JP5018430B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device suitable for a hybrid vehicle.

  Hybrid vehicles that include a power source such as an electric motor or a motor generator in addition to an engine are known. In a hybrid vehicle, an engine is operated in a highly efficient state as much as possible, while an excess or deficiency in driving force or engine braking force is compensated by an electric motor or a motor generator.

  Patent Document 1 describes an example of a speed change mechanism configured to be able to switch between a continuously variable transmission mode and a fixed speed ratio mode in a hybrid vehicle as described above. Specifically, a power distribution mechanism having four rotating elements is configured by combining two planetary gear mechanisms, and the four rotating elements are connected to the engine, the first motor generator, the output shaft, and the brake, respectively. In a state where the brake is released, the engine speed is continuously changed by continuously changing the rotation speed of the first motor generator, and the operation in the continuously variable transmission mode is executed. On the other hand, in a state where the brake is fixed, the gear ratio is fixed by preventing one rotation of the rotating element, and the operation in the fixed gear ratio mode is executed. In addition, a transmission mechanism that switches between a continuously variable transmission mode and a fixed transmission ratio mode is known as a transmission mechanism that uses a meshing mechanism that meshes the teeth of a rotating element and the teeth of a fixed element instead of the conventional wet multi-plate clutch. Yes.

JP 2004-345527 A

  In the technique described in Patent Document 1 described above, fluctuations in output shaft torque (hereinafter also referred to as “shift shock”) occur when shifting between the continuously variable transmission mode and the fixed transmission ratio mode. There was a case. For example, a shift shock may occur when shifting from the fixed gear ratio mode to the continuously variable transmission mode and accelerating. Such a shift shock is considered to occur when the same output cannot be obtained with the same engine power as that before the shift because the loss accompanying the change in the number of revolutions of the inertia element has increased.

  The present invention has been made to solve the above-described problems, and appropriately suppresses a shift shock or the like that may occur when shifting between the continuously variable transmission mode and the fixed transmission ratio mode. It is an object of the present invention to provide a control device for a hybrid vehicle that can perform the above-described operation.

In one aspect of the present invention, an engine, a first motor generator, a power distribution mechanism configured to be connectable to the engine and the first motor generator, and an output shaft to which an output from the power distribution mechanism is transmitted In addition, a control device for a hybrid vehicle that has a second motor generator that outputs torque, and that controls a hybrid vehicle configured to be capable of switching between a continuously variable transmission mode and a fixed transmission ratio mode, A shift power calculating means for calculating a shift power required for shifting based on a current operating point and an operating point after the shifting when shifting between the step shifting mode and the fixed gear ratio mode; based on the power and current engine power, first shift carried out so as not to change the engine power, and, as compared with the case of performing the first shift, d And determining the speed change decision means for determining to perform one of the second shift performed increase or decrease the Jinpawa, wherein when the shift judging means judges that should perform the second speed, the second speed change Shift control means for performing.

The hybrid vehicle control device includes an engine, a first motor generator, a power distribution mechanism configured to be connectable to the engine and the first motor generator, and an output shaft to which an output from the power distribution mechanism is transmitted. And a second motor generator that outputs torque, and is mounted on a hybrid vehicle or the like configured to be able to switch between a continuously variable transmission mode and a fixed transmission ratio mode. Specifically, the shift power calculating means calculates the shift power based on the current operating point and the operating point after the shift, and the shift determining means changes the engine power based on the shift power and the current engine power. It is determined which of the first shift that is performed without being performed and the second shift that is performed by increasing or decreasing the engine power, compared to the case where the first shift is performed . The shift control means performs the second shift when it is determined that the second shift should be performed. Specifically, shifting is performed by increasing the engine power or decreasing the engine power. As a result, it is possible to appropriately suppress a shift shock that may occur during a shift. Further, since it is determined whether or not the second shift should be performed based on the shift power or the like, it is possible to appropriately suppress the deterioration of fuel consumption caused by adjusting the engine power.

In one aspect of the control apparatus for a hybrid vehicle, the shift control means may be configured such that the output shaft torque decreases when the output shaft torque decreases due to a change in the rotational speed of the engine and the first motor generator during the second shift. Shifting is performed by increasing power, and when the output shaft torque increases due to a change in the rotational speed of the engine and the first motor generator during the second shift, the shift is performed by decreasing the engine power. Can do.

In another aspect of the hybrid vehicle control device, the shift control means determines an amount to increase or decrease the engine power based on a shift time when performing the second shift . By increasing or decreasing the engine power based on the determined amount in this way, it is possible to appropriately suppress the deterioration of fuel consumption at the time of shifting.

In another aspect of the hybrid vehicle control device, the shift control means increases the engine power based on at least one of a battery input / output limit and a charge state during a shift in the second shift. Change the amount to decrease or decrease . In this aspect, during shifting, for example, when the battery input / output limit is expected to be approached or when the SOC becomes a predetermined value or less, the amount by which the engine power is increased or decreased is changed. Thereby, it becomes possible to suppress deterioration of a battery life etc. appropriately.

Preferably, the hybrid vehicle control device includes means for adjusting the torque of the second motor generator to stabilize the output shaft torque during the second shift by the shift control means. Thereby, since the fluctuation | variation of the output shaft torque at the time of a 2nd shift can be suppressed appropriately, it becomes possible to improve drivability.

More preferably, the shift determination means performs the determination based on a map defined by the shift power and the current engine power, and the map indicates that the second shift is smaller as the current engine power is smaller. It is set so that it is easier to determine that the second shift is to be performed, and the greater the current engine power is, the easier it is to determine that the second shift should not be performed. As a result, it is possible to appropriately achieve both suppression of shift shock and suppression of deterioration of fuel consumption.

  The control device for a hybrid vehicle in the present invention is mounted on a hybrid vehicle or the like that has an engine and a motor generator as drive sources and is configured to be able to switch between two modes of a continuously variable transmission mode and a fixed transmission ratio mode. Specifically, the shift power calculating means calculates the shift power based on the current operating point and the operating point after the shift, and the shift determining means adjusts the engine power based on the shift power and the current engine power. Then, it is determined whether or not to change the speed. The shift control means adjusts the engine power and shifts when it is determined that the shift should be performed by adjusting the engine power. As a result, it is possible to appropriately suppress a shift shock that may occur during a shift.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Device configuration]
FIG. 1 shows a schematic configuration of a hybrid vehicle to which the present invention is applied. The example of FIG. 1 is a hybrid vehicle called a mechanical distribution type two-motor type, and includes an engine (internal combustion engine) 1, a first motor generator MG 1, a second motor generator MG 2, and a power distribution mechanism 20. An engine 1 corresponding to a power source and a first motor generator MG1 corresponding to a rotation speed control mechanism are connected to a power distribution mechanism 20. The output shaft 3 of the power distribution mechanism 20 is connected to a second motor generator MG2 that is a sub power source for assisting drive torque or braking force. Second motor generator MG2 and output shaft 3 are connected via MG2 transmission 6. Further, the output shaft 3 is connected to the left and right drive wheels 9 via a final reduction gear 8. The first motor generator MG1 and the second motor generator MG2 are electrically connected via a battery, an inverter, or an appropriate controller (see FIG. 2) or directly, and the first motor generator MG1 The second motor generator MG2 is driven by the generated electric power.

  The engine 1 is a heat engine that generates power by burning fuel, and examples thereof include a gasoline engine and a diesel engine. The first motor generator MG1 generates power mainly by receiving torque from the engine 1 and rotating, and a reaction force of torque accompanying power generation acts. By controlling the rotational speed of first motor generator MG1, the rotational speed of engine 1 changes continuously. Such a speed change mode is called a continuously variable speed change mode. The continuously variable transmission mode is realized by a differential action of a power distribution mechanism 20 described later.

  The second motor generator MG2 is a device that assists the driving torque or the braking force. When assisting the drive torque, the second motor generator MG2 receives power supply and functions as an electric motor. On the other hand, when assisting the braking force, the second motor generator MG2 functions as a generator that is rotated by the torque transmitted from the drive wheels 9 to generate electric power.

  FIG. 2 shows a configuration of first and second motor generators MG1 and MG2 and power distribution mechanism 20 shown in FIG.

  The power distribution mechanism 20 is a mechanism that distributes the output torque of the engine 1 to the first motor generator MG1 and the output shaft 3, and is configured to generate a differential action. Specifically, the engine 1 is connected to the first rotating element among the four rotating elements that are provided with a plurality of sets of differential mechanisms and have a differential action, and the first motor generator MG1 is connected to the second rotating element. Are connected, and the output shaft 3 is connected to the third rotating element. The fourth rotating element can be fixed by the brake unit 7. The brake unit 7 is configured by a dog clutch, for example, and is controlled by the brake operation unit 5. In a state where the brake unit 7 does not fix the fourth rotating element, the rotational speed of the engine 1 is continuously changed by continuously changing the rotational speed of the first motor generator MG1, and the continuously variable transmission mode Is realized. On the other hand, in a state where the brake unit 7 is fixing the fourth rotating element, the transmission gear ratio determined by the power distribution mechanism 20 is fixed to the overdrive state (that is, the engine rotational speed is smaller than the output rotational speed). Thus, the fixed gear ratio mode is realized.

  In the present embodiment, as shown in FIG. 2, the power distribution mechanism 20 is configured by combining two planetary gear mechanisms. The first planetary gear mechanism includes a ring gear 21, a carrier 22, and a sun gear 23. The second planetary gear mechanism is a double pinion type and includes a ring gear 25, a carrier 26, and a sun gear 27.

  The output shaft 2 of the engine 1 is connected to the carrier 22 of the first planetary gear mechanism, and the carrier 22 is connected to the ring gear 25 of the second planetary gear mechanism. These constitute the first rotating element. The rotor 11 of the first motor generator MG1 is connected to the sun gear 23 of the first planetary gear mechanism, and these constitute a second rotating element.

  The ring gear 21 of the first planetary gear mechanism and the carrier 26 of the second planetary gear mechanism are connected to each other and to the output shaft 3. These constitute the third rotating element. Further, the sun gear 27 of the second planetary gear mechanism is connected to the rotation shaft 29 and constitutes a fourth rotation element together with the rotation shaft 29. The rotating shaft 29 can be fixed by the brake unit 7.

  The power supply unit 30 includes an inverter 31, a converter 32, an HV battery 33, and a converter 34. The first motor generator MG1 is connected to the inverter 31 by a power line 37, and the second motor generator MG2 is connected to the inverter 31 by a power line 38. The inverter 31 is connected to the converter 32, and the converter 32 is connected to the HV battery 33. Further, the HV battery 33 is connected to the auxiliary battery 35 via the converter 34.

  Inverter 31 exchanges power with motor generators MG1 and MG2. During regeneration of the motor generator, the inverter 31 converts the electric power generated by the motor generators MG1 and MG2 into the direct current and supplies the direct current to the converter 32. Converter 32 converts the electric power supplied from inverter 31 to charge HV battery 33. On the other hand, during the power running of the motor generator, the DC power output from the HV battery 33 is boosted by the converter 32 and supplied to the motor generator MG1 or MG2 via the power supply line 37 or 38.

  The electric power of the HV battery 33 is converted into a voltage by the converter 34 and supplied to the auxiliary battery 35, and used for driving various auxiliary machines.

  The operation of the inverter 31, the converter 32, the HV battery 33, and the converter 34 is controlled by the ECU 4. The ECU 4 controls the operation of each element in the power supply unit 30 by transmitting a control signal S4. A necessary signal indicating the state of each element in the power supply unit 30 is supplied to the ECU 4 as a control signal S4. Specifically, an SOC (State Of Charge) indicating the state of the HV battery 33, an input / output limit value of the battery, and the like are supplied to the ECU 4 as a control signal S4.

  The ECU 4 controls the control signals S1 to S3 by transmitting and receiving them to and from the engine 1, the first motor generator MG1, and the second motor generator MG2. Further, the ECU 4 supplies a brake operation instruction signal S5 to the brake operation unit 5. The brake operation unit 5 operates the brake unit 7 based on the brake operation instruction signal S5, and controls the engagement / release of the rotation shaft 29 that is the fourth rotation element. Although details will be described later, the ECU 4 corresponds to a control device for a hybrid vehicle in the present invention, and functions as a shift power calculation means, a shift determination means, and a shift control means.

[Shift control]
Next, the shift control according to the embodiment of the present invention will be described. In the present embodiment, the ECU 4 described above executes shift control when shifting between the continuously variable transmission mode and the fixed gear ratio mode.

  Here, with reference to FIG. 3, a problem that may occur when shifting from the continuously variable transmission mode to the fixed transmission ratio mode will be described. FIG. 3 shows an example of an alignment chart in the continuously variable transmission mode and the fixed transmission ratio mode. A straight line A1 shows a nomographic chart in the continuously variable transmission mode, and a straight line A2 shows a collinear chart in the fixed gear ratio mode. In the fixed gear ratio mode, the brake unit 7 is fixed as shown by the black circles in FIG. When shifting from the continuously variable transmission mode to the fixed transmission ratio mode, the state changes from the state indicated by the straight line A1 to the state indicated by the straight line A2.

  When the above speed change is performed, a speed change shock or a collapse of the power balance may occur. Such a shift shock or the like is caused by, for example, suddenly changing the rotation speed of the engine 1 and the first motor generator MG1 in a short time, thereby increasing loss due to a change in the rotation speed of the inertial element. This is considered to occur because the same engine power could not obtain the same output. That is, as indicated by the arrows A3 and A4 in FIG. 3, the output shaft torque is reduced by the amount of power used for the rotation change of the engine 1 and the first motor generator MG1, so that the shift shock and the breakdown of the power balance are lost. Is considered to occur.

  Therefore, in the present embodiment, shift control is executed in order to suppress the occurrence of such a shift shock or the like. Specifically, the ECU 4 executes a shift control for adjusting the engine power and performing a shift based on the shift power required for the shift when shifting between the continuously variable transmission mode and the fixed transmission ratio mode. To do. Specifically, the ECU 4 calculates the shift power corresponding to the inertia loss torque of the engine 1 and the first motor generator MG1 when shifting from the continuously variable transmission mode to the fixed gear ratio mode as described above. Based on this speed change power, engine power is added to perform speed change. In the following, a shift performed by adding engine power in this way is referred to as “power added shift”, and a shift performed without substantially changing the engine power is referred to as “normal shift”. The ECU 4 calculates an inertia loss torque associated with changes in the rotational speeds of the engine 1 and the first motor generator MG1 based on the current operating point, the operating point after the shift, and the like, and a value obtained by converting this torque into an engine shaft. Is obtained as the shifting power. As a result, it is possible to appropriately obtain speed change power that does not give a shock to the output shaft torque at the time of power addition speed change.

  According to the power addition shift according to the present embodiment as described above, it is possible to appropriately suppress a shift shock that may occur during a shift.

  Next, a method for determining whether or not the power addition shift should be executed will be described. In the first embodiment, the ECU 4 determines whether or not the power addition shift should be executed based on the shift power obtained as described above and the current engine power. That is, the ECU 4 determines whether the power addition shift or the normal shift should be executed. Such a determination is made from the viewpoint of suppressing deterioration in fuel consumption associated with execution of the power addition shift. Specifically, fuel economy tends to deteriorate when engine power is increased. Therefore, in order to appropriately prohibit the execution of power addition shifts in operating regions where shift shocks and the like can be tolerated (that is, without executing power addition shifts). In order to perform normal gear shifting), the determination as described above is performed.

  FIG. 4 is a diagram for specifically explaining a method of determining whether or not the power addition shift should be executed. FIG. 4 shows the engine power on the horizontal axis and the shift power on the vertical axis, and represents a map defined by the engine power and the shift power. In such a map, a hatching area B1 indicates an area where power addition shift should not be executed (hereinafter referred to as “an addition unnecessary area”), and a hatching area B2 indicates an area where power addition shift should be executed (hereinafter “ It is called “additional required area”). The extra area B1 and the extra area B2 are set based on items that are important for each area, such as a shift time, a shift shock, and a battery power balance. The ECU 4 determines whether or not the power extra shift should be executed depending on whether the shift power calculated as described above and the current engine power are located in the extra area B1 or the extra area B2. To do.

  As can be seen from FIG. 4, in the region where the engine power is relatively small, as shown by an arrow B <b> 3, the ratio of the additional necessary region B <b> 2 is larger than the unnecessary region B <b> 1. This is because shift shocks and the like tend to appear prominently in a region where the engine power is relatively low, and therefore, the power addition shift should be executed to suppress the shift shocks and the like. On the other hand, in the region where the engine power is relatively large, as shown by an arrow B4, it can be seen that the ratio of the unnecessary area B1 to the additional necessary area B2 is large. This is because, in a region where the engine power is relatively large, a shift shock or the like is allowed to some extent, and therefore there is little demand for suppressing the shift shock by executing the power addition shift. In other words, in such a region, a shift shock is allowed to some extent. Therefore, the execution of the power addition shift should be prohibited and priority should be given to suppression of deterioration in fuel consumption. In the region where the shift power is large even in a region where the engine power is relatively large, an additional unnecessary region B1 and an additional necessary region B2 are set so that the power additional shift is executed in order to ensure the power balance.

  As described above, it is possible to effectively suppress the deterioration of fuel consumption accompanying the execution of the power addition shift by determining whether the power addition shift should be executed.

  Next, a method for obtaining a power to be added to the engine power (hereinafter simply referred to as “addition amount”) in the power addition shift will be described. In the present embodiment, the ECU 4 calculates the additional amount in consideration of important items such as a shift time and a shift shock. Further, the ECU 4 obtains the additional amount in consideration of a request for an engine OBD (On Board Diagnosis) (for example, an execution request for failure diagnosis). In this case, when there is a request to increase engine power due to a request from the engine OBD, the ECU 4 determines whether it is possible to accept the request and shift gears, and determines the additional amount. Accordingly, it is possible to appropriately determine whether or not the engine power increase due to the engine OBD request can be performed during the shift.

  FIG. 5 is a diagram illustrating an example of a method for obtaining the additional amount. Here, an example in which the additional amount is obtained based on the shift time will be described. In FIG. 5, the horizontal axis indicates the shift time, and the vertical axis indicates the added power reflection rate. The added power reflection rate corresponds to a ratio of reflecting the added power with respect to the current engine power. Therefore, the amount of addition can be obtained from the current engine power and the additional power reflection rate.

  As indicated by an arrow C1 in FIG. 5, in the region where the shift time is relatively short, the added power reflection rate becomes large. That is, when the shift time is short, a relatively large additional amount is determined. On the other hand, as shown by an arrow C2, in the region where the shift time is relatively long, the added power reflection rate is small. That is, when the shift time is long, a relatively small amount of addition is determined.

  By calculating the additional amount as described above, it is possible to shift with the minimum engine power that ensures drivability and battery protection, and it is possible to appropriately suppress the deterioration of fuel consumption associated with the execution of the additional power shift. It becomes.

  Next, a method for adjusting the torque of second motor generator MG2 at the time of power addition shifting will be described. In the present embodiment, the ECU 4 adjusts the torque of the second motor generator MG2 so that the output shaft torque is stabilized during the power addition shift. Specifically, the ECU 4 performs a shift while adjusting the power generation amount of the second motor generator MG2 so as not to shock the output shaft torque with the added power. This is for the following reasons. Although it is thought that the output shaft torque hardly fluctuates theoretically by performing the power addition shift based on the shift power and the addition amount obtained as described above, it was added due to various other factors. The output shaft torque may vary depending on the power. Therefore, in the present embodiment, the power generation amount is adjusted as described above in order to reliably suppress such fluctuations in the output shaft torque.

  FIG. 6 is a diagram for specifically explaining a method of adjusting the power generation amount of second motor generator MG2. FIG. 6 shows a collinear diagram similar to that shown in FIG. Here, what attached | subjected the code | symbol same as FIG. 3 shall have the same meaning, and the description is abbreviate | omitted.

  By adding the engine power by the power addition shift, the rotational speed of the engine 1 can be increased as shown by the arrow D1. At this time, the output shaft torque can also increase. In the present embodiment, the ECU 4 performs adjustment by generating power with the second motor generator MG2 as indicated by an arrow D3 so as to compensate for such an increase (that is, so that the output shaft torque is stabilized). Further, as indicated by an arrow D2, the ECU 4 performs control so that the electric power generated by the second motor generator MG2 is used for the rotational change power in the first motor generator MG1. Note that the ECU 4 adjusts the power generation amount of the second motor generator MG2 in accordance with the amount of addition described above.

  By performing such control, fluctuations in the output shaft torque at the time of power addition shifting can be appropriately suppressed, so that drivability can be improved. Further, since the electric power generated by the second motor generator MG2 is used for the rotational change power in the first motor generator MG1, the shift time can be shortened and the power balance can be improved (for example, battery input / output). Compliance with restrictions).

  In the above description, the example in which the power generation amount of the second motor generator MG2 is adjusted at the time of the power addition shift is shown, but the power running amount of the second motor generator MG2 may be adjusted. That is, the torque may be output by powering the second motor generator MG2 so that the output shaft torque is stabilized during the power addition shift.

  Next, a method for dealing with a failure that may occur during power addition shifting (hereinafter referred to as “power addition failure”) will be described. In the present embodiment, the ECU 4 adjusts the amount of addition even during a shift when a power addition failure occurs. Specifically, the ECU 4 is configured such that when it is expected to approach the battery input / output limit at the time of the power addition shift (that is, when it is expected that the battery input / output limit cannot be observed), the battery power is disturbed, It is determined that an additional power failure has occurred when the SOC is equal to or lower than a predetermined value (for example, an SOC that causes deterioration of battery life). When it is determined that a power addition failure has occurred, the ECU 4 changes the amount of addition obtained as described above, and executes a power addition shift. Specifically, the ECU 4 executes the shift by reducing the added amount obtained at the start of the power addition shift.

  As described above, the components can be protected by adjusting the amount of addition at the time of power addition failure and performing a shift. For example, deterioration of battery life can be suppressed. In addition, robustness due to failure can be ensured.

  Next, the shift control process according to the present embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing the shift control process according to the present embodiment. The shift control process is basically executed when shifting from the continuously variable transmission mode to the fixed gear ratio mode. The process is repeatedly executed by the ECU 4.

  First, in step S101, the ECU 4 acquires operating state information. Specifically, the ECU 4 determines the rotational speed of each rotating element, the torque, the state of the engaging element such as the brake unit 7 and the clutch, the driver's accelerator, the brake, the shift operation, the battery, the motor generators MG1 and MG2, the inverter 31, and the like. The state is acquired as driving state information. Then, the process proceeds to step S102.

  In step S102, the ECU 4 determines whether or not the vehicle is traveling in the continuously variable transmission mode. Specifically, the ECU 4 determines whether or not the vehicle is traveling in the continuously variable transmission mode based on the driving state information acquired in step S101. For example, the ECU 4 makes a determination based on the rotational speed relationship as shown in FIG. If the vehicle is traveling in the continuously variable transmission mode (step S102; Yes), the process proceeds to step S103. On the other hand, when the vehicle is not traveling in the continuously variable transmission mode (step S102; No), that is, when the vehicle is traveling in the fixed gear ratio mode, the process exits the flow.

  In step S103, the ECU 4 calculates shift power required for shifting from the continuously variable transmission mode to the fixed gear ratio mode. In this case, the ECU 4 calculates the shift power corresponding to the inertia loss torque based on the current operating point and the operating point after the shift. Specifically, ECU 4 calculates an inertia loss torque associated with changes in the rotational speeds of engine 1 and first motor generator MG1 using an arithmetic expression, and obtains a value obtained by converting this torque in terms of engine shaft as the transmission power. Then, the process proceeds to step S104.

  In step S <b> 104, the ECU 4 determines whether or not a power addition shift is to be executed. That is, it is determined whether the power addition shift or the normal shift should be executed. Specifically, the ECU 4 makes a determination based on the speed change power obtained in step S103 and the current engine power. For example, the ECU 4 performs determination based on a map set based on items emphasized for each region, such as a shift time, a shift shock, and a battery power balance, as shown in FIG. In this case, the ECU 4 determines whether or not the power addition shift should be executed depending on whether the shift power and the current engine power are located in the addition unnecessary area B1 or the addition necessary area B2. If the power additional shift is to be executed (step S104; Yes), the process proceeds to step S105. If the power additional shift is not to be performed (step S104; No), the process proceeds to step S108.

  In step S105, the ECU 4 calculates the power (addition amount) to be added to the engine power in the power addition shift. Specifically, the ECU 4 calculates the additional amount in consideration of important items such as a shift time and a shift shock. In one example, the ECU 4 determines the amount of addition based on a map (see FIG. 5) defined by the shift time and the added power reflection rate. In another example, the ECU 4 uses the shift time instead of using the shift time, and calculates the amount of addition in consideration of a request from the engine OBD (for example, execution request for failure diagnosis). In this case, when there is a request to increase engine power due to a request from the engine OBD, the ECU 4 determines whether it is possible to accept the request and shift gears, and determines the additional amount. When the above process ends, the process proceeds to step S106.

  In step S106, the ECU 4 executes a power addition shift. Specifically, the ECU 4 performs a shift from the continuously variable transmission mode to the fixed transmission ratio mode using the engine power added by the additional amount obtained in step S105. In this case, the ECU 4 performs control so that the engine power obtained by increasing the current engine power by the added amount is output from the engine 1. Further, the ECU 4 synchronizes the phase with the engagement element in the brake unit 7 by the first motor generator MG1, engages the brake unit 7, and reduces the torque of the first motor generator MG1 to reduce the brake unit 7. The control is performed to support the engine reaction force.

  Further, in step S106, the ECU 4 adjusts the torque of the second motor generator MG2 so that the output shaft torque is stabilized at the time of such additional power shifting. That is, the ECU 4 performs a shift while adjusting the torque of the second motor generator MG2 so as not to shock the output shaft torque with the added power. Specifically, the ECU 4 causes the second motor generator MG2 to generate power so as to compensate for an increase in output shaft torque due to the power addition shift. Further, the ECU 4 performs control so that the electric power generated by the second motor generator MG2 is used for the rotational change power in the first motor generator MG1. The ECU 4 adjusts the power generation amount of the second motor generator MG2 in accordance with the amount of addition obtained in step S105. When the above process ends, the process proceeds to step S107.

  In step S107, the ECU 4 determines whether or not a power addition failure has occurred. Specifically, the ECU 4 is expected to approach the battery input / output limit (that is, the battery input / output limit is expected not to be observed), the battery power is disturbed, or the SOC is equal to or less than a predetermined value. It is determined whether or not. When the power addition failure has not occurred (step S107; Yes), the process exits the flow. In this case, the ECU 4 continuously executes the current power addition shift. On the other hand, when the power addition failure has occurred (step S107; No), the process returns to step S105. In this case, the ECU 4 performs the process for obtaining the additional amount again (step S105). That is, the added amount is changed, and the power added shift is executed based on the changed added amount. Specifically, the ECU 4 executes a shift by reducing the amount of addition obtained in the previous processing of step S105. For example, the ECU 4 determines an amount for reducing the amount of addition based on the degree of power addition failure or the like.

  On the other hand, in step S108, the ECU 4 determines whether or not the normal shift should be executed. Specifically, the ECU 4 makes a determination according to the driver request torque, the vehicle speed, the state of the battery, and the like based on the information acquired in step S101. When the normal shift is to be executed (step S108; Yes), the process proceeds to step S109. In this case, the ECU 4 performs a normal shift without substantially changing the engine power, that is, without adding the engine power (step S109). Then, the process exits the flow. On the other hand, when the normal shift should not be executed (step S108; No), the process exits the flow.

  According to the shift control process described above, it is possible to appropriately suppress shift shocks and power balance collapse that may occur during shifts. Further, while ensuring drivability and battery protection, deterioration of fuel consumption can be suppressed and gear shifting can be performed appropriately.

[Other Embodiments]
In the above-described embodiment, the shift control performed when shifting from the continuously variable transmission mode to the fixed transmission ratio mode is shown, but the application of the present invention is not limited to such a shift mode. In other embodiments, similar shift control can be performed when shifting from the fixed gear ratio mode to the continuously variable transmission mode. In the above description, the shift control performed by adding the engine power (that is, the shift control performed by increasing the engine power) is shown. However, the shift control can be performed by decreasing the engine power. Specifically, in another embodiment, when the output shaft torque increases due to changes in the rotational speeds of the engine 1 and the first motor generator MG1 (for example, when performing a deceleration shift), the engine power is decreased. Shifting can be performed.

  Here, with reference to FIG. 8, the shift control according to another embodiment will be specifically described. FIG. 8 shows an example of an alignment chart in the continuously variable transmission mode and the fixed transmission gear ratio mode. Straight lines E1 and E3 show collinear charts in the continuously variable transmission mode, and straight line E2 shows a collinear chart in the fixed gear ratio mode. In the above-described embodiment (see FIG. 6 and the like), as shown by the arrow F1, the shift control performed when shifting from the continuously variable transmission mode to the fixed transmission ratio mode is shown. Such shift control can be performed in the same manner when shifting from the fixed gear ratio mode to the continuously variable transmission mode as indicated by the arrow F2. In this case, since the output shaft torque tends to decrease due to a change in the rotational speed of the engine 1 and the first motor generator MG1, the engine power is increased based on the shift power (that is, the engine power is added) to perform the shift. It can be carried out.

  Further, when shifting from the continuously variable transmission mode to the fixed transmission ratio mode as indicated by the arrow F3 and when shifting from the fixed transmission ratio mode to the continuously variable transmission mode as indicated by the arrow F4, Similar shift control can be performed. In this case, since the output shaft torque tends to increase due to changes in the rotational speeds of engine 1 and first motor generator MG1, the engine power can be reduced to perform a shift. Specifically, the method similar to the method described above (see FIG. 7 and the like) is used to determine whether or not to perform a shift by adjusting the engine power, to calculate the amount to adjust the engine power, Fail judgment and the like can be executed.

  Next, FIG. 9 shows an example of a control device for a hybrid vehicle according to another embodiment. In the example of FIG. 9, the hybrid vehicle includes an internal combustion engine (engine) 101, a first motor generator (MG1) 102, and a second motor generator (MG2) 103 as a power unit. The output torque of the engine 101 is distributed to the first motor generator 102 and the output shaft by the power distribution mechanism 104, and the drive torque and brake force are assisted (assisted) by the second motor generator 103. This configuration is called a mechanically distributed two-motor hybrid device.

  The engine 101 is a heat engine that generates power by burning fuel, and examples thereof include a gasoline engine and a diesel engine. The first motor generator 102 generates power mainly by receiving torque from the engine 101 and rotating, and reaction force torque accompanying power generation acts.

  The second motor generator 103 assists (assists) driving torque or braking force. When assisting the driving torque, the second motor generator 103 functions as an electric motor upon receipt of electric power. On the other hand, when assisting the braking force, the second motor generator 103 functions as a generator that is rotated by torque transmitted from drive wheels (not shown) to generate electric power.

  The power distribution mechanism 104 is configured by substantially combining two sets of planetary gear mechanisms. In the example shown in FIG. 9, a Ravigneaux type planetary combination of a single pinion type planetary gear mechanism and a double pinion type planetary gear mechanism. A gear mechanism is used. Specifically, the first sun gear 105 and the ring gear 106 are disposed between the first sun gear 105 that is an external gear and the ring gear 106 that is an internal gear arranged concentrically with the first sun gear 105. A long pinion 107 meshing with each other is disposed. The first sun gear 105, the ring gear 106, and the long pinion 107 constitute a single pinion type planetary gear mechanism. A second sun gear 108 is disposed on the same axis line adjacent to the first sun gear 105, and a short pinion 109 that meshes with the second sun gear 108 meshes with the long pinion 107. Therefore, a double pinion type planetary gear mechanism is configured by the four members of the second sun gear 108, the pinions 109 and 107, and the ring gear 106. A plurality of pairs of long pinions 107 and short pinions 109 meshing with each other are provided, and these pinions 107 and 109 are held by a carrier 110 so as to rotate and revolve.

  Torque is input from the engine 101 to the ring gear 106 in the power distribution mechanism 104. Therefore, the ring gear 106 is an input element.

  Torque is transmitted from the first motor generator 102 to the first sun gear 105 in the power distribution mechanism 104. Therefore, the first sun gear 105 is a reaction force element. Specifically, reaction force shaft 111 is arranged on the same axis as engine 101, and the end of reaction force shaft 111 opposite to engine 101 side is connected to first motor generator via gear pair 112. It is connected to 102 rotors. The stator of the first motor generator 102 is connected and fixed to a fixed part such as the casing 113.

  In the power distribution mechanism 104 described above, four elements of the ring gear 106 serving as an input element, the first sun gear 105 serving as a reaction force element, the second sun gear 108, and the carrier 110 are used as rotating elements. The second sun gear 108 and the carrier 110 are selectively used as output elements. The ring gear 106, the first sun gear 105 or the second sun gear 108, and the carrier 110 are configured to generate a differential action.

  A synchronous coupling mechanism is provided between these output elements and the output member for selectively transmitting torque between them. Specifically, first and second intermediate shafts 114 and 115 that are hollow shafts are rotatably fitted to the outer peripheral side of the reaction force shaft 111, respectively. The second intermediate shaft 115 on the outer peripheral side is connected to the carrier 110, the first intermediate shaft 114 on the inner peripheral side is connected to the second sun gear 108, and the tip side of the second intermediate shaft 115 (opposite to the engine 101). Protruding to the side).

  An output shaft 116 is rotatably arranged parallel to the intermediate shafts 114 and 115 at a predetermined distance from the intermediate shafts 114 and 115. A first speed gear pair 117 and a third speed gear pair 118 are disposed between the first intermediate shaft 114 and the output shaft 116. The gear pairs 117 and 118 are disposed adjacent to each other in the axial direction. A second speed gear pair 119 and a fourth speed gear pair 120 are arranged between the second intermediate shaft 115 and the output shaft 116. The gear pairs 119 and 120 are disposed adjacent to each other in the axial direction.

  Each of the gear pairs 117 to 120 includes a drive gear on the side of each of the intermediate shafts 114 and 115 and a driven gear on the side of the output shaft 116 that is always meshed therewith. The driven gear on the output shaft 116 side of each gear pair 117, 118 is connected to the clutch mechanism 121. The driven gear on the output shaft 116 side of each gear pair 119, 120 is connected to the clutch mechanism 122. The clutch mechanisms 121 and 122 are configured as dog clutches that engage dog teeth that are arranged to face each other. Specifically, in the clutch mechanism 121, by moving the actuator 131 in the left direction in the figure, the output shaft 116 is engaged with the driven gear of the first speed gear pair 117, and the actuator 131 is moved in the right direction in the figure. As a result, the output shaft 116 is engaged with the driven gear of the third speed gear pair 118. Similarly, in the clutch mechanism 122, when the actuator 132 is moved in the left direction in the figure, the output shaft 116 is engaged with the driven gear of the second speed gear pair 119, and the actuator 132 is moved in the right direction in the figure. Thus, the output shaft 116 engages with the driven gear of the fourth speed gear pair 120. As described above, by driving the actuators 131 and 132, any one of the first to fourth speeds can be selected. Such drive control of the actuators 131 and 132 is executed by an ECU (not shown).

  In the above configuration, when one of the first speed to the fourth speed is selected by the speed change mechanism, the present control device operates in the continuously variable speed mode. That is, when the rotational speed of the first motor generator 102 is continuously changed by the power distribution mechanism 104, the rotational speed of the engine 101 is continuously changed, and the operation in the continuously variable transmission mode is executed. On the other hand, when shifting from the first speed to the second speed, from the second speed to the third speed, and from the third speed to the fourth speed, a state where a plurality of gears are fixed to the output shaft, that is, a fixed gear ratio mode It becomes. For example, in FIG. 9, the clutch mechanism 121 is engaged on the first speed gear pair 117 side during operation at the first speed. At the time of shifting from the first speed to the second speed, first, the clutch mechanism 121 is left as it is, the actuator 132 is driven leftward in the figure, and the clutch mechanism 122 is engaged with the second speed gear pair 119 side. At this time, the first speed gear pair 117 and the second speed gear pair 119 are temporarily connected to the output shaft 116 at the same time, that is, the fixed gear ratio mode is set. Similarly, the fixed gear ratio mode also exists when shifting from the second speed to the third speed and from the third speed to the fourth speed.

  The present invention can also be applied at the time of shifting in the control device configured as described above. That is, when shifting between the continuously variable transmission mode and the fixed gear ratio mode, the engine power can be adjusted to perform the shifting.

1 shows a schematic configuration of a hybrid vehicle according to an embodiment. The structure of a motor generator and a power transmission mechanism is shown. The figure for demonstrating the malfunction which generate | occur | produces at the time of gear shifting is shown. The figure for demonstrating the execution determination method of a power addition shift is shown. An example of a method for obtaining the additional amount will be shown. The figure for demonstrating the method to adjust electric power generation amount is shown. It is a flowchart which shows the shift control process which concerns on this embodiment. The figure for demonstrating the shift control which concerns on other embodiment is shown. The structure of the control apparatus by other embodiment is shown.

Explanation of symbols

1 Engine 3 Output shaft 4 ECU
7 Brake part 31 Inverter 32, 34 Converter 33 HV battery 20 Power distribution mechanism MG1 First motor generator MG2 Second motor generator

Claims (6)

An engine, a first motor generator, a power distribution mechanism configured to be connectable to the engine and the first motor generator, and a second that outputs torque to an output shaft to which an output from the power distribution mechanism is transmitted A control device for a hybrid vehicle that controls a hybrid vehicle configured to be capable of switching between a continuously variable transmission mode and a fixed transmission ratio mode.
Shift power calculation means for calculating shift power required for shifting based on the current operating point and the operating point after shifting when shifting between the continuously variable transmission mode and the fixed gear ratio mode;
Based on the shift power and the current engine power, a first shift that is performed without changing the engine power, and a second shift that is performed by increasing or decreasing the engine power as compared with the case where the first shift is performed. Shift determining means for determining which of them to be executed ;
A hybrid vehicle control device comprising: a shift control unit that performs the second shift when the shift determination unit determines that the second shift should be performed. If the output shaft torque decreases due to a change in the rotational speed of the engine and the first motor generator during the second shift, the shift control means increases the engine power to perform the shift, and the second shift 2. The control apparatus for a hybrid vehicle according to claim 1, wherein when the output shaft torque increases due to a change in the rotational speed of the engine and the first motor generator during a shift, the engine power is decreased to perform the shift. 3. The control device for a hybrid vehicle according to claim 1, wherein the shift control means determines an amount to increase or decrease the engine power based on a shift time when performing the second shift . 4. The shift control means changes an amount to increase or decrease the engine power based on at least one of battery input / output limitation and a charging state during a shift in the second shift. The control apparatus of the hybrid vehicle as described in any one of these. 5. The control device for a hybrid vehicle according to claim 1, further comprising a unit that adjusts a torque of the second motor generator to stabilize an output shaft torque during the second shift by the shift control unit. The shift determination means performs the determination based on a map defined by the shift power and the current engine power,
The map is, the more the current engine power is small, the determination is set as likely to be the second to be performed the shifting, as the current engine power is high, to be subjected to the second shift The control device for a hybrid vehicle according to any one of claims 1 to 5, wherein the control device is set so that it can be easily determined that the vehicle is not.

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