Hybrid vehicles
The hybrid vehicle uses a supercharger and control system to rapidly increase engine torque by estimating and controlling engine and motor operations, addressing the delay in conventional hybrid vehicles, ensuring immediate torque response.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2024-11-19
- Publication Date
- 2026-05-29
AI Technical Summary
In conventional hybrid vehicles with a turbocharger, there is a delay in increasing engine torque when the accelerator pedal is depressed from the accelerator-off state, leading to insufficient driving torque output and potential negative torque, which is addressed by employing a supercharger, planetary gear mechanism, and control device to rapidly increase engine output and driving torque.
The hybrid vehicle employs an engine with a supercharger, a planetary gear mechanism, a first and second electric motor, a power storage device, and a control device to estimate and control the engine and motors to output torque at a predetermined rotational speed or higher when the accelerator is released, ensuring rapid torque increase when the pedal is pressed.
This configuration allows for rapid increase in engine output and driving torque when the accelerator pedal is pressed, overcoming the time lag associated with turbocharger operation, enabling immediate torque response.
Smart Images
Figure 2026088848000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a hybrid vehicle, and more particularly to a hybrid vehicle equipped with an engine having a turbocharger.
Background Art
[0002] Conventionally, as this type of hybrid vehicle, there has been proposed a hybrid vehicle including an engine having a turbocharger, a first electric motor, and a planetary gear mechanism in which three rotating elements are connected to three axes of an output shaft of the engine, a rotating shaft of the first electric motor, and a drive shaft connected to drive wheels, and a second electric motor that inputs and outputs power to and from the drive shaft (see, for example, Patent Document 1). In this hybrid vehicle, when an acceleration request is made, the rotational speed of the engine is increased and the driving torque is increased.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, in the above hybrid vehicle, when the accelerator pedal is depressed from the accelerator-off state, the increase in torque from the engine is delayed, and there are cases where sufficient driving torque cannot be output. When the accelerator is off, the required torque becomes negative torque (braking torque), so it is common to perform regenerative control of the second electric motor to output regenerative torque and stop the engine or perform idling operation. When the accelerator pedal is depressed from this state, the engine cannot output a relatively large torque until the turbocharger operates, resulting in a time lag in outputting the driving torque.
[0005] The primary objective of the hybrid vehicle disclosed herein is to enable a rapid increase in engine output and driving torque when the accelerator pedal is pressed after the accelerator has been released. [Means for solving the problem]
[0006] The hybrid vehicle of this disclosure employs the following means to achieve the primary objective described above.
[0007] The hybrid vehicle disclosed herein is An engine with a supercharger, The first electric motor and, A planetary gear mechanism in which three rotating elements are connected to the output shaft of the engine, the rotating shaft of the first electric motor, and the drive shaft connected to the drive wheel, A second electric motor that inputs and outputs power to the aforementioned drive shaft, A power storage device that exchanges power with the first motor and the second motor, A control device that controls the engine, the first electric motor, and the second electric motor, It is a hybrid vehicle equipped with, When the control device estimates that the power output to the drive shaft will increase when the accelerator is released, it controls the engine, the first electric motor, and the second electric motor so that the engine outputs torque at a predetermined rotational speed or higher and the required torque is output to the drive shaft. It is characterized by the following:
[0008] In the hybrid vehicle of this disclosure, when it is estimated that the power output to the drive shaft will increase when the accelerator is released, the engine, the first motor, and the second motor are controlled so that the engine outputs torque at a predetermined rotational speed or higher and the required torque is output to the drive shaft. In this way, when the accelerator pedal is pressed, the output torque from the engine, which is outputting torque at a predetermined rotational speed or higher, can be rapidly increased, and the drive torque corresponding to the amount the accelerator pedal is pressed can be rapidly output to the drive shaft. As a result, when the accelerator pedal is pressed from the time it is released, the output from the engine can be rapidly increased to output drive torque. Here, the predetermined rotational speed is preferably a rotational speed higher than the rotational speed at which the supercharger operates. [Brief explanation of the drawing]
[0009] [Figure 1] This is a schematic diagram showing the configuration of a hybrid vehicle 20 as an embodiment of the present disclosure. [Figure 2] This flowchart shows an example of the accelerator-off processing performed by HVECU70. [Figure 3] This is an explanatory diagram showing an example of a collinear diagram of the planetary gear 30 when the accelerator is released. [Modes for carrying out the invention]
[0010] Next, embodiments for implementing this disclosure will be described. Figure 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 as an embodiment of this disclosure. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, a hybrid electronic control unit (hereinafter referred to as HVECU) 70, and a navigation device 90.
[0011] The engine 22 is configured as a 6-cylinder internal combustion engine that outputs power through four strokes: intake, compression, expansion (explosive combustion), and exhaust, using a fuel such as gasoline or diesel. This engine 22 is equipped with a turbo-type supercharger (so-called turbocharger) 27 that uses exhaust energy to provide supercharging. The engine 22 is operated and controlled by an engine electronic control unit (hereinafter referred to as engine ECU) 22a.
[0012] The supercharger 27 includes a compressor 27b located in the intake pipe 24 connected to the air cleaner 25, a turbine 27a located in the exhaust pipe 26, a connecting shaft 27c connecting the compressor 27b and the turbine 27a, and a wastegate valve 27e provided in a bypass pipe 27d connecting the upstream and downstream sides of the turbine 27a in the exhaust pipe 26. In this supercharger 27, by adjusting the opening of the wastegate valve 27e, the distribution ratio of the amount of exhaust gas flowing through the bypass pipe 27d and the amount of exhaust gas flowing through the turbine 27a is adjusted (the smaller the opening of the wastegate valve 27e, the less exhaust gas flows through the bypass pipe 27d and the more exhaust gas flows through the turbine 27a), the rotational driving force of the turbine 27a is adjusted, the amount of compressed air from the compressor 27b is adjusted, and the boost pressure (intake pressure) of the engine 22 is adjusted. Furthermore, when the wastegate valve 27e is fully open, the engine 22 can operate in the same way as a naturally aspirated engine without a supercharger 27.
[0013] The planetary gear 30 is configured as a single-pinion type planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. The drive shaft 36, which is connected to the drive wheels 39a and 39b via a differential gear 38, is connected to the ring gear of the planetary gear 30. The crankshaft 23 of the engine 22 is connected to the carrier of the planetary gear 30.
[0014] Motors MG1 and MG2 are configured, for example, as synchronous generator motors. The rotor of motor MG2 is connected to the drive shaft 36. Inverters 41 and 42 are used to drive motors MG1 and MG2 and are also connected to the battery 50 via the power line 54. Motors MG1 and MG2 are driven by a motor electronic control unit (hereinafter referred to as "motor ECU") 40, which controls the switching of multiple switching elements (not shown) of inverters 41 and 42.
[0015] The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as "battery ECU") 52. The battery ECU 52 receives input such as the battery voltage Vb from a voltage sensor 51a attached between the terminals of the battery 50, and the battery current Ib from a current sensor 51b attached to the output terminal of the battery 50. The battery ECU 52 calculates the input power Pin and output power Pout of the battery 50 based on the product of the battery voltage Vb and the battery current Ib. The battery ECU 52 also calculates the state of charge (SOC) of the battery 50 based on the integrated value of the battery current Ib.
[0016] The HVECU70 receives inputs such as the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 which detects the operating position of the shift lever 81, the accelerator opening Acc from the accelerator pedal position sensor 84 which detects the amount the accelerator pedal 83 is pressed, the brake pedal position BP from the brake pedal position sensor 86 which detects the amount the brake pedal 85 is pressed, and the vehicle speed V from the vehicle speed sensor 87. The HVECU70 communicates with the engine ECU22a, motor ECU40, and battery ECU52.
[0017] The navigation device 90 includes a main body 92 with a built-in control unit, a GPS antenna 94 that receives information about the current location of the vehicle, and a display 96. The main body 92 has a storage medium (e.g., a hard disk or SSD) in which map information and the like are stored. The map information stores service information (e.g., tourism information, parking lots, etc.) and road information for each driving section (e.g., between traffic lights, between intersections, etc.) as a database. The road information includes distance information, width information, number of lanes information, area information (urban area, suburb), type information (general road, highway), gradient information, legal speed, number of traffic lights, turning radius of each curve, and the like. The display 96 is configured as a touch panel display that can display various information such as information about the current location of the vehicle and the planned driving route to the destination, and allows the user to input various instructions. When a destination is set by the user's operation on the display 96, the main body 92 of the navigation device 90 sets a planned driving route from the current location of the vehicle to the destination based on the map information stored in the main body 92, the current location of the vehicle from the GPS antenna 94, and the destination, and displays the set planned driving route on the display 96 to provide route guidance. The main body 92 exchanges information with the HVECU 70 through communication.
[0018] Next, the operation of the hybrid vehicle 20 configured in this way, particularly the operation when the accelerator is off, will be described. FIG. 2 is a flowchart showing an example of the processing when the accelerator is off, which is executed by the HVECU 70.
[0019] When the accelerator-off processing is executed, the HVECU 70 first determines whether it is estimated that the required torque Td* to be output to the drive shaft 36 will increase when the accelerator pedal 83 is pressed (step S100). The increase in the required torque Td* can be estimated based on the state of the traffic light ahead, the road conditions, past driving history, etc. For example, it can be used when it is predicted that the traffic light ahead will turn green in 2 or 3 seconds, when it is predicted that the road will change from a downhill slope to an uphill slope in 2 or 3 seconds, or when acceleration can be predicted from the user's past driving history. If it is determined that it is not possible to estimate that the required torque Td* will increase, normal control is performed (step S140) and this process is terminated. As for normal control, for example, it is possible to stop the operation of the engine 22 or operate the engine autonomously at idle speed and regenerative control of the motor MG2 so that the required torque Td* (deceleration torque) based on the vehicle speed V and shift position SP is applied.
[0020] When it is determined in step S100 that it can be estimated that the required torque Td* increases, a predetermined rotational speed Neset is set as the target rotational speed Ne* of the engine 22 and a predetermined torque Teset is set as the target torque Te* (step S110). Here, as the predetermined rotational speed Neset, a rotational speed slightly higher than the lower limit rotational speed at which the supercharger 27 functions can be used. As the predetermined torque Teset, a torque slightly higher than the lower limit torque when the supercharger 27 is made to function can be used. Subsequently, the torque command Tm1* of the motor MG1 is set so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne (predetermined rotational speed Neset) (step S120), and the torque command Tm2* of the motor MG2 is set so that the required torque Td* is output to the drive shaft 36 (step S130), and this process is terminated. When the target rotational speed Ne* and the target torque Te* of the engine 22 are set, the engine ECU 22a controls the engine 22 so that the engine 22 operates at the operation point of the target rotational speed Ne* and the target torque Te*. On the other hand, when the torque commands Tm1*, Tm2* are set, the motor ECU 40 performs switching control of the switching elements of the inverters 41, 42 so that the motors MG1, MG2 are driven by the torque commands Tm1*, Tm2*.
[0021] Figure 3 is an explanatory diagram showing an example of a collinear diagram of the planetary gear 30 when the accelerator is released. In the figure, the S axis represents the rotational speed Ns of the sun gear of the planetary gear 30, which corresponds to the rotational speed Nm1 of motor MG1; the C axis represents the rotational speed Nc of the carrier 34, which corresponds to the rotational speed Ne of engine 22; and the R axis represents the rotational speed Nr of the ring gear (drive shaft 36) of the planetary gear 30, which corresponds to the rotational speed Nm2 of motor MG2. The solid line represents the case when the required torque Td* is estimated to increase, and the dashed line represents the case when the required torque Td* is not estimated to increase (normal control). The thick arrows on the three axes in the solid line represent the torques of motor MG1, engine 22, and motor MG2. As shown by the solid line, by setting the rotational speed Ne of the engine 22 to a predetermined rotational speed Neset, the supercharger 27 is activated. When the accelerator pedal 83 is pressed from this state, the torque from the engine 22 is rapidly increased, and the increased required torque Td* can be output to the drive shaft 36.
[0022] In the hybrid vehicle 20 of the embodiment described above, when it is estimated that the required torque Td* increases when the accelerator is released, the engine 22 is operated at a predetermined rotational speed Neset and a predetermined torque Teset, which are slightly higher than the lower limit rotational speed at which the supercharger 27 functions, and the engine 22 and motors MG1 and MG2 are controlled so that the required torque Td* as braking torque is output to the drive shaft 36. As a result, when the accelerator pedal 83 is pressed, the torque from the engine 22 can be quickly increased and the increased required torque Td* can be output to the drive shaft 36.
[0023] In the embodiment of the hybrid vehicle 20, the hybrid vehicle 20 is driven and controlled by three electronic control units: the engine ECU 22a, the motor ECU 40, and the HVECU 70. However, any two of the engine ECU 22a, motor ECU 40, and HVECU 70 may be configured as a single electronic control unit, or all three may be configured as a single electronic control unit.
[0024] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be explained. In the embodiment, the supercharger 27 corresponds to "supercharger", the engine 22 corresponds to "engine", the motor MG1 corresponds to "first electric motor", the planetary gear 30 corresponds to "planetary gear mechanism", the motor MG2 corresponds to "second electric motor", the battery 50 corresponds to "energy storage device", and the engine ECU 22a, motor ECU 40, and HVECU 70 correspond to "control device".
[0025] Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.
[0026] While embodiments of this disclosure have been described above, this disclosure is not limited in any way to these embodiments, and can of course be implemented in various forms without departing from the gist of this disclosure. [Industrial applicability]
[0027] This disclosure can be used in industries such as the hybrid vehicle manufacturing industry. [Explanation of Symbols]
[0028] 20 Hybrid vehicle, 22 Engine, 22a Engine ECU, 23 Crankshaft, 24 Intake pipe, 26 Exhaust pipe, 27 Supercharger, 30 Planetary gear, 36 Drive shaft, 39a, 39b Drive wheels, 41, 42 Inverter, 50 Battery, 52 Battery ECU, 70 HVECU, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 87 Vehicle speed sensor, 90 Navigation system, MG1, MG2 Motor.
Claims
[Claim 1] An engine with a supercharger, The first electric motor and, A planetary gear mechanism in which three rotating elements are connected to the output shaft of the engine, the rotating shaft of the first electric motor, and the drive shaft connected to the drive wheel, A second electric motor that inputs and outputs power to the aforementioned drive shaft, A power storage device that exchanges power with the first motor and the second motor, A control device that controls the engine, the first electric motor, and the second electric motor, A hybrid vehicle equipped with, When the control device estimates that the power output to the drive shaft will increase when the accelerator is released, it controls the engine, the first electric motor, and the second electric motor so that the engine outputs torque at a predetermined rotational speed or higher and the required torque is output to the drive shaft. A hybrid vehicle characterized by the following features.