Vehicle control devices

Abstract

This invention provides a vehicle control device capable of reducing the impact during switching driving modes. The vehicle control device includes an electric generator connected to a first wheel, an engine connected to a first wheel or a second wheel via a power transmission path, a transmission mechanism disposed on the power transmission path, a clutch mechanism disposed on the power transmission path, and a control system for controlling the electric generator, the engine, the transmission mechanism, and the clutch mechanism. The control system includes a first driving mode engaging the clutch mechanism and a second driving mode disengaging the clutch mechanism. When switching from the first driving mode to the second driving mode, the clutch mechanism remains engaged throughout the transition time. In the engaged state, the engine torque is reduced, and the electric generator's operating torque is increased.

Description

Technical Field

[0001] This invention relates to a vehicle control device for controlling a vehicle. Background Technology

[0002] Hybrid vehicles are equipped with an engine and an electric generator as power sources (see Patent Documents 1-3). Furthermore, as driving modes, hybrid vehicles have an EV (Electric Vehicle) mode that uses the electric generator to drive the vehicle, and an HEV (Hybrid Electric Vehicle) mode that uses both the engine and the electric generator to drive the vehicle.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 10-98804

[0006] Patent Document 2: Japanese Patent Application Publication No. 2005-130564

[0007] Patent Document 3: Japanese Patent Application Publication No. 2014-196104 Summary of the Invention

[0008] Technical issues

[0009] However, when switching from HEV mode to EV mode, the clutch between the engine and wheels needs to be disengaged to stop the engine. In HEV mode, where engine torque is increased, this disengagement during mode switching can cause a shock due to excessive torque fluctuations. This shock is a major cause of driver discomfort; therefore, efforts are being made to reduce the shock during mode switching.

[0010] The purpose of this invention is to reduce the impact when switching driving modes.

[0011] Technical solution

[0012] One embodiment of a vehicle control device controls a vehicle, the vehicle control device comprising: an electric generator connected to a first wheel; an engine connected to the first wheel or a second wheel via a power transmission path; a transmission mechanism disposed in the power transmission path; a clutch mechanism disposed in the power transmission path and located between the engine and the transmission mechanism; and a control system having a processor and a memory communicatively connected to each other, and controlling the electric generator, the engine, the transmission mechanism, and the clutch mechanism, the control system including: a first driving mode that engages the clutch mechanism... The control system has two modes: a first driving mode and a second driving mode. The first mode controls the clutch mechanism to be engaged, the engine to be running, and the electric generator to be rotating. The second driving mode controls the clutch mechanism to be disengaged, the engine to be stopped, and the electric generator to be rotating. The control system sets the transition time based on the gear ratio of the transmission mechanism. When switching from the first driving mode to the second driving mode, the clutch mechanism is engaged throughout the transition time. In the engaged state, the engine torque is reduced, and the electric generator's operating torque is increased.

[0013] Technical effect

[0014] In one embodiment, the vehicle control device engages a clutch mechanism during the transition time when switching from a first driving mode to a second driving mode. While the clutch mechanism is engaged, the engine torque is reduced, and the operating torque of the electric generator is increased. This reduces the impact during driving mode switching. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating an example configuration of a vehicle equipped with a vehicle control device as an embodiment of the present invention.

[0016] Figure 2 This is a diagram showing an example of the configuration of a control device for a vehicle.

[0017] Figure 3 It is a diagram that simply shows the basic structure of each control unit.

[0018] Figure 4 This is a graph showing the execution status of EV mode.

[0019] Figure 5A This is a graph showing the execution status of HEV mode.

[0020] Figure 5B This is a graph showing the execution status of HEV mode.

[0021] Figure 6 This is a driving mode diagram showing an example of the execution areas for EV mode and HEV mode.

[0022] Figure 7 This is a flowchart illustrating an example of the execution sequence of driving mode switching control.

[0023] Figure 8 This is a graph illustrating an example of the relationship between the gear ratio and the first time.

[0024] Figure 9 This is a graph illustrating an example of the relationship between vehicle acceleration and a second time interval.

[0025] Figure 10 This is a graph illustrating an example of the relationship between engine torque and a third time.

[0026] Figure 11 This is a timing diagram illustrating the execution status of the driving mode switching control as an example 1.

[0027] Figure 12 This is a timing diagram showing the execution status of the driving mode switching control as a comparative example.

[0028] Figure 13 This is a timing diagram illustrating the execution status of the driving mode switching control as an example 2.

[0029] Figure 14 This is a diagram showing other configuration examples of a powertrain.

[0030] Figure 15 This is a diagram showing other configuration examples of a powertrain.

[0031] Symbol Explanation

[0032] 10: Vehicle control devices

[0033] 11: Vehicles

[0034] 12: Engine

[0035] 15: Electric generator

[0036] 19f: Front wheel (second wheel)

[0037] 19r: Rear wheel (first wheel)

[0038] 22: Continuously Variable Transmission (CVT) (Transmission Mechanism)

[0039] 24: Forward clutch (clutch mechanism)

[0040] 30: Power Transmission Path

[0041] 60: Control System

[0042] 70: Processor

[0043] 71: Memory

[0044] 90f: Front wheel (second wheel)

[0045] 90r: Rear wheel (first wheel)

[0046] 92: Power Transmission Path

[0047] Tt: Conversion time Detailed Implementation

[0048] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. It should be noted that in the following description, the same or substantially the same components and / or elements are labeled with the same symbols and repeated descriptions are omitted.

[0049] [Overall Composition]

[0050] Figure 1 This is a diagram showing an example configuration of a vehicle 11 equipped with a vehicle control device 10 as an embodiment of the present invention. Figure 1 As shown, vehicle 11 is equipped with a powertrain 14 comprising an engine 12 and a transmission 13. The illustrated vehicle 11 is a hybrid vehicle, and an electric generator 15 serving as a power source is mounted in the transmission 13. Furthermore, the rear wheel (first wheel) 19r is connected to the output shaft 16 of the transmission 13 via a drive shaft 17 and a differential mechanism 18. It should be noted that the illustrated powertrain 14 is a rear-wheel drive powertrain for driving the rear wheel 19r, but it is not limited to this. For example, it could be a front-wheel drive powertrain for driving the front wheel (second wheel) 19f, or it could be an all-wheel drive powertrain for driving both the front wheel 19f and the rear wheel 19r.

[0051] Figure 2 This is a diagram showing an example of the configuration of a vehicle control device 10. (As shown...) Figure 2 As shown, the powertrain 14 is equipped with a continuously variable transmission (CVT) 22 consisting of a main pulley 20, a secondary pulley 21, and a drive chain 27. On one side of the main shaft 23 supporting the main pulley 20, the engine 12 is connected via a forward clutch (clutch mechanism) 24 and a torque converter 25. On the other side of the main shaft 23 supporting the main pulley 20, the rotor 15r of an electric generator 15 is connected. Furthermore, on the secondary shaft 26 supporting the secondary pulley 21, the rear wheel 19r is connected via an output shaft 16, a drive shaft 17, and a differential mechanism 18. It should be noted that the forward clutch 24 is a clutch that forms part of the forward / reverse switching mechanism.

[0052] The engine 12 is connected to the rear wheel 19r via a power transmission path 30, which consists of a torque converter 25, a forward clutch 24, a continuously variable transmission (CVT) 22, a drive shaft 17, and a differential mechanism 18. In the illustrated example, as... Figure 2 As shown, the power transmission path 30 consists of a crankshaft 31, a torque converter 25, a turbine shaft 32, a forward clutch 24, a main shaft 23, a continuously variable transmission 22, a countershaft 26, an output shaft 16, a drive shaft 17, and a differential mechanism 18.

[0053] As described above, a forward clutch 24 and a continuously variable transmission (CVT) 22 are provided in the power transmission path 30 connecting the engine 12 and the rear wheel 19r. Furthermore, the forward clutch 24 on the power transmission path 30 is located between the engine 12 and the CVT 22. Additionally, an electric generator 15 is connected to the main shaft 23 constituting the power transmission path 30. That is, the electric generator 15 is connected to the rear wheel 19r from the input side of the CVT 22 via the power transmission path 30.

[0054] A throttle valve 41 for adjusting the intake air volume is provided in the intake manifold 40 of the engine 12. Additionally, the engine 12 is equipped with an injector 42 for injecting fuel into the intake port and / or cylinders, and an ignition device 43 consisting of an igniter and / or spark plugs. Furthermore, an engine rotation sensor 44 for detecting engine speed is provided in the engine 12. In addition, to control the torque output from the engine 12 (hereinafter referred to as engine torque), an engine control unit CU1, which serves as an electronic control unit, is connected to the throttle valve 41, the injector 42, and the ignition device 43.

[0055] To control the forward clutch 24 and / or continuously variable transmission (CVT) 22 of the powertrain 14, a valve unit 45 consisting of multiple solenoid valves and / or oil circuits is provided in the powertrain 14. Furthermore, an oil pump 46 driven by an engine is connected to the valve unit 45. Working oil discharged from the oil pump 46 is supplied to the forward clutch 24 and / or CVT 22, etc., with the supply target and / or pressure controlled by the valve unit 45. In addition, to control the operating state of the forward clutch 24, etc., via the valve unit 45, a transmission control unit CU2, which serves as an electronic control unit, is connected to the valve unit 45. It should be noted that a main rotation sensor 47 for detecting the rotational speed of the main pulley 20 and a secondary rotation sensor 48 for detecting the rotational speed of the auxiliary pulley 21 are connected to the transmission control unit CU2.

[0056] A battery module 51 is connected to the stator 15s of the electric generator 15 via a converter 50. Multiple battery cells 53 constituting a high-voltage battery 52 are assembled in the battery module 51. Furthermore, a main relay 54 is provided in the battery module 51 to control the connection of the high-voltage battery 52, and a battery sensor 55 is provided to detect the charging and discharging current, terminal voltage, and temperature of the high-voltage battery 52. ​​Additionally, a battery control unit CU3, which serves as an electronic control unit, is connected to the battery module 51. The battery control unit CU3 has the function of monitoring the charging and discharging of the high-voltage battery 52 and controlling the main relay 54, etc. Furthermore, the battery control unit CU3 has the function of calculating the State of Charge (SOC) of the high-voltage battery 52 based on the charging and discharging current and / or terminal voltage detected by the battery sensor 55. It should be noted that the SOC of the high-voltage battery 52 represents the ratio of the remaining charge of the high-voltage battery 52, which is the ratio of the stored charge of the high-voltage battery 52 to its full charge capacity.

[0057] Furthermore, a motor control unit CU4, which serves as an electronic control unit, is connected to the converter 50 that performs the power-on control of the electric generator 15. The motor control unit CU4 controls the motor torque output from the electric generator 15 by controlling the converter 50, which is composed of multiple switching elements, etc. It should be noted that the motor torque of the electric generator 15 includes the power operating torque output from the electric generator 15 in the power operation state and the power generating torque output from the electric generator 15 in the power generation state. The direction of action of the power operating torque and the direction of action of the power generating torque are opposite to each other. When the electric generator 15 is controlled in the power operation state, the DC power from the high-voltage battery 52 is converted into AC power by the converter 50 and supplied to the stator 15s. On the other hand, when the electric generator 15 is controlled in the power generation state, the AC power from the stator 15s is converted into DC power by the converter 50 and supplied to the high-voltage battery 52.

[0058] [Control System]

[0059] like Figure 2As shown, the vehicle control device 10 includes a control system 60 composed of multiple electronic control units (ECUs) for controlling the powertrain 14. The ECUs constituting the control system 60 include the engine control unit CU1, transmission control unit CU2, battery control unit CU3, and motor control unit CU4, as described above. Additionally, a vehicle control unit CU5, also constituting the control system 60, outputs control signals to each of the control units CU1 to CU4. These control units CU1 to CU5 are connected via an in-vehicle network 61, such as CAN (Controller Area Network), to enable communication between them. The vehicle control unit CU5 sets the operating target of the powertrain 14 based on input information from the various control units CU1 to CU4 and / or various sensors described later. Then, it generates control signals corresponding to the operating target of the powertrain 14 and outputs these control signals to the various control units.

[0060] As sensors connected to the vehicle control unit CU5, there is a vehicle speed sensor 62 that detects the vehicle speed, which is the driving speed of the vehicle 11; an acceleration sensor 63 that detects the amount of operation of the accelerator pedal; and a brake sensor 64 that detects the amount of operation of the brake pedal. Additionally, an acceleration sensor 65 that detects the vehicle's acceleration acting on the front and rear of the vehicle is connected to the vehicle control unit CU5. Furthermore, a start switch 66 operated by the driver when the control system 60 is activated is connected to the vehicle control unit CU5.

[0061] Figure 3 This is a diagram that simply shows the basic structure of each control unit CU1 to CU5. (For example...) Figure 3 As shown, each control unit CU1 to CU5 has a microcontroller 72 equipped with a processor 70 and a memory 71, etc. A predetermined program is stored in the memory 71, and the instruction set of the program is executed by the processor 70. The processor 70 and the memory 71 are connected in a manner that allows them to communicate with each other. It should be noted that in the illustrated example, one processor 70 and one memory 71 are assembled in the microcontroller 72, but this is not a limitation; multiple processors 70 and multiple memories 71 may be assembled in the microcontroller 72.

[0062] In addition, each control unit CU1 to CU5 is equipped with an input conversion circuit 73, a drive circuit 74, a communication circuit 75, an external memory 76, and a power supply circuit 77. 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 based on signals output from the microcontroller 72. The communication circuit 75 converts signals output from the microcontroller 72 into communication signals for other control units. Furthermore, the communication circuit 75 converts communication signals received from other control units into signals that can be input to the microcontroller 72. The power supply circuit 77 provides a stable power voltage to the microcontroller 72, the input conversion circuit 73, the drive circuit 74, the communication circuit 75, and the external memory 76. Additionally, the external memory 76, such as a non-volatile memory, stores data that should be retained even when the power is off.

[0063] [Driving Mode]

[0064] Figure 4 This is a graph showing the execution status of EV mode. Figure 5A and Figure 5B This diagram illustrates the execution status of the HEV mode. The control system 60 has EV (Electric Vehicle) mode and HEV (Hybrid Electric Vehicle) mode as driving modes. As described later, EV mode is a driving mode in which the engine 12 is stopped and the electric generator 15 is operated, while HEV mode is a driving mode in which both the engine 12 and the electric generator 15 are operated. Furthermore, in this specification, HEV mode is the first driving mode, and EV mode is the second driving mode.

[0065] like Figure 4 As shown, when executing EV mode, the control system 60 controls the forward clutch 24 to disengage, the engine 12 to stop, and the electric generator 15 to operate (rotate). Thus, as... Figure 4 As indicated by the hollow arrow, the power operating torque can be transmitted to the rear wheel 19r, and the vehicle 11 can be driven using the electric generator 15. It should be noted that when the vehicle 11 is decelerated, the electric generator 15 is controlled to regenerative power generation mode, and the kinetic energy of the vehicle 11 is converted into electrical energy and stored in the high-voltage battery 52.

[0066] In addition, as an HEV mode, the control system 60 has an auxiliary mode that controls the electric generator 15 to power operation and a power generation driving mode that controls the electric generator 15 to power generation. Figure 5AAs shown, when the auxiliary mode is executed, the control system 60 controls the forward clutch 24 to be engaged, the engine 12 to be running, and the electric generator 15 to be in power operation (rotation). Thus, as... Figure 5A As indicated by the hollow arrow, the engine torque and power operating torque can be transmitted to the rear wheels 19r, and the vehicle 11 can be driven using the engine 12 and the electric generator 15. It should be noted that when the vehicle 11 is decelerated, the electric generator 15 is controlled to regenerative power generation mode, and the kinetic energy of the vehicle 11 is converted into electrical energy and stored in the high-voltage battery 52.

[0067] like Figure 5B As shown, when the generator-driven driving mode is executed, the control system 60 controls the forward clutch 24 to be engaged, the engine 12 to be running, and the electric generator 15 to be generating power (rotating). Thus, as... Figure 5B As indicated by the hollow arrow, the engine torque can be transmitted to the rear wheel 19r and to the electric generator 15. That is, the engine torque can be used to make the electric generator 15 operate in a power generation state, and the engine torque can be used to make the vehicle 11 move.

[0068] Here, Figure 6 This is a driving mode diagram illustrating an example of the execution areas for EV mode and HEV mode. (Example:) Figure 6 As shown, the driving mode diagram includes a boundary line L1 that divides the execution areas for EV mode and HEV mode. It should be noted that... Figure 6 The requested driving force shown is the driving force requested from the control system 60 to the powertrain 14. The control system 60 can, for example, set the requested driving force based on the throttle opening, which is the amount of operation of the accelerator pedal. That is, the more the throttle opening increases, the larger the requested driving force is set, and the more the throttle opening decreases, the smaller the requested driving force is set.

[0069] like Figure 6 As indicated by arrow A, if the requested driving force and / or vehicle speed decreases below the boundary line L1 in HEV mode, the control system 60 switches the driving mode from HEV mode to EV mode. That is, it switches from auxiliary mode to EV mode when driving in auxiliary mode, and from power generation mode to EV mode when driving in power generation mode. On the other hand, as... Figure 6 As indicated by the middle arrow B, if the requested driving force and / or vehicle speed increases beyond the boundary line L1 in EV mode, the driving mode switches from EV mode to HEV mode.

[0070] As described above, the HEV mode includes an auxiliary mode and a power generation driving mode. Which mode to execute, auxiliary mode or power generation driving mode, is determined based on factors such as the state of charge (SOC) of the high-voltage battery 52. ​​For example, when the requested driving force and / or vehicle speed increases beyond the boundary line L1, if the SOC of the high-voltage battery 52 exceeds a predetermined value, the driving mode is switched from EV mode to auxiliary mode. Conversely, when the requested driving force and / or vehicle speed increases beyond the boundary line L1, if the SOC of the high-voltage battery 52 is below a predetermined value, the driving mode is switched from EV mode to power generation driving mode.

[0071] [Driving Mode Switching Control (Flowchart)]

[0072] Next, we will explain the driving mode switching control that switches the driving mode from HEV mode to EV mode. Figure 7 This is a flowchart illustrating an example of the execution sequence of driving mode switching control. Additionally, Figure 8 This is a graph illustrating an example of the relationship between the gear ratio and the first time T1. Furthermore, Figure 9 This is a graph illustrating an example of the relationship between vehicle acceleration and a second time interval T2. Figure 10 This is a graph illustrating an example of the relationship between engine torque and the third time point T3. It should be noted that, in Figure 7 The flowchart shows the steps, each involving processes executed by one or more processors 70 constituting the control system 60. Additionally, Figure 7 The driving mode switching control shown is a control system that is executed by the control system 60 according to each predetermined cycle after the driver operates the start switch 66 to start the control system 60, which is composed of the vehicle control unit CU5, etc.

[0073] like Figure 7 As shown, in step S10, the control system 60 determines whether it is in the process of executing HEV mode. That is, in step S10, the control system 60 determines whether it is in the process of executing auxiliary mode or generator driving mode. In step S10, if it is determined that it is in the process of executing HEV mode, the control system 60 proceeds to step S11 and determines whether the first conversion flag is set to ON (valid). Here, the first conversion flag is a control flag that is set to ON when it has been decided to switch from HEV mode to EV mode. That is, as... Figure 6 As shown by symbol x1, the first switching flag is a control flag that is set to ON when the driving state of vehicle 11 is below boundary line L1 by requesting driving force and / or vehicle speed reduction in HE V mode.

[0074] In step S11, if it is determined that the first transition flag is set to ON, the control system 60 proceeds to step S12, setting the transition time Tt. That is, in step S12, the control system 60 sets a first time T1, a second time T2, and a third time T3 based on the gear ratio, vehicle acceleration, and engine torque, and adds these times T1 to T3 to set the transition time Tt. Here, as... Figure 8 As shown, the lower the gear ratio of the continuously variable transmission (CVT) 22, the longer the first time T1 constituting the transition time Tt is set. Additionally, as... Figure 9 As shown, the vehicle acceleration increases towards the acceleration side (+ side), and the second time T2 is set shorter accordingly; conversely, the vehicle acceleration increases towards the deceleration side (- side), and the second time T2 is set shorter accordingly. That is, as... Figure 9 As shown, the smaller the absolute value of the vehicle acceleration, the longer the second time T2, which constitutes the transition time Tt, is set. Furthermore, as... Figure 10 As shown, the greater the engine torque, the longer the third time T3, which constitutes the transition time Tt, is set.

[0075] Furthermore, the gear ratio of the continuously variable transmission (CVT) 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. It should be noted that the gear ratio of the CVT 22 is the ratio of the output speed to the input speed, that is, the ratio of the speed of the main shaft 23 to the speed of the countershaft 26. In other words, a change in gear ratio towards the lower end means that the gear ratio value increases, and a change in gear ratio towards the higher end means that the gear ratio value decreases.

[0076] like Figure 7 As shown, if a transition time Tt is set in step S12, the control system 60 proceeds to step S13 to perform a mode switching process. That is, in step S13, the control system 60 engages the forward clutch 24, reducing engine torque and increasing the operating torque of the electric generator 15. Then, the control system 60 proceeds to step S14 to determine whether the transition time Tt has elapsed since the start of the mode switching process. If, in step S14, it is determined that the transition time Tt has not elapsed, the control system 60 returns to step S13 and continues performing the mode switching process. On the other hand, if, in step S14, it is determined that the transition time Tt has elapsed, the control system 60 proceeds to step S15, disengages the forward clutch 24, and sets the second transition flag, indicating completion of the switch to EV mode, to ON.

[0077] Thus, the control system 60 sets a transition time Tt based on the gear ratio, vehicle acceleration, and engine torque, and performs mode switching processing throughout this transition time Tt, thereby switching the driving mode from HEV mode to EV mode. Specifically, the forward clutch 24 is controlled to be engaged throughout the entire transition time Tt set based on the gear ratio, vehicle acceleration, and engine torque. Then, while the forward clutch 24 is engaged, the engine torque is reduced, and the power operating torque of the electric generator is increased. This reduces the impact when the forward clutch 24 disengages and allows for a smoother switch from HEV mode to EV mode without causing discomfort to the driver.

[0078] [Driving Mode Switching Control (Timing Diagram)]

[0079] [Example 1]

[0080] Next, as Example 1, the above-mentioned driving mode switching control will be explained according to the timing diagram. Figure 11 This is a timing diagram illustrating the execution status of the driving mode switching control as an example of Embodiment 1. It should be noted that, in Figure 11 In this context, "Tcl" is the clutch torque transmitted by the forward clutch 24, "Tpri" is the input torque to the main pulley 20, and "Tmg" is the motor torque (power operating torque, generator torque).

[0081] like Figure 11 As shown, at time t11, the power generation driving mode (symbol a1) as the HEV mode is executed. Therefore, the forward clutch 24 is controlled to be engaged (symbol b1), the engine torque, i.e., the clutch torque Tcl, is increased (symbol c1), and the motor torque Tmg is increased on the power generation side (symbol d1). Next, as shown at time t12, if the first conversion flag is set to ON (symbol e1), the forward clutch 24 is kept engaged (symbol b2), the engine torque, i.e., the clutch torque Tcl, is decreased (symbol c2), and the motor torque Tmg is increased on the power operation side (symbol d2). It should be noted that in Figure 11 In the example shown, since it is in generator driving mode, as indicated by symbol d2, after reducing the generator torque of generator 15, the power operating torque of generator 15 is increased. Next, as indicated by time t13, if the second conversion flag is set to ON (symbol f1) after the conversion time Tt, the forward clutch 24 is controlled to disengage (symbol b3), and the driving mode is switched to EV mode (symbol a2). Furthermore, if the forward clutch 24 is controlled to disengage (symbol b3), the injector 42 is controlled to cut off fuel (symbol g1).

[0082] Thus, the forward clutch 24 remains engaged throughout the entire transition time Tt, reducing engine torque and increasing the operating torque of the electric generator 15. Consequently, when the forward clutch 24 disengages, the engine torque, i.e., the clutch torque Tcl, can be sufficiently reduced, and the disengagement shock of the forward clutch 24 can be minimized. Furthermore, because the operating torque of the electric generator 15 is increased, even when engine torque is reduced, as indicated by arrow α1, excessive fluctuations in vehicle acceleration can be suppressed, and the driving mode can be switched without causing discomfort to the driver.

[0083] Moreover, such as Figure 8 As shown, the lower the gear ratio of the continuously variable transmission (CVT) 22, the longer the transition time Tt for reducing engine torque is set. When the CVT 22 is controlled to the lower side, the engine torque is amplified and transmitted to the rear wheel 19r, a situation where the engine torque is cut off along with clutch disengagement, making vehicle acceleration prone to fluctuations. By setting a longer transition time Tt under such driving conditions, engine torque can be sufficiently reduced, and the disengagement shock of the forward clutch 24 can be reduced. Therefore, driving modes can be switched without causing discomfort to the driver.

[0084] In addition, such as Figure 9 As shown, the smaller the absolute value of vehicle acceleration, the longer the transition time Tt for reducing engine torque should be set. A small absolute value of vehicle acceleration refers to a situation where changes in vehicle acceleration accompanying clutch disengagement can easily cause discomfort to the driver. By setting a longer transition time Tt under such driving conditions, engine torque can be sufficiently reduced, and changes in vehicle acceleration accompanying clutch disengagement can be suppressed. Therefore, driving modes can be switched without causing discomfort to the driver.

[0085] In addition, such as Figure 10 As shown, the greater the engine torque, the longer the transition time Tt for reducing engine torque is set. A situation with high engine torque refers to a condition where the engine torque is cut off due to clutch disengagement, causing fluctuations in vehicle acceleration. By setting a longer transition time Tt under such driving conditions, the engine torque can be sufficiently reduced, and the disengagement shock of the forward clutch 24 can be minimized. This allows for switching driving modes without causing discomfort to the driver.

[0086] It should be noted that, although in Figure 11In the illustrated embodiment 1, the engine torque and motor torque are controlled in a way that keeps the vehicle acceleration constant, that is, in a way that keeps the input torque Tpri to the main pulley 20 constant, but this is not a limitation. For example, the engine torque and motor torque can also be controlled in a way that increases the vehicle acceleration, or the engine torque and motor torque can be controlled in a way that decreases the vehicle acceleration.

[0087] [Comparative Example]

[0088] Figure 12 This is a timing diagram illustrating the execution status of the driving mode switching control as a comparative example. For example... Figure 12 As shown, at time t21, the power generation driving mode (symbol a1) as the HEV mode is executed. Therefore, the forward clutch 24 is controlled to be engaged (symbol b1), the engine torque, i.e., the clutch torque Tcl, is increased (symbol c1), and the motor torque Tmg is increased on the power generation side (symbol d1). Next, as shown at time t22, if the first switching flag is set to ON (symbol e1), the forward clutch 24 is controlled to be disengaged (symbol b2), and the driving mode is switched to EV mode (symbol a2). In addition, if the forward clutch 24 is controlled to be disengaged (symbol b2), the injector 42 is controlled to be in a fuel cut-off state (symbol g1).

[0089] Thus, when the engine torque and motor torque are not controlled using the transition time Tt, but rather the forward clutch 24 is disengaged along with the ON setting of the first transition flag, the clutch torque Tcl decreases sharply (symbol c2) due to clutch disengagement. That is, as shown by arrow α2, the vehicle acceleration changes drastically due to clutch disengagement, causing significant discomfort to the driver as the driving mode changes. In contrast, when the engine torque and motor torque are controlled using the transition time Tt, as... Figure 11 As indicated by arrow α1, it can suppress excessive fluctuations in vehicle acceleration and switch driving modes without causing discomfort to the driver.

[0090] [Example 2]

[0091] Although Figure 11 In the example shown, the driving mode is switched from generator driving mode to EV mode, but it is not limited to this; the driving mode can also be switched from auxiliary mode to EV mode. Figure 13 This is a timing diagram illustrating the execution status of the driving mode switching control as an example 2.

[0092] like Figure 13As shown, at time t31, the auxiliary mode (symbol a1) as the HEV mode is executed. Therefore, the forward clutch 24 is controlled to be engaged (symbol b1), the engine torque, i.e., the clutch torque Tcl, is increased (symbol c1), and the motor torque Tmg is increased on the power operation side (symbol d1). Next, as shown at time t32, if the first conversion flag is set to ON (symbol e1), the forward clutch 24 is kept engaged (symbol b2), the engine torque, i.e., the clutch torque Tcl, is decreased (symbol c2), and the motor torque Tmg is increased on the power operation side (symbol d2). Next, as shown at time t33, if the second conversion flag is set to ON (symbol f1) after the conversion time Tt, the forward clutch 24 is controlled to be disengaged (symbol b3), and the driving mode is switched to EV mode (symbol a2). In addition, if the forward clutch 24 is controlled to be disengaged (symbol b3), the injector 42 is controlled to be in a fuel cut-off state (symbol g1).

[0093] Thus, the forward clutch 24 remains engaged throughout the entire transition time Tt, reducing engine torque and increasing the operating torque of the electric generator 15. Consequently, when the forward clutch 24 disengages, the engine torque, i.e., the clutch torque Tcl, can be sufficiently reduced, and the disengagement shock of the forward clutch 24 can be minimized. Furthermore, because the operating torque of the electric generator 15 is increased, even when engine torque is reduced, as shown by arrow α3, excessive fluctuations in vehicle acceleration can be suppressed, and the driving mode can be switched without causing discomfort to the driver. It should be noted that... Figure 13 In the example shown, the transition time Tt is also set based on the gear ratio, vehicle acceleration, and engine torque.

[0094] [Other implementations of the powertrain]

[0095] As a component of the powertrain 14, it is not limited to Figure 2 The configuration shown can also be a power transmission system with other configurations. Figure 14 and Figure 15 This is a diagram showing other configuration examples of a powertrain.

[0096] like Figure 14As shown, the engine 12 is connected to the rear wheel 19r via a power transmission path 30, which is constructed of a rotating shaft, etc. A forward clutch 24 and a continuously variable transmission (CVT) 22 are provided in the power transmission path 30 connecting the engine 12 and the rear wheel 19r. The forward clutch 24 is located between the engine 12 and the CVT 22. Furthermore, an electric generator 15 is connected to the countershaft 26 constituting the power transmission path 30 via a gear train 80. That is, the electric generator 15 is connected to the rear wheel 19r from the output side of the CVT 22 via the power transmission path 30. Even a vehicle control device that controls such a powertrain 81 can function in the same way as the vehicle control device 10 described above. Figure 14 Or the above Figure 4 In the example shown, the engine 12 and the electric generator 15 are connected to the rear wheel 19r, but this is not the only example. For instance, it could also be for... Figure 1 The configuration shown is such that the engine 12 and the electric generator 15 are connected to the front wheel 19f. In this configuration, the front wheel 19f functions as the first wheel, and the rear wheel 19r functions as the second wheel.

[0097] like Figure 15 As shown, an electric generator 15 is connected to the rear wheel (first wheel) 90r via a power transmission path 91. Additionally, an engine 12 is connected to the front wheel (second wheel) 90f via a power transmission path 92, which is constructed of a rotating shaft, etc. A forward clutch 24 and a continuously variable transmission (CVT) 22 are provided in the power transmission path 92 connecting the engine 12 and the front wheel 90f. Furthermore, the forward clutch 24 on the power transmission path 92 is located between the engine 12 and the CVT 22. Thus, in the illustrated powertrain 93, the engine 12 is connected to the front wheel 90f, while the electric generator 15 is connected to the rear wheel 90r. Even the vehicle control device controlling such a powertrain 94 can function in the same way as the vehicle control device 10 described above. It should be noted that a configuration where the engine 12 is connected to the rear wheel 90r and the electric generator 15 is connected to the front wheel 90f is also possible. In this configuration, the front wheel 90f functions as the first wheel, and the rear wheel 90r functions as the second wheel. Alternatively, an in-wheel motor, located within the hub of either the front wheel 90f or the rear wheel 90r, can be used as the electric generator 15.

[0098] This invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit. In the above description, the control system 60 is composed of multiple control units CU1 to CU5, but it is not limited to this. For example, the control system 60 may be composed of a single control unit. Furthermore, in the above description, a continuously variable transmission (CVT) mechanism 22 composed of a pair of pulleys 20 and 21 is used as the transmission mechanism provided in the power transmission path 30, but it is not limited to this; it may also be a planetary gear type and / or a parallel shaft type automatic transmission mechanism. Additionally, the forward clutch 24 may be a friction clutch or a meshing clutch. Furthermore, in... Figure 11 In the example shown, the injector 42 is controlled to a fuel cut-off state after the forward clutch 24 is disengaged, but it is not limited to this; the injector 42 can also be controlled to a fuel cut-off state before the forward clutch 24 is disengaged.

[0099] exist Figure 11 , Figure 13 In the example shown, the engine torque and motor torque (power operating torque, generator torque) are continuously varied throughout the entire transition time Tt, but this is not a limitation. For example, at any point during the transition time Tt, the engine torque can be reduced, or the power operating torque of the electric generator 15 can be increased. Even in this case, with the forward clutch 24 engaged, the engine torque can be reduced and the power operating torque increased, thus reducing the impact when the forward clutch 24 is disengaged. That is, when the control system 60 switches from HEV mode to EV mode, the forward clutch 24 is engaged throughout the entire transition time Tt, and with the forward clutch 24 engaged, the torque of the engine 12 is reduced, and the power operating torque of the electric generator 15 is increased.

[0100] In the above explanation, the transition time Tt is set based on the gear ratio, vehicle acceleration, and engine torque, but it is not limited to these. For example, the transition time Tt can be set based solely on the gear ratio, or it can be set based on both the gear ratio and vehicle acceleration, or it can be set based on both the gear ratio and engine torque. Alternatively, the transition time Tt can be set based on at least one of the gear ratio, vehicle acceleration, and engine torque. Furthermore, in... Figures 8-10 In the example shown, the times T1 to T3 constituting the transition time Tt are set continuously, but this is not a limitation; the times T1 to T3 can also be set in stages. Furthermore, in the above explanation, the transition time Tt is calculated by adding the times T1 to T3, but this is not a limitation. For example, coefficients can be set based on the gear ratio, vehicle acceleration, and engine torque, and the transition time Tt can be calculated by multiplying the coefficients by the base time.

Claims

1. A control device for a vehicle, characterized by comprising: To take control of the vehicle. The vehicle control device has the following features: An electric generator, which is connected to the first wheel; An engine that is connected to the first or second wheel via a power transmission path; A transmission mechanism is disposed in the power transmission path; A clutch mechanism is disposed in the power transmission path and located between the engine and the transmission mechanism; as well as The control system includes a processor and a memory that are interconnected in a manner capable of communicating with each other, and controls the electric generator, the engine, the transmission mechanism, and the clutch mechanism. The control system includes: In the first driving mode, the clutch mechanism is controlled to be engaged, the engine is controlled to be running, and the electric generator is controlled to be rotating. as well as The second driving mode controls the clutch mechanism to be disengaged, the engine to be stopped, and the electric generator to be running. The lower the gear ratio of the transmission mechanism, the longer the conversion time will be set by the control system. When the control system switches from the first driving mode to the second driving mode, the clutch mechanism is engaged throughout the switching time. In the engaged state of the clutch mechanism, the torque of the engine is reduced and the power operating torque of the electric generator is increased.

2. The vehicle control device according to claim 1, characterized in that, The smaller the absolute value of the vehicle acceleration, the longer the control system sets the transition time.

3. The vehicle control device according to claim 1, characterized in that, The greater the torque of the engine, the longer the control system sets the transition time.

4. The vehicle control device according to claim 2, characterized in that, The greater the torque of the engine, the longer the control system sets the transition time.

5. The vehicle control device according to any one of claims 1 to 4, characterized in that, The first driving mode is a driving mode in which the clutch mechanism is controlled to be engaged, the engine is controlled to be running, and the electric generator is controlled to be generating electricity.

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