JP2009173196A - Hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for controlling a hybrid vehicle capable of making the charging state of a battery raised, and simultaneously operating an internal combustion engine, in an operating state with low fuel consumption, when the charging state of the battery supplying power to a motor is low, and vehicle speed is low. <P>SOLUTION: The hybrid vehicle 1 has a first clutch 21, capable of engaging an engine output shaft 8 and a first input shaft 27 of a first transmission mechanism 30, and a second clutch 22, capable of engaging an engine output shaft 8 and a second input shaft 28 of a second transmission mechanism 40. When the charging state of a secondary battery 120 is not higher than a determination value and vehicle speed is not higher than a determination vehicle speed, an ECU 100 operates the internal combustion engine 5, at an engine load at which the fuel consumption becomes the lowest according to an engine rotation speed, and also operates a motor 50 as a generator, by setting a value subtracting required drive torque which is required to be generated in a drive wheel 88 from an engine driven torque acted on the drive wheel 88 by a mechanical power from the engine output shaft 8 as regenerative braking torque which makes the drive wheel act as a power generator. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a hybrid vehicle including an internal combustion engine and a motor generator as a prime mover, and capable of performing regenerative braking that brakes the drive wheel by engaging the drive wheel and the rotor and operating the motor generator as a generator. About.

  2. Description of the Related Art In recent years, in a vehicle transmission, in order to eliminate interruption of transmission of mechanical power at the time of shifting, a first transmission mechanism configured with a first group of shift stages and a shift stage other than the first group are used. Two transmission mechanisms including a second transmission mechanism composed of two groups of shift stages are provided, and further includes an input shaft of the first transmission mechanism (hereinafter referred to as a first input shaft) and an output shaft of the internal combustion engine (hereinafter referred to as a first input shaft). A first clutch capable of engaging with the engine output shaft, and a second clutch capable of engaging with the input shaft of the second speed change mechanism (hereinafter referred to as the second input shaft) and the engine output shaft. It is known that a so-called dual clutch transmission is used that shifts by alternately switching these two clutches.

  Patent Document 1 below includes an internal combustion engine (engine) and a motor generator (hereinafter simply referred to as “motor”) as a prime mover, a dual clutch transmission as a transmission mechanism, and a dual clutch transmission. A vehicle power transmission system in which a rotor of a motor is engaged with at least one of two input shafts of the machine is disclosed.

  Patent Document 2 below discloses a hybrid vehicle that includes an internal combustion engine (engine) and a motor (motor generator) as a prime mover and is equipped with a dual clutch transmission. In Patent Document 2, when a steady running or a light load running is performed when a charging capacity is insufficient, a driving wheel is driven by mechanical power from an engine while a motor generator is operated as a generator. It has been proposed that a part of mechanical energy generated by the engine is converted into electric energy and stored by driving the (rear wheel).

JP 2002-204504 A JP 2005-329813 A

  When a hybrid vehicle equipped with such a dual clutch type transmission continues for a long time at a low speed such as when there is a traffic jam, for example, the mechanical power from the motor is transmitted to the lowest speed side in the second transmission mechanism. It is possible to perform vehicle travel (hereinafter referred to as motor travel) in which only the motor is selected and used as a prime mover by shifting the speed at a shift speed (hereinafter referred to as the lowest speed speed) and transmitting it to the drive wheels. However, if the motor is driven when the vehicle travels at a low speed such as in a traffic jam for a long time, the state-of-charge of the battery that supplies power to the motor (hereinafter referred to as a secondary battery) There is a problem that the motor travel cannot be continued for a long time because the SOC) decreases.

  Further, the mechanical power from the internal combustion engine is shifted by the lowest speed of the first speed change mechanism or the second speed change mechanism and transmitted to the drive wheel, and the mechanical power from the motor is transferred to the lowest speed of the second speed change mechanism. It is also possible to perform vehicle travel (hereinafter referred to as hybrid travel) using both an internal combustion engine and a motor generator as a prime mover by shifting the speed by the speed and transmitting it to the drive wheels. In this case, although it is possible to suppress a decrease in the storage state of the secondary battery as compared with the case where the motor travel is continued, the internal combustion engine is operated at a light load and a low rotational speed. The rate becomes high and the problem that the energy efficiency as a hybrid vehicle is bad arises.

  In addition, the vehicle driving | running | working which selects and uses only an internal combustion engine as a motor | power_engine by changing the mechanical motive power from an internal combustion engine by the minimum speed stage of a 1st transmission mechanism or a 2nd transmission mechanism, and transmitting to a driving wheel (henceforth, In order to prevent the internal combustion engine from stalling when the vehicle is stopped, the frequency of engaging / disengaging the first clutch and the second clutch is reduced. There is a problem that the driving performance is not good.

  Therefore, in a hybrid vehicle having a dual clutch transmission and having a motor rotor engaged with one of the two input shafts, the secondary battery can be used when the secondary battery has a low storage state and the vehicle speed is low. There is a demand for a control technology that increases the energy storage state of the vehicle and operates the internal combustion engine under operating conditions with a low fuel consumption rate as much as possible so that the vehicle as a whole travels with good energy efficiency.

  The present invention has been made in view of the above, and supplies power to a motor in a hybrid vehicle including a dual clutch transmission and having a motor rotor engaged with one of two input shafts. It is an object of the present invention to provide a control technique that can increase the battery storage state and operate the internal combustion engine in an operation state with a low fuel consumption rate when the battery storage state is low and the vehicle speed is low.

  In order to achieve the above object, a hybrid vehicle according to the present invention includes an internal combustion engine that outputs mechanical power from an engine output shaft, a motor generator that operates as a generator and can brake a rotor, and an engine output shaft. The first input shaft receives the mechanical power of the first gear, the first speed change mechanism capable of shifting the speed by any one of a plurality of shift speeds and transmitting it to the drive wheels, the mechanical output shaft and the mechanical force from the rotor Power is received by a second input shaft that engages with the rotor, and a second speed change mechanism that is capable of shifting gears by any one of a plurality of shift speeds and transmitting the power to drive wheels, an engine output shaft, A first clutch capable of engaging with one input shaft, a second clutch capable of engaging with an engine output shaft and a second input shaft, engagement / release states of the first and second clutches, Selection of the gear position in the second transmission mechanism, the internal combustion engine and the motor And a control unit capable of controlling the operation of the generator, and a hybrid vehicle capable of engaging the drive wheel and the rotor and operating the motor generator as a generator to perform regenerative braking that brakes the drive wheel. The control means has a fuel consumption rate corresponding to the engine speed when the storage state of the secondary battery that supplies power to the motor generator is equal to or less than the determination value and the vehicle speed is equal to or less than the determination vehicle speed. The value obtained by operating the internal combustion engine at the lowest engine load and subtracting the required drive torque required to be generated in the drive wheel from the engine drive torque acting on the drive wheel by the mechanical power from the engine output shaft, The motor generator is operated as a generator by setting the regenerative braking torque to be applied to the drive wheels.

  In the hybrid vehicle according to the present invention, the control means includes storage means for storing a fuel consumption rate map that defines a fuel consumption rate with respect to the engine rotation speed and the engine load, and the fuel is generated based on the engine rotation speed and the fuel consumption rate map. The engine load with the lowest consumption rate can be estimated.

  In the hybrid vehicle according to the present invention, the mechanical power from the first speed change mechanism and the second speed change mechanism is integrated in the power integration mechanism and transmitted to the drive wheels. The minimum speed of the first speed change mechanism is The reduction gear ratio is set to be larger than the lowest speed of the second speed change mechanism, and the control means selects the lowest speed in the first speed change mechanism and the second speed change mechanism, and engages the first clutch. And the second clutch is disengaged, the mechanical power from the engine output shaft is shifted by the lowest speed of the first transmission mechanism, transmitted to the power integration mechanism, and transmitted to the power integration mechanism A part of the mechanical power can be transmitted to the driving wheel, and the remaining can be transmitted to the rotor after being changed by the lowest speed of the second speed change mechanism.

  In the hybrid vehicle according to the present invention, the lowest speed of the first speed change mechanism is set to have a larger reduction ratio than the lowest speed of the second speed change mechanism, and the control means is the lowest speed of the second speed change mechanism. The first clutch is disengaged and the second clutch is engaged, and a part of the mechanical power transmitted from the engine output shaft to the second input shaft is reduced to the minimum of the second transmission mechanism. It is possible to change the speed at a high speed and transmit it to the drive wheel and to transmit the rest to the rotor.

  In the hybrid vehicle according to the present invention, when the vehicle speed is equal to or lower than the second determination vehicle speed set to a value lower than the determination vehicle speed, the first transmission mechanism and the second transmission mechanism respectively When the lowest gear is selected, the first clutch is engaged and the second clutch is released, and the vehicle speed exceeds the second determination vehicle speed, the lowest gear is selected in the second transmission mechanism, One clutch can be released and the second clutch can be engaged.

  According to the present invention, the internal combustion engine is operated with the engine load having the lowest fuel consumption rate in accordance with the engine rotation speed, and a part of the mechanical power from the internal combustion engine is transmitted to the drive wheel, so that the drive wheel is desired. While generating the required drive torque, the remaining mechanical power can be transmitted to the rotor and converted into electric power by the motor generator to increase the storage state of the secondary battery.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  First, the structure of the hybrid vehicle and drive device which concern on a present Example is demonstrated using FIGS. 1-3. FIG. 1 is a schematic diagram showing a schematic configuration of a hybrid vehicle and a drive device. FIG. 2 is a schematic diagram showing a structure of a dual clutch mechanism provided in the drive device. FIG. 3 is a schematic diagram showing the structure of a modified dual clutch mechanism.

  The hybrid vehicle 1 includes an internal combustion engine 5 and a motor generator 50 (hereinafter simply referred to as “motor”) as a prime mover for rotationally driving the drive wheels 88. The motor 50 is included in the drive device 10 that shifts mechanical power from the internal combustion engine 5 and transmits the mechanical power to the drive wheels 88. The internal combustion engine 5 is coupled with the drive device 10 including the motor 50 and mounted on the hybrid vehicle 1. The hybrid vehicle 1 is provided with an electronic control device 100 (hereinafter referred to as ECU) for a hybrid vehicle as a control means for controlling the internal combustion engine 5 and the drive device 10. The ECU 100 is provided with a ROM (not shown) as storage means for storing various control constants.

  The internal combustion engine 5 is a heat engine that converts fuel energy into mechanical power by combustion and outputs it, and is a piston reciprocating engine. The internal combustion engine 5 includes a fuel injection device, an ignition device, and a throttle valve device (not shown). These devices are controlled by the ECU 100. The mechanical power generated by the internal combustion engine 5 is output from an output shaft (crankshaft) 8. The output side of the internal combustion engine 5 (hereinafter referred to as the engine output shaft) is coupled to the input side of a dual clutch mechanism 20 of the drive device 10 described later, for example, a clutch housing 14a (see FIG. 2). The ECU 100 can adjust the mechanical power output from the engine output shaft 8 of the internal combustion engine 5. The internal combustion engine 5 is provided with a crank angle sensor (not shown) that detects a rotational angle position (hereinafter referred to as a crank angle) of the engine output shaft 8, and sends a signal related to the crank angle to the ECU 100. Yes.

  Further, the hybrid vehicle 1 is a power transmission device that transmits mechanical power from the internal combustion engine 5 and the motor 50 as a prime mover to the drive wheels 88, and the mechanical power from the engine output shaft 8 and the motor 50 is shifted to torque. A drive device 10 is provided that can output toward the drive shaft 80 by changing the angle.

  The drive device 10 uses either the first clutch 21 or the second clutch 22 to transmit mechanical power from the engine output shaft 8 of the internal combustion engine 5 to a transmission mechanism described later, and the internal combustion engine 5. The mechanical power transmitted from the first clutch 21 through the first clutch 21 is received by the first input shaft 27 and shifted by any one of the first group of gears 31, 33, 35, 39 for propulsion. The first transmission mechanism 30 that can be transmitted to the shaft 66 and the mechanical power transmitted from the internal combustion engine 5 via the second clutch 22 are received by the second input shaft 28, and the second gear stages 42 and 44 are received. , 46 and the second transmission mechanism 40 that can be transmitted to the propulsion shaft 66 and the left and right that reduce the mechanical power transmitted to the propulsion shaft 66 and engage with the drive wheels 88. Final reduction gear 70 distributed to the drive shaft 80 The has. That is, the dual clutch transmission includes the dual clutch mechanism 20, the first transmission mechanism 30, and the second transmission mechanism 40.

  The first speed change mechanism 30 and the second speed change mechanism 40 have six speed stages from the first speed gear stage 31 to the sixth speed gear stage 46 in the forward direction, and one gear stage in the reverse direction and the reverse gear stage. 39. The reduction ratios of the first to sixth gear stages 31 to 46, which are forward shift stages, are the first speed gear stage 31, the second speed gear stage 42, the third speed gear stage 33, and the fourth speed gear stage 44. The fifth speed gear stage 35 and the sixth speed gear stage 46 are set so as to decrease in this order.

  The first speed change mechanism 30 is configured as a parallel shaft gear device having a plurality of gear pairs. The first group of shift speeds is an odd speed, that is, a first speed gear stage 31, a third speed gear stage 33, and the like. The fifth speed gear stage 35 and the reverse gear stage 39 are included. In the first speed change mechanism 30, the first speed gear stage 31 among the forward speed stages 31, 33, and 35 is the lowest speed stage (hereinafter referred to as the lowest speed stage).

  The first speed gear stage 31 is composed of a pair of gears, and is provided to be rotatable around a first speed main gear 31a coupled to the first input shaft 27 and a first output shaft 37. A first speed counter gear 31c meshing with the main gear 31a is provided. The first speed change mechanism 30 is provided with a first speed coupling mechanism 31e corresponding to the first speed gear stage 31 and capable of engaging the first speed counter gear 31c and the first output shaft 37. ing.

  The ECU 100 selects the first speed gear stage 31, that is, the first speed coupling mechanism 31e is engaged, and the first speed counter gear 31c and the first output shaft 37 are engaged, whereby the first input shaft The mechanical power from 27 is transmitted to the first output shaft 37 via the first speed main gear 31a and the first speed counter gear 31c. As a result, the first speed change mechanism 30 can shift the mechanical power received from the first input shaft 27 by the first speed gear 31 and change the torque to be transmitted to the first output shaft 37. It has become.

  The third speed gear stage 33 is composed of a gear pair, and is provided to be rotatable about a third speed main gear 33a coupled to the first input shaft 27 and a first output shaft 37. A third speed counter gear 33c that meshes with the main gear 33a is provided. The first speed change mechanism 30 is provided with a third speed coupling mechanism 33e corresponding to the third speed gear stage 33 and capable of engaging the third speed counter gear 33c and the first output shaft 37. ing.

  When the ECU 100 selects the third speed gear stage 33, that is, the third speed coupling mechanism 33e is engaged, and the third speed counter gear 33c and the first output shaft 37 are engaged, the first speed change mechanism 30 can shift the mechanical power received from the first input shaft 27 by the third speed gear stage 33 and change the torque to be transmitted to the first output shaft 37.

  The fifth speed gear stage 35 is composed of a gear pair, and is provided rotatably about a fifth speed main gear 35a coupled to the first input shaft 27 and a first output shaft 37. A fifth speed counter gear 35c meshing with the fifth speed main gear 35a is provided. The first speed change mechanism 30 is provided with a fifth speed coupling mechanism 35e corresponding to the fifth speed gear stage 35 and capable of engaging the fifth speed counter gear 35c and the first output shaft 37. ing.

  When the ECU 100 selects the fifth speed gear stage 35, that is, the fifth speed coupling mechanism 35e is engaged, and the fifth speed counter gear 35c and the first output shaft 37 are engaged, the first speed change is performed. The mechanism 30 can transmit the mechanical power received from the first input shaft 27 to the first output shaft 37 by changing the torque by the fifth gear 35 and changing the torque.

  The reverse gear stage 39 meshes with the reverse main gear 39 a coupled to the first input shaft 27, the reverse intermediate gear 39 b meshed with the reverse main gear 39 a, and the reverse intermediate gear 39 b, and rotates around the first output shaft 37. And a reverse counter gear 39c which is a loosely provided gear. The first transmission mechanism 30 is provided with a reverse coupling mechanism 39e that can engage the reverse counter gear 39c and the first output shaft 37 corresponding to the reverse gear stage 39.

  When the ECU 100 selects the reverse gear stage 39, that is, the reverse coupling mechanism 39e is engaged, and the reverse counter gear 39c and the first output shaft 37 are engaged, the first transmission mechanism 30 is The mechanical power received from the input shaft 27 can be transmitted to the first output shaft 37 by changing the rotational direction in the reverse direction and changing the speed by changing the reverse gear stage 39 and changing the torque.

  A first drive gear 37 c is coupled to the first output shaft 37 of the first transmission mechanism 30, and the first drive gear 37 c meshes with the power integrated gear 58. A propulsion shaft 66 is coupled to the power integrated gear 58. The propulsion shaft 66 is engaged with a drive shaft 80 to which drive wheels 88 are coupled via a final reduction gear 70 described later. That is, the first output shaft 37 of the first transmission mechanism 30 is engaged with the drive shaft 80 and the drive wheels 88.

  As described above, the switching of the coupling mechanisms 31e, 33e, 35e, and 39e in the first transmission mechanism 30 between the engaged state and the released state (non-engaged state) is controlled by the ECU 100 via the actuator (not shown). The When selecting any one of the shift speeds 31, 33, 35, 39 of the first transmission mechanism 30, the ECU 100 engages the coupling mechanism corresponding to the selected shift speed, The coupling mechanism corresponding to the speed stage not selected in the first speed change mechanism 30 is set to the released state. As a result, the first transmission mechanism 30 shifts the mechanical power received by the first input shaft 27 at the selected shift speed, transmits it to the first output shaft 37, and outputs it to the drive shaft 80. It is possible.

  On the other hand, like the first transmission mechanism 30, the second transmission mechanism 40 is configured as a parallel shaft gear device having a plurality of gear pairs, and the second group of shift stages is an even stage, that is, the second speed. The gear stage 42 includes a fourth speed gear stage 44 and a sixth speed gear stage 46. A rotor 52 of a motor 50 described later is coupled to the input shaft 28 (hereinafter referred to as a second input shaft) of the second transmission mechanism 40. In the second speed change mechanism 40, the second speed gear stage 42 is the lowest speed stage (the lowest speed stage) among the speed stages 42, 44, and 46. In other words, the first speed gear stage 31 that is the lowest speed stage of the first transmission mechanism 30 is set to have a larger reduction ratio than the second speed gear stage 42 that is the lowest speed stage of the second transmission mechanism 40.

  The second speed gear stage 42 is composed of a pair of gears, and is provided so as to be rotatable about a second speed main gear 42 a coupled to the second input shaft 28 and a second output shaft 48. A second speed counter gear 42c meshing with the main gear 42a is provided. The second speed change mechanism 40 is provided with a second speed coupling mechanism 42e corresponding to the second speed gear stage 42 and capable of engaging the second speed counter gear 42c and the second output shaft 48. ing.

  The ECU 100 selects the second speed gear stage 42, that is, the second speed coupling mechanism 42e is engaged, and the second speed counter gear 42c and the second output shaft 48 are engaged with each other. The mechanical power from the shaft 28 is transmitted to the second output shaft 48 via the second speed main gear 42a and the second speed counter gear 42c. As a result, the second speed change mechanism 40 can shift the mechanical power received from the second input shaft 28 by the second speed gear stage 42, change the torque, and transmit it to the second output shaft 48. It has become.

  The fourth speed gear stage 44 is composed of a gear pair, and is provided rotatably around a fourth speed main gear 44a coupled to the second input shaft 28 and a second output shaft 48. A fourth speed counter gear 44c that meshes with the main gear 44a is provided. The second speed change mechanism 40 is provided with a fourth speed coupling mechanism 44e corresponding to the fourth speed gear stage 44 and capable of engaging the fourth speed counter gear 44c with the second output shaft 48. ing.

  When the ECU 100 selects the fourth speed gear stage 44, that is, the fourth speed coupling mechanism 44e is engaged, and the fourth speed counter gear 44c and the second output shaft 48 are engaged, The mechanism 40 can transmit the mechanical power received from the second input shaft 28 to the second output shaft 48 by changing the torque by the fourth gear stage 44 and changing the torque.

  The sixth speed gear stage 46 is composed of a gear pair, and is provided rotatably around a sixth speed main gear 46a coupled to the second input shaft 28 and a second output shaft 48. And a sixth counter gear 46c that meshes with the main gear 46a. The second speed change mechanism 40 is provided with a sixth speed coupling mechanism 46e corresponding to the sixth speed gear stage 46 so that the sixth speed counter gear 46c and the second output shaft 48 can be engaged.

  When the ECU 100 selects the sixth speed gear stage 46, that is, the sixth speed coupling mechanism 46e is engaged, and the sixth speed counter gear 46c and the second output shaft 48 are engaged, the second speed change is performed. The mechanism 40 can transmit the mechanical power received from the second input shaft 28 to the second output shaft 48 by changing the torque by the sixth gear stage 46 and changing the torque.

  A second drive gear 48 c is coupled to the second output shaft 48 of the second speed change mechanism 40, and the second drive gear 48 c meshes with the power integrated gear 58. A propulsion shaft 66 is coupled to the power integrated gear 58, and the propulsion shaft 66 is engaged with a drive shaft 80 coupled to a drive wheel 88 via a final reduction gear 70 described later. That is, the second output shaft 48 of the second transmission mechanism 40, the drive shaft 80, and the drive wheels 88 are engaged.

  As described above, switching of the coupling mechanisms 42e, 44e, 46e in the second transmission mechanism 40 between the engaged state and the released state (non-engaged state) is controlled by the ECU 100 via the actuator (not shown). When the ECU 100 selects any one of the shift stages 42, 44, 46 of the second transmission mechanism 40, the ECU 100 sets the coupling mechanism corresponding to the selected shift stage to the engaged state and sets the second shift stage. The coupling mechanism corresponding to the gear stage not selected in the mechanism 40 is set to the released state. As a result, the second speed change mechanism 40 shifts the mechanical power received by the second input shaft 28 at the selected speed, transmits it to the second output shaft 48, and outputs it to the drive shaft 80. Is possible.

  Further, the drive device 10 of the hybrid vehicle 1 transmits a mechanical power output from the engine output shaft 8 by the internal combustion engine 5 to one of the first transmission mechanism 30 and the second transmission mechanism 40. As shown, a dual clutch mechanism 20 is provided. The dual clutch mechanism 20 includes a first clutch 21 that is a friction clutch device capable of engaging the engine output shaft 8 and the first input shaft 27 of the first speed change mechanism 30, and the engine output shaft 8 and the second speed change. The second clutch 22 is a friction clutch device capable of engaging with the second input shaft 28 of the mechanism 40. The first clutch 21 and the second clutch 22 may be a wet multi-plate clutch or a dry single-plate clutch.

  The first clutch 21 includes a disc-shaped friction plate, and is configured by a friction type disk clutch that transmits mechanical power by the frictional force of the friction plate. The first clutch 21 is configured to be able to engage the engine output shaft 8 of the internal combustion engine 5 and the first input shaft 27 of the first transmission mechanism 30. When the first clutch 21 is engaged, the engine output shaft 8 and the first input shaft 27 rotate together, and mechanical power from the engine output shaft 8 is transmitted to the gear stage 31 of the first transmission mechanism 30. , 33, 35, 39 can be shifted and transmitted toward the drive wheel 88. That is, the first clutch 21 is provided corresponding to the gear stages 31, 33, 35, 39 of the first transmission mechanism 30.

  On the other hand, like the first clutch 21, the second clutch 22 is configured by a friction type disk clutch or the like, and engages the engine output shaft 8 of the internal combustion engine 5 and the second input shaft 28 of the second transmission mechanism 40. It is possible to combine them. By bringing the second clutch 22 into the engaged state, the engine output shaft 8 and the second input shaft 28 rotate together, and mechanical power from the engine output shaft 8 is transmitted to the gear stage 42 of the second transmission mechanism 40. , 44, 46 can be shifted and transmitted to the drive wheel 88. That is, the second clutch 22 is provided corresponding to the gear stages 42, 44, 46 of the second transmission mechanism 40.

  Switching between the engaged state and the released state (non-engaged state) of the first clutch 21 and the second clutch 22 is controlled by the ECU 100 via an actuator (not shown). In the dual clutch mechanism 20, the ECU 100 sets the mechanical power from the internal combustion engine 5 to the first clutch 21 or the second clutch 22 by engaging one and releasing the other. Transmission to either one of the first transmission mechanism 30 and the second transmission mechanism 40 is possible.

  Here, an example of a detailed structure of the dual clutch mechanism 20 including the first clutch 21 and the second clutch 22 will be described with reference to FIG. As shown in FIG. 2, in the dual clutch mechanism 20, a clutch housing 14 a of the dual clutch mechanism 20 is coupled to the engine output shaft 8. That is, the clutch housing 14a rotates integrally with the engine output shaft 8. The clutch housing 14a is configured to be able to accommodate friction plates 27a and 28a described later.

  On the other hand, the first input shaft 27 of the first transmission mechanism 30 and the second input shaft 28 of the second transmission mechanism 40 are arranged coaxially and have a double shaft structure. Specifically, the first input shaft 27 is configured as a hollow shaft, and the second input shaft 28 extends into the first input shaft 27. The second input shaft 28 that is an inner shaft is configured to be longer in the axial direction than the first input shaft 27 that is an outer shaft. First, main gears 31 a, 33 a, 35 a, 39 a of the respective gear stages of the first transmission mechanism 30 are arranged from the engine output shaft 8 side toward the drive wheel 88 side, and then the second transmission mechanism 40. Main gears 42a, 44a, 46a of the respective speed stages are provided.

  A disc-shaped friction plate 27 a is coupled to the end of the first input shaft 27, while a friction plate 28 a is similarly coupled to the end of the second input shaft 28. The friction plates 27a and 28a are accommodated in the clutch housing 14a. The first clutch 21 has a friction counterpart plate (not shown) provided to face the friction plate 27a, and an actuator (not shown) that drives the friction counterpart plate. When the friction counter plate presses the friction plate 27 a against the clutch housing 14 a, the first clutch 21 can engage the engine output shaft 8 and the first input shaft 27 of the first transmission mechanism 30. Yes.

  Similarly, the second clutch 22 has a friction mating plate (not shown) provided facing the friction plate 28a and presses the friction plate 28a against the clutch housing 14a. The second input shaft 28 of the two speed change mechanism 40 can be engaged. In the dual clutch mechanism 20, the driving of the friction counterpart plate provided corresponding to each of the first and second clutches 21 and 22 is controlled by the ECU 100.

  In the detailed structure of the dual clutch mechanism 20 described above, the first input shaft 27 of the first transmission mechanism 30 and the second input shaft 28 of the second transmission mechanism 40 are arranged coaxially. The detailed structure of the mechanism 20 is not limited to this. For example, as shown in FIG. 3, the first input shaft 27 and the second input shaft 28 may be arranged to extend in parallel with a predetermined interval. In the dual clutch mechanism 20 of this modification, a drive gear 14 c is coupled to the end of the engine output shaft 8. The first gear 16 and the second gear 18 are meshed with the drive gear 14 c, the first gear 16 is coupled to the first clutch 21, and the second gear 18 is coupled to the second clutch 22. ing. The first clutch 21 is configured to be able to engage the first input shaft 27 of the first transmission mechanism 30 and the first gear 16 that engages with the engine output shaft 8. On the other hand, the second clutch 22 is configured to be able to engage the second input shaft 28 of the second transmission mechanism 40 and the second gear 18 that engages with the engine output shaft 8.

  Each of the first and second clutches 21 and 22 can be configured by an arbitrary clutch mechanism such as a friction clutch. By alternately switching the engaged state and the released state in the first clutch 21 and the second clutch 22, the mechanical power of the internal combustion engine 5 output from the engine output shaft 8 is transferred from the drive gear 14c to the first transmission mechanism. It is transmitted to either the 30 first input shaft 27 or the second input shaft 28 of the second speed change mechanism 40. The engagement / release state of the first and second clutches 21 and 22 is controlled by the ECU 100.

  The drive device 10 of the hybrid vehicle 1 is provided with a motor 50 as a prime mover. The motor 50 has a function as an electric motor that converts supplied electric power into mechanical power and outputs it, and a rotating electric machine that has a function as an electric generator that converts input mechanical power into electric power and recovers it, This is a so-called motor generator. The motor 50 is constituted by a permanent magnet type AC synchronous motor, and receives a supply of three-phase AC power from an inverter 110 described later to form a rotating magnetic field, and a rotor that is attracted to the rotating magnetic field and rotates. And the rotor 52. The motor 50 is provided with a resolver (not shown) that detects the rotational angle position of the rotor 52, and sends a signal related to the rotational angle position of the rotor 52 to the ECU 100.

  The rotor 52 of the motor 50 is coupled to the second input shaft 28 of the second transmission mechanism 40, and the mechanical power (torque) output from the rotor 52 by the motor 50 is the second input shaft of the second transmission mechanism 40. 28. That is, in the drive device 10, the second of the first input shaft 27 and the second input shaft 28 provided corresponding to the first transmission mechanism 30 and the second transmission mechanism 40 constituting the dual clutch transmission, respectively. The input shaft 28 is engaged with the rotor 52 of the motor 50. Further, the motor 50 can convert mechanical power (torque) transmitted from the drive wheels 88 to the rotor 52 via the second output shaft 48 into AC power and collect it in the secondary battery 120. Yes.

  In addition, between the 2nd input shaft 28 and the rotor 52, the speed reduction mechanism which decelerates the rotational speed of the rotor 52 and transmits to the 2nd input shaft 28, the rotational speed of the rotor 52 is shifted, and the 2nd input shaft It is also possible to provide a speed change mechanism for transmitting to 28.

  In the following description, the fact that the motor 50 functions as an electric motor and the motor 50 outputs mechanical power from the rotor 52 is referred to as “power running”. On the other hand, the motor 50 is caused to function as a generator, and mechanical power transmitted from the driving wheel 88 to the rotor 52 of the motor 50 is converted into electric power and recovered. The braking of the rotation of the rotor 52 and the member (for example, the drive wheel 88) engaged therewith is referred to as “regenerative braking”. That is, the hybrid vehicle 1 can perform regenerative braking in which the rotation of the drive wheels 88 is transmitted to the rotor 52 and the motor 50 functions as a generator to brake the drive wheels 88.

  Further, the torque acting on the drive shaft 80 and the drive wheel 88 engaged with the rotor 52 of the motor 50 by performing regenerative braking is referred to as “regenerative braking torque”. The ECU 100 controls power running and regenerative braking by the motor 50, that is, switching of functions of the motor 50 as an electric motor / generator and regenerative braking torque.

  The hybrid vehicle 1 is provided with an inverter 110 as a power supply device that supplies AC power to the motor 50. The inverter 110 is configured to convert DC power supplied from the secondary battery 120 into AC power and supply the AC power to the motor 50. The inverter 110 is also configured to convert the AC power from the motor 50 into DC power and collect it in the secondary battery 120. The ECU 100 controls the power supply from the inverter 110 to the motor 50 and the power recovery from the motor 50.

  Further, the drive device 10 of the hybrid vehicle 1 includes a final reduction device 70 that decelerates mechanical power transmitted from the prime mover to the propulsion shaft 66 and distributes it to the left and right drive shafts 80 engaged with the drive wheels 88. Is provided. The final reduction gear 70 includes a drive pinion 68 coupled to the propulsion shaft 66, and a differential mechanism 74 in which the drive pinion 68 and the ring gear 72 mesh with each other at right angles. The final reduction device 70 decelerates mechanical power transmitted from at least one of the prime mover, that is, the internal combustion engine 5 and the motor 50 to the propulsion shaft 66 by the drive pinion 68 and the ring gear 72, and the right and left drive shafts by the differential mechanism 74. The drive wheels 88 distributed to 80 and coupled to the drive shaft 80 can be rotationally driven.

  Further, the hybrid vehicle 1 is provided with a wheel speed sensor (not shown) that detects the rotational speed of the drive wheels 88, and sends a signal related to the detected rotational speed of the drive wheels 88 to the ECU 100. In addition, the hybrid vehicle 1 is provided with a battery monitoring unit (not shown) that detects the state of charge (SOC) of the secondary battery 120 that supplies power to the motor 50. A signal related to the storage state of the secondary battery 120 is sent to the ECU 100.

  The hybrid vehicle 1 includes an ECU 100 as a control unit that controls the internal combustion engine 5 and the motor 50, the first and second clutches 21 and 22, and the first and second transmission mechanisms 30 and 40 in a coordinated manner. Is provided. Further, the ECU 100 engages / releases the gears selected in the first transmission mechanism 30 and the second transmission mechanism 40, that is, the coupling mechanisms 31e to 46e, and the engagement between the first and second clutches 21 and 22. Detect / disconnect state.

  The ECU 100 also includes a signal related to the rotational angle position (crank angle) of the engine output shaft 8 from a crank angle sensor (not shown), a signal related to the rotational angle position of the rotor 52 of the motor 50 from the resolver, and wheels. A signal relating to the rotational speed of the drive wheel 88 from the speed sensor is detected. Further, the ECU 100 detects a signal related to an operation amount of an accelerator pedal from an accelerator pedal position sensor (not shown). In addition, ECU 100 detects a signal related to the storage state of secondary battery 120.

  Based on these signals, the ECU 100 calculates various control variables. The control variables include the rotational speed of the engine output shaft 8 of the internal combustion engine 5 (hereinafter referred to as engine rotational speed), the torque output from the engine output shaft 8 by the internal combustion engine 5 (hereinafter referred to as engine load), and the motor. The rotational speed of the 50 rotors 52 (hereinafter referred to as the motor rotational speed), the "regenerative braking torque" that is the torque acting on the drive wheels 88 and the drive shaft 80 by performing regenerative braking, and the regenerative braking. The regenerative braking power, which is mechanical power acting on the drive wheels 88 and the drive shaft 80, the engaged / released state of the first and second clutches 21 and 22, and the current selection in the first and second transmission mechanisms 30 and 40 And the driving speed of the hybrid vehicle 1 (hereinafter referred to as the vehicle speed), the state of charge (SOC) of the secondary battery 120, and the driving shaft 80 and the driving wheels 88 required by the driver. Rude Torque (hereinafter, referred to as the required driving torque) and the like are included.

  Based on these control variables, the ECU 100 knows the operating states of the internal combustion engine 5 and the motor 50, and the gear position and speed change operation selected in the first and second speed change mechanisms 30, 40, that is, each coupling mechanism. It is possible to control the engaged / released states of 31e to 46e and the engaged / released states of the first clutch 21 and the second clutch 22. Further, the ECU 100 can control the power running and regenerative braking of the motor 50, that is, the motor rotation speed, the motor output torque, and the regenerative braking torque, and the operating state of the internal combustion engine 5, that is, the engine load and the engine rotation speed. It has become.

  In the hybrid vehicle 1 configured as described above, the ECU 100 selects any one of the first speed stages 31, 33, 35, 39 of the first speed change mechanism 30, and the corresponding coupling mechanism. Is engaged, and the first clutch 21 is further engaged and the second clutch 22 is disengaged, so that the engine output shaft 8 has the first input shaft 27, the first output shaft 37, the power The drive shaft 80 is engaged through the integrated gear 58, the propulsion shaft 66, and the final reduction gear 70. As a result, the first speed change mechanism 30 receives the mechanical power output from the engine output shaft 8 of the internal combustion engine 5 by the first input shaft 27, and shifts (odd number) 31, 33, 35, and reverse It is possible to change the torque at the selected gear stage among the gear stages 39, change the torque, and output the torque toward the drive shaft 80 engaged with the drive wheels 88.

  In this case, the rotation of the drive wheel 88 is transmitted to the second output shaft 48 of the second transmission mechanism 40 via the power integration gear 58. When the ECU 100 selects any one of the second speed stages 42, 44, 46 of the second speed change mechanism 40 and puts the corresponding coupling mechanism into the engaged state, the power integration gear 58 The mechanical power transmitted from the second output shaft 48 to the second output shaft 48 is shifted by the selected gear among the gears (even-numbered gears) 42, 44, 46 of the second transmission mechanism 40, and is transmitted to the second input shaft 28. The rotor 52 of the motor 50 is rotated by being transmitted. When the ECU 100 does not select any of the gear stages 42, 44, 46 of the second transmission mechanism 40, that is, when all of the coupling mechanisms 42e, 44e, 46e of the second transmission mechanism 40 are in the released state, the second Power transmission is interrupted between the output shaft 48 and the second input shaft 28, and the rotation of the drive wheels 88 is not transmitted to the second input shaft 28.

  On the other hand, the ECU 100 selects any one of the second speed stages 42, 44, 46 of the second speed change mechanism 40 and puts the corresponding coupling mechanisms 42e, 44e, 46e into an engaged state. In addition, the engine output shaft 8 can be connected to the second input shaft 28, the second output shaft 48, the power integrated gear 58, the propulsion by further engaging the second clutch 22 and disengaging the first clutch 21. The drive shaft 80 is engaged via the shaft 66 and the final reduction gear 70. As a result, the second speed change mechanism 40 receives the mechanical power output from the engine output shaft 8 of the internal combustion engine 5 and the rotor 52 of the motor 50 by the second input shaft 28, and each speed stage (even number stage) 42. , 44, and 46, the speed is changed at a selected speed, the torque is changed, and the output can be output toward the drive shaft 80 engaged with the drive wheel 88.

  In this case, the rotation of the drive wheel 88 is transmitted to the first output shaft 37 of the first transmission mechanism 30 via the power integration gear 58. The ECU 100 selects any one of the first gear stages 31, 33, 35, 39 of the first transmission mechanism 30, and puts the corresponding coupling mechanisms 31e, 33e, 35e, 39e into an engaged state. The mechanical power transmitted from the power integrated gear 58 to the first output shaft 37 is selected from among the shift stages (odd stages) 31, 33, 35 and the reverse gear stage 39 of the first transmission mechanism 30. The speed is changed by the shift speed and transmitted to the first input shaft 27 to rotate the first input shaft 27. Note that when the ECU 100 does not select any of the gear stages 31, 33, 35, and 39 of the first transmission mechanism 30, that is, the coupling mechanisms 31e, 33e, 35e, and 39e of the first transmission mechanism 30 are all in a released state. Sometimes, power transmission is interrupted between the first output shaft 37 and the first input shaft 27, and the rotation of the drive wheels 88 is not transmitted to the first input shaft 27.

  In the hybrid vehicle 1 configured as described above, the transmission of power between the engine output shaft 8 and the drive wheels 88 is interrupted at the time of shifting by alternately connecting the first clutch 21 and the second clutch 22. The details can be described below.

  First, the ECU 100 selects one of the shift stages 31 to 46 of the first and second transmission mechanisms 30 and 40. For example, when the selected gear stage is the first speed gear stage 31 among the gear stages 31, 33, 35, 39 of the first transmission mechanism 30, the ECU 100 sets the first speed cup corresponding to the first speed gear stage 31. The ring mechanism 31e is brought into the engaged state, and the other coupling mechanisms 33e, 35e, 39e are brought into the released state. Then, the ECU 100 puts the first clutch 21 into an engaged state and puts the second clutch 22 into a released state. As a result, the driving device 10 receives the mechanical power from the internal combustion engine 5 by the first input shaft 27, and is the first selected shift stage among the first stage (odd number) shift stages 31, 33, 35. The speed is changed by the first gear 31 and transmitted from the first output shaft 37 to the drive shaft 80, so that the drive wheels 88 can be rotationally driven.

  At this time, the ECU 100 is one speed higher (high gear) side than the first speed gear 31 which is the speed selected in the first speed change mechanism 30 among the speeds 42, 44, 46 of the second speed change mechanism 40. The second input gear 28 of the second speed change mechanism 40 is idled by selecting the second speed gear stage 42 that is the first speed change stage and bringing the corresponding second speed coupling mechanism 42e into the engaged state. In this manner, a gear shifting operation from the first speed gear stage 31 to the second speed gear stage 42, that is, an engagement / release operation of the first clutch 21 and the second clutch 22 is prepared.

  Then, when performing a shift (upshift) from the first speed gear stage 31 of the first transmission mechanism 30 to the second speed gear stage 42 of the second transmission mechanism 40, the ECU 100 places the first clutch 21 in the released state. However, by bringing the second clutch 22 into the engaged state, the driving device 10 performs an operation of re-clipping the first clutch 21 and the second clutch 22, so-called “clutch-to-clutch”. With this operation, the driving device 10 gradually moves the power transmission path from the engine output shaft 8 from the first input shaft 27 of the first transmission mechanism 30 to the second input shaft 28 of the second transmission mechanism 40. The shift to the second gear stage 42 is completed.

  In this manner, the driving device 10 shifts from the first speed gear stage 31 that is the odd speed stage to the speed stage of the first transmission mechanism 30, that is, the second speed gear that is the even speed stage of the second transmission mechanism 40. At the time of shifting to the stage 42, it is possible to shift without causing any interruption in power transmission from the engine output shaft 8 to the drive shaft 80.

  Moreover, the hybrid vehicle 1 can implement | achieve various vehicle driving | running | working (running mode) by using together or selecting and using the internal combustion engine 5 and the motor 50 as a motor. For example, “engine traveling” which is a vehicle traveling that selectively uses only the internal combustion engine 5 as a prime mover, “hybrid traveling” that is a vehicle traveling that uses both the internal combustion engine 5 and the motor 50 as a prime mover, and only the motor 50 is selectively used as a prime mover. There are “motor running” which is vehicle running.

  These vehicle travels are automatically and sequentially switched by the ECU 100 in accordance with the vehicle driving force required by the driver and the storage state of the secondary battery 120 that stores the power supplied to the motor 50. Hereinafter, the control of the ECU 100 in each travel mode and the operations of the internal combustion engine 5, the first clutch 21 and the second clutch 22, the first transmission mechanism 30, the second transmission mechanism 40, and the motor 50 will be described together.

  The ECU 100 causes the first clutch 21 to be in an engaged state and the second clutch 22 to be in a released state, so that the drive device 10 can transfer mechanical power from the engine output shaft 8 of the internal combustion engine 5 to the first input shaft. 27, and is shifted by any one of the shift stages 31, 33, 35, 39 of the first transmission mechanism 30, and transmitted from the first output shaft 37 to the drive shaft 80 via the power integrated gear 58, and driven wheels. 88 can be driven to rotate. In this way, the hybrid vehicle 1 can realize engine running in which only the internal combustion engine 5 is selectively used as a prime mover when the first clutch 21 is engaged.

  In this case, since the second output shaft 48 is engaged with the drive wheel 88 and the drive shaft 80 via the power integration gear 58, any one of the coupling mechanisms 42e, 44e, 46e of the second transmission mechanism 40 is used. When one is in the engaged state, the second input shaft 28 rotates at a rotation speed proportional to the rotation speed of the drive wheels 88, that is, the vehicle speed of the hybrid vehicle 1.

  At this time, the ECU 100 causes the motor 50 to power and transmit the output torque from the rotor 52 to the second input shaft 28, so that the drive device 10 can generate mechanical power from the engine output shaft 8 of the internal combustion engine 5 and the motor. The mechanical power from the 50 rotors 52 can be shifted by the first speed change mechanism 30 and the second speed change mechanism 40 and can be integrated by the power integration gear 58 and transmitted to the drive shaft 80. In this way, the hybrid vehicle 1 can achieve hybrid travel using the internal combustion engine 5 and the motor 50 together as a prime mover when the first clutch 21 is in the engaged state.

  On the other hand, when the ECU 100 puts the first clutch 21 into the disengaged state and puts the second clutch 22 into the engaged state, the drive device 10 receives the mechanical power from the engine output shaft 8 of the internal combustion engine 5 as the second input. The shaft is received by the shaft, and is shifted by any one of the gear stages 42, 44, and 46 of the second transmission mechanism 40, transmitted from the second output shaft 48 to the drive shaft 80 via the power integration gear 58, and driven wheels 88. Can be rotationally driven. In this way, the hybrid vehicle 1 can achieve engine running in which only the internal combustion engine 5 is selectively used as a prime mover when the second clutch 22 is in an engaged state.

  In this case, since the first output shaft 37 is engaged with the drive wheel 88 and the drive shaft 80 via the power integration gear 58, the coupling mechanisms 31e, 33e, 35e, 39e of the first transmission mechanism 30 are connected. When any one is in the engaged state, the first input shaft 27 rotates at a rotational speed proportional to the traveling speed of the hybrid vehicle 1 (hereinafter referred to as a vehicle speed).

  At this time, the ECU 100 causes the motor 50 to power and transmit the output torque from the rotor 52 to the second input shaft 28, so that the driving device 10 can generate mechanical power from the rotor 52 of the motor 50 and the engine of the internal combustion engine 5. Mechanical power from the output shaft 8 can be integrated by the second input shaft 28, shifted by the second transmission mechanism 40, and transmitted to the drive shaft 80 via the power integrated gear 58. In this manner, the hybrid vehicle 1 can achieve hybrid traveling using the internal combustion engine 5 and the motor 50 together as a prime mover when the second clutch 22 is in an engaged state.

  In addition, when the hybrid vehicle 1 performs motor travel using only the motor 50 as a prime mover, unlike the above-described engine travel and hybrid travel control, the ECU 100 uses both the first clutch 21 and the second clutch 22. In the released state, the motor 50 is powered. The ECU 100 selects any one of the shift stages 42, 44, 46 of the second transmission mechanism 40 and puts the corresponding coupling mechanism into the engaged state. The driving device 10 receives the mechanical power from the rotor 52 of the motor 50 by the second input shaft 28, changes the speed at a speed selected from the speeds 42, 44, 46 of the second speed change mechanism 40, The drive wheel 88 is rotated by being transmitted from the integrated gear 58 to the drive shaft 80.

  In the hybrid vehicle 1 configured as described above, when the vehicle travels at a low speed such as in a traffic jam for a long time, the mechanical power from the motor 50 is used as the second lowest speed stage in the second transmission mechanism 40. It is possible to run the motor by shifting the speed by the speed gear stage 42 and transmitting it to the driving wheel 88. However, if the vehicle travels at a low speed such as in a traffic jam for a long time, if the motor travels, the state of charge (SOC) of the secondary battery 120 decreases and the motor travel cannot be continued for a long time. is there.

  On the other hand, the mechanical power from the internal combustion engine 5 is changed by the first speed gear stage 31 that is the lowest speed stage of the first transmission mechanism 30 or the second speed gear stage 42 that is the lowest speed stage of the second transmission mechanism 40. Thus, hybrid driving can be performed by transmitting the driving force to the driving wheel 88 and shifting the mechanical power from the motor 50 to the driving wheel 88 by changing the speed by the second gear stage 42. In this case, although it is possible to suppress a decrease in the storage state of the secondary battery 120 as compared with the case where the motor travel is continued, the internal combustion engine 5 is operated at a light load and a low rotational speed. As a result, the fuel consumption rate of the hybrid vehicle 1 becomes high and the energy efficiency of the hybrid vehicle 1 is poor.

  The mechanical power from the internal combustion engine 5 is shifted by the first speed gear stage 31 or the second speed gear stage 42 and transmitted to the drive wheels 88, so that the engine travels at a low speed such as in a traffic jam. If the vehicle travels continuously, the frequency of performing the engagement / release operation of the first clutch 21 and the second clutch 22 is increased to prevent the internal combustion engine 5 from stalling when the vehicle is stopped, and the drivability is not good. There is.

  Therefore, in the hybrid vehicle 1 that includes the dual clutch transmission (20, 30, 40) and the rotor 52 of the motor 50 is engaged with one of the first input shaft 27 and the second input shaft 28, two When the storage state of the secondary battery 120 is low and the vehicle speed is low, the internal combustion engine 5 is operated under operating conditions with as low a fuel consumption rate as possible while increasing the storage state of the secondary battery 120, so that the vehicle as a whole is energy efficient. Therefore, there is a demand for a control technology that performs good traveling.

  Therefore, in the hybrid vehicle 1 according to the present embodiment, the ECU 100 as the control unit has the highest fuel consumption rate when the storage state of the secondary battery 120 is equal to or less than the determination value and the vehicle speed is equal to or less than the determination vehicle speed. The internal combustion engine 5 is operated with a lower engine load, and a value obtained by subtracting the required drive torque required to be generated in the drive wheel from the engine drive torque acting on the drive wheel by mechanical power from the engine output shaft is driven. The regenerative braking torque to be applied to the wheels is set to operate the motor as a generator. Hereinafter, control of the hybrid vehicle executed by the ECU will be described with reference to FIGS. 1 and 4 to 8.

  FIG. 4 is a flowchart showing the integrated control of the hybrid vehicle executed by the ECU. FIG. 5 is a flowchart showing the selection gear stage and engagement clutch determination control executed by the ECU. FIG. 6 is a flowchart showing prime mover cooperative control executed by the ECU. FIG. 7 is a diagram showing the relationship between the engine speed and engine load of the internal combustion engine and the fuel consumption rate. FIG. 8 is a diagram illustrating an example of a temporal change in drive torque generated in the drive wheels.

  As shown in FIG. 4, in step S102, the ECU 100 acquires various control variables. The control variables include the vehicle speed of the hybrid vehicle 1, the state of charge of the secondary battery 120 (hereinafter simply referred to as “SOC”), the selected gear stage in the first and second transmission mechanisms 30, 40, 1 and the engagement / release states of the second clutches 21 and 22 are included.

  In step S104, ECU 100 determines whether or not the vehicle speed is equal to or lower than determination vehicle speed A set in advance. The determination vehicle speed A is set to a vehicle speed at which mechanical power from the internal combustion engine 5 is required to be shifted by the first speed gear stage 31 or the second speed gear stage 42 and transmitted to the drive wheels 88. 20 km / h. The determination vehicle speed A is obtained in advance by a matching experiment or the like, and is stored in a ROM (not shown) of the ECU 100.

  When it is determined that the vehicle speed is higher than the determination vehicle speed A (No), the ECU 100 selects the gear position greater than or equal to the third speed gear stage 33 and travels in the vehicle in step S106. At this time, the vehicle travel is selected from motor travel, hybrid travel, and engine travel according to the required driving force and SOC. Note that “selecting a gear stage greater than or equal to the third speed gear stage 33” means selecting the third speed gear stage 33 in the first transmission mechanism 30 and setting the second speed gear stage 42 in the second transmission mechanism 40. The state to select is included. In other words, it means a state where at least one of the first transmission mechanism 30 and the second transmission mechanism 40 has selected a gear position having a reduction ratio lower than that of the third speed gear stage 33.

  On the other hand, when it is determined that the vehicle speed is equal to or lower than the determination vehicle speed A (Yes), in step S110, the ECU 100 determines whether or not the SOC is equal to or less than a predetermined determination value X. This determination value X is obtained in advance by a matching experiment or the like, and is stored in the ROM of the ECU 100 as a control constant.

  When it is determined that the SOC exceeds the preset determination value X (No), ECU 100 determines that the SOC is high and the motor travel can be continued for a relatively long time, and in step S112. The second speed gear stage 42 is selected in the second speed change mechanism 40. In step S114, motor running is executed. Specifically, both the first and second clutches 21 and 22 are disengaged, and the motor 50 is driven to change the mechanical power from the rotor 52 by the second speed gear stage 42 and drive it. Transmit to wheel 88.

  On the other hand, when it is determined that the SOC is equal to or less than the predetermined determination value X (Yes), in step S120, the ECU 100 selects the first gear stage selected by the first and second transmission mechanisms 30, 40, and the first gear stage. And the control process (henceforth "selected gear stage and engagement clutch determination control") which determines the clutch made into an engagement state among the 2nd clutches 21 and 22 is performed.

  As shown in FIG. 5, in step S122 of the selected gear stage and engagement clutch determination control routine, the ECU 100 sets the vehicle speed, the engagement / release states of the first and second clutches 21 and 22 as various control variables, The gear stage selected in the first and second transmission mechanisms 30 and 40 is acquired.

  In step S124, ECU 100 determines whether or not the vehicle speed is equal to or lower than determination vehicle speed B set to a value lower than determination vehicle speed A. The determination vehicle speed B is obtained in advance by a matching experiment or the like, and is stored in the ROM of the ECU 100 as a control constant.

  When it is determined that the vehicle speed exceeds the determination vehicle speed B (No), in step S126, the ECU 100 in the second transmission mechanism 40, the second speed gear stage 42 that is the lowest speed stage (the lowest speed stage). Select. In addition, the selection of the gear position in the first transmission mechanism 30 can be arbitrary.

  In step S128, the ECU 100 puts the first clutch 21 in a released state and puts the second clutch 22 in an engaged state. As a result, the hybrid vehicle 1 can transmit the mechanical power from the engine output shaft 8 from the second clutch 22 to the second input shaft 28 of the second transmission mechanism 40.

  On the other hand, when it is determined that the vehicle speed is equal to or lower than the determination vehicle speed B (Yes), the ECU 100 selects the first speed gear stage 31 in the first transmission mechanism 30 and the second transmission mechanism 40 in step S130. , The second gear stage 42 is selected.

  In step S132, the ECU 100 places the first clutch 21 in the engaged state and places the second clutch 22 in the released state. Thus, the hybrid vehicle 1 can transmit the mechanical power from the engine output shaft 8 from the first clutch 21 to the first input shaft 27 of the first transmission mechanism 30. Then, the control returns from the selected gear stage and engagement clutch determination control routine to the hybrid vehicle integrated control routine shown in FIG.

  Then, in step S140, a control process (hereinafter referred to as “primary motor cooperative control”) for cooperatively controlling the internal combustion engine 5 and the motor 50 as the prime mover is executed.

  As shown in FIG. 6, in step S142 of the prime mover cooperative control routine, the ECU 100 represents a driving force required to be generated on the driving wheel 88 by the driver as a control variable (hereinafter referred to as a required driving force, denoted by a reference symbol Trd. And the engine rotational speed Ne is acquired. In addition, the shift stage selected in the first and second transmission mechanisms 30 and 40 determined in the selected gear stage and engagement clutch determination control routine, and the engagement / The release state is acquired as a control variable (flag).

  In step S144, the ECU 100 determines the engaged gear, the gear selected by the speed change mechanism corresponding to the clutch determined by the selected gear and engagement clutch determination control routine, and the vehicle speed. Based on this, the engine rotational speed Ne is calculated. For example, when it is determined Yes in step S124, the first clutch 21 is in an engaged state, and the first speed gear stage 31 is selected in the first transmission mechanism 30 corresponding to the first clutch 21. . The ECU 100 calculates the engine rotational speed Ne based on the reduction ratio of the first speed gear 31 and the vehicle speed.

  In step S146, the ECU 100 estimates the engine load Te at which the fuel consumption rate is lowest in the internal combustion engine 5 from the engine rotational speed Ne. As shown in FIG. 7, the internal combustion engine 5 can obtain the fuel consumption rate according to the engine rotation speed and the engine load, which are the operating states of the internal combustion engine 5. The fuel consumption rate with respect to the engine rotation speed and the engine load is obtained in advance by a conformity experiment or the like, and a fuel consumption rate map that defines the fuel consumption rate with respect to the engine rotation speed and the engine load is stored in the ROM of the ECU 100 as a control constant. ing. The ECU 100 can calculate the engine load Te having the lowest fuel consumption rate based on the engine rotational speed Ne acquired as a control variable and the above-described fuel consumption rate map.

  The engine load Te is the torque output from the engine output shaft 8 by the internal combustion engine 5, and the fuel consumption rate [g / kWh] is the fuel mass [g] consumed in the internal combustion engine 5 and the engine output. It is a ratio to the mechanical energy [kWh] output from the shaft 8.

  In step S148, the ECU 100 calculates the engine load Te, the clutch in the engaged state of the first and second clutches 21 and 22, and the first and second transmission mechanisms 30 and 40. The engine drive torque Ted is calculated based on the shift speed selected in the speed change mechanism corresponding to the clutch.

  The engine driving torque is a torque that acts on the driving wheel 88 when mechanical power output from the engine output shaft 8 of the internal combustion engine 5 is transmitted to the driving wheel 88, and propels the hybrid vehicle 1.・ Torque in the driving direction.

  On the other hand, the regenerative braking torque is a torque that acts on the drive wheel 88 by operating the motor 50 as a generator in a state where the rotor 52 of the motor 50 and the drive wheel 88 are engaged. This is the torque in the direction of braking the vehicle 1. In other words, the engine driving torque is a torque whose rotation direction is opposite.

In step S150, ECU 100 sets a value obtained by subtracting required drive torque Trd from calculated engine drive torque Ted as regenerative braking torque Tgd. That is, the required drive torque Trd has a relationship of the following formula (1) from the engine drive torque Ted and the regenerative braking torque Tgd.
Trd = Ted−Tgd (1)

  In step S152, the motor regenerative torque Tg is calculated based on the set regenerative braking torque Tgd and the reduction ratio of the second gear stage 42. “Motor regeneration torque” is torque that is input to the rotor 52 when the motor 50 is caused to function as a generator, and the motor output torque that is output from the rotor 52 when the motor 50 is powered and the rotation direction. Is the reverse torque. The motor regenerative torque Tg can be obtained based on the regenerative braking torque Tgd, the final reduction ratio of the final reduction gear 70, the reduction ratio of the shift stage (second speed gear stage) selected in the second transmission mechanism 40, and the like. it can.

  In step S154, the ECU 100 causes the internal combustion engine 5 to operate at the engine load Te, which is the operating state with the lowest fuel consumption rate, according to the engine speed, and at the motor regeneration torque Tg using the motor 50 as a generator. Operate. The internal combustion engine 5 operates at the engine load Te and outputs mechanical power from the engine output shaft 8, and the drive device 10 transmits the mechanical power from the engine output shaft 8 to the drive wheels 88 and the rotor 52. The motor 50 converts the mechanical power transmitted to the rotor 52 into electric power and collects it in the secondary battery 120.

  Specifically, when it is determined in the selected gear stage and engagement clutch determination control routine that the first clutch 21 is in the engaged state and the second clutch 22 is in the released state, the drive device 10 is the engine output shaft. 8 is transmitted from the first clutch 21 to the first input shaft 27, is shifted by the first speed gear 31 that is the lowest speed of the first transmission mechanism 30, and is transmitted to the power integrated gear 58. To do. Furthermore, the drive device 10 transmits a part of the mechanical power transmitted to the power integrated gear 58 to the drive wheel 88 and transmits the rest from the power integrated gear 58 to the second output shaft 48, The speed is changed by the speed gear 42 and transmitted from the second input shaft 28 to the rotor 52.

  On the other hand, in the selected gear stage and engagement clutch determination control routine, when it is determined that the first clutch 21 is disengaged and the second clutch 22 is engaged, the drive device 10 receives power from the engine output shaft 8. Mechanical power is transmitted from the second clutch 22 to the second input shaft 28. The driving device 10 shifts a part of the mechanical power transmitted to the second input shaft 28 by the second speed gear stage 42 that is the lowest speed stage of the second transmission mechanism 40 and transmits it to the driving wheels 88. In addition, the remainder is transmitted from the second input shaft 28 to the rotor 52.

  The ECU 100 applies the engine drive torque Ted to the drive wheels 88 by mechanical power from the engine output shaft 8 and operates the motor 50 as a generator to cause the drive wheels 88 to be opposite to the engine drive torque Ted. The regenerative braking torque Tgd in the direction is applied. That is, the value obtained by subtracting the regenerative braking torque Tgd from the engine drive torque Ted is the total drive torque (Ted−Tgd) generated in the drive wheel 88, and this value is the required drive torque Trd.

  In this way, the ECU 100 operates the internal combustion engine 5 with the engine load Te having the lowest fuel consumption rate, and transmits a part of the mechanical power from the internal combustion engine 5 to the drive wheels 88, so that the drive wheels 88 are desired. While the required drive torque Trd is generated, the remaining mechanical power is transmitted to the rotor 52, converted into electric power by the motor 50, and collected in the secondary battery 120. As a result, the fuel consumption rate of the internal combustion engine 5 can be suppressed as much as possible, and the state of charge (SOC) of the secondary battery 120 can be increased, and the hybrid vehicle 1 as a whole can travel with good energy efficiency.

  Then, the routine returns again to the hybrid vehicle integrated control routine shown in FIG. Thus, as shown in FIG. 8, in the hybrid vehicle 1, even if the required drive torque Trd and vehicle speed required by the driver change, the first and second transmission mechanisms 30 and 40 according to the vehicle speed and the SOC. The internal combustion engine corresponding to the engine speed that changes according to the clutch to be selected and the engagement / release state of the first and second clutches 21 and 22 is determined and the clutch to be engaged with the selected gear 5 is operated at the engine load with the lowest fuel consumption rate to generate the required drive torque in the drive wheels 88, and the state of charge of the secondary battery 120 can be raised with excess mechanical power.

  As described above, the hybrid vehicle 1 according to this embodiment includes the internal combustion engine 5 that outputs mechanical power from the engine output shaft 8, the motor 50 that operates as a generator and can brake the rotor 52, and the engine output. A first shift that can receive mechanical power from the shaft 8 by the first input shaft 28, change the speed by any one of the plurality of shift stages 31, 33, 35, and 39 and transmit it to the drive wheels 88. The mechanical power from the mechanism 30 and the engine output shaft 8 and the rotor 52 is received by the second input shaft 28 engaged with the rotor 52, and the speed is changed by any one of the plurality of shift stages 42, 44, 46. The second transmission mechanism 40 that can transmit toward the drive wheel 88, the first clutch 21 that can engage the engine output shaft 8 and the first input shaft 27, the engine output shaft 8 and the second input shaft. A second clutch 22 engageable with the first clutch The ECU 100 includes an engagement / disengagement state of the clutches 21 and 22, selection of gear positions in the first and second transmission mechanisms 30 and 40, and an ECU 100 as control means capable of controlling the operation of the internal combustion engine 5 and the motor 50. ing.

  The ECU 100 as the control means has the lowest fuel consumption rate when the storage state of the secondary battery 120 that supplies power to the motor 50 is equal to or less than the determination value X and the vehicle speed is equal to or less than the determination vehicle speed A. A value obtained by operating the internal combustion engine 5 with the engine load and subtracting the required drive torque Trd required to be generated in the drive wheel 88 from the engine drive torque Ted acting on the drive wheel 88 by the mechanical power from the engine output shaft 8. Is set to the regenerative braking torque Tgd to be applied to the drive wheels, and the motor 50 is operated as a generator. The internal combustion engine 5 is operated with the engine load Te having the lowest fuel consumption rate, and a part of the mechanical power from the internal combustion engine 5 is transmitted to the drive wheels 88 to cause the drive wheels 88 to have a desired required drive torque Trd (Ted -Tgd), the remaining mechanical power can be transmitted to the rotor 52 and converted into electric power by the motor 50 to increase the state of charge (SOC) of the secondary battery.

  Further, in the hybrid vehicle according to the present embodiment, the ECU 100 includes a ROM (storage means) that stores a fuel consumption rate map that defines the fuel consumption rate with respect to the engine rotation speed and the engine load, and the engine rotation speed and the fuel consumption rate. The engine load with the lowest fuel consumption rate was estimated based on the map. A fuel consumption rate map is obtained in advance by a conformance experiment or the like, and stored in the ROM of the ECU 100 as a control constant, so that the engine load at which the fuel consumption rate is the lowest can be easily estimated according to the engine speed. Can do.

  In the hybrid vehicle 1 according to the present embodiment, the mechanical power from the first transmission mechanism 30 and the second transmission mechanism 40 is integrated in the power integration gear 58 (power integration mechanism) and transmitted to the drive wheels 88. The first speed gear 31 that is the lowest speed of the first speed change mechanism 30 has a reduction ratio set larger than that of the second speed gear 42 that is the lowest speed of the second speed change mechanism 40. The ECU 100 selects the first speed gear stage 31 and the second speed gear stage 42 in the first transmission mechanism 30 and the second transmission mechanism 40, respectively, and puts the first clutch 21 into the engaged state and the second clutch. 22 is in a released state, the mechanical power from the engine output shaft 8 is shifted by the first gear 31 and transmitted to the power integrated gear 58. Of the mechanical power transmitted to the power integrated gear 58, , Partly driving wheel 88 Together to transmit, the remainder was assumed to be transmitted to the rotor 52 by shifting the second speed gear 42. The hybrid vehicle 1 changes the mechanical power from the engine output shaft 8 by a first speed gear 31 that is the lowest speed among the speeds of the first speed change mechanism 30 and the second speed change mechanism 40. Since it is transmitted to the drive wheels 88, the engine rotational speed can be made as high as possible with respect to the vehicle speed, which is useful when the vehicle travels at a very low speed or when the required driving force is relatively large.

  Further, in the hybrid vehicle 1 according to the present embodiment, the first speed gear stage 31 that is the lowest speed stage of the first transmission mechanism 30 is compared with the second speed gear stage 42 that is the lowest speed stage of the second transmission mechanism 40. The ECU 100 selects the second speed gear stage 42 that is the lowest speed stage in the second speed change mechanism 40, puts the first clutch 21 in a released state, and engages the second clutch 22. In the combined state, a part of the mechanical power transmitted from the engine output shaft 8 to the second input shaft 28 is shifted by the second speed gear stage 42 and transmitted to the drive wheels 88, and the rest is transferred to the rotor 52. To be communicated to. By transmitting the mechanical power from the engine output shaft 8 by the second speed gear stage 42 and transmitting it to the drive wheels 88, the engine rotational speed can be reduced as compared with the case where the first speed gear stage 31 is used. it can. If the mechanical power from the engine output shaft 8 is shifted by the first speed gear 31 and transmitted to the drive wheels 88, the engine rotational speed becomes too high and the internal combustion engine 5 has an engine load with a high fuel consumption rate. This is useful when it is difficult to operate.

  Further, in the hybrid vehicle 1 according to the present embodiment, the ECU 100 determines that the first speed change mechanism 30 and the first speed change mechanism 30 and the second speed change mechanism 30 when the vehicle speed is equal to or lower than the second determination vehicle speed B set to a value lower than the determination vehicle speed A. In the two speed change mechanism 40, the first speed gear 31 and the second speed gear 42 are selected, the first clutch 21 is engaged, the second clutch 22 is disengaged, and the vehicle speed is the second determination vehicle speed. If it exceeds B, the second speed gear stage 42, which is the lowest speed stage, is selected in the second transmission mechanism 40, the first clutch 21 is disengaged and the second clutch 22 is engaged. did. By changing the engine rotation speed when the drive wheel 88 and the engine output shaft 8 are engaged according to the vehicle speed, the internal combustion engine 5 can be operated as much as possible with an engine load having a low fuel consumption rate.

  In this embodiment, the motor (motor generator) 50 provided as a prime mover converts the supplied electric power into mechanical power and outputs it, and converts the input mechanical power into electric power. However, the motor generator according to the present invention is not limited to this. The motor generator only needs to be able to brake the rotor. For example, the motor generator may be configured by a generator having only a function of converting mechanical power transmitted to the rotor into electric power.

  In the present embodiment, the first speed change mechanism 30 transmits the mechanical power received by the first input shaft 27 from the first output shaft 37 to the power integrated gear 58 that engages with the drive wheels 88, The speed change mechanism 40 transmits the mechanical power received by the second input shaft 28 from the second output shaft 48 to the power integrated gear 58. However, the first speed change mechanism 30 and the second speed change mechanism 40 are different from each other. However, the present invention is not limited to this. The first speed change mechanism 30 and the second speed change mechanism 40 only need to be able to transmit the mechanical power received by the input shafts 27 and 28 to the drive wheels 88, for example, the first speed change mechanism 30 and the second speed change mechanism 40, for example. The speed change mechanism 40 may transmit mechanical power received by the first input shaft 27 and the second input shaft 28 to a common output shaft that engages with the drive wheels 88, respectively.

  In this embodiment, the drive device 10 shifts mechanical power from the engine output shaft 8 of the internal combustion engine 5 and the rotor 52 of the motor 50 by at least one of the first transmission mechanism 30 and the second transmission mechanism 40. Thus, the power integrated gear 58 is transmitted to the driving wheel 88 via the propulsion shaft 66 and the differential mechanism 74 of the final reduction gear 70. However, the driving wheel is transmitted from the first transmission mechanism 30 and the second transmission mechanism 40. The mode of power transmission toward 88 is not limited to this. In the drive device 10, the first speed change mechanism 30 and the second speed change mechanism 40 only need to be able to transmit the mechanical power received by the first input shaft 27 and the second input shaft 28 to the drive wheels 88, respectively. For example, the power integrated gear 58 or the first and second drive gears 37c and 48c engaged with the power integrated gear 58 may directly drive the ring gear 72 of the differential mechanism 74.

  As described above, the present invention is useful for a hybrid vehicle including an internal combustion engine and a motor as a prime mover and including a dual clutch transmission, and in particular, an input shaft of one of the two transmission mechanisms. It is useful for a hybrid vehicle in which the rotor of the motor is engaged.

1 is a schematic diagram illustrating a schematic configuration of a hybrid vehicle according to an embodiment. It is a schematic diagram explaining the structure of the dual clutch mechanism which concerns on a present Example. It is a schematic diagram explaining the structure of the dual clutch mechanism of the modification concerning a present Example. It is a flowchart which shows the hybrid vehicle integrated control which the control means (ECU) of the hybrid vehicle which concerns on a present Example performs. It is a flowchart which shows the selection gear stage and engagement clutch determination control which the control means (ECU) of the hybrid vehicle which concerns on a present Example performs. It is a flowchart which shows the motor | power_engine cooperation control which the control means (ECU) of the hybrid vehicle which concerns on a present Example performs. It is a figure explaining the relationship between the engine speed of an internal combustion engine, an engine load, and a fuel consumption rate. It is a figure which shows an example of the time change of the drive torque which arises in a drive wheel in the hybrid vehicle which concerns on a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 5 Internal combustion engine 8 Engine output shaft 10 Drive apparatus 20 Dual clutch mechanism 21 1st clutch 22 2nd clutch 27 1st input shaft 28 2nd input shaft 30 1st speed change mechanism 31,33,35,39 Gear stage ( (Gear stage, gear pair)
37 First output shaft 40 Second transmission mechanism 42, 44, 46 Gear stage (gear stage, gear pair)
48 Second output shaft 50 Motor (motor generator)
52 Motor rotor 58 Power integrated gear (Power integrated mechanism)
66 Propulsion shaft 70 Final reduction device 74 Differential mechanism 80 Drive shaft 88 Drive wheel 100 Electronic control device for hybrid vehicle (ECU, control means, storage means)

Claims (5)

An internal combustion engine that outputs mechanical power from the engine output shaft;
A motor generator that can act as a generator and brake the rotor;
A first speed change mechanism capable of receiving mechanical power from an engine output shaft by a first input shaft, shifting the speed by any one of a plurality of shift speeds, and transmitting it to drive wheels;
A second input shaft that receives mechanical power from the engine output shaft and the rotor by a second input shaft that engages with the rotor, can be shifted by any one of a plurality of shift stages, and can be transmitted to the drive wheels. A transmission mechanism;
A first clutch capable of engaging the engine output shaft and the first input shaft;
A second clutch capable of engaging the engine output shaft and the second input shaft;
Control means capable of controlling engagement / release states of the first and second clutches, selection of gear positions in the first and second transmission mechanisms, and operation of the internal combustion engine and the motor generator;
With
A hybrid vehicle capable of regenerative braking that engages a drive wheel and a rotor and operates a motor generator as a generator to brake the drive wheel,
The control means
When the storage state of the secondary battery that supplies power to the motor generator is less than or equal to the determination value and the vehicle speed is less than or equal to the determination vehicle speed,
The internal combustion engine is operated at an engine load at which the fuel consumption rate becomes the lowest according to the engine speed,
A value obtained by subtracting the required drive torque required to be generated in the drive wheel from the engine drive torque that is applied to the drive wheel by mechanical power from the engine output shaft is set as the regenerative braking torque that is applied to the drive wheel. A hybrid vehicle characterized by operating a generator as a generator. The hybrid vehicle according to claim 1,
The control means
Storage means for storing a fuel consumption rate map that defines a fuel consumption rate with respect to the engine speed and the engine load;
A hybrid vehicle characterized by estimating an engine load having the lowest fuel consumption rate based on an engine rotation speed and a fuel consumption rate map. In the hybrid vehicle according to claim 1 or 2,
Mechanical power from the first speed change mechanism and the second speed change mechanism is integrated in the power integration mechanism and transmitted to the drive wheels.
The minimum speed of the first speed change mechanism is set to have a larger reduction ratio than the minimum speed of the second speed change mechanism,
The control means
In each of the first speed change mechanism and the second speed change mechanism, the lowest speed stage is selected, the first clutch is engaged, and the second clutch is released.
Mechanical power from the engine output shaft is shifted at the lowest speed of the first speed change mechanism and transmitted to the power integration mechanism, and part of the mechanical power transmitted to the power integration mechanism is transmitted to the drive wheels. In addition, a hybrid vehicle is characterized in that the remainder is shifted by the lowest speed of the second transmission mechanism and transmitted to the rotor. In the hybrid vehicle according to claim 1 or 2,
The minimum speed of the first speed change mechanism is set to have a larger reduction ratio than the minimum speed of the second speed change mechanism,
The control means
In the second speed change mechanism, the lowest speed is selected, the first clutch is disengaged and the second clutch is engaged,
A part of the mechanical power transmitted from the engine output shaft to the second input shaft is shifted by the lowest speed of the second speed change mechanism and transmitted to the drive wheel, and the rest is transmitted to the rotor. Hybrid vehicle. In the hybrid vehicle according to claim 3 or 4,
The control means
When the vehicle speed is equal to or lower than the second determination vehicle speed set to a value lower than the determination vehicle speed, the lowest speed stage is selected in each of the first transmission mechanism and the second transmission mechanism, and the first clutch is engaged. And the second clutch is released,
When the vehicle speed exceeds the second determination vehicle speed, the hybrid vehicle is characterized in that the lowest speed stage is selected in the second transmission mechanism, the first clutch is disengaged and the second clutch is engaged.

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