JP2009248913A - Hybrid car and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To charge an electricity accumulating device by giving priority to fuel consumption when the residual capacity of the electricity accumulating device becomes small while a vehicle travels not in a normal traveling mode in which a vehicle travels in harmony with responsiveness, fuel consumption and a driving environment to some extents but in a fuel priority traveling mode in which fuel consumption is given priority. <P>SOLUTION: When a fuel consumption priority mode is selected, a charging power restriction Pblim (chain line) is set with respect to a vehicle speed V in such a trend that restriction to a power to be charged in an electricity accumulating device is more relaxed than a charging power restriction Pblim (solid line) to be set when a normal traveling mode is selected, and a target charging power to be charged in the electricity accumulation device is set within a set charging power restriction Pblim, and an engine and the two motors are controlled so that the target charging power can be input/output to/from the electricity accumulating device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle, and more specifically, an internal combustion engine that outputs power for traveling, a generator that generates power using the power from the internal combustion engine, a motor that outputs power for traveling, a generator, and a motor and electric power. The present invention relates to a hybrid vehicle including a power storage means for performing exchanges and a control method thereof.

Conventionally, as this type of hybrid vehicle, an engine, a generator that generates power using the power from the engine, a traveling motor that outputs driving power, and exchange of electric power with the generator and the traveling motor are performed. The thing provided with a battery is proposed (for example, refer patent document 1). In this hybrid vehicle, when the vehicle speed is low, the engine operating point is set avoiding the vehicle resonance band, so that the generator can generate power while suppressing noise and vibration felt by the driver.
Japanese Patent Laid-Open No. 11-103501

  In a hybrid vehicle, the engine is operated at a relatively low speed in consideration of fuel consumption. Therefore, when the remaining battery capacity (SOC) decreases, the engine is reduced so that a certain amount of power is output from the engine to charge the battery. There is a case where the engine is operated in a region where vibration of high torque and abnormal noise are likely to occur. At this time, if the vehicle speed is high, vibration and noise generated by driving the engine at low rotation and high torque are masked by vibration and noise due to traveling, but when the vehicle speed is low, it is not masked. By limiting to a small value, the engine is not operated at a low rotation and high torque. On the other hand, some hybrid vehicles include a switch for switching to a fuel consumption priority traveling mode in which fuel consumption is prioritized for a user who desires to travel with priority on fuel efficiency even if slight noise or vibration occurs. When traveling in such a fuel consumption priority traveling mode, priority is given to fuel efficiency, and therefore processing different from the normal traveling mode is desired as processing when the remaining battery capacity (SOC) decreases.

  The main object of the hybrid vehicle and the control method thereof according to the present invention is to charge the power storage device with priority on fuel efficiency when the remaining capacity of the power storage device becomes small during traveling in the fuel efficiency priority traveling mode.

  The hybrid vehicle of the present invention and its control method employ the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An internal combustion engine that outputs power for traveling, a generator that generates power using the power from the internal combustion engine, an electric motor that outputs power for traveling, and an electric storage means that exchanges electric power with the generator and the motor A hybrid vehicle comprising:
Vehicle speed detection means for detecting the vehicle speed;
Mode switching setting means for switching between a normal driving mode for driving with a certain degree of harmony between responsiveness, fuel consumption, and driving environment, and a fuel consumption priority driving mode for driving with priority on fuel consumption over the normal driving mode;
A required driving force setting means for setting a required driving force required for traveling;
When the charging request for charging the power storage means is made, and when the normal travel mode is set by the mode switching setting means, the charge limit value obtained using the first relationship with respect to the detected vehicle speed The internal combustion engine, the generator, and the electric motor are controlled so as to run with the set required driving force while the power storage means is charged within a range, and the fuel consumption priority accompanying mode is set by the mode switching setting means. The power storage within the range of the charge limit value obtained using the second relationship in which electric power having a larger absolute value than the first relationship is obtained as the charge limit value with respect to the detected vehicle speed. Control means for controlling the internal combustion engine, the generator and the electric motor so as to travel with the set required driving force while the means is charged;
It is a summary to provide.

  In the hybrid vehicle of the present invention, when a charge request for charging the power storage means is made, a normal travel mode is set in which the mode switching setting means travels with a certain degree of harmony between responsiveness, fuel consumption, and driving environment. Sometimes, the internal combustion engine, the generator, and the motor are controlled to run with the required driving force required for running while the power storage means is charged within the range of the charging limit value obtained using the first relationship with respect to the vehicle speed. When the fuel consumption priority traveling mode is set in which the fuel consumption is prioritized over the normal traveling mode by the mode switching setting means, electric power having a larger absolute value than the first relationship is obtained as the charge limit value with respect to the vehicle speed. The internal combustion engine, the generator, and the electric motor are driven so as to travel with the required driving force while the power storage means is charged within the range of the charging limit value obtained using the second relationship. To your. As a result, when the fuel consumption priority driving mode is set, the driver may feel a slight vibration or noise, but the fuel consumption is improved as compared to when the normal driving mode is set, that is, the fuel consumption. The power storage means can be charged with priority.

  In the hybrid vehicle of the present invention, the first relationship may be a relationship in which electric power having a smaller absolute value is obtained as the charge limit value as the vehicle speed is lower. This is based on the fact that vibration and noise from the internal combustion engine are masked when the vehicle speed is high because vibration and noise due to traveling are also large.

  Further, in the hybrid vehicle of the present invention, the drive shaft connected to the axle, the output shaft of the internal combustion engine, and the rotation shaft of the generator are connected to the three shafts so as to enter any two of the three shafts. Three-axis power input / output means for inputting / outputting power to / from the remaining shafts based on the output power may be provided, and the electric motor may be capable of inputting / outputting power to / from the drive shaft.

The hybrid vehicle control method of the present invention includes:
An internal combustion engine that outputs power for traveling, a generator that generates power using the power from the internal combustion engine, an electric motor that outputs power for traveling, and an electric storage means that exchanges electric power with the generator and the motor And mode switching setting means for switching and setting a normal driving mode for driving with a certain degree of harmony between responsiveness, fuel consumption, and driving environment, and a fuel consumption priority driving mode for driving with priority on fuel consumption over the normal driving mode. A hybrid vehicle control method comprising:
When the charge request for charging the power storage means is made, and when the normal travel mode is set by the mode switching setting means, the charge limit value is obtained within the range of the charge limit value obtained using the first relationship with respect to the vehicle speed. The internal combustion engine, the generator, and the electric motor are controlled to run with the required driving force required for running while the power storage means is charged, and the vehicle speed when the fuel consumption priority accompanying mode is set by the mode switching setting means In contrast, the request is made while the power storage means is charged within the range of the charge limit value obtained using the second relationship in which the power having a larger absolute value than the first relationship is obtained as the charge limit value. Controlling the internal combustion engine, the generator, and the electric motor so as to travel by driving force;
It is characterized by that.

  In this hybrid vehicle control method of the present invention, when the charging request for charging the power storage means is made, the mode switching setting means sets the normal driving mode for traveling with a certain degree of harmony between responsiveness, fuel consumption, and driving environment. The internal combustion engine, the generator, and the electric motor so as to travel with the required driving force required for traveling while the power storage means is charged within the range of the charging limit value obtained by using the first relationship with respect to the vehicle speed. When the fuel consumption priority traveling mode is set in which the fuel consumption is prioritized over the normal traveling mode by the mode switching setting means, electric power having a larger absolute value than the first relationship is charged with respect to the vehicle speed. The internal combustion engine and the generator so as to travel with the required driving force while the power storage means is charged within the range of the charging limit value obtained using the second relationship obtained as a value. To control and motivation. As a result, when the fuel consumption priority driving mode is set, some vibrations and noise may occur, but the fuel efficiency is improved as compared to when the normal driving mode is set, that is, the fuel consumption is given priority. The power storage means can be charged.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, And a hybrid electronic control unit 70 for controlling the entire vehicle.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil. The engine electronic control unit (hereinafter referred to as engine ECU) 24 performs fuel injection control, ignition control, and intake air amount adjustment. Under control of operation such as control. The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a crank position from a crank position sensor (not shown) that detects the crank angle of the crankshaft 26 of the engine 22. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22, based on a crank position from a crank position sensor (not shown).

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. Further, the battery ECU 52 calculates the remaining capacity SOC based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50, or the battery ECU 52 based on the calculated remaining capacity SOC and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge 50, are calculated. The input / output limits Win and Wout of the battery 50 are set to basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limit correction coefficient and the input limit are set based on the remaining capacity SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal position Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the fuel efficiency and comfort mounted near the driver's seat The eco switch signal ESW from the eco switch 89 that is set by switching between the normal travel mode for traveling and the fuel efficiency priority mode for traveling with priority over the normal travel mode is input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing. The eco switch signal ESW is a signal that is turned on when the fuel efficiency priority mode is set and turned off when the normal travel mode is set.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so as to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when the accelerator opening Acc is relatively small and the battery 50 requests charging will be described. FIG. 2 is a flowchart showing an example of a drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm1, of the motors MG1, MG2. Nm2, the remaining capacity SOC of the battery 50, the input / output restrictions Win and Wout of the battery 50, the eco switch signal ESW from the eco switch 89, and the like are input (step S100). The target charging power Pb * to be charged to the battery 50 is set by the target charging power setting process to be performed (step S110). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. The remaining capacity SOC of the battery 50 and the input / output limits Win and Wout are calculated based on the integrated value of the charge / discharge current of the battery 50, the battery temperature Tb of the battery 50, and the remaining capacity SOC of the battery 50. What is set based on this is input from the battery ECU 52 by communication. Now, it is considered that the battery 50 is requesting charging, and a value smaller than a target remaining capacity SOC * described later is input as the remaining capacity SOC of the battery 50. The target charging power setting process will be described later for convenience of explanation.

  Next, the required torque Tr * and the drive shaft required power to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the accelerator opening Acc and the vehicle speed V. Pr * is set (step S120). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 4 shows an example of the required torque setting map. The drive shaft required power Pr * can be calculated by multiplying the set required torque Tr * by the rotation speed Nr of the ring gear shaft 32a. The rotational speed Nr of the ring gear shaft 32a is obtained by multiplying the vehicle speed V by a conversion factor k (Nr = k · V), or the rotational speed Nm2 of the motor MG2 is divided by the gear ratio Gr of the reduction gear 35 (Nr = Nm2 / Gr).

  Subsequently, by subtracting the target charging power Pb * from the driving shaft required power Pr * and adding a loss Loss, the required power Pe * required for the engine 22 is set (step S130), and the set required power Pe * is set. Based on this, the target rotational speed Ne * and the target torque Te * are set as operating points for operating the engine 22 (step S140). This setting is performed based on an operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 5 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Ne * × Te *).

  Next, using the target rotational speed Ne * of the engine 22, the rotational speed Nm2 of the motor MG2, the gear ratio ρ of the power distribution and integration mechanism 30, and the gear ratio Gr of the reduction gear 35, the target of the motor MG1 is expressed by the following equation (1). Based on the calculated target rotational speed Nm1 *, the input rotational speed Nm1 of the motor MG1, the target torque Te * of the engine 22, and the gear ratio ρ of the power distribution and integration mechanism 30, the formula (2) is calculated. To calculate the torque command Tm1 * of the motor MG1 (step S150). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 6 shows an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in the rotating elements of the power distribution and integration mechanism 30 when traveling with the power output from the engine 22. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. Equation (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / (Gr ・ ρ) (1)
Tm1 * =-ρ ・ Te * / (1 + ρ) + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (2)

  Then, the torque command Tm1 * set as the required torque Tr * is divided by the gear ratio ρ of the power distribution and integration mechanism 30 and further divided by the gear ratio Gr of the reduction gear 35 to obtain the torque to be output from the motor MG2. A temporary torque Tm2tmp, which is a temporary value, is calculated by the following equation (3) (step S160), and the input / output limits Win and Wout of the battery 50 and the set torque command Tm1 * are multiplied by the current rotational speed Nm1 of the motor MG1. The torque limits Tm2min and Tm2max as upper and lower limits of the torque that may be output from the motor MG2 by dividing the deviation from the power consumption (generated power) of the motor MG1 obtained by the number of revolutions Nm2 of the motor MG2 ) And formula (5) (step S170), and the set temporary torque Tm2tmp is used as the torque limit Tm2. in, and limited by Tm2max to set the torque command Tm2 * of the motor MG2 (step S180). Here, Expression (3) can be easily derived from the alignment chart of FIG.

Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (3)
Tm2min = (Win-Tm1 * ・ Nm1) / Nm2 (4)
Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (5)

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. Torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are transmitted to motor ECU 40 (step S190), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * controls the intake air amount in the engine 22 so that the engine 22 is operated at the operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as fuel injection control and ignition control. Further, the motor ECU 40 that has received the torque commands Tm1 * and Tm2 * controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. To do. By such control, the engine 22 can be efficiently operated within the range of the input / output limits Win and Wout of the battery 50, and the required torque Tr * can be output to the ring gear shaft 32a as a drive shaft to travel.

  Next, the target charging power setting process will be described. In the target charging power setting process of FIG. 3, first, temporary charging power Pbtmp as a temporary value of power to be charged to the battery 50 is set based on the input remaining capacity SOC of the battery 50 (step S200), and the eco switch It is determined whether the signal ESW is on or off (step S210). In the embodiment, the temporary charging power Pbtmp is stored in the ROM 74 as a temporary charging power setting map by predetermining the relationship between the remaining capacity SOC and the temporary charging power Pbtmp, and from the stored map when the remaining capacity SOC is given. The corresponding temporary charging power Pbtmp is derived and set. FIG. 7 shows an example of the temporary charging power setting map. Note that the case where the remaining capacity SOC of the battery 50 is smaller than the target remaining capacity SOC * is considered now, but FIG. 7 is used when the remaining capacity SOC is larger than the target remaining capacity SOC * for reference. A map for setting the discharge power to be discharged from the battery 50 is also shown by a broken line. As shown in the figure, the temporary charging power Pbtmp tends to increase toward the maximum charging power Pbmin (negative value in the embodiment) as the maximum power allowed for charging the battery 50 as the remaining capacity SOC decreases. Set to For example, 50% or 60% can be used as the target remaining capacity SOC *.

  When the eco switch signal ESW is off, that is, during normal driving when the normal driving mode is selected, the charging power limit Pblim is set based on the vehicle speed V and the map during normal driving (step S220), and the eco switch signal ESW is turned on. In other words, that is, when the fuel efficiency priority mode is selected, the charging power limit Pblim is set based on the vehicle speed V and the map of the fuel efficiency priority (step S230), and the temporary charging power Pbtmp is limited by the charging power limit Pblim. The target charging power Pb * is set (step S240), and the target charging power setting process is terminated. In the embodiment, the charging power limit Pblim is stored in the ROM 74 as a charging power limit setting map for each mode selected in advance by selecting the relationship between the vehicle speed V and the charging power limit Pblim, and the vehicle speed V is given. The corresponding charging power limit Pblim is derived from the stored map and set. FIG. 8 shows an example of the charging power limit setting map. In the figure, the solid line indicates a map during normal driving, and the alternate long and short dash line indicates a map when priority is given to fuel consumption. As shown by the solid line, the charging power limit Pblim is set to a constant value when the vehicle speed V is equal to or higher than the threshold value Vref and the maximum charging power Pbmin is set when the vehicle speed V is lower than the threshold value Vref. The smaller the value is, the smaller the absolute value is set toward the value Pb1, that is, the charged power tends to be reduced. When fuel consumption is prioritized, the maximum charged power Pbmin is constantly set regardless of the vehicle speed V as shown by the one-dot chain line. The Here, the threshold value Vref is a vehicle speed set in advance as a vehicle speed near the lower limit vehicle speed of the vehicle speed at which the noise and vibration can be masked by noise and vibration due to traveling even when the engine 22 is operated in a region where the noise and vibration are large. Can be used. The value Pb1 is a value whose absolute value is smaller than the maximum charging power Pbmin (a value that is small as charging power), and avoids a region in which vibration or noise is likely to occur when used as the required power Pe * of the engine 22. A value determined in advance based on characteristics of the engine 22 or the like can be used as the power at which the operating point of the engine 22 is set. In the embodiment, since the target charging power Pb * is set by limiting the temporary charging power Pbtmp with the charging power limit Pbmin, the temporary charging power Pbtmp is set and the vehicle speed is set when the vehicle speed V is equal to or higher than the threshold value Vref during normal driving. When V is less than the threshold value Vref, the charging power is limited and set as the vehicle speed V is small. When fuel efficiency is prioritized, the temporary charging power Pbtmp is set regardless of the vehicle speed. When the target charging power Pb * is set in this way, as described in the driving control routine of FIG. 2, the target charging power Pb * is subtracted from the driving shaft required power Pr * required for the ring gear shaft 32a as the driving shaft. The required power Pe * required for the engine 22 is set by adding the loss Loss (step S130), and the target operating point of the engine 22 is set using the set required power Pe * (step S140). FIG. 9 shows an example of the target operating point of the engine 22 set using the target charging power Pb * set by the target charging power setting process when the vehicle speed V is low and the battery 50 requests charging. In the figure, the solid line is an operation line for operating the engine 22 efficiently, and the broken line is an efficiency curve showing the efficiency of the engine 22 as a contour line. In the embodiment, it is considered that the accelerator opening degree Acc is relatively small, that is, the drive shaft required power Pr * is relatively small, and the required power Pe * required for the engine 22 is also a relatively small value. Generally, as indicated by the broken line, the engine 22 tends to be more efficient at outputting a large torque at the same rotation speed. When the required power Pe * is relatively small, a booming noise or There are cases where the engine is operated in a low-rotation high-torque region (shaded region in the figure) where vibrations and noise due to resonance are likely to occur. Although the vibration and noise are masked by vibration and noise caused by running when the vehicle speed V is high, the vibration and noise caused by running are reduced and not masked when the vehicle speed V is low, and the driver is uncomfortable. For this reason, during normal running, as indicated by the solid line in FIG. 8, in a region where the vehicle speed V is less than the threshold value Vref, the electric power to be charged in the battery 50 is limited as the vehicle speed V decreases. Thus, as shown in FIG. 9, the driving point set during normal driving can avoid a region where vibrations or abnormal noises are likely to occur, and can suppress a sense of discomfort given to the driver. On the other hand, when charging power is limited and small power is output from the engine 22, vibration and noise generated from the engine 22 can be suppressed, but the efficiency of the engine 22 is reduced. As described above, the charging power limit Pblim is set so as to relax the limit as compared with the normal traveling. That is, when the fuel efficiency is prioritized, the driver wants to improve the fuel efficiency. Therefore, the operating point of the engine 22 is set without imposing a limit on the electric power to be charged in the battery 50 as compared with the normal driving. As a result, as shown in FIG. 9, when the fuel consumption is prioritized, the driver may feel a slight vibration or noise, but the fuel efficiency is improved as compared with the normal driving, that is, the fuel 50 is prioritized. Can be charged.

  According to the hybrid vehicle 20 of the embodiment described above, the charging power limit Pblim is set with respect to the vehicle speed V so that the restriction on the power to be charged in the battery 50 is relaxed when fuel efficiency is prioritized compared to the normal driving. The target charge power Pb * to be charged to the battery 50 is set using the charge power limit Pblim set together with this, and the target charge power Pb * is input to and output from the battery 50 and the required torque is applied to the ring gear shaft 32a as the drive shaft. Since the engine 22 and the motors MG1 and MG2 are controlled so as to travel by outputting Tr *, the driver may feel some vibrations or abnormal noise from the engine 22 when fuel efficiency is prioritized, but compared to during normal driving. Thus, the battery 50 can be charged by improving the fuel consumption, that is, giving priority to the fuel consumption.

  In the hybrid vehicle 20 of the embodiment, the maximum charging power Pbmin is set to be constant regardless of the vehicle speed V as the charging power limit Pblim at the time of priority on fuel consumption, but the absolute value is larger with respect to the vehicle speed than during normal driving. For example, when the vehicle speed V is less than the threshold value Vref, the absolute value increases toward the value Pb2 that has a larger absolute value than the value Pb1 and a smaller absolute value than the maximum charging power Pbmin. Electric power that tends to decrease may be set.

  In the hybrid vehicle 20 of the embodiment, the motor MG2 is attached to the ring gear shaft 32a as the drive shaft via the reduction gear 35. However, the motor MG2 may be directly attached to the ring gear shaft 32a, or Instead, the motor MG2 may be attached to the ring gear shaft 32a via a transmission such as a 2-speed, 3-speed, or 4-speed.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is changed by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modification of FIG. May be output to an axle (an axle connected to the wheels 64a and 64b in FIG. 10) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  Further, in the present embodiment, the content of the present invention has been described as the hybrid vehicle 20, but such a hybrid vehicle control method may be employed.

  Here, the correspondence between the main elements of the embodiments and the modified examples and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “internal combustion engine”, the motor MG1 corresponds to the “generator”, the motor MG2 corresponds to the “electric motor”, the battery 50 corresponds to the “power storage unit”, and the vehicle speed sensor 88. Corresponds to “vehicle speed detection means”, the eco switch 89 corresponds to “mode switching setting means”, and sets the required torque Tr * based on the accelerator opening degree Acc and the vehicle speed V in FIG. The hybrid electronic control unit 70 that executes the processing of S120 corresponds to “required driving force setting means”, sets the temporary charging power Pbtmp based on the remaining capacity SOC of the battery 50, and when the eco switch signal ESW is off, that is, During normal driving, the charging power limit Pblim is set based on the vehicle speed V and the normal driving map, and when the eco switch signal ESW is on, that is, fuel consumption priority. Is set with a charging power limit Pblim based on the vehicle speed V and a map when fuel efficiency is prioritized, the temporary charging power Pbtmp is limited with the charging power limit Pblim, and a target charging power Pb * is set, and this target charging power Pb * is set. Is input to the battery 50 and the target rotational speed Ne * of the engine 22 and the target are set so as to travel by outputting the required torque Tr * to the ring gear shaft 32a as the drive shaft within the range of the input / output limits Win and Wout of the battery 50. The hybrid electronic control for executing the drive control routine of FIG. 2 for setting the torque Te * and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 and transmitting them to the engine ECU 24 and the motor ECU 40 and the target charging power setting process of FIG. Engine EC that controls engine 22 based on unit 70, target rotational speed Ne *, and target torque Te * 24 and the torque command Tm1 *, the motor ECU40 for controlling the motor MG1, MG2 corresponds to a "control unit" based on Tm2 *. Further, the power distribution and integration mechanism 30 corresponds to “three-shaft power input / output means”, and the anti-rotor motor 230 also corresponds to “generator”.

  Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. The “generator” is not limited to the motor MG1 and the anti-rotor motor 230 configured as a synchronous generator motor, and any type of generator may be used as long as it generates power using power from an internal combustion engine, such as an induction motor. It does not matter as a generator. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any motor as long as it outputs driving power such as an induction motor. The “storage means” is not limited to the battery 50 as a secondary battery, and may be anything as long as it exchanges power with a generator or an electric motor such as a capacitor. The “vehicle speed detection means” is not limited to the vehicle speed sensor 88, and any device that detects the vehicle speed may be used. The “mode switching means” is not limited to the eco switch 89, and the fuel consumption in which the fuel consumption is given priority over the normal driving mode and the normal driving mode in which the vehicle travels with a certain degree of harmony between responsiveness, fuel consumption, and driving environment. Any method may be used as long as the priority driving mode is switched and set. The “required driving force setting means” is not limited to the one that sets the required torque Tr * based on the accelerator opening Acc and the vehicle speed V, but sets the required torque based only on the accelerator opening Acc. If the required driving force required for traveling is set, such as those for which the required torque is set based on the traveling position on the traveling route, such as those for which the driving route is set in advance I do not care. The “control means” is not limited to the combination of the hybrid electronic control unit 70, the engine ECU 24, and the motor ECU 40, and may be configured by a single electronic control unit. Further, as the “control means”, the temporary charging power Pbtmp is set based on the remaining capacity SOC of the battery 50, and based on the vehicle speed V and the map for normal driving when the eco switch signal ESW is OFF, that is, normal driving. The charging power limit Pblim is set. When the eco switch signal ESW is on, that is, when the fuel efficiency is prioritized, the charging power limit Pblim is set based on the vehicle speed V and the fuel efficiency priority map, and the temporary charging power Pbtmp is set as the charging power limit Pblim. The target charging power Pb * is set in a limited manner, and the target charging power Pb * is input / output to / from the battery 50, and the required torque is applied to the ring gear shaft 32a as the drive shaft within the range of the input / output limits Win, Wout of the battery 50. The target rotational speed Ne *, the target torque Te *, and the motors MG1, MG of the engine 22 so as to travel by outputting Tr *. Is not limited to controlling the engine 22 and the motors MG1 and MG2 by setting the torque commands Tm1 * and Tm2 *, and when the charging request for charging the power storage means is made, the mode switching setting means When the normal driving mode in which the vehicle travels with a certain degree of harmony between responsiveness, fuel consumption, and driving environment is set, the power storage means is charged within the range of the charging limit value obtained using the first relationship with respect to the vehicle speed. When the internal combustion engine, the generator, and the motor are controlled to travel with the required driving force required for traveling, and the fuel efficiency priority traveling mode is set in which the fuel consumption is prioritized over the normal traveling mode by the mode switching setting unit. The range of the charge limit value obtained using the second relationship in which electric power having a larger absolute value than the first relationship with respect to the vehicle speed is obtained as the charge limit value. In controlling an internal combustion engine and the generator and the motor so that the accumulator unit is traveling by the required driving force while being charged, but may be any so long as. Further, the “three-axis power input / output means” is not limited to the power distribution and integration mechanism 30 described above, but four or more using a double pinion type planetary gear mechanism or a combination of a plurality of planetary gear mechanisms. Any one of the three axes connected to the three axes of the drive shaft, the output shaft, and the rotating shaft of the generator, such as those connected to the other shaft and those having a different operation action from the planetary gear such as a differential gear As long as the power is input / output to / from the remaining shafts based on the power input / output to / from the two shafts, any device may be used.

  Note that the correspondence between the main elements of the embodiment and the modified example and the main elements of the invention described in the column of means for solving the problem is described in the column of means for the embodiment to solve the problem. Since this is an example for specifically describing the best mode for carrying out the invention, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in the vehicle manufacturing industry.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 4 is a flowchart showing an example of a drive control routine executed by a hybrid electronic control unit 70. It is a flowchart which shows an example of a target charging power setting process. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, the target rotational speed Ne *, and the target torque Te * are set. FIG. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of a power distribution and integration mechanism 30 when traveling with power output from an engine 22; It is explanatory drawing which shows an example of the map for temporary charging power setting. It is explanatory drawing which shows an example of the map for charge power restriction setting. It is explanatory drawing which shows an example of the target operating point of the engine 22 set using the target charging power Pb * set by the target charging power setting process when the vehicle speed V is small and the remaining capacity SOC of the battery 50 is small. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

Explanation of symbols

  20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier 35, reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line , 60 gear mechanism, 62 differential gear, 63a, 63b drive wheel, 64a, 64b wheel, 70 electronic control unit for hybrid, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch , 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 89 Eco switch, 230 Counter rotor motor, 232 Inner rotor, 234 Outer rotor , MG1, MG2 motors.

Claims (4)

An internal combustion engine that outputs power for traveling, a generator that generates power using the power from the internal combustion engine, an electric motor that outputs power for traveling, and an electric storage means that exchanges electric power with the generator and the motor A hybrid vehicle comprising:
Vehicle speed detection means for detecting the vehicle speed;
Mode switching setting means for switching and setting a normal driving mode for driving with a certain degree of harmony between responsiveness, fuel consumption, and driving environment, and a fuel consumption priority driving mode for driving with priority on fuel consumption over the normal driving mode;
Required driving force setting means for setting required driving force required for traveling;
When the charge request for charging the power storage means is made, and when the normal travel mode is set by the mode switching setting means, the charge limit value obtained using the first relationship with respect to the detected vehicle speed The internal combustion engine, the generator, and the electric motor are controlled to run with the set required driving force while the power storage means is charged within a range, and a fuel consumption priority running mode is set by the mode switching setting means. The power storage is performed within a range of a charge limit value obtained using a second relationship in which electric power having a larger absolute value than the first relationship is obtained as the charge limit value with respect to the detected vehicle speed. Control means for controlling the internal combustion engine, the generator and the electric motor so as to travel with the set required driving force while the means is charged;
A hybrid car with   The hybrid vehicle according to claim 1, wherein the first relationship is a relationship in which electric power having a smaller absolute value is obtained as the charge limit value as the vehicle speed is smaller. A hybrid vehicle according to claim 1 or 2,
It is connected to three shafts, that is, a drive shaft coupled to an axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator, and the remaining power is determined based on power input / output to / from any two of the three shafts. Equipped with a three-axis power input / output means to input and output power to the shaft,
The electric motor can input and output power to the drive shaft.
Hybrid car. An internal combustion engine that outputs power for traveling, a generator that generates power using the power from the internal combustion engine, an electric motor that outputs power for traveling, and an electric storage means that exchanges electric power with the generator and the motor And mode switching setting means for switching and setting a normal driving mode for driving with a certain degree of harmony between responsiveness, fuel consumption, and driving environment, and a fuel consumption priority driving mode for driving with priority on fuel consumption over the normal driving mode. A hybrid vehicle control method comprising:
When the charge request for charging the power storage means is made, and when the normal travel mode is set by the mode switching setting means, the charge limit value is obtained within the range of the charge limit value obtained using the first relationship with respect to the vehicle speed. The internal combustion engine, the generator, and the electric motor are controlled to run with the required driving force required for running while the power storage means is charged, and the vehicle speed when the fuel consumption priority accompanying mode is set by the mode switching setting means In contrast, the request is made while the power storage means is charged within the range of the charge limit value obtained using the second relationship in which the power having a larger absolute value than the first relationship is obtained as the charge limit value. Controlling the internal combustion engine, the generator, and the electric motor so as to travel by driving force;
A control method for a hybrid vehicle.

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