JP2009132190A - Controller for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a hybrid vehicle capable of preventing a mode for controlling a power distribution device from being frequently changed. <P>SOLUTION: The controller is provided for a hybrid vehicle having a power distribution device in which an input element, a reaction element and an output element are connected to a drive source, a generator and a driveshaft, respectively so that power can be transmitted. The controller is capable of switching the mode between a continuously variable transmission mode in which rotation speed ratio between the drive source and the driveshaft is continuously varied and a fixed transmission mode in which rotation speed ratio is fixed by preventing rotation of one of the elements constituting the power distribution device. The controller has a period determining means (step S4) for determining whether or not a predetermined period has elapsed since the transmission mode was last changed, and a mode selection means (step S5) which prohibits the transmission mode from being changed again if the requirements for changing the transmission mode again are met before the predetermined period elapses. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid vehicle capable of continuously controlling a gear ratio of a power distribution device.

  In recent years, a hybrid vehicle has been proposed that is equipped with an engine that outputs torque by burning fuel and a motor / generator that outputs torque by supplying electric power, and that can transmit the torque of the engine and motor / generator to wheels. Yes. In such a hybrid vehicle, driving and stopping of the engine and the motor / generator are controlled based on various conditions, thereby improving fuel efficiency, reducing noise, and reducing exhaust gas. ing.

  As described above, Patent Document 1 describes an example of a hybrid vehicle equipped with a plurality of types of driving force sources. In the hybrid vehicle described in Patent Document 1, the crankshaft of the engine is connected to a power distribution mechanism. This power distribution mechanism has a first planetary gear mechanism and a second planetary gear mechanism. The first planetary gear mechanism has a large sun gear and a ring gear arranged on the same axis, and a carrier that supports a large pinion gear meshed with the large sun gear and the ring gear. The second planetary gear mechanism has a small sun gear and a small pinion gear meshed with the small sun gear. A small sun gear and a large sun gear are coupled so as to rotate together to form a stepped pinion mechanism. That is, both the small sun gear and the large pinion gear are supported by the carrier so that they can rotate and revolve. The carrier is connected to the engine via the input shaft so as to be able to transmit power, and the large sun gear is connected to the rotor of the first motor / generator. In addition, a brake for controlling rotation / stop of the small sun gear is provided. Furthermore, the output shaft of the power distribution mechanism is connected to the ring gear. This output shaft is connected to the drive wheel. A second motor / generator is connected to the output shaft.

  The power distribution mechanism is a transmission capable of continuously controlling the speed ratio between the input shaft and the output shaft, and can specifically switch between a continuously variable transmission state and an overdrive state. For example, when the required driving force or the engine load is small, the overdrive state is selected, and when the required driving force or the engine load is large, the continuously variable transmission state is selected. When the brake is released is a continuously variable transmission state. When engine torque is input to the carrier in this continuously variable transmission state, the large sun gear becomes a reaction force member, and torque is transmitted to the output shaft. At this time, by controlling the rotation speed of the first motor / generator, the speed ratio of the power distribution mechanism can be controlled steplessly, and the speed ratio can be set to less than 1 or more than 1 It is. On the other hand, when the brake is engaged, a state in which the speed ratio of the power distribution mechanism is smaller than “1”, that is, an overdrive state is set. When engine torque is input to the carrier in this overdrive state, the small sun gear becomes a reaction force member, and torque is output from the ring gear.

  In this way, the engine torque is transmitted to the output shaft of the power distribution mechanism, and the torque is transmitted to the drive wheels. It is also possible to drive the second motor / generator as an electric motor and transmit the torque to the driving wheels to assist the driving force. On the other hand, it is also possible to transmit a part of the power transmitted from the engine to the output shaft to the second motor / generator and generate power by the second motor / generator. Furthermore, when the vehicle is repulsive, part of the power transmitted from the wheels to the output shaft can be transmitted to the second motor / generator, and the second motor / generator can generate power. The engine, the first motor / generator, and the second motor / generator are mounted, and the engine, the first motor / generator, and the second motor / generator are connected to the rotating elements of the differential gear transmission, respectively. An example of a hybrid vehicle control device capable of continuously controlling the gear ratio of the differential gear transmission is also described in Patent Document 2. When controlling the gear ratio of the differential gear transmission described in Patent Document 2, it is possible to selectively change between the fixed transmission mode and the continuously variable transmission mode.

JP 2004-345527 A JP 2005-16559 A

  By the way, in the control apparatus of the hybrid vehicle described in Patent Document 1, when the required driving force or the engine load in the vehicle frequently changes, there is a possibility that the continuously variable transmission state and the overdrive state are frequently switched.

  The present invention has been made against the background described above, and provides a control device for a hybrid vehicle capable of avoiding frequent changes in the speed change mode for controlling the change range of the speed change ratio of the power distribution device. The purpose is to do.

  The present invention includes a driving force source that generates power to be transmitted to a wheel, a drive shaft that is connected to the wheel so as to be able to transmit power, a generator that converts kinetic energy into electrical energy, and a plurality of differentially rotatable gears. A power distribution device having a rotation element and three rotation elements of the plurality of rotation elements separately connected to the driving force source, the generator, and the drive shaft so as to be able to transmit power; A continuously variable transmission mode in which a rotational speed ratio between the driving force source and the driving shaft is continuously changed; and any one of the driving force source, the generator, and the driving shaft among the plurality of rotating elements; In the control apparatus for a hybrid vehicle configured to be able to switch between a fixed speed change mode for fixing the rotation speed ratio by preventing rotation of a rotating element that is not connected, the fixed speed change mode A mode change determining means for determining whether or not a mode change between the gear and the continuously variable transmission mode has been performed, and a vehicle occupant when the transmission mode is changed again after the change between the transmission modes. A period determining means for determining whether or not a predetermined period with a sense of incongruity has elapsed, and a mode for determining whether or not a condition for changing the shift mode again is satisfied after the shift modes are changed. If the condition for changing the shift mode again is satisfied before the predetermined period elapses from when the change request determination unit and the change between the shift modes are performed, the change mode is selected from the currently selected shift mode. It is characterized by comprising mode selection means for prohibiting changing to another shift mode.

  In the present invention, an electric motor that generates torque to be transmitted to the wheels is provided, and the fixed speed change mode is performed even when the speed ratio between the driving force source and the driving shaft is limited to less than 1. The mode change request determining means is selected in a running state of the vehicle that can avoid vibration and noise generated in a power transmission path from the driving force source to the wheels, and the mode change request determining means has a vehicle speed less than a predetermined vehicle speed. Or a means for determining that a condition for changing the speed change mode again is satisfied when the required driving force becomes a predetermined value or more, and the mode selection means is configured to change the fixed speed change mode from the continuously variable speed change mode. If the condition for changing the speed change mode again is satisfied before the predetermined period elapses from the time when the mode is changed, the change is transmitted from the electric motor to the wheels. It is prohibited to change from the currently selected fixed transmission mode to the continuously variable transmission mode by maintaining the vehicle speed above the predetermined vehicle speed by increasing the torque, or maintaining the driving force above the predetermined value. It is preferable to include the means to do.

  In the present invention, the mode selection means determines the power supplied to the electric motor, and changes from the currently selected fixed shift mode to the continuously variable shift mode based on the determination result. It is preferable to include means for determining whether or not to prohibit.

  In the present invention, an electric power supply device for supplying electric power to the electric motor is provided, and the mode selection means transmits the torque transmitted from the electric motor to the wheel when increasing the torque transmitted from the electric motor to the wheel. Means for determining the power demand torque and determining whether or not the electric power for generating the demand torque in the electric motor is equal to or lower than the upper limit value of the output power in the power supply device; and When it is determined that the electric power generated by the electric motor is equal to or lower than the upper limit value of the output electric power in the electric power supply device, the torque transmitted from the electric motor to the wheels is increased to drive the vehicle and the vehicle By maintaining the force in a state in which the fixed transmission mode is selected, it is possible to change from the currently selected fixed transmission mode to the continuously variable transmission mode. The torque transmitted from the motor to the wheel when it is determined that the power for generating the required torque by the motor exceeds the upper limit value of the output power in the power supply device. Means for changing from the currently selected fixed speed change mode to the continuously variable speed change mode without increasing.

  In the present invention, an electric power supply device for supplying electric power to the electric motor is provided, and the mode selection means transmits the torque transmitted from the electric motor to the wheel when increasing the torque transmitted from the electric motor to the wheel. Means for determining the required torque and determining whether or not the electric power for generating the required torque in the electric motor remains in the electric power supply device, and for generating the required torque in the electric motor. When it is determined that electric power remains in the power supply device, the torque transmitted from the electric motor to the wheels is increased, and the vehicle speed and the driving force of the vehicle are selected in the fixed shift mode And maintaining the required torque in the electric motor with means for prohibiting the change from the currently selected fixed speed change mode to the continuously variable speed change mode. When it is determined that the power to be generated does not remain in the power supply device, the continuously variable transmission from the currently selected fixed transmission mode is performed without increasing the torque transmitted from the motor to the wheels. And a means for changing to the mode.

  In this invention, the mode selection means determines whether or not the durability of the power supply device that supplies power to the electric motor is reduced, and the durability of the power supply device is reduced. If it is determined, it may include means for prohibiting selection of the fixed shift mode.

  According to the present invention, when a change is made between the fixed speed change mode and the continuously variable speed change mode, the vehicle occupant feels uncomfortable if the speed change mode is changed again after the change between the speed change modes. It is determined whether or not a predetermined period having If there is a request to change the transmission mode again from the time when the transmission modes are changed before the predetermined period elapses, the currently selected transmission mode is changed to another transmission mode. Prohibit that. Therefore, it is possible to suppress frequent changes in the speed change mode selected for controlling the rotation speed ratio between the drive force source and the drive shaft.

  In this invention, the power distribution device has a plurality of rotational elements capable of differential rotation, for example, four rotational elements, and any one of the rotational elements is an input element, and any of the rotational elements is an output element. The remaining two rotating elements selectively become reaction force elements. The input element is connected to the driving force source, and the output element is connected to the driving shaft. Furthermore, a generator is connected to one rotating element that becomes the reaction force element, and the rotation of the other rotating element that becomes the reaction force element can be prevented. The driving force source is a power device that generates power to be transmitted to the wheels, and at least one of an engine, an electric motor, a hydraulic motor, a flywheel system, and the like can be used as the driving force source. Further, the power distribution device has a function as a continuously variable transmission capable of continuously changing the rotation speed ratio (speed ratio) between the driving force source and the driving shaft. The input element, the output element, and the reaction force element constituting the power distribution device, that is, the four elements are connected to each other so as to be differentially rotatable and transmit power. As such a power distribution device, for example, a continuously variable transmission using a planetary mechanism can be used. As the planetary mechanism, it is possible to use a planetary gear mechanism that transmits power by the meshing force of gears, or a planetary roller mechanism that transmits power by traction transmission using the shearing force of hydraulic oil. Further, the three elements are elements having a function of transmitting power, and the four elements include elements such as a gear, a carrier, a connecting drum, a rotating shaft, a pulley, a roller, a sprocket, and a chain. In the present invention, the fixed speed change mode and the continuously variable speed change mode are modes used to change the control range of the rotational speed ratio between the drive force source and the drive shaft, and between the drive force source and the drive shaft. As for the rotation speed ratio, the fixed shift mode has a narrower control range than the continuously variable transmission mode.

  Furthermore, the electric motor in the present invention is a driving force source that generates torque transmitted to the wheels, and a motor / generator having a function as a generator in addition to the function as an electric motor can be used. Furthermore, the present invention provides a two-wheel drive vehicle in which the power of the drive force source is transmitted to either the front wheels or the rear wheels, or a four-wheel drive vehicle in which the power of the drive force source is transmitted to both the front wheels and the rear wheels. It is applicable to any of these. Furthermore, the wheel to which the torque of the driving force source is transmitted and the wheel to which the torque of the electric motor is transmitted may be the same or different. For example, a four-wheel drive vehicle configured such that the torque of the driving force source is transmitted to the front wheels and the torque of the electric motor is transmitted to the rear wheels may be used. On the other hand, a two-wheel drive vehicle configured such that the torque of the driving force source is transmitted to the front wheels and the torque of the electric motor is transmitted to the front wheels may be used. Further, a two-wheel drive vehicle configured such that the torque of the driving force source is transmitted to the rear wheels and the torque of the electric motor is transmitted to the rear wheels may be used. Furthermore, the drive shaft in the present invention is a rotating element that connects the output element and the wheel so that power can be transmitted. The drive shaft includes a gear, a carrier, a connecting drum, a rotating shaft, a pulley, a roller, a sprocket, a chain, and the like. Elements are included. That is, the drive shaft is not limited to a shaft shape.

  Next, the present invention will be specifically described with reference to the drawings. FIG. 2 is a schematic configuration diagram of a hybrid vehicle (hereinafter abbreviated as “vehicle”) of the FR (front engine / rear drive; engine front and rear wheel drive) type according to an embodiment of the present invention. In FIG. 2, the vehicle 1 has an engine 2 as a driving force source. As the engine 2, an internal combustion engine, specifically, a gasoline engine, a diesel engine, an LPG engine, or the like can be used. The engine 2 is a power device that outputs thermal energy when fuel is burned as kinetic energy. In this embodiment, it is assumed that a torque control device, for example, a gasoline engine having an electronic throttle valve, a fuel injection amount control device, an ignition timing control device, and the like is used as the engine 2. A power distribution device 4 is provided in a power transmission path from the engine 2 to the wheels 3. A casing 5 is arranged in a space of a floor (not shown) of the vehicle 1, and a power distribution device 4 is arranged in the casing 5.

  The power distribution device 4 has two sets of planetary gear mechanisms. First, the first planetary gear mechanism 6 is a single pinion type planetary gear mechanism. That is, the first planetary gear mechanism 6 includes a sun gear 7 and a ring gear 8 that are arranged on the same axis, and a carrier 10 that holds a pinion gear 9 that meshes with the sun gear 7 and the ring gear 8 so as to rotate and revolve. Yes. The carrier 10 is an input member of the power distribution device 4. The input shaft 11 is connected to the carrier 10 so as to be able to transmit power, specifically, so as to rotate integrally therewith, and the input shaft 11 and the crankshaft 12 of the engine 2 are connected so as to be able to transmit power. ing. In the power transmission path between the crankshaft 12 and the input shaft 11, a damper mechanism, a torque limiter mechanism, a clutch mechanism, or the like can be provided. The damper mechanism is a mechanism that absorbs torque fluctuations, the torque limiter is a mechanism that limits the transmitted torque to a set torque or less, and the clutch mechanism is a mechanism that controls the torque capacity.

  In the specific example of FIG. 2, the rotation axes (not shown) of the input shaft 11 and the crankshaft 12 are arranged along the front-rear direction of the vehicle 1. Further, a first motor / generator MG1 is provided in the casing 5. A first motor / generator MG <b> 1 is arranged between the engine 2 and the first planetary gear mechanism 6 in a direction along the rotational axis of the input shaft 11. The first motor / generator MG1 has both a power running function (function as an electric motor) that converts electrical energy into kinetic energy and a regeneration function (function as a generator) that converts kinetic energy into electrical energy. . The first motor / generator MG <b> 1 has a stator 13 and a rotor 14, and the stator 13 is fixed to the casing 5. The rotor 14 is connected to the sun gear 7 so as to rotate integrally.

  The second planetary gear mechanism 15 constituting the power distribution device 4 is a double pinion type planetary gear mechanism. That is, the second planetary gear mechanism 15 includes a sun gear 16 and a ring gear 17 that are coaxially arranged, a first pinion gear 18 that meshes with the sun gear 16, a second pinion gear 19 that meshes with the ring gear 17 and the first pinion gear 18, and A carrier 20 holds the first pinion gear 18 and the second pinion gear 19 so as to be capable of rotating and revolving. The carrier 20 and the ring gear 8 are connected to rotate integrally, and the ring gear 17 and the carrier 10 are connected to rotate integrally. An output shaft 21 that rotates integrally with the carrier 20 is provided. The output shaft 21 is an element that transmits the torque output from the power distribution device 4 to the wheels 3, and the input shaft 11 and the output shaft 21 are arranged coaxially. Further, the first planetary gear mechanism 6 is disposed between the first motor / generator MG1 and the second planetary gear mechanism 15 in the direction along the rotation axis. Further, a brake BK that provides a braking force to the sun gear 16 is provided. As the brake BK, a friction brake or a mesh brake can be used. As the actuator 32 for controlling the braking force of the brake BK, either an electromagnetic actuator or a hydraulic actuator may be used.

  On the other hand, the output shaft 21 is connected to the final reduction gear 22, and the wheels 3 are connected to the final reduction gear 22 via the axle shaft 30. The reduction ratio of the final reduction gear 22 is determined so that the rotation speed of the axle shaft 30 is lower than the rotation speed of the output shaft 21. Further, a second motor / generator MG2 is disposed between the second planetary gear mechanism 15 and the final reduction gear 22 in the direction along the rotation axis. The second motor / generator MG2 may be arranged either inside the casing 5 or outside the casing 5. The second motor / generator MG2 has both a power running function for converting electrical energy into kinetic energy and a regeneration function for converting kinetic energy into electrical energy. The second motor / generator MG <b> 2 has a stator 23 and a rotor 24. Further, a transmission 25 is provided between the second planetary gear mechanism 15 and the final reduction gear 22 in the direction along the rotation axis. FIG. 2 shows a layout in which the transmission 25 is arranged behind the second motor / generator MG2 in the front-rear direction of the vehicle 1.

  Further, the transmission 25 may be disposed either inside the casing 5 or outside the casing 5. The transmission 25 connects the rotor 24 of the second motor / generator MG2 and the output shaft 21 so that power can be transmitted. Further, the transmission 25 includes an input element 26 and an output element 31 and is configured to be able to change a gear ratio between the input element 26 and the output element 31. The transmission 25 may be either a stepped transmission that can change the gear ratio stepwise or a continuously variable transmission that can change the gear ratio steplessly. Further, the transmission ratio of the transmission 25 is configured to be changeable by a value larger than “1” or a value equal to or larger than “1”. When a stepped transmission is used as the transmission 25, a selection gear type transmission or a planetary gear type transmission can be employed. On the other hand, when a continuously variable transmission is used as the transmission 25, a toroidal continuously variable transmission or a belt-type continuously variable transmission can be employed. The input element 26 is connected to the rotor 24 so that power can be transmitted, and the output element 31 is connected to the output shaft 21 so that power can be transmitted.

  Further, both the first motor / generator MG1 and the second motor / generator MG2 are those in which the rotor rotates, and each motor / generator may be either a DC type or an AC type. In this specific example, a case where a three-phase AC motor / generator is used will be described. All the motors / generators are connected to the power storage device 28 via the inverter 27. As the power storage device 28, a capacitor or a battery can be used. As described above, an electric circuit for transferring power is formed between each motor / generator and the power storage device 28. A fuel cell may be provided in addition to the power storage device 28, and a circuit for supplying power from the fuel cell to each motor / generator may be provided. A fuel cell is a device that generates an electromotive force by reacting oxygen and hydrogen. In addition, it is also possible to form an electric circuit that enables transmission / reception of electric power between the motors / generators without passing through the power storage device 28.

  Further, the control system of the vehicle 1 will be described. An electronic control device 33 is provided as a controller, and the electronic control device 33 includes the engine speed, the speed of each motor / generator, the vehicle speed, and the charging of the power storage device 28. Signals such as quantity, power generated in the fuel cell, power generation request to the motor / generator, acceleration request in the vehicle 1, braking request in the vehicle 1, and shift position are input. The electronic control device 33 stores data such as an upper limit value of output power in the power storage device 28 and an upper limit value of output power in the fuel cell in advance. The electronic control unit 33 outputs a signal for controlling the transmission ratio of the transmission 25, a signal for controlling the brake BK, a signal for controlling the engine 2, and a signal for controlling each motor / generator. The signal for controlling the engine 2 includes a signal for controlling stop / operation of the engine 2, a signal for controlling the engine speed, and a signal for controlling the engine torque. The signal for controlling the motor / generator includes a signal for controlling the motor / generator for power running or regenerative control, a signal for controlling the rotational speed of the motor / generator, and a signal for controlling the torque of the motor / generator. The signal for controlling the brake BK includes a signal for controlling the braking force applied from the brake BK to the sun gear 16.

  Next, a control example of the vehicle 1 shown in FIG. 2 will be described. First, the required driving force for the vehicle 1 is determined based on the vehicle speed and the accelerator opening, and the target output of the engine 2 and the target output of the second motor / generator MG2 are determined based on the required driving force. When the engine output is controlled based on the target output of the engine 2, basically, the target rotational speed of the engine 2 and the target torque of the engine are set so that the operation state of the engine 2 is along the optimum fuel consumption line. Can be obtained. Here, a map for obtaining the target rotational speed and target torque of the engine 2 based on the optimum fuel consumption line is stored in the electronic control unit 33 in advance. Then, the gear ratio of the power distribution device 4 is controlled in order to bring the actual rotational speed of the engine 2 closer to the target rotational speed. When controlling the gear ratio of the power distribution device 4, a mode switching map shown in FIG. 3 can be used. This mode switching map is stored in the electronic control unit 33, and according to this mode switching map, the driving range in which the fixed shift mode is selected and the driving range in which the continuously variable transmission mode is selected include the vehicle speed and acceleration. The request is shown as a parameter. Basically, when the continuously variable transmission mode is selected, the target rotational speed and the target torque of the engine 2 are controlled so that the operating state of the engine 2 is in line with the optimal fuel consumption line. . On the other hand, when priority is given to suppressing power loss, the fixed speed change mode is selected. As will be described later, when the fixed speed change mode is selected, the speed ratio of the power distribution device 4 is limited to less than “1”. When the continuously variable transmission mode is selected, the transmission ratio of the power distribution device 4 can be arbitrarily changed within a range of less than “1” or greater than “1”.

  In the map of FIG. 3, the accelerator opening or the required driving force and the vehicle speed are parameters. In the map of FIG. 3, the fixed speed change mode is selected when the vehicle speed is equal to or higher than a predetermined vehicle speed V1 and the accelerator opening is less than a predetermined value θ1. On the other hand, when the vehicle speed is lower than the predetermined vehicle speed V1, or when the vehicle speed is equal to or higher than the predetermined vehicle speed V1 and the accelerator opening is equal to or larger than the predetermined value θ1, the continuously variable transmission is performed. A mode is selected. As described above, when the required driving force is high or the acceleration request is high, the continuously variable transmission mode is selected. First, an example of the technical reason for distinguishing the driving range in which the fixed shift mode is selected from the driving range in which the continuously variable mode is selected using the vehicle speed V1 as a threshold value will be described. Since the engine 2 is a device that burns fuel and outputs motive power, the combustion state of the fuel becomes unstable and the engine torque fluctuates in a low vehicle speed range where the engine speed is low. Vibration and noise are likely to occur in the power transmission path to the wheel 3.

  For this reason, even when the gear ratio of the power distribution device 4 is limited to less than “1”, the vibration and noise generated in the power transmission path from the engine 2 to the wheels 3 are such that the passenger of the vehicle 1 does not feel uncomfortable. Therefore, the map of FIG. 3 is determined so that the fixed speed change mode is selected in the driving region of the vehicle speed V1 or higher with the vehicle speed V1 as a threshold value. Even when this fixed speed change mode is selected, the engine speed and the engine torque are controlled so that the actual driving force approaches the required driving force, but the engine speed and the engine torque are in line with the optimum fuel consumption line. is not. On the other hand, when the continuously variable transmission mode is selected, the gear ratio of the power distribution device 4 can be controlled to be “1” or more, so that the engine speed is set to a high speed even at a low vehicle speed. The vibration and noise generated in the power transmission path from the engine 2 to the wheels 3 can be suppressed to the extent that the passenger of the vehicle 1 does not feel uncomfortable. The degree of vibration and noise in the power transmission path may be obtained according to conditions such as the torque fluctuation characteristics of the engine 2 and the natural frequency of the power transmission path.

  Next, an example of a technical reason for distinguishing between an operation region in which the fixed transmission mode is selected and an operation region in which the continuously variable transmission mode is selected using the predetermined value θ1 of the accelerator opening as a threshold value will be described. . When the fixed speed change mode is selected, the speed ratio of the power distribution device 4 is limited to less than “1”, so that the output torque of the power distribution device 4 is reduced rather than the input torque of the power distribution device 4. For this reason, when the required driving force is high, the driving force may be insufficient. In this embodiment, even when the gear ratio of the power distribution device 4 is limited to less than “1”, the predetermined value θ1 is set as a threshold value that can secure the output torque of the power distribution device 4 according to the required driving force. Has been decided. In other words, in a driving region where the required driving force is higher than the predetermined value θ1, if the gear ratio of the power distribution device 4 is less than “1”, the driving force may be insufficient. The map of FIG. 3 is configured so that a continuously variable transmission mode that can be set to “1” or more is selected. On the other hand, in the operation region where the required driving force is less than the predetermined value θ1, even if the gear ratio of the power distribution device 4 is less than “1”, there is little possibility that the driving force will be insufficient. The map of FIG. 3 is configured so that the fixed transmission mode in which is limited to less than “1” is selected.

  Next, the control of the gear ratio of the power distribution device 4 will be described based on FIG. 4 and FIG. As a mode for controlling the power distribution device 4, a fixed shift mode and a continuously variable transmission mode can be selectively switched. 4 and 5 show the positional relationship and the rotational state of the elements constituting the power distribution device 4 and the rotating elements connected to the elements. 4 and 5, “stop” indicates that the rotating element stops, “normal” indicates that the rotating element rotates in the forward direction, and “reverse” indicates that the rotating element rotates in the reverse direction. Show. The positive direction is the same rotation direction as the rotation direction of the crankshaft 12 of the engine 2. 4 and 5, since the first planetary gear mechanism 6 is a single pinion type planetary gear mechanism, the carrier 10 is disposed between the sun gear 7 and the ring gear 8.

  On the other hand, since the second planetary gear mechanism 15 is a double pinion type planetary gear mechanism, the ring gear 17 is disposed between the sun gear 16 and the carrier 20. Further, since the carrier 10 and the ring gear 17 are connected so as to rotate integrally, the carrier 10 and the ring gear 17 are shown at the same position on the collinear diagrams of FIGS. 4 and 5. Further, since the carrier 20 and the ring gear 8 are connected so as to rotate integrally, the carrier 20 and the ring gear 8 are shown at the same position on the collinear diagrams of FIGS. 4 and 5. 4 and 5, the sun gear 16 is disposed between the sun gear 7 and the ring gear 8, and the carrier 10 is disposed between the sun gear 16 and the ring gear 8. As shown in FIGS. 4 and 5, the power distribution device 4 has four rotating elements that are differentially rotatable with respect to each other. Further, the second motor / generator MG2 is connected to the output shaft 21 via the transmission 25, but is shown as (MG2) at the same position as the carrier 20 in FIGS. 4 and 5 for convenience.

  First, when the fixed speed change mode is selected, the brake BK functions as a reaction force generator. That is, the braking force of the brake BK is increased and the sun gear 16 is fixed (stopped) as shown in FIG. For this reason, the fact that the fixed transmission mode is selected may be referred to as “lock”. In addition, the power distribution device 4 is mechanically coupled so that the carrier 20 and the ring gear 8 rotate together, and the ring gear 17 and the carrier 10 are coupled so as to rotate together. Therefore, when engine torque is input to the carrier 10 and the ring gear 17 via the input shaft 11, reaction force is received by the brake BK and the sun gear 16, and torque is output from the carrier 20. The torque of the carrier 20 is transmitted to the wheel 3 via the output shaft 21, the final reduction gear 22, and the axle shaft 30, and a driving force is generated.

  Then, by controlling the engine speed, the gear ratio between the input speed and the output speed of the power distribution device 4 can be changed steplessly (continuously). Further, since the sun gear 16 is fixed when the fixed speed change mode is selected, the speed ratio of the power distribution device 4 is limited to less than “1”. That is, since the power distribution device 4 functions as a speed increaser, the torque output from the power distribution device 4 is lower than the input torque to the power distribution device 4. When the fixed speed change mode is selected and the engine speed is positive, the first motor / generator MG1 is reversely rotated by the engine torque. In this case, the first motor / generator MG1 can perform regenerative control (power generation control) or cause the rotor 14 to idle without performing regenerative control. Further, the power transmitted from the engine 2 to the output shaft 21 is transmitted to the second motor / generator MG2, and the second motor / generator MG2 performs regenerative control (power generation control), and the generated power is charged in the power storage device 28. It is also possible to do. On the other hand, when the acceleration request for the vehicle 1 increases and the torque transmitted to the wheels 3 increases, the power is supplied from the power storage device 28 to the second motor / generator MG2, and the second motor / generator MG2 is supplied. Can be driven as an electric motor. Furthermore, when the fixed speed change mode is selected, the rotational speed of the carrier 20 is higher than the rotational speed of the first motor / generator MG1. Furthermore, since the transmission ratio of the transmission 25 is set to “1” or more, the rotation speed of the second motor / generator MG2 is equal to or higher than the rotation speed of the output shaft 21. For this reason, when the second motor / generator MG2 is subjected to power running control and the speed ratio of the transmission 25 is larger than “1”, the torque of the second motor / generator MG2 is amplified and transmitted to the output shaft 21. Is done.

  On the other hand, when the continuously variable transmission mode is selected, the braking force applied from the brake BK to the sun gear 16 is reduced, and the sun gear 16 can rotate as shown in FIG. That is, when the continuously variable transmission mode is selected, the brake BK is released and the sun gear 16 is unlocked, so “selecting the continuously variable transmission mode” may be referred to as “unlock”. When the continuously variable transmission mode is selected and the engine torque is input to the carrier 10 via the input shaft 11, the reaction force is received by the first motor / generator MG1 and output from the ring gear 8. Torque is transmitted to the output shaft 21. That is, the first motor / generator MG1 functions as a reaction force generator. When the first motor / generator MG1 rotates forward and takes on the reaction force of the engine torque, the first motor / generator MG1 is regeneratively controlled, and the generated power is charged in the power storage device 28. On the other hand, when the first motor / generator MG1 rotates in the reverse direction, electric power is supplied from the power storage device 28 to the first motor / generator MG1, and the first motor / generator MG1 is driven as an electric motor to generate engine torque. Responsible for the reaction.

  When the continuously variable transmission mode is selected, the speed ratio between the input rotational speed and the output rotational speed of the power distribution device 4 is controlled continuously by controlling the rotational speed of the first motor / generator MG1. Can be changed continuously). Further, when the continuously variable transmission mode is selected, the transmission ratio of the power distribution device 4 can be selected to be less than “1” or “1” or more. When the gear ratio of the power distribution device 4 exceeds “1”, the power distribution device 4 functions as a speed reducer, and torque is amplified in the power distribution device 4. The case where the gear ratio of the power distribution device 4 is less than “1” is indicated by a broken line in FIG. On the other hand, the case where the gear ratio of the power distribution device 4 exceeds “1” is indicated by a one-dot chain line in FIG. In the collinear diagram of FIG. 5, the case where the first motor / generator MG1 is rotating forward is shown, but the case where the first motor / generator MG1 rotates reversely or may stop. Furthermore, as indicated by a solid line in FIG. 5, the speed ratio of the power distribution device 4 can be controlled to “1”.

  Further, regardless of whether the fixed speed change mode or the continuously variable speed change mode is selected, power is supplied to the second motor / generator MG2 to drive it as an electric motor, and the torque of the second motor / generator MG2 is changed. It is possible to transmit to the output shaft 21 via the machine 25. In addition, when electric power is supplied from the power storage device 28 to the second motor / generator MG2 to be driven as an electric motor and the torque of the second motor / generator MG2 is transmitted to the output shaft 21, fuel is supplied to the engine 2. Alternatively, the supply of fuel to the engine 2 may be stopped. The “fuel supply to the engine 2 is stopped” includes a case where the engine 2 is idling and a case where the engine 2 is stopped. Furthermore, even when either the fixed transmission mode or the continuously variable transmission mode is selected, a part of the power transmitted from the engine 2 to the output shaft 21 is transmitted to the second motor / generator MG2 to generate power. The generated power can be charged in the power storage device 28 or the generated power can be supplied to the first motor / generator MG1.

  Next, conditions for selecting a mode for controlling the power distribution device 4 will be described. The mode for controlling the power distribution device 4 is determined based on the fuel efficiency of the engine 2 and the power transmission efficiency in the power transmission path from the engine 2 to the wheels 3. First, the fuel consumption of the engine 2 will be described. In the vehicle 1, the required driving force for the vehicle 1 is obtained based on the vehicle speed and the accelerator opening, and the target output of the engine 2 and the target output of the second motor / generator MG2 are obtained based on the required driving force. When the engine output is controlled based on the target output of the engine 2, basically, the target rotational speed of the engine 2 and the target torque of the engine are set so that the operation state of the engine 2 is along the optimum fuel consumption line. Can be obtained. As described based on the alignment charts of FIGS. 4 and 5, when the continuously variable transmission mode is selected, the control range of the transmission ratio of the power distribution device 4 is larger than when the fixed transmission mode is selected. Is wide. Therefore, when giving priority to the fuel consumption of the engine 2, the continuously variable transmission mode is selected.

  On the other hand, as described with reference to the collinear diagram of FIG. 4, when the fixed speed change mode is selected, the reaction force of the engine torque is handled by the brake BK. Therefore, the first motor / generator MG1 and the second motor / The amount of electric power flowing between the generator MG2 and the electric circuit is reduced, and an increase in the amount of electric loss can be suppressed. Therefore, when priority is given to the increase in the amount of electric loss over the fuel consumption of the engine 2, the fixed speed change mode can be selected. Note that, regardless of whether the fixed speed change mode or the continuously variable speed change mode is selected, the electronic throttle valve is used to bring the actual torque of the engine 2 closer to the target torque in parallel with the control of the speed ratio of the power distribution device 4. The opening degree of the engine and the ignition timing are controlled.

  By the way, when the mode for controlling the power distribution device 4 is changed using the map of FIG. 3, when the running state of the vehicle 1 repeatedly crosses the threshold shown in FIG. There is a possibility that the shift mode is frequently switched and the control becomes busy. Therefore, control examples for suppressing frequent switching between the fixed speed change mode and the continuously variable speed change mode will be sequentially described.

(Control example 1)
First, the control example 1 is demonstrated based on the flowchart of FIG. In FIG. 1, it is determined whether or not the fixed speed change mode is currently selected (locked) (step S1). If the determination in step S1 is affirmative, measurement of the switching prohibition counter (count up) is started (step S2). The “switching prohibition counter” in step S2 is “elapsed time from when the continuously variable transmission mode is changed to the fixed transmission mode”. The technical significance of “elapsed time” will be described later.

  Following this step S2, it is determined whether or not there is a request to change from the currently selected fixed transmission mode to the continuously variable transmission mode again (step S3). The determination in step S3 is indicated by “Unlock requested?” In FIG. If the determination in step S3 is affirmative, it is determined whether or not the “elapsed time at which measurement was started in step S2 (switching prohibition counter)” exceeds a “predetermined predetermined time (a certain time)”. Determination is made (step S4). The technical significance of this predetermined time will be described. If the mode for controlling the power distribution device 4 is changed, the braking force applied from the brake BK to the sun gear 16 may change, and the torque output from the power distribution device 4 may change, which may be felt as a shock. is there. For this reason, when the mode which controls the power distribution device 4 is changed frequently within a short time, it is thought that the passenger | crew of the vehicle 1 has a discomfort and drivability deteriorates. Therefore, after the previous mode change, even if the condition for changing the mode is satisfied again, it is prohibited to change the mode again for a certain period of time, and the passenger of the vehicle 1 feels uncomfortable. In order to avoid having it, “predetermined time” is set. The predetermined time is experimentally obtained by changing the mode of the power distribution device 4 and stored in the electronic control device 33.

  If a negative determination is made in step S4, the occupant of the vehicle 1 may feel uncomfortable if the currently selected fixed transmission mode is changed to the continuously variable transmission mode. Therefore, if a negative determination is made in step S4, the process proceeds to step S5, and the engine operating point (rotation speed and torque) is maintained by maintaining the fixed speed change mode. In step S5, the second motor / generator MG2 is driven as an electric motor, and the torque transmitted from the second motor / generator MG2 to the output shaft 21 is increased. In this way, the torque transmitted from the second motor / generator MG2 to the output shaft 21 is increased, so that a driving force that meets the high load requirement can be obtained. In this step S5, when increasing the torque transmitted from the second motor / generator MG2 to the output shaft 21, the control for increasing the torque of the second motor / generator MG2 without changing the gear ratio of the transmission 25, or Any of the control for performing the shift to increase the gear ratio of the transmission 25 without changing the torque of the second motor / generator MG2 may be selected.

  On the other hand, if the determination in step S4 is affirmative, it means that there is no possibility that the occupant of the vehicle 1 will feel uncomfortable even if the currently selected fixed transmission mode is changed to the continuously variable transmission mode. . Therefore, if an affirmative determination is made in step S4, the process proceeds to step S6, where control is performed to change from the currently selected fixed transmission mode to the continuously variable transmission mode (unlocking is performed) and a switching prohibition counter ( The process of returning the measured elapsed time) to zero is performed, and this control routine is terminated. Further, when a negative determination is made in step S3, this control routine is terminated.

  Furthermore, the negative determination at the determination time of step S1 means that the continuously variable transmission mode is currently selected. Therefore, when a negative determination is made in step S1, measurement of the switching prohibition counter is started (counted up) (step S7). The “switch prohibition counter” in step S7 means “elapsed time from the time when the fixed shift mode is changed to the continuously variable shift mode”. Following this step S7, it is determined whether or not there is a request (lock request) for changing again from the currently selected continuously variable transmission mode to the fixed transmission mode (step S8). If the determination in step S8 is affirmative, it is determined whether or not the “elapsed time at which measurement was started in step S7 (switching prohibition counter)” exceeds a “predetermined predetermined time (a certain time)”. Determination is made (step S9). The technical meaning of the predetermined time used for the determination in step S9 is the same as the technical meaning of the predetermined time described in step S4. Further, the predetermined time used in step S4 and the predetermined time used in step S9 may be the same or different. If a negative determination is made in step S9, if the currently selected continuously variable transmission mode is changed to the fixed transmission mode, the occupant of the vehicle 1 may feel uncomfortable. Is maintained (unlocked) (step S10), and this control routine is terminated.

  On the other hand, if an affirmative determination is made in step S9, there is no possibility that the occupant of the vehicle 1 will feel uncomfortable even if the currently selected continuously variable transmission mode is changed to the fixed transmission mode. become. Therefore, if the determination in step S9 is affirmative, control to change from the currently selected continuously variable transmission mode to the fixed transmission mode is performed (locking execution) and a switching prohibition counter (measured elapsed time) Is returned to zero (step S11), and this control routine is terminated.

  In steps S2 and S7, the elapsed time from the time when the previous mode was changed is measured, and in steps S4 and S9, it is determined whether or not the elapsed time has exceeded a predetermined time. This is an example in which it is determined by “time” whether or not the occupant of the vehicle 1 has a sense of discomfort when the mode is frequently changed. On the other hand, when the mode is frequently changed, it is possible to determine whether or not the occupant of the vehicle 1 has an uncomfortable feeling based on the “vehicle travel distance”. In this case, in step S2 and step S7, a travel distance from the time when the previous mode was changed is measured, and in steps S4 and S9, a control routine is performed so as to determine whether or not the travel distance has exceeded a predetermined distance. Configure. If the travel distance does not exceed the predetermined distance, a negative determination is made in steps S4 and S9. If the travel distance exceeds the predetermined distance, a positive determination is made in steps S4 and S9. .

  As described above, in the control example of FIG. 1, even when the running state of the vehicle 1, specifically, the vehicle speed and the accelerator opening frequently cross the threshold values shown in FIG. Thus, it is possible to prevent the fixed speed change mode and the continuously variable speed change mode from being changed frequently and continuously, and to prevent the passenger of the vehicle 1 from feeling uncomfortable. Therefore, drivability is improved. In the routine that proceeds to step S5, neither the power running control nor the regenerative control is performed by the first motor / generator MG1, so that the power loss in the electric circuit connected to the first motor / generator MG1 can be reduced.

  Here, the correspondence between the configuration described in this embodiment and the configuration of the present invention will be described. The engine 2 corresponds to the driving force source of the present invention, and the power distribution device 4 is the power distribution device of the present invention. The input shaft 11 and the carrier 10 correspond to the input element of the present invention, the sun gears 7 and 16 correspond to the reaction force element of the present invention, the carrier 20 corresponds to the output element of the present invention, The output shaft 21 corresponds to the drive shaft of the present invention, the wheel 3 corresponds to the wheel of the present invention, the second motor / generator MG2 corresponds to the electric motor in the present invention, the power storage device 28 and the fuel cell are This corresponds to the power supply apparatus in the present invention. Further, the flowchart of FIG. 1 shows a control example corresponding to claims 1 and 2. The correspondence between the functional means shown in FIG. 1 and the configuration of the present invention will be described. Steps S3 and S8 correspond to the mode change request determination means of the present invention, and steps S2, S4, S7 and S9 correspond to the period determination means of the present invention. S5 and S10 correspond to the mode selection means of the present invention. Whether or not the condition for changing the speed change mode again is established is determined based on the running state of the vehicle, for example, the vehicle speed and the required driving force. Furthermore, the elapsed time and the travel distance correspond to the “predetermined period” of the present invention. Further, in the power distribution device 4 described above, the ring gear 8 and the output shaft 21 are connected so as to be able to transmit power, specifically, so as to rotate integrally, and the carrier 10 and the engine 2 are connected so as to be able to transmit power. Has been. Therefore, the gear ratio of the power distribution device 4 is equivalent to the “rotational speed ratio between the driving force source and the driving shaft” in the present invention.

(Control example 2)
Next, a control example 2 will be described with reference to FIG. In FIG. 6, steps that perform the same processing as in FIG. 1 are assigned the same step numbers as in FIG. Further, the control of FIG. 6 is not executed alone but in combination with the control of FIG. In FIG. 6, if the determination is affirmative in step S1, the process proceeds to step S3. If the determination is affirmative in step S3, the required power for the second motor / generator MG2 is set to the second motor / generator MG2. It is determined whether or not the power to be generated by generator MG2 exceeds the upper limit of the output power of power storage device 28 (step S12). The upper limit of the output power of the power storage device 28 depends on the temperature, and the upper limit of the output power can be obtained based on the temperature. The process of step S12 is shown in FIG. 6 as “the motor driving force request exceeds the battery output upper limit”. If a negative determination is made in step S12, the power required to generate the required power for the second motor / generator MG2 by the second motor / generator MG2 is stored in the power storage device 28 (battery capacity). Is sufficient) (step S13). If the determination in step S13 is affirmative, the second motor / generator MG2 is driven as an electric motor to satisfy the required power, and the process proceeds to step S5.

  On the other hand, if a negative determination is made in step S13, the required power cannot be satisfied even if the second motor / generator MG2 is driven as an electric motor, and the process proceeds to step S6. If the determination in step S12 is affirmative, the process proceeds to step S6. If a negative determination is made in step S1, the processing from step S7 to step S11 is performed as in FIG. In the control example of FIG. 6, when a fuel cell is provided in addition to the power storage device 28, it is also possible to make the determinations in step S <b> 12 and step S <b> 13 in consideration of the output power of the fuel cell.

  In the control example of FIG. 6, the same effect as that of the control example of FIG. In addition, it is possible to avoid a decrease in the remaining capacity of the power storage device 28 by the process that proceeds from step S12 to step S6 or the process that proceeds from step S13 to step S6. As described above, in the control example 2, it is possible to determine the power supplied to the second motor / generator MG2 based on the upper limit value of the output power of the power storage device 28 and the upper limit value of the output power of the fuel cell. Based on the determination result, it is determined whether or not to prohibit changing the speed change mode again. This control example 2 corresponds to claims 3, 4, and 5, and steps S12, S13, steps S5, S6 correspond to mode selection means.

(Control example 3)
Next, a control example 3 will be described with reference to FIG. In FIG. 7, steps that perform the same processing as in FIGS. 1 and 6 are assigned the same step numbers as in FIGS. Further, the control of FIG. 7 is not executed alone but in combination with the control of FIG. In FIG. 7, it is first determined whether or not the charge amount (battery capacity) of the power storage device 28 is equal to or greater than a certain value (step S14). The amount of charge used for the determination in step S14 is used to determine the durability of the power storage device 28, and is obtained experimentally and stored in the electronic control device 33. The predetermined amount of charge used in step S14 is much smaller than the amount of charge used for the determination in step S14. If the determination in step S14 is affirmative, the process proceeds to step S1 because the durability of the power storage device 28 is unlikely to decrease.

  On the other hand, when a negative determination is made in step S14, it is considered that the durability of the power storage device 28 is reduced when power is taken out from the power storage device 28. Therefore, the selection of the fixed speed change mode is prohibited, the continuously variable speed change mode is maintained (unlocked) (step S15), and this control routine is ended. In this way, when the continuously variable transmission mode is used, the electric power supplied to the second motor / generator MG2 is smaller than when the fixed transmission mode is selected, and the engine torque is generated by the first motor / generator MG1. If power is generated when the reaction force is applied, the power storage device 28 can be charged. Therefore, the charge amount of power storage device 28 can be increased to a predetermined value or more used for the determination in step S14, and power storage device 28 can be protected. In the control example of FIG. 7, the same effect as the control example of FIGS. 1 and 6 can be obtained with respect to a portion that performs the same processing as the control example of FIGS. 1 and 6. This control example 3 corresponds to claim 6 and steps S14 and S15 correspond to mode selection means.

  As the power distribution device of the present invention, it is possible to use a device provided with a set of planetary mechanisms. For example, it is possible to use a single pinion type planetary gear mechanism having a sun gear and a ring gear and a carrier for holding the pinion gear. In this configuration, the carrier is an input member, the sun gear is a reaction force member, and the ring gear is an output member. Further, a motor / generator and a brake can be used as a reaction force generator connected to the sun gear. This brake may be either a friction brake or a mesh brake. When the power distribution device is configured as described above, in the fixed speed change mode, the sun gear is stopped by the brake or the sun gear is stopped by the motor / generator. That is, by controlling the engine speed, the speed ratio of the power distribution device can be controlled steplessly within a range of less than “1”. On the other hand, in the continuously variable transmission mode, the brake is released and the speed of the motor / generator is controlled so that the speed ratio of the power distribution device is less than “1” or greater than “1”. It can be controlled steplessly within the range. In addition, when using one set of planetary mechanisms as a power distribution device, it is also possible to use a planetary roller mechanism instead of the planetary gear mechanism. The power train shown in FIG. 2 is a rear wheel drive vehicle configured to transmit the power of the engine 2 to the rear wheels. However, the present invention is applied to a front wheel drive vehicle configured to transmit the engine power to the front wheels. It is also possible to apply. In this case, the rotation axis of the rotating element is arranged in the vehicle width direction.

It is a flowchart which shows the example 1 of control performed with the control apparatus of the hybrid vehicle of this invention. It is a conceptual diagram which shows the power train and control system of the hybrid vehicle to which this invention is applied. It is a figure which shows an example of the map used for control of the power distribution apparatus shown by FIG. FIG. 3 is a collinear diagram illustrating a state of a rotating element when the power distribution device illustrated in FIG. 2 is controlled in a fixed speed change mode. FIG. 3 is a collinear diagram showing a state of a rotating element when the power distribution device shown in FIG. 2 is controlled in a continuously variable transmission mode. It is a flowchart which shows the control example 2 performed with the control apparatus of the hybrid vehicle of this invention. It is a flowchart which shows the example 3 of control performed with the control apparatus of the hybrid vehicle of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 3 ... Wheel, 4 ... Power distribution device, 7, 16 ... Sun gear, 8 ... Ring gear, 10 ... Carrier, 11 ... Input shaft, 20 ... Carrier, 21 ... Output shaft, 28 ... Power storage device BK ... Brake, MG1 ... First motor / generator, MG2 ... Second motor / generator.

Claims (6)

A driving force source that generates power to be transmitted to the wheels; a driving shaft that is connected to the wheels so as to be able to transmit power; a generator that converts kinetic energy into electrical energy; and a plurality of rotational elements that are capable of differential rotation. And a power distribution device in which three of the plurality of rotating elements are separately connected to the driving force source, the generator, and the driving shaft so as to be capable of transmitting power, and
A continuously variable transmission mode in which a rotational speed ratio between the driving force source and the driving shaft is continuously changed; and any one of the driving force source, the generator, and the driving shaft among the plurality of rotating elements; In a hybrid vehicle control device configured to be able to switch between a fixed speed change mode for fixing the rotational speed ratio by preventing rotation of a rotating element that is not connected,
Mode change determination means for determining whether or not a mode change between the fixed transmission mode and the continuously variable transmission mode has been performed;
A period determining means for determining whether or not a predetermined period of time when the vehicle occupant feels uncomfortable when changing the shift mode again from the time when the shift modes are changed; and
Mode change request determining means for determining whether or not a condition for changing the shift mode again is satisfied after the change between the shift modes is performed;
If the condition for changing the transmission mode again is satisfied before the predetermined period has elapsed since the change between the transmission modes, the current transmission mode is changed to another transmission mode. A control device for a hybrid vehicle, comprising: mode selection means for prohibiting the operation. An electric motor that generates torque to be transmitted to the wheel is provided;
The fixed speed change mode avoids vibration and noise generated in the power transmission path from the driving force source to the wheels even when the speed ratio between the driving force source and the driving shaft is limited to less than 1. Is selected based on the vehicle running state,
The mode change request determination means includes means for determining that a condition for changing the shift mode again is satisfied when the vehicle speed is less than a predetermined vehicle speed or when the required driving force is a predetermined value or more. ,
When the condition for changing the speed change mode again is satisfied before the predetermined period elapses from the time when the step change speed mode is changed to the fixed speed change mode, the mode selection means By increasing the torque transmitted from the electric motor to the wheels, the vehicle speed is maintained at a predetermined vehicle speed or higher, or the driving force is maintained at a predetermined value or higher, so that a continuously variable transmission from the currently selected fixed transmission mode is performed. The hybrid vehicle control device according to claim 1, further comprising means for prohibiting the mode change.   Whether the mode selection means determines the electric power supplied to the electric motor and prohibits the change from the currently selected fixed transmission mode to the continuously variable transmission mode based on the determination result; The hybrid vehicle control device according to claim 2, further comprising means for determining A power supply device for supplying power to the motor is provided;
The mode selection means includes
When the torque transmitted from the electric motor to the wheel is increased, the required torque to be transmitted from the electric motor to the wheel is determined, and the electric power for generating the required torque by the electric motor is the power supply Means for determining whether the output power is less than or equal to an upper limit value of the apparatus;
When it is determined that the electric power for generating the required torque in the electric motor is less than or equal to the upper limit value of the output electric power in the electric power supply device, the torque transmitted from the electric motor to the wheels is increased, Means for inhibiting changing from the currently selected fixed transmission mode to the continuously variable transmission mode by maintaining the vehicle speed and the driving force of the vehicle in a state in which the fixed transmission mode is selected;
When it is determined that the electric power for generating the required torque in the electric motor exceeds the upper limit value of the output electric power in the electric power supply device, the torque transmitted from the electric motor to the wheels is not increased. 4. The control apparatus for a hybrid vehicle according to claim 3, further comprising means for changing from the currently selected fixed speed change mode to the continuously variable speed change mode. A power supply device for supplying power to the motor is provided;
The mode selection means includes
When the torque transmitted from the electric motor to the wheel is increased, a required torque to be transmitted from the electric motor to the wheel is determined, and electric power for generating the required torque by the electric motor is the power supply device. Means for determining whether or not it remains,
When it is determined that the electric power for generating the required torque in the electric motor remains in the electric power supply device, the torque transmitted from the electric motor to the wheels is increased to drive the vehicle speed and the vehicle. Means for inhibiting changing from the currently selected fixed transmission mode to the continuously variable transmission mode by maintaining the force in a state in which the fixed transmission mode is selected;
When it is determined that the electric power for generating the required torque in the electric motor does not remain in the electric power supply device, it is currently selected without increasing the torque transmitted from the electric motor to the wheels. 4. The control apparatus for a hybrid vehicle according to claim 3, further comprising means for changing from a fixed transmission mode to a continuously variable transmission mode.   When the mode selection means determines whether or not the condition of the power supply device that supplies power to the electric motor decreases in durability, and determines that the condition of the electric power supply device decreases. 6. The control apparatus for a hybrid vehicle according to claim 3, further comprising means for prohibiting selection of the fixed transmission mode.

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