torque of the motor when the motor rotation speed falls below a rotation speed corresponding to the idle rotation speed of the engine in the EV mode, and the control unit executes rotation suppression control to suppress rotation of the drive wheels when the pseudo engine stall control is executed. As a result, the control device for a hybrid vehicle according to one embodiment of the present invention can reproduce the behavior at the time of engine stall occurrence similar to that of a conventional manual transmission-equipped vehicle. EXAMPLES

[0011] A hybrid vehicle equipped with a control device according to an embodiment of the present invention will now be described with reference to the drawings.

[0012] As shown in FIG. 1, a hybrid vehicle 1 according to this embodiment includes an engine 2, a motor generator 3 as a motor, a manual transmission 4 as a gearbox, a differential 5, drive wheels 6, and an ECU (Electric Control Unit) 10 as a control unit.

[0013] A plurality of cylinders are formed in the engine 2. In this embodiment, the engine 2 is configured to perform a series of four strokes, which are an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, for each cylinder.

[0014] An ISG (Integrated Starter Generator) 20 is connected to the engine 2. The ISG 20 is connected to the crankshaft of the engine 2 via a power transmission member 21 such as a belt. The ISG 20 has a function of an electric motor that rotates when supplied with electric power to drive the engine 2, and a function of a generator that converts the rotational force input from the crankshaft into electric power.

[0015] The motor generator 3 functions as an electric motor that is driven by power supplied from a battery 31 via an inverter 30, and also functions as a generator that performs regenerative power generation by a reverse driving force input from the differential 5.

[0016] The motor generator 3 is provided in a power transmission path between the manual transmission 4 and left and right drive wheels 6, and is connected to the left and right drive wheels 6 so as to be able to transmit power to them.

[0017] Under the control of the ECU 10, the inverter 30 converts DC power supplied from the battery 31 into three-phase AC power and supplies it to the motor generator 3, and also converts the three-phase AC power generated by the motor generator 3 into DC power to charge the battery 31. The battery 31 is formed of a secondary battery such as a lithium ion battery.

[0018] The manual transmission 4 is configured by a manual transmission that changes the speed of the rotation output from the engine 2 at a gear ratio corresponding to one of a plurality of gear stages and outputs the rotation to left and right drive wheels 6. The output shaft of the manual transmission 4 is connected to the left and right drive wheels 6 via a differential 5. The output shaft of the motor generator 3 is connected to the output shaft of the manual transmission 4. In other words, the motor generator 3 and the manual transmission 4 are each connected to the drive wheels 6 so as to be able to transmit drive force independently, and the drive force of the engine 2 and the drive force of the motor generator 3, which are changed in speed by the manual transmission 4, are transmitted to the drive wheels 6.

[0019] The gears that can be established by the manual transmission 4 include, for example, forward driving gears ranging from a low gear 1 to a high gear 5, and a reverse gear. The number of driving gears varies depending on the specifications of the hybrid vehicle 1, and is not limited to the above-mentioned 1 to 5 gears.

[0020] The gear positions in the manual transmission 4 can be changed in response to the driver's operation of the clutch pedal 71 and the shift lever 40. The operating position of the shift lever 40 is detected by a shift position sensor 41. The shift position sensor 41 is connected to the ECU 10 and transmits the detection result to the ECU 10.

[0021] The manual transmission 4 is provided with a neutral switch 42. The neutral switch 42 is connected to the ECU 10. The neutral switch 42 detects a state in which no gear shift is established in the manual transmission 4, that is, a neutral state, and is turned on when the manual transmission 4 is in a neutral state.

[0022] A clutch 7 is provided in the power transmission path between the engine 2 and the manual transmission 4. For example, a dry single-plate friction clutch can be used as the clutch 7. The engine 2 and the manual transmission 4 are connected via the clutch 7.

[0023] The clutch 7 is switched between an engaged state in which power is transmitted between the engine 2 and the manual transmission 4, a released state in which power is not transmitted, and a half-clutch state in which torque is transmitted with a rotation difference, by the operation of the clutch actuator 70 in conjunction with the operation of the clutch pedal 71 by the driver. In other words, when a gear shift is established in the manual transmission 4, the clutch 7 is switched between an engaged state in which the engine 2 and the drive wheels 6 are connected, and a released state in which they are not connected. The clutch 7 is a clutch-by-wire type clutch, and the clutch actuator 70 is connected to the ECU 10 and controlled by the ECU 10.

[0024] The ECU 10 controls the clutch actuator 70 according to the depression amount of the clutch pedal 71 operated by the driver, so as to perform an operation equivalent to that of a so-called manual clutch in which the clutch pedal 71 and the clutch operate in mechanical cooperation. Note that in an EV mode, which will be described later, the ECU 10 can release the clutch 7 when it is not operated by the driver and the depression of the clutch pedal 71 is not detected.

[0025] The amount of depression of the clutch pedal 71 is detected by a clutch pedal sensor 72. The clutch pedal sensor 72 is connected to the ECU 10 and transmits a signal corresponding to the amount of depression of the clutch pedal 71 to the ECU 10.

[0026] The hybrid vehicle 1 is equipped with an accelerator pedal 90 that is operated by the driver. The amount of depression of the accelerator pedal 90 is detected by an accelerator opening sensor 91. The accelerator opening sensor 91 is connected to the ECU 10, detects the amount of depression of the accelerator pedal 90 as an accelerator opening, and transmits a signal corresponding to the accelerator opening to the ECU 10.

[0027] The hybrid vehicle 1 is equipped with a brake pedal 92 that is operated by the driver. The amount of depression of the brake pedal 92 is detected by a brake pedal sensor 93. The brake pedal sensor 93 is connected to the ECU 10 and transmits a signal corresponding to the amount of depression of the brake pedal 92 to the ECU 10.

[0028] The ECU 10 is composed of a computer unit having a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, etc., an input port, and an output port.

[0029] The ROM of the computer unit stores various constants, various maps, and the like, as well as a program for causing the computer unit to function as the ECU 10. That is, the CPU executes the program stored in the ROM using the RAM as a working area, causing the computer unit to function as the ECU 10 in this embodiment.

[0030] In addition to the above-mentioned sensors, a vehicle speed sensor 11 is connected to the ECU 10. The vehicle speed sensor 11 detects the vehicle speed of the hybrid vehicle 1 and transmits the detection result to the ECU 10.

[0031] The ECU 10 is adapted to switch the driving mode of the hybrid vehicle 1. In this embodiment, an EV mode and an HEV mode are set as the driving modes.

[0032] The EV mode is a driving mode in which the clutch 7 is released and the hybrid vehicle 1 is driven by the power of the motor generator 3. The HEV mode is a driving mode in which the clutch 7 is engaged and the hybrid vehicle 1 is driven by the power of the engine 2, or the engine 2 and the motor generator 3. In detail, the EV mode in the hybrid vehicle 1 according to this embodiment is a mode in which the output characteristics and speed range are set according to the gear stage of the manual transmission 4 selected by the driver's operation, and the vehicle is driven with an output (driving force) corresponding to the amount of depression of the accelerator pedal 90 by the driver detected by the accelerator opening sensor 91. The HEV mode is a driving mode in which the hybrid vehicle 1 is driven by the driving force generated by the engine 2, and is a driving mode in which the hybrid vehicle 1 is driven by auxiliary use of the power of the motor generator 3.

[0033] The ECU 10 switches between the EV mode and the HEV mode based on, for example, the accelerator opening and the engine speed.

[0034] For example, when the driver requested torque determined by the accelerator opening exceeds the HEV transition threshold while traveling in the EV mode, the ECU 10 restarts the engine 2 to transition to the HEV mode.

[0035] For example, when the driver requested torque, which is determined by the accelerator opening and the engine rotation speed, falls below the EV shift threshold while traveling in the HEV mode, the ECU 10 stops the engine 2 and shifts to the EV mode.

[0036] In the EV mode, in order to reproduce the characteristics of a stepped manual transmission even though the driving force transmission path does not pass through the manual transmission 4, the ECU 10 calculates a virtual engine rotation speed, a virtual engine torque, a virtual inertia torque, etc. corresponding to the current driving speed from the operation status of the accelerator pedal 90 and the clutch pedal 71 according to the selected gear stage of the manual transmission 4. Then, the output of the motor generator 3 is adjusted based on the results of these calculations.

[0037] In the EV mode, the ECU 10 executes the pseudo engine stall control when the rotation speed of the motor generator 3 (hereinafter referred to as the "motor rotation speed") falls below the rotation speed at the vehicle speed corresponding to the idle rotation speed of the engine 2 in the selected gear position of the manual transmission 4 (hereinafter referred to as the "MG_idle rotation speed"). This pseudo engine stall control is executed when the clutch pedal 71 is not operated (depressed) by the driver. The pseudo engine stall control reduces the torque of the motor generator 3 (hereinafter referred to as the "motor torque") to reproduce a pseudo engine stall as if the engine 2 had stalled. In the pseudo engine stall control, it is preferable to control the motor torque to 0. In the pseudo engine stall control, the pseudo engine stall control is executed by setting the rotation speed corresponding to the gear position as a threshold value. Furthermore, the threshold value of the rotation speed may be changed and controlled according to the depression amount of the accelerator pedal 90 detected by the accelerator opening sensor 91. In other words, even if the rotation speed falls below the MG_idle rotation speed, if the accelerator pedal 90 is depressed heavily, the threshold value is lowered to continue control of the output characteristics according to the gear position without immediately executing the pseudo engine stall control. By implementing such control, it is possible to more closely approximate a running state using the driving force of the engine 2. Furthermore, the ECU 10 may be configured to execute the pseudo engine stall control when the motor rotation speed, which will be described later, falls below a predetermined rotation speed Nmth.

[0038] When the pseudo engine stall control is executed and the motor rotation speed further decreases, the ECU 10 executes rotation suppression control to suppress the rotation of the drive wheels 6. Specifically, the ECU 10 executes the rotation suppression control when the motor rotation speed becomes equal to or lower than a predetermined rotation speed Nmth that is lower than the MG_idle rotation speed during execution of the pseudo engine stall control. In other words, after the pseudo engine stall control is executed, if the motor rotation speed is not restored by operation of the accelerator pedal 90 or the clutch pedal 71 and the motor rotation speed further decreases, the rotation suppression control is executed.

[0039] The predetermined rotation speed Nmth may be changed according to the established gear. Since the braking effect of the engine 2 on the vehicle body differs depending on the gear, a lower predetermined rotation speed Nmth can be used in a low gear where the braking effect is greater than in a high gear. This allows the rotation suppression control to be performed relatively gently even in a low gear, and the possibility of recovery by operating the accelerator pedal 90 in a low gear can be made closer to the behavior and state of a vehicle equipped with a conventional manual transmission.

[0040] Furthermore, the ECU 10 may be configured to execute the rotation suppression control when the motor rotation speed falls below the MG_idle rotation speed. Also, the ECU 10 may be configured to execute the pseudo engine stall control and the rotation suppression control when the motor rotation speed falls below a predetermined rotation speed Nmth.

[0041] The rotation suppression control is a control in which the clutch 7 is engaged to connect the engine 2 and the manual transmission 4 to a connected state in which power can be transmitted. The rotation suppression control is performed when any of the gear stages is established in the manual transmission 4. That is, in the rotation suppression control, the ECU 10 suppresses the rotation of the drive wheels 6 by engaging the clutch 7 using the stopped engine 2. In detail, when the clutch 7 is engaged, the friction torque and motoring (idling) torque of the stopped engine 2 become a load, and the rotation of the drive wheels 6 is suppressed. As a result, the behavior and state of the hybrid vehicle 1 when the pseudo engine stall control is executed becomes similar to the behavior and state of the hybrid vehicle 1 when an engine stall occurs in a conventional manual transmission vehicle. Furthermore, the behavior of the hybrid vehicle 1 becomes the same as the behavior of the hybrid vehicle 1 when an engine stall occurs in the HEV mode. That is, the state when an engine stall occurs in a conventional manual transmission vehicle is reproduced, including the display in the meter. The driver can recognize from the display in the meter that the vehicle is in a state different from the state in which the engine 2 is stopped by the idling stop. Therefore, the driver can perform the operation during engine stall without making a mistake, instead of the normal operation of restarting the engine from an idling stop. Specifically, just as the engine can be restarted by simply depressing the clutch pedal 71, the rotation suppression control and pseudo engine stall control are terminated, the clutch 7 is released, and the display in the meter is set to the driving state.

[0042] In addition, since suddenly engaging the clutch 7 due to the rotation suppression control causes the stopped engine 2 to suddenly brake the vehicle body, the clutch 7 may be engaged so as to gradually reduce the vehicle speed relatively gently, or may be engaged after the vehicle speed becomes extremely low. Also, when the rotation suppression control is executed, the clutch 7 that has been released for the EV mode is not simply engaged, but may be quickly controlled to a clutch position that corresponds to the operating position of the clutch pedal 71 operated by the driver, and the clutch 7 may be engaged at that clutch position.

[0043] When the driver operates the clutch pedal 71 while the rotation suppression control is being executed, the ECU 10 stops the execution of the rotation suppression control. That is, when the driver depresses the clutch pedal 71 while the rotation suppression control is being executed, the ECU 10 releases the clutch 7 to release the rotation suppression control. As a result, the rotation suppression of the drive wheels 6 is released by depressing the clutch pedal 71, and the behavior of the hybrid vehicle 1 becomes the same as when the clutch pedal 71 is depressed when the engine stall occurs in the HEV mode.

[0044] The rotation suppression control described above is assumed to be executed when the hybrid vehicle 1 slows down from a running state and the motor rotation speed drops abnormally, or when the hybrid vehicle 1 is running and the driver makes a mistake in selecting a gear shift stage and the motor rotation speed drops abnormally. In contrast, when starting, the situation in which an engine stall occurs cannot be determined only from the motor rotation speed. For this reason, the rotation suppression control based on the predetermined rotation speed Nmth is not started when the hybrid vehicle 1 is stopped or when the vehicle speed is very low, but is started when the vehicle speed is relatively high. Specifically, when the hybrid vehicle 1 is stopped or when the vehicle speed has never exceeded the predetermined vehicle speed Vth since starting, the ECU 10 does not start the rotation suppression control based on the predetermined rotation speed Nmth, but starts the pseudo engine stall control based on the engine stall determination at the time of starting, and starts the rotation suppression control. The ECU 10 determines the engine stall at the time of starting based on the operation state of the clutch pedal 71 and the accelerator pedal 90 by the driver, taking into account the established gear shift stage and the running resistance of the hybrid vehicle 1, such as the gradient of the road surface.

[0045] When the speed of the hybrid vehicle 1 decreases and the motor rotation speed decreases, the predetermined rotation speed Nmth is set according to the established gear. For example, when a medium to high gear stage of 3rd gear or higher is established, a first rotation speed Nm1 is set as the predetermined rotation speed Nmth, and when a low gear stage is established, a second rotation speed Nm2 lower than the first rotation speed Nm1 is set as the predetermined rotation speed Nmth. The above-mentioned predetermined vehicle speed Vth is an extremely low vehicle speed close to vehicle speed = 0.

[0046] Next, a flow of processing by the ECU 10 according to this embodiment will be described with reference to Fig. 2. The processing shown in Fig. 2 is repeatedly executed at predetermined time intervals while the hybrid vehicle 1 is in operation.

[0047] 2, the ECU 10 determines whether the driving mode of the hybrid vehicle 1 is the EV mode (step S1). If the ECU 10 determines in step S1 that the driving mode is not the EV mode, the ECU 10 ends the process shown in FIG.

[0048] When the ECU 10 determines in step S1 that the driving mode is the EV mode, the ECU 10 determines whether or not the pseudo engine stall control is being executed (step S2). For example, the ECU 10 can determine whether or not the pseudo engine stall control is being executed by determining whether or not the motor rotation speed is lower than the MG_idle rotation speed.

[0049] If the ECU 10 determines in step S2 that the pseudo engine stall control is not being executed, the ECU 10 ends the process shown in Fig. 2. If the ECU 10 determines in step S2 that the pseudo engine stall control is being executed, the ECU 10 determines whether the vehicle speed is equal to or lower than a predetermined vehicle speed Vth (step S3).

[0050] When the ECU 10 determines in step S3 that the vehicle speed is equal to or lower than the predetermined vehicle speed Vth, it determines that the pseudo engine stall control during the starting operation is being executed, and proceeds to the process of step S8, which will be described later.

[0051] When the ECU 10 determines in step S3 that the vehicle speed is not equal to or lower than the predetermined vehicle speed Vth, it determines that the pseudo engine stall control during traveling is being executed, and proceeds to the process of step S4.

[0052] In step S4, ECU 10 checks whether the established gear is a medium-to-high gear that is 3rd gear or higher, and if it determines that the gear is 3rd gear or higher, it sets the first rotation speed Nm1 as the predetermined rotation speed Nmth at which rotation suppression control is started (step S5), and proceeds to processing in step S7.

[0053] When the ECU 10 determines in step S4 that the gear position is not a medium-high gear position equal to or higher than the third gear position, the ECU 10 sets the second rotation speed Nm2 as a predetermined rotation speed Nmth used in the determination in step S7 described later (step S6), and proceeds to the process of step S7. The second rotation speed Nm2 is a rotation speed lower than the first rotation speed Nm1.

[0054] In step S7, the ECU 10 judges whether the motor rotation speed is equal to or lower than the predetermined rotation speed Nmth. If the ECU 10 judges in step S7 that the motor rotation speed is not equal to or lower than the predetermined rotation speed Nmth, the ECU 10 ends the process shown in FIG.

[0055] When the ECU 10 determines in step S7 that the motor rotation speed is equal to or lower than the predetermined rotation speed Nmth, it operates the clutch actuator 70 to engage the clutch 7, i.e., executes rotation suppression control (step S8). As a result, the friction torque and motoring (idling) torque of the stopped engine 2 become a load, suppressing the rotation of the drive wheels 6.

[0056] Next, the ECU 10 judges whether or not the driver has performed a clutch operation during execution of the rotation suppression control, that is, whether or not the driver has depressed the clutch pedal 71 (step S9). If the ECU 10 judges in step S9 that the clutch operation has not been performed, the ECU 10 ends the process shown in FIG.

[0057] When it is determined in step S9 that the clutch operation is being performed, the ECU 10 releases the clutch 7 that is in an engaged state (step S10), that is, releases the rotation suppression control, and ends the process shown in FIG.

[0058] As described above, the control device for a hybrid vehicle according to this embodiment is configured to execute pseudo engine stall control when the motor rotation speed falls below the MG_idle rotation speed in EV mode, and once the pseudo engine stall control has been executed, to execute rotation suppression control that suppresses rotation of the drive wheels 6 depending on the subsequent motor rotation speed, the amount of depression of the accelerator pedal 90, changes in vehicle speed, and the operation status of the clutch pedal 71.

[0059] With this configuration, the control device for the hybrid vehicle according to this embodiment suppresses the rotation of the drive wheels 6 through rotation suppression control, making it possible to reproduce the behavior and vehicle state when an engine stall occurs, similar to that of a vehicle equipped with a conventional manual transmission.

[0060] In a vehicle equipped with a conventional manual transmission, for example, if an engine stall occurs on a slope, the drive wheels and the engine remain connected to transmit power unless the driver performs an operation to release the clutch, so that the friction torque and motoring (idling) torque of the stopped engine become a load and suppress the rotation of the drive wheels. This prevents a vehicle equipped with a conventional manual transmission from sliding down the slope when an engine stall occurs on a slope.

[0061] In contrast, the control device for the hybrid vehicle according to this embodiment can prevent the hybrid vehicle 1 from slipping back, similar to a vehicle equipped with a conventional manual transmission, by executing the above-mentioned rotation suppression control when a pseudo engine stall occurs, for example, on a slope, even during EV mode when the clutch 7 is released.

[0062] In this way, the control device for the hybrid vehicle 1 according to this embodiment can reproduce the behavior when an engine stall occurs in the same manner as in a vehicle equipped with a conventional manual transmission, thereby reducing the sense of discomfort felt by the driver and improving marketability.

[0063] Furthermore, the behavior of the hybrid vehicle 1 when the pseudo engine stall control is executed is the same as the behavior of the hybrid vehicle 1 when an engine stall occurs in the HEV mode, so that it is possible to prevent the driver from feeling uncomfortable due to the difference in the behavior of the hybrid vehicle between the EV mode and the HEV mode. Furthermore, since the vehicle state can be made the same, subsequent operations such as restarting can also be made the same.

[0064] Furthermore, the control device for a hybrid vehicle according to this embodiment is configured to execute rotation suppression control when the motor rotation speed is equal to or lower than a predetermined rotation speed Nmth that is lower than the MG_idle rotation speed while the pseudo engine stall control is being executed.

[0065] With this configuration, the control device for a hybrid vehicle according to this embodiment can make the behavior of the hybrid vehicle 1 when pseudo engine stall control is executed more similar to the behavior of a vehicle equipped with a conventional manual transmission when an engine stall occurs.

[0066] Furthermore, since the control device for the hybrid vehicle according to this embodiment suppresses the rotation of the drive wheels 6 by engaging the clutch 7 during rotation suppression control, it is possible to utilize loads such as the friction torque and motoring (idling) torque of the engine 2 while it is stopped to suppress the rotation of the drive wheels 6, similar to a vehicle equipped with a conventional manual transmission.

[0067] Furthermore, the control device for the hybrid vehicle according to this embodiment stops the execution of the rotation suppression control when the driver operates the clutch pedal 71, and therefore can cut off the power transmission path between the drive wheels 6 and the engine 2, similar to a vehicle equipped with a conventional manual transmission. This makes it possible to make the behavior when the clutch pedal 71 is operated with the rotation of the drive wheels 6 suppressed the same as that of a vehicle equipped with a conventional manual transmission.

[0068] In the control system for a hybrid vehicle according to this embodiment, the predetermined rotation speed Nmth is set to a lower rotation speed when the vehicle speed is high than when the vehicle is stopped or the vehicle speed is low.

[0069] With this configuration, the control device for the hybrid vehicle according to this embodiment can make it difficult to execute rotation suppression control in response to, for example, a decrease in motor rotation speed caused by a shift operation error while driving, or a decrease in motor rotation speed caused by a decrease in vehicle speed.

[0070] In this embodiment, an example has been described in which the hybrid vehicle control device according to the present invention is applied to the hybrid vehicle 1 shown in FIG. 1, but the present invention is not limited to this and may be applied to a hybrid vehicle 101 according to a modified example shown in FIG. 3.

[0071] As shown in Fig. 3, a hybrid vehicle 101 according to the modified example is a vehicle in which a motor generator 3 is provided on a power transmission path between an engine 2 and a manual transmission 4. In this modified example, the same components as those in this embodiment are denoted by the same reference numerals.

[0072] Furthermore, an automatic clutch 108, the engagement or release of which is controlled by an ECU (not shown), is provided between the engine 2 and the motor generator 3. Also, a clutch 7, which is actuated by a clutch actuator in conjunction with the operation of the clutch pedal by the driver, is provided between the motor generator 3 and the manual transmission 4 as a manual clutch.

[0073] In the hybrid vehicle 101 according to this modified example, when pseudo engine stall control is executed, an ECU (not shown) executes rotation suppression control to suppress rotation of the drive wheels 6 by engaging the clutch 7 and the automatic clutch 108.

[0074] The hybrid vehicle 101 according to this modified example can also provide the same operational effects as those of this embodiment.

[0075] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made therein without departing from the spirit and scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0076] 1, 101 Hybrid vehicle 2 Engine 3 Motor generator (motor) 4 Manual transmission 6 Drive wheels 7. Clutch 10 ECU (control unit) 11 Vehicle speed sensor 40 Shift lever 41 Shift position sensor 70 Clutch actuator 71 Clutch pedal 72 Clutch pedal sensor 90 Accelerator pedal 91 Accelerator opening sensor

Claims

1. The engine, a transmission that changes the rotation of the engine at a speed ratio corresponding to a gear stage and outputs the rotation to a drive wheel; a clutch that is provided in a power transmission path between the engine and the transmission and that is switched between an engaged state in which power is transmitted between the engine and the transmission and a released state in which the power is not transmitted in response to an operation of a clutch pedal by a driver; a motor provided in a power transmission path between the transmission and the drive wheels and connected to be able to transmit power to the drive wheels without passing through the transmission or the clutch; A control device for a hybrid vehicle in which the gear stage of the transmission is changed in response to an operation of the clutch pedal and a shift lever by a driver, A control device for a hybrid vehicle, comprising: an EV mode in which the clutch is released and the vehicle runs on power from the motor as a driving mode; and a control unit that executes control to reduce the torque of the motor when the motor rotation speed in the EV mode falls below a rotation speed corresponding to the idle rotation speed of the engine, and executes rotation suppression control to suppress rotation of the drive wheels while the control is being executed.

2. 2. The control device for a hybrid vehicle according to claim 1, wherein the control unit executes the rotation suppression control when the motor rotation speed is equal to or lower than a predetermined rotation speed that is lower than a rotation speed corresponding to an idle rotation speed of the engine during execution of control to reduce the torque of the motor.

3. 3. The control device for a hybrid vehicle according to claim 1, wherein the control unit, in the rotation suppression control, suppresses rotation of the drive wheels by engaging the clutch.

4. 4. The control device for a hybrid vehicle according to claim 1, wherein the control unit stops execution of the rotation suppression control when the driver operates the clutch pedal.

5. 3. The control device for a hybrid vehicle according to claim 2, wherein the predetermined rotation speed is set to a lower rotation speed when the established gear shift stage is a low gear shift stage than when the established gear shift stage is a high gear shift stage.

Images