Vehicle control device

Abstract

To reduce shock when switching a travel mode.SOLUTION: A vehicular control device includes: a motor generator which is connected to a first wheel; an engine which is connected to the first wheel or a second wheel through a power transmission path; a transmission mechanism which is provided in the power transmission path; a clutch mechanism which is provided in the power transmission path; and a control system which controls the motor generator, the engine, the transmission mechanism, and the clutch mechanism. The control system has a first travel mode for fastening the clutch mechanism and a second travel mode for releasing the clutch mechanism. When switching from the first travel mode to the second travel mode, the control system fastens the clutch mechanism over the transfer time, and reduces torque of the engine and increases power running torque of the motor generator in a state of fastening the clutch mechanism.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a vehicle control device that controls a vehicle. [Background technology]

[0002] A hybrid vehicle is equipped with an engine and a motor generator as a power source (see Patent Documents 1 to 3). In addition, the hybrid vehicle has two driving modes: an EV (Electric Vehicle) mode in which the vehicle is driven using the motor generator, and an HEV (Hybrid Electric Vehicle) mode in which the vehicle is driven using the engine and the motor generator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-98804 [Patent Document 2] JP 2005-130564 A [Patent Document 3] JP 2014-196104 A Summary of the Invention [Problem to be solved by the invention]

[0004] When switching the driving mode from HEV mode to EV mode, it is necessary to release the clutch between the engine and the wheels in order to disconnect the engine from the wheels and stop it. If the engine torque is increased in the HEV mode, there is a risk of a shock occurring due to excessive torque fluctuations when the clutch is released to switch the driving mode. The occurrence of such a shock is a factor that gives the driver a sense of discomfort, so there is a demand for reducing the shock occurring when switching the driving mode.

[0005] An object of the present invention is to reduce the shock that occurs when switching driving modes. [Means for solving the problem]

[0006] A vehicle control device according to one embodiment is a vehicle control device for controlling a vehicle, the vehicle control device including: a motor generator connected to a first wheel; an engine connected to the first wheel or the second wheel via a power transmission path; a speed change mechanism provided in the power transmission path; a clutch mechanism provided in the power transmission path and positioned between the engine and the speed change mechanism; and a control system including a processor and a memory communicatively connected to each other, the processor and the memory communicatively connected to each other, and controlling the motor generator, the engine, the speed change mechanism, and the clutch mechanism. do. The control system includes a first running mode in which the clutch mechanism is controlled to an engaged state, the engine is controlled to an operating state, and the motor generator is controlled to a rotating state, and a second running mode in which the clutch mechanism is controlled to a released state, the engine is controlled to a stopped state, and the motor generator is controlled to a rotating state. do. The control system controls the speed change ratio of the transmission mechanism. As the voltage becomes lower, Transition time long setting do. When switching from the first driving mode to the second driving mode, the control system engages the clutch mechanism for the transition time, and with the clutch mechanism engaged, reduces the torque of the engine and increases the power torque of the motor generator. A vehicle control device according to one embodiment is a vehicle control device for controlling a vehicle, the vehicle control device including a motor generator connected to a first wheel, an engine connected to the first wheel or the second wheel via a power transmission path, a speed change mechanism provided in the power transmission path, a clutch mechanism provided in the power transmission path and positioned between the engine and the speed change mechanism, and a control system including a processor and a memory communicably connected to each other, and controlling the motor generator, the engine, the speed change mechanism, and the clutch mechanism. The control system includes a first driving mode in which the clutch mechanism is controlled to an engaged state, the engine is controlled to an operating state, and the motor generator is controlled to a rotating state, and a second driving mode in which the clutch mechanism is controlled to a released state, the engine is controlled to a stopped state, and the motor generator is controlled to a rotating state. The control system sets a transition time based on a gear ratio of the speed change mechanism and an absolute value of vehicle acceleration. The control system sets the transition time to be longer as the absolute value of the vehicle acceleration becomes smaller. When switching from the first driving mode to the second driving mode, the control system engages the clutch mechanism for the transition time, and with the clutch mechanism engaged, reduces the torque of the engine and increases the power torque of the motor generator. Effect of the Invention

[0007] In one embodiment, when switching from a first driving mode to a second driving mode, the vehicle control device engages a clutch mechanism for a transition time, and while the clutch mechanism is engaged, reduces the torque of the engine and increases the power torque of the motor generator, thereby reducing the shock when switching the driving mode. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing an example of the configuration of a vehicle equipped with a vehicle control device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram illustrating an example of the configuration of a vehicle control device. [Diagram 3] FIG. 2 is a diagram simply illustrating the basic structure of each control unit. [Figure 4] FIG. 11 is a diagram showing an execution state of an EV mode. [Figure 5A] FIG. 11 is a diagram showing an execution state of an HEV mode. [Figure 5B] FIG. 11 is a diagram showing an execution state of an HEV mode. [Figure 6] 4 is a driving mode map showing an example of an execution region of an EV mode and an HEV mode. [Figure 7] 4 is a flowchart showing an example of an execution procedure of a driving mode switching control. [Figure 8] FIG. 4 is a diagram showing an example of a relationship between a gear ratio and a first time. [Figure 9] FIG. 11 is a diagram illustrating an example of a relationship between vehicle acceleration and a second time. [Figure 10] FIG. 11 is a diagram illustrating an example of a relationship between engine torque and a third time. [Figure 11] 4 is a timing chart showing an execution state of the running mode switching control according to the first embodiment. [Figure 12] 5 is a timing chart showing an execution state of driving mode switching control as a comparative example. [Figure 13] 10 is a timing chart showing an execution state of a running mode switching control according to a second embodiment. [Figure 14] FIG. 13 is a diagram showing another example of the configuration of the powertrain. [Figure 15] FIG. 13 is a diagram showing another example of the configuration of the powertrain. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or substantially same configurations and elements will be designated by the same reference numerals and will not be described repeatedly.

[0010] [Overall configuration] FIG. 1 is a diagram showing an example of the configuration of a vehicle 11 equipped with a vehicle control device 10 according to an embodiment of the present invention. As shown in FIG. 1, the vehicle 11 is equipped with a powertrain 14 equipped with an engine 12 and a transmission 13. The vehicle 11 shown in the figure is a hybrid vehicle, and a motor generator 15 is incorporated in the transmission 13 as a power source. In addition, rear wheels (first wheels) 19r are connected to an output shaft 16 of the transmission 13 via a propeller shaft 17 and a differential mechanism 18. The powertrain 14 shown in the figure is a powertrain for rear-wheel drive that drives the rear wheels 19r, but is not limited to this. For example, it may be a powertrain for front-wheel drive that drives the front wheels (second wheels) 19f, or it may be an all-wheel drive powertrain that drives both the front wheels 19f and the rear wheels 19r.

[0011] FIG. 2 is a diagram showing a configuration example of the vehicle control device 10. As shown in FIG. 2, the power train 14 is provided with a continuously variable transmission mechanism (transmission mechanism) 22 consisting of a primary pulley 20, a secondary pulley 21, and a drive chain 27. The engine 12 is connected to one side of a primary shaft 23 supporting the primary pulley 20 via a forward clutch (clutch mechanism) 24 and a torque converter 25. The rotor 15r of the motor generator 15 is connected to the other side of the primary shaft 23 supporting the primary pulley 20. Furthermore, the rear wheels 19r are connected to a secondary shaft 26 supporting the secondary pulley 21 via an output shaft 16, a propeller shaft 17, and a differential mechanism 18. The forward clutch 24 is a clutch that constitutes a part of a forward / reverse switching mechanism.

[0012] The engine 12 and the rear wheels 19r are connected via a power transmission path 30 that includes the torque converter 25, the forward clutch 24, the continuously variable transmission mechanism 22, the propeller shaft 17, the differential mechanism 18, etc. In the illustrated example, as shown in Fig. 2, the power transmission path 30 includes the crankshaft 31, the torque converter 25, the turbine shaft 32, the forward clutch 24, the primary shaft 23, the continuously variable transmission mechanism 22, the secondary shaft 26, the output shaft 16, the propeller shaft 17, and the differential mechanism 18.

[0013] As described above, the forward clutch 24 and the continuously variable transmission mechanism 22 are provided on the power transmission path 30 that connects the engine 12 and the rear wheel 19r. The forward clutch 24 on the power transmission path 30 is located between the engine 12 and the continuously variable transmission mechanism 22. Furthermore, the motor generator 15 is connected to the primary shaft 23 that constitutes the power transmission path 30. In other words, the motor generator 15 is connected from the input side of the continuously variable transmission mechanism 22 to the rear wheel 19r via the power transmission path 30.

[0014] An intake manifold 40 of the engine 12 is provided with a throttle valve 41 that adjusts the amount of intake air. The engine 12 is also provided with an injector 42 that injects fuel into the intake port and cylinder, and an ignition device 43 consisting of an igniter, a spark plug, etc. The engine 12 is also provided with an engine rotation sensor 44 that detects the engine speed. In order to control the torque output from the engine 12 (hereinafter referred to as engine torque), an engine control unit CU1, which is an electronic control unit, is connected to the throttle valve 41, the injector 42, the ignition device 43, etc.

[0015] In order to control the forward clutch 24, the continuously variable transmission mechanism 22, and the like of the powertrain 14, a valve unit 45 consisting of a plurality of electromagnetic valves, oil passages, and the like is provided in the powertrain 14. An oil pump 46 driven by an engine or the like is connected to the valve unit 45. The hydraulic oil discharged from the oil pump 46 is supplied to the forward clutch 24, the continuously variable transmission mechanism 22, and the like after the supply destination, pressure, and the like are controlled by the valve unit 45. In order to control the operating state of the forward clutch 24, etc. via the valve unit 45, a transmission control unit CU2, which is an electronic control unit, is connected to the valve unit 45. A primary rotation sensor 47 that detects the rotation speed of the primary pulley 20 and a secondary rotation sensor 48 that detects the rotation speed of the secondary pulley 21 are connected to the transmission control unit CU2.

[0016] A battery module 51 is connected to the stator 15s of the motor generator 15 via an inverter 50. A plurality of battery cells 53 constituting a high-voltage battery 52 are incorporated in the battery module 51. Furthermore, the battery module 51 is provided with a main relay 54 for controlling the connection of the high-voltage battery 52, and a battery sensor 55 for detecting the charge / discharge current, terminal voltage, temperature, and the like of the high-voltage battery 52. ​​A battery control unit CU3, which is an electronic control unit, is also connected to the battery module 51. The battery control unit CU3 has a function of monitoring the charge / discharge of the high-voltage battery 52 and controlling the main relay 54 and the like. The battery control unit CU3 also has a function of calculating a state of charge (SOC) of the high-voltage battery 52 based on the charge / discharge current, terminal voltage, and the like detected by the battery sensor 55. The SOC of the high-voltage battery 52 is a ratio indicating the remaining amount of electricity in the high-voltage battery 52, and is the ratio of the amount of stored electricity to the full charge capacity of the high-voltage battery 52.

[0017] Further, a motor control unit CU4, which is an electronic control unit, is connected to the inverter 50 that controls the energization of the motor generator 15. The motor control unit CU4 controls the motor torque output from the motor generator 15 by controlling the inverter 50, which is composed of a plurality of switching elements and the like. The motor torque of the motor generator 15 includes a powering torque output from the motor generator 15 in a powering state and a generated torque output from the motor generator 15 in a generating state. The acting direction of the powering torque and the acting direction of the generated torque are opposite to each other. When the motor generator 15 is controlled to be in a powering state, the DC power from the high-voltage battery 52 is converted to AC power via the inverter 50 and supplied to the stator 15s. On the other hand, when the motor generator 15 is controlled to be in a generating state, the AC power from the stator 15s is converted to DC power via the inverter 50 and supplied to the high-voltage battery 52.

[0018] [Control System] As shown in FIG. 2, the vehicle control device 10 is provided with a control system 60 consisting of a plurality of electronic control units in order to control the powertrain 14. The electronic control units constituting the control system 60 include the engine control unit CU1, the transmission control unit CU2, the battery control unit CU3, and the motor control unit CU4 described above. The electronic control units constituting the control system 60 also include a vehicle control unit CU5 that outputs control signals to the control units CU1 to CU4. These control units CU1 to CU5 are connected to each other so as to be able to communicate with each other via an in-vehicle network 61 such as a CAN (Controller Area Network). The vehicle control unit CU5 sets an operation target for the powertrain 14 based on input information from the various control units CU1 to CU4 and various sensors described later. Then, the vehicle control unit CU5 generates control signals according to the operation targets of the powertrain 14 and outputs these control signals to the various control units.

[0019] Sensors connected to the vehicle control unit CU5 include a vehicle speed sensor 62 that detects the vehicle speed, which is the traveling speed of the vehicle 11, an accelerator sensor 63 that detects the amount of accelerator pedal operation, and a brake sensor 64 that detects the amount of brake pedal operation. An acceleration sensor 65 that detects vehicle acceleration acting on the front and rear of the vehicle is also connected to the vehicle control unit CU5. A start switch 66 that is operated by the driver when starting up the control system 60 is also connected to the vehicle control unit CU5.

[0020] Fig. 3 is a diagram simply illustrating the basic structure of each of the control units CU1 to CU5. As shown in Fig. 3, each of the control units CU1 to CU5 has a microcontroller 72 incorporating a processor 70, a memory 71, and the like. A predetermined program is stored in the memory 71, and an instruction set of the program is executed by the processor 70. The processor 70 and the memory 71 are connected to each other so as to be able to communicate with each other. In the illustrated example, one processor 70 and one memory 71 are incorporated in the microcontroller 72, but this is not limited thereto, and multiple processors 70 may be incorporated in the microcontroller 72, and multiple memories 71 may be incorporated in the microcontroller 72.

[0021] Each of the control units CU1 to CU5 is provided with an input conversion circuit 73, a drive circuit 74, a communication circuit 75, an external memory 76, a power supply circuit 77, and the like. The input conversion circuit 73 converts signals input from various sensors into signals that can be input to the microcontroller 72. The drive circuit 74 generates drive signals for actuators such as the valve unit 45 described above based on signals output from the microcontroller 72. The communication circuit 75 converts signals output from the microcontroller 72 into communication signals directed to other control units. The communication circuit 75 also converts communication signals received from other control units into signals that can be input to the microcontroller 72. The power supply circuit 77 supplies a stable power supply voltage to the microcontroller 72, the input conversion circuit 73, the drive circuit 74, the communication circuit 75, the external memory 76, and the like. The external memory 76, such as a non-volatile memory, stores data that should be retained even when power is not applied.

[0022] [Driving mode] Fig. 4 is a diagram showing an execution state of the EV mode, and Figs. 5A and 5B are diagrams showing an execution state of the HEV mode. The control system 60 has an EV (Electric Vehicle) mode and an HEV (Hybrid Electric Vehicle) mode as driving modes. As described later, the EV mode is a driving mode in which the engine 12 is stopped and the motor generator 15 is operated, and the HEV mode is a driving mode in which the engine 12 and the motor generator 15 are operated. In this specification, the HEV mode is a first driving mode, and the EV mode is a second driving mode.

[0023] As shown in Fig. 4, when executing the EV mode, the control system 60 controls the forward clutch 24 to a released state, controls the engine 12 to a stopped state, and controls the motor generator 15 to a powering state (rotating state). As a result, as shown by the white arrow in Fig. 4, the powering torque can be transmitted to the rear wheels 19r, and the vehicle 11 can be driven using the motor generator 15. When decelerating the vehicle 11, the motor generator 15 is controlled to a regenerative power generation state, and the kinetic energy of the vehicle 11 is converted into electrical energy and stored in the high-voltage battery 52.

[0024] The control system 60 also has, as the HEV mode, an assist mode in which the motor generator 15 is controlled to a power running state, and a power generation travel mode in which the motor generator 15 is controlled to a power generating state. As shown in FIG. 5A, when executing the assist mode, the control system 60 controls the forward clutch 24 to an engaged state, controls the engine 12 to an operating state, and controls the motor generator 15 to a power running state (rotating state). As a result, as shown by the white arrows in FIG. 5A, the engine torque and power running torque can be transmitted to the rear wheels 19r, and the vehicle 11 can be driven using the engine 12 and the motor generator 15. When decelerating the vehicle 11, the motor generator 15 is controlled to a regenerative power generating state, and the kinetic energy of the vehicle 11 is converted into electric energy and stored in the high voltage battery 52.

[0025] As shown in Fig. 5B, when executing the power-generating traveling mode, the control system 60 controls the forward clutch 24 to an engaged state, controls the engine 12 to an operating state, and controls the motor generator 15 to a power-generating state (rotating state). This makes it possible to transmit engine torque to the rear wheels 19r and to the motor generator 15, as shown by the white arrows in Fig. 5B. In other words, the vehicle 11 can be driven using the engine torque while operating the motor generator 15 in a power-generating state using the engine torque.

[0026] Here, Fig. 6 is a driving mode map showing an example of an execution region of the EV mode and the HEV mode. As shown in Fig. 6, a boundary line L1 is set in the driving mode map to divide the execution region of the EV mode and the HEV mode. The required driving force shown in Fig. 6 is a driving force required by the control system 60 to the powertrain 14. The control system 60 can set the required driving force based on, for example, the accelerator opening, which is the amount of operation of the accelerator pedal. That is, the required driving force is set to be larger as the accelerator opening increases, and the required driving force is set to be smaller as the accelerator opening decreases.

[0027] As shown by arrow A in Fig. 6, when the required driving force or vehicle speed drops below boundary line L1 in HEV mode, the control system 60 switches the driving mode from HEV mode to EV mode. That is, if the vehicle was traveling in assist mode, the mode is switched from assist mode to EV mode, and if the vehicle was traveling in power generation driving mode, the mode is switched from power generation driving mode to EV mode. On the other hand, as shown by arrow B in Fig. 6, when the required driving force or vehicle speed increases to exceed boundary line L1 in EV mode, the driving mode is switched from EV mode to HEV mode.

[0028] As described above, the HEV mode includes the assist mode and the power generation traveling mode, and whether the assist mode or the power generation traveling mode is executed is determined based on the SOC of the high-voltage battery 52, etc. For example, when the required driving force or the vehicle speed increases to exceed the boundary line L1, if the SOC of the high-voltage battery 52 exceeds a predetermined value, the traveling mode is switched from the EV mode to the assist mode. Also, when the required driving force or the vehicle speed increases to exceed the boundary line L1, if the SOC of the high-voltage battery 52 is below a predetermined value, the traveling mode is switched from the EV mode to the power generation traveling mode.

[0029] [Driving mode switching control (flowchart)] Next, a description will be given of a driving mode switching control for switching the driving mode from the HEV mode to the EV mode. FIG. 7 is a flowchart showing an example of the execution procedure of the driving mode switching control. FIG. 8 is a diagram showing an example of the relationship between the gear ratio and the first time T1. FIG. 9 is a diagram showing an example of the relationship between the vehicle acceleration and the second time T2, and FIG. 10 is a diagram showing an example of the relationship between the engine torque and the third time T3. Each step shown in the flowchart of FIG. 7 shows a process executed by one or more processors 70 constituting the control system 60. The driving mode switching control shown in FIG. 7 is a control executed by the control system 60 at predetermined intervals after the driver operates the start switch 66 and the control system 60 consisting of the vehicle control unit CU5 and the like is started.

[0030] As shown in FIG. 7, in step S10, the control system 60 determines whether the HEV mode is being executed. That is, in step S10, the control system 60 determines whether the assist mode or the power generation traveling mode is being executed. If it is determined in step S10 that the HEV mode is being executed, the control system 60 proceeds to step S11 and determines whether the first transition flag is set to ON. Here, the first transition flag is a control flag that is set to ON when it is determined to switch from the HEV mode to the EV mode. That is, the first transition flag is a control flag that is set to ON at the timing when the driving state of the vehicle 11 falls below the boundary line L1 due to a decrease in the required driving force or vehicle speed in the HEV mode, as shown by the symbol x1 in FIG. 6.

[0031] If it is determined in step S11 that the first transition flag is set to ON, the control system 60 proceeds to step S12 and sets the transition time Tt. That is, in step S12, the control system 60 sets the first time T1, the second time T2, and the third time T3 based on the gear ratio, the vehicle acceleration, and the engine torque, and sets the transition time Tt by adding up these times T1 to T3. Here, as shown in FIG. 8, the first time T1 constituting the transition time Tt is set longer as the gear ratio of the continuously variable transmission mechanism 22 becomes lower. Also, as shown in FIG. 9, the second time T2 is set shorter as the vehicle acceleration increases toward the acceleration side (+ side), and the second time T2 is set shorter as the vehicle acceleration increases toward the deceleration side (- side). That is, as shown in FIG. 9, the second time T2 constituting the transition time Tt is set longer as the absolute value of the vehicle acceleration decreases. Furthermore, as shown in FIG. 10, the third time T3 constituting the transition time Tt is set longer as the engine torque increases.

[0032] The gear ratio of the continuously variable transmission 22 is calculated by the transmission control unit CU2, the engine torque is calculated by the engine control unit CU1, and the vehicle acceleration is detected by the acceleration sensor 65. Out Force vs. rotational speed Enter The ratio is the ratio of the rotational speed of the primary shaft 23 to the rotational speed of the secondary shaft 26. In other words, a change in the gear ratio to the low side means that the value of the gear ratio becomes larger, and a change in the gear ratio to the high side means that the value of the gear ratio becomes smaller.

[0033] As shown in FIG. 7, when the transition time Tt is set in step S12, the control system 60 proceeds to step S13 and executes the mode switching process. That is, in step S13, the control system 60 controls the forward clutch 24 to an engaged state, reduces the engine torque, and increases the power torque of the motor generator 15. Then, the control system 60 proceeds to step S14 and determines whether the transition time Tt has elapsed since the start of the mode switching process. If it is determined in step S14 that the transition time Tt has not elapsed, the control system 60 returns to step S13 and continues executing the mode switching process. On the other hand, if it is determined in step S14 that the transition time Tt has elapsed, the control system 60 proceeds to step S15, controls the forward clutch 24 to a released state, and sets a second transition flag, which means that switching to the EV mode has been completed, to ON.

[0034] In this way, the control system 60 sets the transition time Tt based on the gear ratio, vehicle acceleration, and engine torque, and executes the mode switching process over this transition time Tt to switch the driving mode from the HEV mode to the EV mode. That is, the forward clutch 24 is controlled to be in an engaged state over the transition time Tt that is set based on the gear ratio, vehicle acceleration, and engine torque. Then, with the forward clutch 24 in an engaged state, the engine torque is reduced and the power torque of the motor generator is increased. This reduces the shock when the forward clutch 24 is released, and the driving mode can be switched from the HEV mode to the EV mode without giving a sense of discomfort to the driver.

[0035] [Driving mode switching control (timing chart)] [Example 1] Next, the above-mentioned running mode switching control will be described with reference to a timing chart as Example 1. Fig. 11 is a timing chart showing the execution state of the running mode switching control as Example 1. In Fig. 11, "Tcl" is the clutch torque transmitted by the forward clutch 24, "Tpri" is the input torque to the primary pulley 20, and "Tmg" is the motor torque (power torque, power generation torque).

[0036] As shown in Fig. 11, at time t11, the power generation travel mode, which is the HEV mode, is executed (symbol a1), so that the forward clutch 24 is controlled to be in the engaged state (symbol b1), the engine torque, i.e., the clutch torque Tcl, is increased (symbol c1), and the motor torque Tmg is increased to the power generation side (symbol d1). Subsequently, as shown in time t12, when the first transition flag is set to ON (symbol e1), the forward clutch 24 is controlled to be in the engaged state (symbol b2), the engine torque, i.e., the clutch torque Tcl, is decreased (symbol c2), and the motor torque Tmg is increased to the power running side (symbol d2). Note that in the example shown in Fig. 11, since the power generation travel mode is in effect, the power generation torque of the motor generator 15 is decreased and then the power running torque of the motor generator 15 is increased, as shown in symbol d2. Next, as shown at time t13, when the transition time Tt has elapsed and the second transition flag is set to ON (symbol f1), the forward clutch 24 is controlled to the released state (symbol b3) and the driving mode is switched to the EV mode (symbol a2). In addition, when the forward clutch 24 is controlled to the released state (symbol b3), the injector 42 is controlled to the fuel cut state (symbol g1).

[0037] In this way, the forward clutch 24 is engaged over the transition time Tt, the engine torque is reduced, and the powering torque of the motor generator 15 is increased. As a result, when the forward clutch 24 is released, the engine torque, i.e., the clutch torque Tcl, can be sufficiently reduced, and the release shock of the forward clutch 24 can be reduced. In addition, because the powering torque of the motor generator 15 is increased, even when the engine torque is reduced, excessive fluctuations in the vehicle acceleration can be suppressed as shown by the arrow α1, and the driving mode can be switched without causing a sense of discomfort to the driver.

[0038] Moreover, as shown in Fig. 8, as the gear ratio of the continuously variable transmission mechanism 22 becomes lower, the transition time Tt for reducing the engine torque is set longer. A situation in which the continuously variable transmission mechanism 22 is controlled to the lower side is a situation in which the engine torque is amplified and transmitted to the rear wheels 19r, and the interruption of the engine torque accompanying the clutch release is likely to cause fluctuations in the vehicle acceleration. By setting the transition time Tt longer in such a driving situation, the engine torque can be sufficiently reduced, and the release shock of the forward clutch 24 can be reduced. This makes it possible to switch the driving mode without giving a sense of discomfort to the driver.

[0039] As shown in FIG. 9, the transition time Tt for reducing engine torque is set longer as the absolute value of vehicle acceleration becomes smaller. A situation where the absolute value of vehicle acceleration is small is a situation where the change in vehicle acceleration accompanying clutch release is likely to give the driver a sense of discomfort. By setting the transition time Tt longer in such a driving situation, the engine torque can be sufficiently reduced and the fluctuation in vehicle acceleration accompanying clutch release can be suppressed. This makes it possible to switch the driving mode without giving the driver a sense of discomfort.

[0040] Also, as shown in Fig. 10, the transition time Tt for reducing the engine torque is set longer as the engine torque increases. A situation where the engine torque is high is a situation where the engine torque interruption caused by the clutch release is likely to cause fluctuations in the vehicle acceleration. By setting the transition time Tt longer in such a driving situation, the engine torque can be sufficiently reduced, and the release shock of the forward clutch 24 can be reduced. This makes it possible to switch the driving mode without giving the driver a sense of discomfort.

[0041] 11, the engine torque and the motor torque are controlled so as to keep the vehicle acceleration constant, that is, so as to keep the input torque Tpri to the primary pulley 20 constant, but this is not limiting. For example, the engine torque and the motor torque may be controlled so as to increase the vehicle acceleration, or so as to decrease the vehicle acceleration.

[0042] [Comparative Example] Fig. 12 is a timing chart showing the execution state of the traveling mode switching control as a comparative example. As shown in Fig. 12, at time t21, the power generation traveling mode, which is the HEV mode, is executed (symbol a1), so that the forward clutch 24 is controlled to the engaged state (symbol b1), the engine torque, i.e., the clutch torque Tcl, is increased (symbol c1), and the motor torque Tmg is increased to the power generation side (symbol d1). Then, as shown at time t22, when the first transition flag is set to ON (symbol e1), the forward clutch 24 is controlled to the released state (symbol b2), and the traveling mode is switched to the EV mode (symbol a2). In addition, when the forward clutch 24 is controlled to the released state (symbol b2), the injector 42 is controlled to the fuel cut state (symbol g1).

[0043] In this way, if the forward clutch 24 is controlled to the released state in response to the first transition flag being set to ON without controlling the engine torque and motor torque using the transition time Tt, the clutch torque Tcl will suddenly decrease due to the clutch release (symbol c2). In other words, as shown by arrow α2, the vehicle acceleration will suddenly change due to the clutch release, causing the driver to feel a great sense of discomfort when the driving mode is switched. In contrast, if the engine torque and motor torque are controlled using the transition time Tt, excessive fluctuations in the vehicle acceleration can be suppressed, as shown by arrow α1 in FIG. 11, and the driving mode can be switched without causing the driver to feel a sense of discomfort.

[0044] [Example 2] In the example shown in Fig. 11, the driving mode is switched from the power generation driving mode to the EV mode, but this is not limited to this, and the driving mode may be switched from the assist mode to the EV mode. Here, Fig. 13 is a timing chart showing the execution status of the driving mode switching control as the second embodiment.

[0045] As shown in FIG. 13, at time t31, the assist mode, which is the HEV mode, is executed (symbol a1), so that the forward clutch 24 is controlled to be in the engaged state (symbol b1), the engine torque, i.e., the clutch torque Tcl, is increased (symbol c1), and the motor torque Tmg is increased to the power running side (symbol d1). Then, as shown at time t32, when the first transition flag is set to ON (symbol e1), the forward clutch 24 is controlled to be in the engaged state (symbol b2), the engine torque, i.e., the clutch torque Tcl, is decreased (symbol c2), and the motor torque Tmg is increased to the power running side (symbol d2). Next, as shown at time t33, when the transition time Tt has elapsed and the second transition flag is set to ON (symbol f1), the forward clutch 24 is controlled to be in the released state (symbol b3), and the traveling mode is switched to the EV mode (symbol a2). Also, when the forward clutch 24 is controlled to be in the released state (symbol b3), the injector 42 is controlled to be in the fuel cut state (symbol g1).

[0046] In this way, the forward clutch 24 is engaged over the transition time Tt, the engine torque is reduced, and the powering torque of the motor generator 15 is increased. As a result, when the forward clutch 24 is released, the engine torque, i.e., the clutch torque Tcl, can be sufficiently reduced, and the release shock of the forward clutch 24 can be reduced. Furthermore, since the powering torque of the motor generator 15 is increased, even if the engine torque is reduced, excessive fluctuations in the vehicle acceleration can be suppressed as shown by the arrow α3, and the driving mode can be switched without giving a sense of discomfort to the driver. Note that, even in the example shown in FIG. 13, the transition time Tt is set based on the gear ratio, the vehicle acceleration, and the engine torque.

[0047] [Other Powertrain Embodiments] The configuration of the powertrain 14 is not limited to that shown in Fig. 2, and may be a powertrain having another configuration. Fig. 14 and Fig. 15 are diagrams showing other examples of the powertrain configuration.

[0048] As shown in FIG. 14, the engine 12 and the rear wheel 19r are connected via a power transmission path 30 formed of a rotating shaft and the like. The power transmission path 30 connecting the engine 12 and the rear wheel 19r is provided with a forward clutch 24 and a continuously variable transmission mechanism 22. The forward clutch 24 is located between the engine 12 and the continuously variable transmission mechanism 22. The secondary shaft 26 constituting the power transmission path 30 is connected to the motor generator 15 via a gear train 80. That is, the motor generator 15 is connected to the rear wheel 19r from the output side of the continuously variable transmission mechanism 22 via the power transmission path 30. Even a vehicle control device that controls such a power train 81 can be made to function in the same manner as the vehicle control device 10 described above. In the examples shown in FIG. 14 and the above-mentioned FIG. 4, the engine 12 and the motor generator 15 are connected to the rear wheel 19r, but this is not limited thereto. For example, the engine 12 and the motor generator 15 may be connected to the front wheel 19f shown in FIG. 1. In this case, the front wheel 19f functions as a first wheel, and the rear wheel 19r functions as a second wheel.

[0049] As shown in FIG. 15, the motor generator 15 is connected to the rear wheel (first wheel) 90r via a power transmission path 91. The engine 12 is connected to the front wheel (second wheel) 90f via a power transmission path 92 formed of a rotating shaft or the like. The forward clutch 24 and the continuously variable transmission mechanism 22 are provided in the power transmission path 92 connecting the engine 12 and the front wheel 90f. The forward clutch 24 on the power transmission path 92 is located between the engine 12 and the continuously variable transmission mechanism 22. Thus, in the illustrated power train 93, the engine 12 is connected to the front wheel 90f, while the motor generator 15 is connected to the rear wheel 90r. Even a vehicle control device that controls such a power train 94 can function in the same manner as the vehicle control device 10 described above. Note that a configuration in which the engine 12 is connected to the rear wheel 90r, while the motor generator 15 is connected to the front wheel 90f may be used. In this case, the front wheel 90f functions as a first wheel, and the rear wheel 90r functions as a second wheel. Also, the motor generator 15 may be a so-called in-wheel motor provided within the hub of the front wheel 90f or the rear wheel 90r.

[0050] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the gist of the present invention. In the above description, the control system 60 is configured by a plurality of control units CU1 to CU5, but the present invention is not limited to this. For example, the control system 60 may be configured by one control unit. In the above description, the continuously variable transmission mechanism 22 consisting of a pair of pulleys 20 and 21 is used as the transmission mechanism provided in the power transmission path 30, but the present invention is not limited to this, and may be a planetary gear type or a parallel shaft type automatic transmission mechanism. In addition, the forward clutch 24 may be a friction clutch or a mesh clutch. In the example shown in FIG. 11, the injector 42 is controlled to a fuel cut state after the forward clutch 24 is released, but the present invention is not limited to this, and the injector 42 may be controlled to a fuel cut state before the forward clutch 24 is released.

[0051] In the examples shown in Fig. 11 and Fig. 13, the engine torque and the motor torque (powering torque, power generation torque) are changed continuously over the transition time Tt, but the present invention is not limited to this. For example, the engine torque may be decreased and the powering torque of the motor generator 15 may be increased at any timing within the transition time Tt. Even in this case, the engine torque can be decreased and the powering torque can be increased while the forward clutch 24 is engaged, and the shock when the forward clutch 24 is released can be reduced. That is, when switching from the HEV mode to the EV mode, the control system 60 engages the forward clutch 24 over the transition time Tt, and while the forward clutch 24 is engaged, the torque of the engine 12 is decreased and the powering torque of the motor generator 15 is increased.

[0052] In the above description, the transition time Tt is set based on the gear ratio, the vehicle acceleration, and the engine torque, but the present invention is not limited thereto. For example, the transition time Tt may be set based only on the gear ratio, the transition time Tt may be set based on the gear ratio and the vehicle acceleration, or the transition time Tt may be set based on the gear ratio and the engine torque. The transition time Tt may be set based on at least one of the gear ratio, the vehicle acceleration, and the engine torque. In the example shown in FIG. 8 to FIG. 10, the times T1 to T3 constituting the travel time Tt are set continuously, but the present invention is not limited thereto, and the times T1 to T3 may be set stepwise. In the above description, the travel time Tt is calculated by adding the times T1 to T3, but the present invention is not limited thereto. For example, a coefficient may be set based on the gear ratio, the vehicle acceleration, and the engine torque, and the travel time Tt may be calculated by multiplying the coefficient by the basic time. [Explanation of symbols]

[0053] 10 Vehicle control device 11 Vehicles 12 Engine 15 Motor generator 19f Front wheel (2nd wheel) 19r Rear wheel (first wheel) 22 Continuously variable transmission (transmission mechanism) 24 Forward clutch (clutch mechanism) 30 Power transmission path 60 Control System 70 Processors 71 Memory 90f front wheel (2nd wheel) 90r rear wheel (1st wheel) 92 Power transmission path Tt Transition Time

Claims

1. A vehicle control device that controls a vehicle, A motor generator connected to the first wheel; an engine connected to the first wheel or the second wheel via a power transmission path; a speed change mechanism provided in the power transmission path; a clutch mechanism provided in the power transmission path and positioned between the engine and the transmission mechanism; a control system including a processor and a memory communicatively connected to each other, the control system controlling the motor generator, the engine, the transmission mechanism, and the clutch mechanism; having The control system includes: a first traveling mode in which the clutch mechanism is controlled to an engaged state, the engine is controlled to an operating state, and the motor generator is controlled to a rotating state; a second traveling mode in which the clutch mechanism is controlled to a released state, the engine is controlled to a stopped state, and the motor generator is controlled to a rotating state; Equipped with the control system sets a transition time longer as the gear ratio of the transmission mechanism becomes lower, the control system engages the clutch mechanism for the transition time when switching from the first driving mode to the second driving mode, and reduces the torque of the engine and increases the power torque of the motor generator while the clutch mechanism is engaged. Vehicle control device.

2. 2. The vehicle control device according to claim 1, The control system sets the transition time to be longer as the absolute value of the vehicle acceleration becomes smaller. Vehicle control device.

3. 3. The vehicle control device according to claim 1, The control system sets the transition time to be longer as the torque of the engine increases. Vehicle control device.

4. The vehicle control device according to any one of claims 1 to 3, The first traveling mode is a traveling mode in which the clutch mechanism is controlled to an engaged state, the engine is controlled to an operating state, and the motor generator is controlled to a power generating state. Vehicle control device.

5. A vehicle control device that controls a vehicle, A motor generator connected to the first wheel; an engine connected to the first wheel or the second wheel via a power transmission path; a speed change mechanism provided in the power transmission path; a clutch mechanism provided in the power transmission path and positioned between the engine and the transmission mechanism; a control system including a processor and a memory communicatively connected to each other, the control system controlling the motor generator, the engine, the transmission mechanism, and the clutch mechanism; having The control system includes: a first traveling mode in which the clutch mechanism is controlled to an engaged state, the engine is controlled to an operating state, and the motor generator is controlled to a rotating state; a second traveling mode in which the clutch mechanism is controlled to a released state, the engine is controlled to a stopped state, and the motor generator is controlled to a rotating state; Equipped with the control system sets a transition time based on a gear ratio of the transmission mechanism and an absolute value of vehicle acceleration; the control system sets the transition time to be longer as the absolute value of the vehicle acceleration becomes smaller; the control system engages the clutch mechanism for the transition time when switching from the first driving mode to the second driving mode, and reduces the torque of the engine and increases the power torque of the motor generator while the clutch mechanism is engaged. Vehicle control device.

Images