JP2009132189A - Controller for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a hybrid vehicle capable of enhancing the efficiency of power generation if there is a request for power generation. <P>SOLUTION: The controller is provided for a hybrid vehicle having a power distribution device where an input element and a reaction element are connected to a drive source and generators, respectively to permit power transmission and an output element is connected to wheels via drive shafts to permit power transmission. The controller is capable of switching between a stepless variable speed mode in which rotation speed ratio between the drive source and the drive shafts is steplessly varied and a fixed variable speed mode in which rotation speed ratio is fixed. A first and a second generator are provided as the generators, the second generator having higher efficiency of power generation than the first generator. The controller has a power generation control means (step S9 to S14) which generates power using the second generator when the fixed variable speed mode is selected as a mode for controlling the rotation speed ratio and when there is a request for power generation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid vehicle having a configuration in which a generator is connected to a power transmission path from a power distribution device to a wheel.

  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. The case where 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 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. An example of a hybrid vehicle control device in which an engine and a motor / generator are mounted as a plurality of driving force sources and the motor / generator can generate electric power is also described in Patent Document 2.

JP 2004-345527 A JP 7-75207 A

  Incidentally, since the second motor / generator described in Patent Document 1 has a function of assisting the torque transmitted to the wheels, it is a device having a large physique designed for high power and high output specifications. For this reason, when the torque transmitted from the power distribution mechanism to the wheels is relatively low, such as when the power distribution mechanism is in an overdrive state, a power generation request is generated and the second motor / generator When power generation is performed, the power generation efficiency may decrease.

  The present invention has been made against the background of the above circumstances, and is a hybrid vehicle capable of improving the power generation efficiency of the generator even when the torque transmitted from the power distribution device to the wheels is relatively low. It aims to provide a control device.

  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 device 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 also not connected, as the generator The first generator and the second generator are provided, and the power generation efficiency in the case of generating electric power at a predetermined rotation speed or higher and below a predetermined torque is second than that of the first generator. The generator is configured to be higher, the fixed speed change mode is selected as the mode for controlling the rotation speed ratio, and when there is a power generation request, power generation control means for generating power with the second generator It is characterized by having.

  In the present invention, a clutch that connects either the first generator or the second generator to the drive shaft so as to be able to transmit power is provided, and when the first generator generates power, First clutch control means for controlling the clutch so as to connect the first generator to the drive shaft so that power can be transmitted, and to interrupt a power transmission path between the second generator and the drive shaft. When generating power with the second generator, the second generator is connected to the drive shaft so that power can be transmitted, and a power transmission path between the first generator and the drive shaft is provided. When switching the generator that generates power between the second clutch control means that controls the clutch so as to be shut off, and the first generator and the second generator, rotation of the generator that generates power after switching Number of the drive shaft After the rolling speed is matched, a generator that generates electric power and said drive shaft may be provided with a rotational speed control means for controlling said clutch so as to connect in a power transmission.

  According to this invention, the power distribution device can steplessly control the rotation speed ratio between the driving force source and the driving shaft. In addition, as a mode for controlling the rotation speed ratio between the driving force source and the drive shaft, a fixed transmission mode for fixing the rotation speed ratio and a continuously variable transmission mode capable of changing the rotation speed ratio continuously. Switching is possible. Furthermore, it is possible to generate power with the generator by the power transmitted between the drive shaft and the wheels. When the fixed transmission mode is selected, the torque output from the power distribution device is lower than that when the continuously variable transmission mode is selected, but the second generator generates power. For this reason, the power generation efficiency is higher than when power is generated by the first generator.

  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. In the present invention, for example, a continuously variable transmission using a planetary mechanism can be used as the power distribution device having four elements capable of differential rotation. As the planetary mechanism, it is possible to use a planetary gear mechanism that transmits power by the meshing force of a gear, or a planetary roller mechanism that transmits power by traction transmission by the shearing force of hydraulic oil. Further, the four 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.

  Furthermore, the 1st generator and the 2nd generator are provided as a generator, and the electric power generation functions differ. Specifically, the second generator has a higher power generation efficiency than the first generator in the case where power is generated at a predetermined rotation speed or higher and below a predetermined torque. . Furthermore, as the first generator and the second generator, it is possible to use a motor / generator having a function as an electric motor in addition to a function as a generator. Furthermore, the drive shaft is an element that transmits power, and includes elements such as a gear, a carrier, a connecting drum, a rotating shaft, a pulley, a belt, a roller, a sprocket, and a chain. In the present invention, the “drive shaft that can rotate with the rotation of the wheel” means that power can be transmitted between the wheel and the drive shaft. Is configured to rotate. That is, the drive shaft is not limited to a shaft shape. The clutch is a device that connects the first generator and the second generator to the transmission member so that power can be transmitted selectively. As this clutch, a friction clutch or a mesh clutch is used. it can. In addition, a hydraulic actuator or an electromagnetic actuator can be used as the actuator that operates the operation member of the clutch. Furthermore, the present invention can be applied to either a two-wheel drive vehicle or a four-wheel drive vehicle.

  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. 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 (rear 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 operation 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 has MG2, a power running function that converts electrical energy into kinetic energy, and a regenerative function that converts kinetic energy into electrical energy. The second motor / generator MG <b> 2 has a stator 23 and a rotor 24. Further, a third motor / generator MG3 is disposed 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 third motor / generator MG3 is arranged behind the second motor / generator MG2 in the front-rear direction of the vehicle 1. Further, the third motor / generator MG3 may be disposed either inside the casing 5 or outside the casing 5. The third motor / generator MG3 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 third motor / generator MG3 includes a stator 25 and a rotor 26.

  Further, the first motor / generator MG1, the second motor / generator MG2, and the third motor / generator MG3 are all the ones 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. Further, the power storage device 28 is configured to be able to supply power to the auxiliary device 29. The auxiliary device 29 is a device other than a device that is mounted on the vehicle 1 and generates power used for traveling of the vehicle 1, for driving or operating the auxiliary device 29, and for the auxiliary device 29. Electric power is used to perform the function. The auxiliary device 29 includes, for example, a lighting device, a wiper, an air conditioner, an acoustic device, a power window, and the like. 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.

  Furthermore, when the second motor / generator MG2 and the third motor / generator MG3 are compared, their power generation characteristics are different. Specifically, the power generation efficiency when generating electric power at a predetermined rotation speed (predetermined high rotation speed) or more and less than a predetermined torque (predetermined low torque) is the second motor generator The rating is determined so that the third motor / generator MG3 is higher than the MG2. The predetermined high rotational speed and the predetermined low torque used when making a difference in power generation efficiency will be described later. Further, the second motor / generator MG2 has a function of generating high torque to be transmitted to the wheels 3, whereas the third motor / generator MG3 has a function of generating high torque to be transmitted to the wheels 3. There is no motor generator dedicated to power generation, in particular, dedicated to power generation of power supplied to the auxiliary device 29. Specific methods for making the third motor / generator MG3 have higher power generation efficiency than the second motor / generator MG2 include the following methods. If both the second motor / generator MG2 and the third motor / generator MG3 are of the same type, for example, a structure in which a coil is wound around a laminated iron core, the number of iron cores to be laminated is set to the third motor more than the second motor / generator MG2. A method of reducing the iron loss by reducing the number of generators MG3 can be mentioned.

  Further, the power generation efficiency can be varied by using different types of motor generators for the second motor generator MG2 and the third motor generator MG3. For example, a structure in which a coil is wound around a laminated iron core can be used as the second motor / generator MG2, and a coreless motor / generator can be used as the third motor / generator MG3. A coreless motor / generator has higher power generation efficiency because it has no iron core. Even if the power generation efficiency of the third motor / generator MG3 is higher than the power generation efficiency of the second motor / generator MG2, the third motor / generator MG3 is smaller than the second motor / generator MG2. It is made compact. That is, the length in the direction along the rotation axis and the outer diameter centered on the rotation axis are shorter (smaller) in the third motor / generator MG3 than in the second motor / generator MG2.

  Further, a clutch 31 is provided for connecting the second motor / generator MG2 and the third motor / generator MG3 to the output shaft 21 so as to selectively transmit power. As the clutch 31, either a meshing clutch or a friction clutch may be used. Further, a dog clutch can be used as the meshing clutch. The dog clutch has a configuration in which an operating force is not applied to the operating member after the operating member is operated and engaged. In any case, a hydraulic actuator, an electric actuator, a magnetic actuator, or the like can be used as the actuator 34 that operates the clutch 31. Further, in this embodiment, the clutch 31 is disposed between the second motor / generator MG2 and the third motor / generator MG3 in the direction along the rotation axis. 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. The signals such as the amount, the load in the auxiliary device 29, the power generation request for the motor / generator, the acceleration request in the vehicle 1, the braking request in the vehicle 1, and the shift position are input.

  The electronic control unit 33 outputs a signal for controlling the clutch 31 and 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 clutch 31 includes a signal for controlling whether the output shaft 21 is connected to the second motor / generator MG2 or the third motor / generator MG3 so that power can be transmitted, and a 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, the target rotational speed of the engine 2 and the target torque of the engine are obtained so that the operation state of the engine 2 is along the optimum fuel consumption line. 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. The gear ratio of the power distribution device 4 is a rotation speed ratio between the engine 2 and the output shaft 21. When the speed ratio of the power distribution device 4 is controlled, a mode switching map shown in FIG. 3 can be used. This mode switching map is stored in the electronic control unit 33. 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 the accelerator. The opening degree (or required driving force) is shown as a parameter. When the continuously variable transmission mode is selected, basically, the target rotational speed and target torque of the engine 2 are obtained based on the optimum fuel consumption line. On the other hand, when priority is given to suppressing power loss, the fixed speed change mode is selected.

  In the map of FIG. 3, the accelerator opening is used as the acceleration request. 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. An example of the technical reason for determining the operation region in which the fixed transmission mode is selected and the operation region in which the continuously variable transmission mode is selected will be described. A region where vibration and noise generated in the power transmission path from the engine 2 to the wheels 3 can be suppressed to such an extent that the occupant of the vehicle 1 does not feel uncomfortable even when the speed ratio of the power distribution device 4 is fixed to less than “1”. The map shown in FIG. 3 can be determined so that the fixed speed change mode is selected in an operation region in which the vehicle occupant does not feel uncomfortable and the target torque of the engine 2 can be secured. Is possible. 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. Here, a description will be given of how to obtain “predetermined high rotational speed” and “predetermined low torque” used when there is a difference in power generation efficiency between the second motor / generator MG2 and the third motor / generator MG3. The predetermined high rotational speed can be obtained based on the vehicle speed in the region where the fixed speed change mode is selected and the reduction ratio of the final reduction gear. The predetermined low torque can be obtained based on the vehicle speed at which the fixed speed change mode is selected, the speed ratio of the power distribution device 4, the engine torque selected at the fixed speed change mode, and the like.

  Control of the power distribution device 4 will be described based on the alignment charts of FIGS. 4 and 5. 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, a 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 clutch 31, but is shown as (MG2) in the same position as the carrier 20 in FIGS.

  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. 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 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. 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, even when the fixed speed change mode or the continuously variable speed change mode is selected, electric 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 applied to the clutch. It is possible to transmit to the output shaft 21 via 31. 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.

  Furthermore, when the amount of charge of the power storage device 28 is insufficient, when power supplied to the first motor / generator MG1 is supplied, or when power is supplied to the auxiliary device 29, a power generation request is generated. In this case, the second motor / generator MG2 or the third motor / generator MG3 can generate power. A specific control example in the case where such a power generation request is generated and the second motor / generator MG2 or the third motor / generator MG3 generates power will be described with reference to the flowchart of FIG. In the flowchart of FIG. 1, the engine torque is transmitted to the wheels 3 via the output shaft 21 to generate driving force, or the vehicle 1 travels in a repulsive manner and the kinetic energy is from the wheels 3. It can be executed in any case where it is transmitted to the output shaft 21. First, it is determined whether or not the fixed transmission mode is selected as a mode for controlling the transmission ratio of the power distribution device 4 (step S1).

  If the determination in step S1 is affirmative, it is determined whether or not there is a request to switch from the fixed transmission mode to the continuously variable transmission mode (step S2). The determination in step S2 is made using the map of FIG. If a negative determination is made in step S2, the process returns. On the other hand, if the determination in step S2 is affirmative, “from the state in which the third motor / generator MG3 is connected to the output shaft 21 to the state in which the second motor / generator MG2 is connected to the output shaft 21; It is determined whether or not the “flag for switching the operation state of the clutch 31” is turned on (step S3). The process of step S3 is shown in FIG. 1 as “ON flag indicating that MG3 → MG2 clutch is being switched?”. When a negative determination is made in step S3, a “flag indicating that the operation state of the clutch 31 is being switched so that the third motor / generator MG3 is connected to the output shaft 21 so that power can be transmitted” is set. The control is performed to turn off the “flag indicating that the operation state of the clutch 31 is being switched so that the second motor / generator MG2 is connected to the output shaft 21 so that power can be transmitted” (step S4). In step S4, a process of setting the rotation speed of the third motor / generator MG3 at the time when the fixed speed change mode is selected as the target rotation speed (Nmg2tag) of the second motor / generator MG2 is executed. In FIG. 1, the processing in step S4 is shown as “flag ON indicating that MG3 → MG2 clutch is being switched”, “flag OFF indicating that MG2 → MG3 clutch is being switched”, and “Nmg2tag ← MG3 rotational speed”.

  Following step S4, control is performed to match (match) the actual rotational speed of the second motor / generator MG2 with the target rotational speed (Nmg2tag) (step S5). In step S5, the second motor / generator MG2 is driven as an electric motor to control the actual rotational speed. Note that if the determination in step S3 is affirmative, the process proceeds to step S5. Following this step S5, it is determined whether or not the actual rotational speed of the second motor / generator MG2 matches the target rotational speed (Nmg2tag) (step S6). If a negative determination is made in step S6, the process returns. On the other hand, if the determination in step S6 is affirmative, the clutch is arranged such that the second motor / generator MG2 is connected to the output shaft 21 and the third motor / generator MG3 is disconnected from the output shaft 21. 31 is controlled (step S7). The process of step S7 is shown as “clutch switching process (MG3 → MG2)” in FIG. Following this step S7, the "flag indicating that the control of the clutch 31 is being switched so as to connect the second motor / generator MG2 to the output shaft 21 so that power can be transmitted" is turned off (step S8), and the return To do. The process of step S8 is shown in FIG. 1 as “OFF flag indicating that MG3 → MG2 clutch is being switched”.

  On the other hand, if the continuously variable transmission mode is selected at the time of determination in step S1, and a negative determination is made in step S1, it is determined whether or not there is a request to switch from the continuously variable transmission mode to the fixed transmission mode. (Step S9). If a negative determination is made in step S9, the process returns. On the other hand, if the determination in step 9 is affirmative, “from the state in which the second motor / generator MG2 is connected to the output shaft 21 to the state in which the third motor / generator MG3 is connected to the output shaft 21; It is determined whether or not the “flag for switching the operating state of the clutch 31” is turned on (step S10). The process of step S10 is shown in FIG. 1 as “ON flag indicating MG2 → MG3 clutch switching”. If a negative determination is made in step S10, the “flag indicating that the control of the clutch 31 is being switched so that the second motor / generator MG2 is connected to the output shaft 21 so as to be able to transmit power” is turned on. Then, control is performed to turn off the “flag indicating that the operation state of the clutch 31 is being switched so that the third motor / generator MG3 is connected to the output shaft 21 so that power can be transmitted” (step S11). In step S11, a process of setting the rotation speed of the second motor / generator MG2 at the time when the continuously variable transmission mode is selected as the target rotation speed (Nmg3tag) of the third motor / generator MG3 is executed. In FIG. 1, the processing of these steps S11 is shown as “a flag ON indicating that the MG2 → MG3 clutch is being switched”, “a flag OFF indicating that the MG3 → MG2 clutch is being switched”, and “Nmg3tag ← MG2 rotational speed”. .

  Following this step S11, control is performed to match (match) the actual rotational speed of the third motor / generator MG3 with the target rotational speed (Nmg3tag) (step S12). In step S12, the third motor / generator MG3 is driven as an electric motor to control the actual rotational speed. Note that if the determination in step S10 is affirmative, the process proceeds to step S12. Following this step S12, it is determined whether or not the actual rotational speed of the third motor / generator MG3 matches the target rotational speed (Nmg3tag) (step S13). If a negative determination is made in step S13, the process returns. On the other hand, if the determination in step S13 is affirmative, the clutch is arranged such that the third motor / generator MG3 is connected to the output shaft 21 and the second motor / generator MG2 is disconnected from the output shaft 21. 31 is controlled (step S14). The process of step S14 is shown as “clutch switching process (MG2 → MG3)” in FIG. Following this step S14, the "flag indicating that the clutch 31 is being switched so that the third motor / generator MG3 is connected to the output shaft 21 so that power can be transmitted" is turned off (step S15), and the process returns. The process of step S15 is shown in FIG. 1 as “OFF flag indicating MG2 → MG3 clutch switching”.

  As described above, in the control example of FIG. 1, when the fixed speed change mode is selected, power is generated by the third motor / generator MG3. In the situation where the fixed speed change mode is selected, the first motor / generator MG1 does not handle the reaction force. Therefore, when the continuously variable speed change mode is selected and the first motor / generator MG1 is controlled by the power running, the reaction force is received. Less power consumption than In addition, 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 is output from the power distribution device 4 compared to when the continuously variable speed change mode is selected. Torque is also low torque. In this embodiment, the power generation efficiency of the third motor / generator MG3 is higher than that of the second motor / generator MG2 when power generation is performed at a predetermined high rotation speed or higher and less than a predetermined low torque. Has a high characteristic. In other words, the third motor / generator MG3 is designed to have a lower power specification than the second motor / generator MG2. Therefore, when power generation is performed in a situation where the fixed speed change mode is selected, the power generation efficiency can be increased.

  When the second motor / generator MG2 and the third motor / generator MG3 are selectively connected to the output shaft 21, the rotational speed of the connected motor / generator is matched with the rotational speed of the output shaft 21. Therefore, since the motor / generator for generating power and the output shaft 21 are connected by the clutch 31, the occurrence of shock due to the engagement of the clutch 21 can be suppressed. Further, when the fixed speed change mode is selected, the clutch 31 is controlled so that the power transmission path between the output shaft 21 and the second motor / generator MG2 is cut off. Therefore, a part of the power of the output shaft 21 can be prevented from being consumed by the idling of the second motor / generator MG2, and the power generation efficiency of the third motor / generator MG3 is further improved. Furthermore, when a dog clutch is used as the clutch 31, it is not necessary to apply an operating force to the operating member when the engagement is completed, so that power loss can be reduced.

  The correspondence between the configuration described in this specific example 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 input shaft 11 and the carrier 10 correspond to the input elements of the present invention. The ring gear 8 and the carrier 20 correspond to the output element of the present invention, the sun gears 7 and 16 correspond to the reaction force element of the present invention, the output shaft 21 corresponds to the drive shaft of the present invention, and the second The motor / generator MG2 and the third motor / generator MG3 correspond to the generator of the present invention. The second motor / generator MG2 corresponds to the first generator of the present invention. The third motor / generator MG3 corresponds to the generator. This corresponds to the second generator of the 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.

  The correspondence between the functional means shown in FIG. 1 and the configuration of the present invention will be described. Steps S2, S3, S4, S5, S6, S7, and S8 are the first clutch control means in the present invention. Steps S9, S10, S11, S12, S13, S14, and S15 correspond to the second clutch control means in the present invention, and steps S4, S5, S6, and S7, and steps S11, S12, S13, and S14 are included. This corresponds to the rotational speed control means in the present invention.

  In this embodiment, it is also possible to adopt a layout in which the arrangement position of the second motor / generator MG2 and the arrangement position of the third motor / generator MG3 are reversed in the front-rear direction of the vehicle 1. Furthermore, in the case of a vehicle configured to transmit engine power to the front wheels, for example, a front wheel drive vehicle, the rotation axis of the rotating element is arranged in the width direction of the vehicle. Further, it is possible to use a power distribution 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.

It is a flowchart which shows the example 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.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 7, 16 ... Sun gear, 8 ... Ring gear, 10 ... Carrier, 11 ... Input shaft, 20 ... Carrier, 21 ... Output shaft, BK ... Brake, MG1 ... First motor generator, MG2 ... 2nd motor generator, MG3 ... 3rd motor generator.

Claims (2)

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,
As the generator, a first generator and a second generator are provided, and the power generation efficiency in the case of generating power at a predetermined rotation speed or higher and below a predetermined torque is the first power generation. The second generator is configured higher than the machine,
A hybrid vehicle characterized in that a fixed speed change mode is selected as a mode for controlling the rotational speed ratio, and power generation control means for generating power with the second generator when there is a power generation request. Control device. A clutch is provided to connect either the first generator or the second generator to the drive shaft so that power can be transmitted;
When power is generated by the first generator, the first generator is connected to the drive shaft so that power can be transmitted, and the power transmission path between the second generator and the drive shaft is interrupted. First clutch control means for controlling the clutch,
When power is generated by the second generator, the second generator is connected to the drive shaft so that power can be transmitted, and the power transmission path between the first generator and the drive shaft is interrupted. Second clutch control means for controlling the clutch,
When switching the generator that generates power between the first generator and the second generator, after matching the rotational speed of the generator that generates power after switching with the rotational speed of the drive shaft, 2. The hybrid vehicle control device according to claim 1, further comprising a rotation speed control means for controlling the clutch so as to connect a generator for generating power and the drive shaft so that power can be transmitted.

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