JP6048335B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a control device that controls traveling of a vehicle having an engine (engine) and a rotating machine (motor) having a power generation function as a driving force source for traveling, that is, a so-called hybrid vehicle.

  A hybrid vehicle is a vehicle equipped with an internal combustion engine (hereinafter referred to as an engine) such as a gasoline engine or a diesel engine as a driving power source, and a rotating machine having a power generation function. And it is a vehicle which can improve a fuel consumption by utilizing each characteristic which an engine and a rotary machine have, and can aim at reduction of exhaust gas. An example of an invention relating to such a hybrid vehicle is described in Patent Document 1.

  The hybrid vehicle described in Patent Document 1 includes a power split mechanism including an engine, a first rotating machine, a second rotating machine, and a planetary gear mechanism having three rotating elements. Further, a transmission for shifting the power output from the engine and transmitting it to the power split mechanism is provided. The transmission is provided with a switching mechanism for selectively setting the low speed side gear stage (direct connection stage) and the high speed side gear stage.

  In Patent Document 2 and Patent Document 3, a power split mechanism including an engine, a first rotating machine, a second rotating machine, and a planetary gear mechanism having three rotating elements, and an output shaft of the engine are provided. A vehicle having an engagement device that is fixed so as not to rotate is described. In the vehicles described in Patent Document 2 and Patent Document 3, the power split mechanism functions as a speed reduction mechanism or a speed increase mechanism by engaging the engagement device and fixing the output shaft of the engine. In this state, the motor can be driven to drive both the first rotating machine and the second rotating machine.

Japanese Patent No. 5141802 JP 2008-265598 A JP 2008-265600 A

  In the vehicle described in the above-mentioned Patent Document 1, a high-speed side gear stage is set during high-speed cruising, for example, by providing a transmission capable of selecting and setting a high-speed side gear stage. In addition, the input rotational speed for the power split mechanism can be increased without increasing the engine rotational speed. Therefore, even when the output rotation speed of the power split mechanism increases according to the vehicle speed, the input rotation speed of the power split mechanism can be kept relatively high. Therefore, since the rotation speed of the first rotating machine is close to 0, the first rotating machine can be used regardless of whether the first rotating machine functions as a generator or a power source. The amount of power generation or output of becomes smaller. As a result, since the electric load is reduced, it is said that the power transmission efficiency of the vehicle as a whole can be improved by reducing the power loss of the vehicle such as power loss.

  On the other hand, in the configuration in which the low speed side gear stage and the high speed side gear stage can be selected and set as in the vehicle described in Patent Document 1, for example, using the output of the engine During reverse travel, the low speed side gear is set and the second rotating machine is reversely rotated, that is, rotated in the direction opposite to the rotational direction of the engine so as to output the drive torque in the reverse direction. It has become. In that case, the direction of the torque output by the second rotating machine is opposite to the output torque of the engine. Also, when the engine is cranked and started when traveling by at least one of the first rotating machine and the second rotating machine, the second rotating machine outputs torque in the direction opposite to the engine output torque. Will do.

In the vehicle described in Patent Document 1 as described above, the direction of the torque output by the second rotating machine when traveling backward by the output of the engine or when starting the engine during traveling by the output of the rotating machine And the direction of the torque of the engine may be opposite. Therefore, the output torque of the engine and the output torque of the second rotating machine cancel each other, and the torque output to the drive shaft may decrease. As a result, the driving force of the vehicle may be reduced during traveling.

The present invention has been made paying attention to the above technical problem, and in a vehicle using an engine and two rotating machines as a driving force source, it is possible to prevent a decrease in driving torque of the vehicle during traveling. The object is to provide a control device.

In order to achieve the above object, the invention of claim 1 is a vehicle having an engine, a first rotating machine, and a second rotating machine as driving force sources, wherein the first rotating element and the first rotating element are When rotating, it becomes a reaction force element and rotates at a rotation speed determined based on the rotation speed of the second rotation element to which the first rotating machine is connected, and the rotation speed of the first rotation element and the second rotation element. A power split that is composed of a differential gear device having a second rotating machine and a third rotating element to which a drive shaft is connected, and that splits or combines and transmits power between the drive force source and the drive shaft. A mechanism and a low speed stage that amplifies or directly transmits the output torque of the engine to the first rotating element and a high speed stage that reduces the output torque of the engine and transmits it to the first rotating element can be selectively set. With a variable speed change mechanism The vehicle control apparatus, when the engine is started by cranking the when that is traveling forward the vehicle using the output of the second rotating machine, the transmission device for setting the high speed stage by the shift mechanism It is provided with the control apparatus characterized by the above-mentioned.

  The invention according to claim 2 includes, in the invention according to claim 1, the means for setting the high speed stage by the speed change mechanism when the speed change means causes the vehicle to travel backward using the output of the engine. This is a control device characterized by that.

  According to the present invention, an inertia torque canceling means for canceling or reducing an inertia torque generated when the shift position is switched by a driver's manual shift can be further provided by the output torque of the first rotating machine.

  According to the present invention, the inertia torque canceling means is configured to provide the torque for causing the vehicle to travel after the control for canceling or reducing the inertia torque by the first rotating machine is terminated. Means for outputting by at least one of the second rotating machines may be included.

According to the present invention, for example, when the vehicle travels backward using the output of the engine, or when the engine is cranked and started when traveling by the output of the rotating machine, the output torque of the engine is When the direction of the torque acting on the first rotating element of the power split mechanism to be transmitted is opposite to the direction of the torque output by the second rotating machine, the high speed stage is set by the speed change mechanism. Therefore, the torque from the engine is reduced and transmitted to the first rotating element of the power split mechanism. The drive torque output from the power split mechanism to the drive shaft is a difference torque between the output torque of the second rotating machine and the torque acting on the first rotating element, but the torque from the engine is reduced as described above. The drive torque increases as much as possible. Therefore, even when the direction of the torque acting on the first rotating element of the power split mechanism is opposite to the direction of the torque output by the second rotating machine, it is possible to prevent or suppress a decrease in driving torque. . As a result, a decrease in the driving force of the vehicle definitive during running can be prevented or suppressed.

It is a skeleton figure which shows typically the power train of the hybrid vehicle which can be made into object by this invention. FIG. 2 is a table collectively showing operating states of clutches and brakes and motor / generators in each driving state of the power train shown in FIG. 1. FIG. FIG. 2 is a collinear diagram of a power split mechanism and a transmission unit in the power train shown in FIG. 1, showing a state where the vehicle is running with the output of a second motor / generator alone FIG. 2 is a collinear diagram for a power split mechanism and a transmission unit in the power train shown in FIG. 1, showing a state where the vehicle is running with outputs of both a first motor / generator and a second motor / generator. FIG. 2 is a collinear diagram of a power split mechanism and a transmission unit in the power train shown in FIG. FIG. 2 is a collinear diagram for a power split mechanism and a transmission unit in the power train shown in FIG. 1, showing a neutral state when the engine is started. It is a block diagram which shows typically the control system in the control apparatus which concerns on this invention. FIG. 2 is a collinear diagram for a power split mechanism and a transmission unit in the power train shown in FIG. 1, showing a state where the vehicle is traveling backward using the output of the engine. It is a flowchart for demonstrating an example of the control performed with the control apparatus which concerns on this invention. FIG. 9 is a time chart showing changes in engine speed, rotation speeds and torques of motors / generators when the control shown in the flowchart of FIG. 8 is executed. FIG. FIG. 2 is a collinear diagram of a power split mechanism and a transmission unit in the power train shown in FIG. 1, showing a state in which the engine is cranked and started when the motor is running.

  Next, the present invention will be specifically described with reference to the drawings. The present invention relates to a control device that controls an engine such as an engine (hereinafter referred to as an engine) and a vehicle including a rotating machine such as a motor or a motor / generator (hereinafter referred to as a motor or a motor / generator) as a driving force source. It is. In particular, the vehicle is a so-called two-motor hybrid vehicle having two motors, a motor for controlling the rotational speed and torque of the engine and a motor for generating a driving force.

  As the engine, a gasoline engine is the most common. However, the engine in the present invention may be an internal combustion engine using a fuel other than gasoline, such as a diesel engine or a gas engine. In addition, the motor is preferably a motor having a power generation function (that is, a motor / generator). May be.

  Furthermore, the hybrid vehicle or its control device targeted by the present invention can select a travel mode in which the vehicle travels with the power output from the engine and a travel mode in which the motor is driven with the electric power stored in the battery. It is configured. In the driving mode in which the vehicle travels with the power output by the engine, a part of the power is transmitted to the drive wheels, and the motor / generator is driven by the other part of the power to generate power. A mode for driving and driving, a mode for generating power by driving a generator with an engine, and a mode for driving by driving the motor with the electric power may be set. In addition, the mode in which power is supplied from the battery to the motor is set to a mode in which the vehicle runs with one of the motors, a mode in which the two motors (or motor generators) are driven together, and the like. It may be configured.

  FIG. 1 is a skeleton diagram showing an example of a power train in a hybrid vehicle Ve that can be the subject of the present invention. In the example shown here, the power output from the engine 1 is divided into the first motor / generator 2 side and the drive shaft 4 side, and the electric power generated by the first motor / generator 2 is supplied to the second motor / generator 3. The so-called two-motor hybrid vehicle Ve is configured to apply the driving force of the second motor / generator 3 to the driving shaft 4. The power split mechanism 5 used in the hybrid vehicle Ve shown here is constituted by a differential mechanism having three rotating elements. More specifically, a planetary gear mechanism having a sun gear as a first rotation element, a carrier as a second rotation element, and a ring gear as a third rotation element among the three rotation elements. In the example shown in FIG. 1, a single pinion type planetary gear mechanism is used.

  The planetary gear mechanism constituting the power split mechanism 5 is arranged on the same axis as the engine 1, and the first motor / generator 2 is connected to the sun gear 6. The first motor / generator 2 is arranged adjacent to the power split mechanism 5 on the side opposite to the engine 1, and the rotor 2 a is connected to the sun gear 6. A ring gear 7 is arranged concentrically with the sun gear 6. The pinion gear meshing with the sun gear 6 and the ring gear 7 is held by a carrier 8 so as to be able to rotate and revolve, and the carrier 8 is connected to the output shaft 1 a of the engine 1. Further, a drive gear 9 is connected to the ring gear 7. The drive gear 9 is disposed between the engine 1 and the power split mechanism 5.

  A countershaft 10 is arranged in parallel with the rotation center axis of the power split mechanism 5 and the first motor / generator 2 described above. A counter driven gear 11 meshing with the drive gear 9 is attached to the counter shaft 10 so as to rotate integrally. The counter driven gear 11 is constituted by a gear having a smaller diameter than the drive gear 9. Accordingly, when torque is transmitted from the power split mechanism 5 toward the countershaft 10, a deceleration action (torque amplification action) is generated.

  Furthermore, the torque output from the second motor / generator 3 can be added to the torque transmitted from the power split mechanism 5 to the drive shaft 4. That is, the second motor / generator 3 is arranged in parallel with the counter shaft 10, and the reduction gear 12 connected to the rotor 3 a is engaged with the counter driven gear 11. The reduction gear 12 is constituted by a gear having a smaller diameter than the counter driven gear 11. Therefore, the torque output from the second motor / generator 3 is amplified and transmitted to the counter driven gear 11 or the counter shaft 10.

  A counter drive gear 13 is provided on the counter shaft 10 so as to rotate integrally therewith, and the counter drive gear 13 meshes with a ring gear 15 of a differential gear 14 that is a final reduction gear. In FIG. 1, for the convenience of drawing, the position of the differential gear 14 is shifted to the right side in FIG.

  The first motor / generator 2 and the second motor / generator 3 are each connected to a battery via a controller such as an inverter (not shown). In each of the first motor / generator 2 and the second motor / generator 3, the current is controlled so as to function as a motor or a generator. The engine 1 is configured such that its throttle opening and ignition timing are controlled, and is further configured to control automatic stop, start and restart.

  Furthermore, a transmission unit 16 is provided between the engine 1 and the power split mechanism 5. The transmission unit 16 is configured to be switched between a direct connection stage and an acceleration stage, that is, an overdrive (O / D) stage. The transmission unit 16 includes a single pinion type planetary gear mechanism, the output shaft 1a of the engine 1 is connected to the carrier 17, and the ring gear 18 rotates integrally with the carrier 8 of the power split mechanism 5 described above. To be connected. A clutch C1 is provided between the sun gear 19 and the carrier 17 to connect the sun gear 19 and the carrier 17 and to release the connection. Further, a brake B1 is provided for fixing the sun gear 19 in a non-rotatable state and releasing the fixing. The clutch C1 and the brake B1 can be configured by a friction engagement mechanism that is engaged by, for example, hydraulic pressure.

  The transmission 16 is connected to the carrier 17 and the sun gear 19 of the planetary gear mechanism by engaging the clutch C1. As a result, the entire planetary gear mechanism rotates as a unit, and a so-called direct connection state in which no speed increasing action and speed reducing action are generated is obtained. Therefore, by engaging the brake B1 in addition to the clutch C1, the entire transmission unit 16 is integrally fixed, and the rotation of the carrier 8 and the engine 1 in the power split mechanism 5 is stopped. On the other hand, by engaging only the brake B1, the sun gear 19 in the transmission unit 16 becomes a fixed element, and the carrier 17 becomes an input element. Therefore, the ring gear 18 that is an output element rotates at a higher rotational speed than the carrier 17 and in the same direction as the carrier 17. That is, the transmission unit 16 functions as a speed increasing mechanism. In other words, an O / D stage is set.

  FIG. 2 collectively shows the engagement and disengagement states of the clutch C1 and the brake B1 in each of the travel modes and the reverse travel state, and the operation states of the first motor / generator 2 and the second motor / generator 3. is there. To briefly explain each operation state, “EV” in FIG. 2 indicates a motor travel mode. In the so-called “single motor travel mode”, the clutch C1 and the brake B1 are released, the second motor / generator 3 is operated as a motor (M), and the first motor / generator 2 functions as a generator (G). Be made. The first motor / generator 2 may idle. When the power source brake action (emblem action) is generated in the “single motor travel mode”, both the clutch C1 and the brake B1 are engaged, and the carrier 8 in the power split mechanism 5 cannot rotate. Fixed to. This state is shown in a collinear diagram in FIG.

  In the “twin motor travel mode” of the motor travel modes, both the first motor / generator 2 and the second motor / generator 3 are caused to function as motors. Then, in order to output the torque of the first motor / generator 2 from the drive gear 9 to the counter driven gear 11, both the clutch C1 and the brake B1 are engaged, and the carrier 8 of the power split mechanism 5 rotates. Fixed in impossible state. Therefore, the power split mechanism 5 functions as a speed reducer, and the torque of the first motor / generator 2 is amplified and output from 9 to the counter driven gear 11. This state is shown in an alignment chart in FIG.

  On the other hand, “HV” in FIG. 2 indicates a hybrid drive state in which the engine 1 is driven. In a state where the vehicle Ve is traveling at a light load and a medium to high vehicle speed, the transmission unit 16 is set to the O / D stage (High). That is, the clutch C1 is released and the brake B1 is engaged. This state is shown in an alignment chart in FIG. In this state, as described above, the first motor / generator 2 controls the engine speed to a speed with good fuel efficiency. In this case, the electric power generated by causing the first motor / generator 2 to function as a generator is supplied to the second motor / generator 3. As a result, the second motor / generator 3 operates as a motor and outputs drive torque. Further, when a large driving force is required, such as when the accelerator opening is increased at a low vehicle speed, the transmission unit 16 is controlled to be in a directly connected (Low) state. That is, the clutch C1 is engaged and the brake B1 is released, so that the entire transmission unit 16 is rotated integrally. In this case, the first motor / generator 2 is operated as a generator and the second motor / generator 3 is operated as a motor. Note that the alignment chart of FIG. 6 shows a state in which the vehicle Ve is stopped with the neutral set. In this state, the clutch C1 is engaged and the brake B1 is released, so that the transmission unit 16 is controlled to be in a directly connected (Low) state. The rotational speed of the engine 1 is the idling rotational speed.

  The electronic control unit (ECU) that performs the operation control of the engine 1 as described above, the operation control of the first motor / generator 2 and the second motor / generator 3, the engagement / release control of the clutch C1 and the brake B1, and the like. ) 20 is provided. A control system of the electronic control unit 20 is shown in a block diagram in FIG.

  The electronic control unit 20 according to the present invention includes a hybrid control unit (HV-ECU) 21 that performs overall control for traveling, a motor generator for controlling the first motor generator 2 and the second motor generator 3. A control device (MG-ECU) 22 and an engine control device (E / G-ECU) 23 for controlling the engine 1 are provided. Each of these control devices 21, 22, and 23 is configured mainly with a microcomputer, performs an operation using input data and data stored in advance, and outputs the operation result to a control command signal Is configured to output as

Examples of input data input to the electronic control unit 20 include, for example, vehicle speed, accelerator opening, rotation speed of the first motor / generator 2, rotation speed of the second motor / generator 3, rotation speed of the ring gear 7 ( output shaft rotational speed), the rotational speed of the engine 1, such as SOC of the battery, are input to the hybrid control equipment 21. Examples of command signals output from the electronic control unit 20 include, for example, a torque command value for the first motor / generator 2, a torque command value for the second motor / generator 3, a torque command value for the engine 1, and , the hydraulic pressure command value PC1 of the clutch C1, and, a hydraulic command value PB1 of the brake B1 is adapted to be outputted from the hybrid control equipment 21.

  The torque command value of the first motor / generator 2 and the torque command value of the second motor / generator 3 are input to the motor / generator control device 22 as control data. The motor / generator control device 22 is configured to perform calculations based on these torque command values and output current command signals for the first motor / generator 2 and the second motor / generator 3. Further, the engine torque command signal is input to the engine control device 23 as control data. The engine control device 23 is configured to perform calculation based on the engine torque command signal and output a throttle opening signal for an electronic throttle valve (not shown), an ignition signal for controlling the ignition timing, and the like. ing.

  As described above, in the hybrid vehicle Ve configured as described above, in the hybrid vehicle described in Patent Document 1 as described above, for example, when the vehicle travels backward by the output of the engine 1, the second motor When the engine 1 is started while the motor is running by the output of the generator 3, the direction of the torque output from the second motor / generator may be opposite to the direction of the torque of the engine 1. In this case, the output torque of the engine 1 and the output torque of the second motor / generator 3 cancel each other, and the torque output to the drive shaft 4 may be reduced, thereby reducing the driving force of the vehicle. was there.

  Specifically, for example, when the vehicle travels backward by the output of the engine 1, the clutch C1 is engaged and the transmission unit 16 is controlled to be in the direct connection (Low) state in the conventional technique. The first motor / generator 2 is operated as a generator, and the second motor / generator 3 is operated as a motor. The rotation direction of the drive shaft 4 in this case is controlled in the reverse travel direction by controlling the rotation direction and the rotation speed of the first motor / generator 2 and the second motor / generator 3. This state is indicated by a broken line in the alignment chart of FIG. In this state, since the transmission unit 16 is in the direct connection state, the output torque of the engine 1 is transmitted to the carrier 8 of the power split mechanism 5 without being increased or decreased. Therefore, the torque acting on the carrier 8 has the same direction as the output torque of the engine 1 and is a torque in the direction of moving the vehicle Ve forward. On the other hand, the torque output by the second motor / generator 3 in this case is the torque in the direction of moving the vehicle Ve backward. Therefore, in this case, the direction of the output torque of the engine 1 and the direction of the output torque of the second motor / generator 3 are opposite to each other. Therefore, if the output torque of the engine 1 is large, the output torque of the second motor / generator 3 cancels out, and the drive torque output from the power split mechanism 5 to the drive shaft 4 decreases. As a result, the vehicle Ve is driven. There was a possibility that the power would be reduced.

  Therefore, the vehicle control apparatus according to the present invention is configured to execute the control shown in the flowchart of FIG. 9 below as an example, with the hybrid vehicle Ve configured as described above as a control target.

  The routine shown in the flowchart of FIG. 9 is repeatedly executed every predetermined short time. In the flowchart of FIG. 9, it is first determined whether or not the vehicle Ve is traveling in the “engine traveling mode” (step S1). If the travel mode of the vehicle Ve is not the “engine travel mode” and the determination is negative in step S1, this routine is temporarily terminated without executing the subsequent control.

  On the other hand, when the traveling mode of the vehicle Ve is the “engine traveling mode” and the determination is affirmative in step S1, the process proceeds to step S2. Then, it is determined whether or not the shift position of the vehicle Ve is set to reverse (R). If the shift position of the vehicle Ve has not yet been set to reverse (R), and if a negative determination is made in step S2, this routine is temporarily terminated without executing the subsequent control.

  On the other hand, if the shift position of the vehicle Ve is set to reverse (R) and the determination is affirmative in step S2, the process proceeds to step S3. And the transmission part 16 is set to O / D stage (High). Specifically, the clutch C1 is controlled to the released state, and the brake B1 is controlled to the engaged state. This state is indicated by a solid line in the alignment chart of FIG. In this state, since the transmission unit 16 is in an overdrive state, the output torque of the engine 1 is reduced and transmitted to the carrier 8 of the power split mechanism 5. The torque acting on the carrier 8 has the same direction as the output torque of the engine 1 and is a torque in a direction in which the vehicle Ve moves forward. On the other hand, the torque output by the second motor / generator 3 in this case is the torque in the direction of moving the vehicle Ve backward. Therefore, also in this case, the direction of the output torque of the engine 1 is opposite to the direction of the output torque of the second motor / generator 3. However, in this case, since the output torque of the engine 1 is reduced, even if the output torque of the engine 1 and the output torque of the second motor / generator 3 cancel each other, the power split mechanism 5 drives the drive shaft 4. The decrease in the drive torque output to is reduced. Therefore, a decrease in driving force of the vehicle Ve can be prevented or suppressed.

  As described above, when the shift control for setting the transmission unit 16 in the overdrive state is performed in step S3, the routine is once ended.

  When the control shown in the flowchart of FIG. 9 as described above is executed, an example of changes in the engine speed and the speed and torque of the first motor / generator 2 and the second motor / generator 3 is shown in FIG. It is shown in the chart. Specifically, in the time chart of FIG. 10, when the shift position of the vehicle Ve is switched from neutral (N) to reverse (R), the state in which the transmission unit 16 is switched to the O / D stage (High) is shown. Show.

  In the state where the neutral (N) is set, the clutch C1 is engaged and the transmission unit 16 is in the direct connection (Low) state. When the shift position of the vehicle Ve is switched from neutral (N) to reverse (R) from that state at time t1, shift control for switching the shift stage of the transmission unit 16 is started in accordance with the shift position switching. Specifically, first, the engagement hydraulic pressure of the clutch C1 is gradually reduced at time t2. Subsequently, the engagement hydraulic pressure of the brake B1 is increased. In particular, from time t3 to time t5, the engagement hydraulic pressure of the brake B1 is gradually increased.

  When the gears are switched as described above, the engine speed Ne is kept constant. However, when the clutch C1 is switched from the engaged state to the released state, the rotational speed of the first motor / generator 2 is increased. To rise. This is because the inertia torque related to the first motor / generator 2 increases. Therefore, in the present invention, in order to reduce such inertia torque, the first motor / generator 2 is controlled to output torque from time t4 to time t6. Thus, the inertia torque generated when the shift position of the vehicle Ve is switched from neutral (N) to reverse (R) is canceled by the output torque of the first motor / generator 2, that is, the inertia torque is canceled or reduced. can do. When the gears are switched as described above, the fluctuation of the inertia torque of the vehicle Ve can be prevented or suppressed, and the drivability of the vehicle Ve can be improved.

  At time t5, when it is determined that the switching control from neutral (N) to reverse (R) is finished, the brake B1 is fully engaged at time t6, so that the neutral (N) reverse (R Switching to) is completed. Further, the torque control of the first motor / generator 2 for canceling the inertia torque related to the first motor / generator 2 is terminated in accordance with the switching. Then, after the end of the torque control for canceling the inertia torque, the torque for traveling backward by the second motor / generator 3 is output. In this state, the first motor / generator 2 is controlled so as to be responsible for the reaction force torque.

  In the above specific example, as a situation in which the direction of the output torque of the engine 1 and the direction of the output torque of the second motor / generator 3 are opposite to each other, a case where the vehicle travels backward by the output of the engine 1 is exemplified. In addition to this, for example, when the engine 1 is cranked and started when the motor is running with the output of the second motor / generator 3, the direction of the output torque of the engine 1 and the output of the second motor / generator 3 are also used. The direction of torque is opposite.

  This state is shown in a collinear diagram in FIG. As indicated by a broken line in the collinear diagram of FIG. 11, in the prior art, the first motor / generator 2 and the second motor / generator 3 are engaged with the clutch C1 engaged and the transmission unit 16 directly connected (Low). With this output, the engine 1 is cranked (the engine speed is increased), and the engine 1 is started. In this state, since the transmission unit 16 is in the direct connection (Low) state, the friction torque of the engine 1 is transmitted to the carrier 8 of the power split mechanism 5 as it is. Therefore, the torque in the direction opposite to the output torque of the engine 1 acts on the carrier 8 as it is. This is the torque in the direction of moving the vehicle Ve backward. On the other hand, the torque output by the second motor / generator 3 in this case is the torque in the direction of moving the vehicle Ve forward. Accordingly, in this case, the direction of the friction torque of the engine 1 is opposite to the direction of the output torque of the second motor / generator 3. Therefore, if the friction torque of the engine 1 is large, the output torque of the second motor / generator 3 cancels out, and the drive torque output from the power split mechanism 5 to the drive shaft 4 becomes small. As a result, the vehicle Ve is driven. There was a possibility that the power would be reduced.

  Thus, in the present invention, when the engine 1 is started when the motor is running with the output of the second motor / generator 3 as described above, the transmission unit 16 is also in the same manner as in the above-described specific example. Shift control for setting the shift speed to the O / D speed (High) is executed. This state is indicated by a solid line in the alignment chart of FIG. In this state, since the transmission unit 16 is in an overdrive state, the friction torque of the engine 1 is reduced and transmitted to the carrier 8 of the power split mechanism 5. Therefore, in this case, since the friction torque of the engine 1 is reduced, even if the friction torque of the engine 1 and the output torque of the second motor / generator 3 cancel each other, the power split mechanism 5 and the drive shaft 4 The decrease in the drive torque output to is reduced. Therefore, a decrease in driving force of the vehicle Ve can be prevented or suppressed.

As described above, according to the vehicle control device of the present invention, for example, when the vehicle Ve travels backward using the output of the engine 1, or when the motor travels, the engine 1 is cranked. In the case of starting, for example, when the direction of the torque acting on the carrier 8 of the power split mechanism 5 to which the output torque of the engine 1 is transmitted is opposite to the direction of the torque output by the second motor / generator 3, the transmission unit At 16, an O / D stage (High) which is a high speed stage is set. Therefore, torque is reduced and transmitted from the engine 1 to the carrier 8 of the power split mechanism 5. The drive torque output from the power split mechanism 5 to the drive shaft 4 is a difference torque between the output torque of the second motor / generator 3 and the torque acting on the carrier 8, but the torque from the engine 1 as described above. The drive torque is increased by the amount that is reduced. Therefore, even if the direction of the torque acting on the carrier 8 of the power split mechanism 5 is opposite to the direction of the torque output by the second motor / generator 3, it is possible to prevent or suppress a decrease in the drive torque. it can. That is, a decrease in the driving force of the vehicle Ve for definitive during running can be prevented or suppressed. As a result, the drivability of the vehicle Ve can be improved.

  In the above-described specific example, a so-called two-motor type vehicle including the engine 1, the first motor / generator 2 and the second motor / generator 3 as driving force sources as vehicles to be controlled in the present invention. Although the configuration of the hybrid vehicle has been described as an example, for example, it may be a hybrid vehicle including an engine and a plurality of three or more motor generators. Moreover, what is called a plug-in hybrid vehicle which can charge a battery directly from an external power supply may be sufficient.

  DESCRIPTION OF SYMBOLS 1 ... Engine (engine | engine; ENG), 1a ... Output shaft, 2 ... 1st motor generator (1st rotary machine; MG1), 3 ... 2nd motor generator (2nd rotary machine; MG2), 4 ... Drive shaft 5 ... Power split mechanism, 6 ... Sun gear, 7 ... Ring gear, 8 ... Carrier, 9 ... Drive gear, 10 ... Counter shaft, 11 ... Counter driven gear, 12 ... Reduction gear, 13 ... Counter drive gear, 16 ... Transmission unit, DESCRIPTION OF SYMBOLS 17 ... Carrier, 18 ... Ring gear, 19 ... Sun gear, 20 ... Electronic control unit (ECU), 21 ... Hybrid control unit (HV-ECU), 22 ... Motor / generator control unit (MG-ECU), 23 ... Engine control unit (E / G-ECU), B1 ... brake, C1 ... clutch, Ve ... hybrid vehicle.

Claims (2)

A vehicle having an engine, a first rotating machine, and a second rotating machine as a driving force source, the first rotating element and a reaction force element when the first rotating element rotates and the first rotating machine A second rotating element connected, and a third rotating element rotating at a rotational speed determined based on the rotational speeds of the first rotating element and the second rotating element and connected to the second rotating machine and the drive shaft A power splitting mechanism that splits or combines and transmits power between the driving force source and the driving shaft, and amplifies or directly outputs the engine output torque. In a vehicle control device comprising: a low speed stage to be transmitted to one rotation element; and a transmission mechanism capable of selectively setting a high speed stage to reduce the output torque of the engine and transmit it to the first rotation element.
When the engine is cranked and started when the vehicle is traveling forward using the output of the second rotating machine, there is provided speed change means for setting the high speed stage with the speed change mechanism. A vehicle control device characterized by the above.   2. The vehicle control device according to claim 1, wherein the speed change means includes means for setting the high speed stage by the speed change mechanism when the vehicle travels backward using the output of the engine.

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