JP2012096584A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of energy efficiency as a whole vehicle, while suppressing excessive temperature rise of an electric motor in an object equipped with a mechanical oil pump which supplies cooling liquid to a cooling object which is driven by an internal combustion engine and contains an electric motor.SOLUTION: When an operation stop prohibition flag F, in which a value 1 is set, when an engine operation stop is forbidden, while a value 0 is set, when intermittent operation of the engine is carried out, is value 0 (S310), value 1 is set to the operation stop prohibition flag F, when the motor temperature Tmo reaches more than the predetermined temperature Tmoref (S330). When the set operation stop prohibition flag F is value 0, the engine and two motors are controlled to run, while carrying out intermittent operation of the engine, and when the operation stop prohibition flag F is value 1, the engine and two motors are controlled to run while continuing operation of the engine.

Description

  The present invention relates to a hybrid vehicle, and more specifically, an internal combustion engine capable of outputting power to a first axle, and an electric motor capable of outputting power to a first axle or a second axle different from the first axle, The present invention relates to a hybrid vehicle including a secondary battery capable of exchanging electric power with an electric motor, and a mechanical oil pump that is driven by an internal combustion engine and supplies a cooling liquid to a cooling target including the electric motor.

  Conventionally, this type of hybrid vehicle is a vehicle that can run using the power from the engine and the power from the motor, and that does not automatically stop the engine when a motor lock (rotation stop) is detected. (For example, refer nonpatent literature 1).

INSIGHT Service Manual Structure (7-8), Honda Motor Co., Ltd., February 2009

  In such a hybrid vehicle, in which the cooling oil is supplied to the motor by a mechanical oil pump driven by the engine and the motor is cooled, when the motor lock is detected, the engine is continuously stopped without being automatically stopped. When the motor is operated, the cooling oil is continuously supplied to the motor, so that an increase in the temperature of the motor due to the current flowing only in a specific phase of the motor can be suppressed. However, even when the motor lock is detected, when the motor does not need to be cooled with the cooling oil, such as when the motor temperature is low, the engine may be run wastefully. Energy efficiency will deteriorate.

  A hybrid vehicle according to the present invention includes a mechanical oil pump that is driven by an internal combustion engine and supplies a cooling liquid to a cooling target including an electric motor. The hybrid vehicle suppresses an excessive increase in temperature of the electric motor and increases energy efficiency of the entire vehicle. The main purpose is to suppress the decline.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An internal combustion engine capable of outputting power to a first axle, an electric motor capable of outputting power to the first axle or a second axle different from the first axle, and exchange of electric power with the motor are possible. A hybrid vehicle comprising: a secondary battery; and a mechanical oil pump that is driven by the internal combustion engine and supplies a cooling liquid to a cooling target including the electric motor,
Required driving force setting means for setting required driving force required for traveling;
When the temperature of the electric motor is lower than a predetermined temperature set as a lower limit of a temperature range in which the temperature rise of the electric motor is to be suppressed, the internal combustion engine is caused to travel with the set required driving force while being intermittently operated. When the temperature of the electric motor is equal to or higher than the predetermined temperature, the internal combustion engine and the electric motor are controlled so as to run with the set required driving force while the internal combustion engine is continuously operated. Control means for
It is a summary to provide.

  In the hybrid vehicle of the present invention, when the temperature of the motor is lower than a predetermined temperature set as the lower limit of the temperature range in which the temperature rise of the motor should be suppressed, the required driving force required for traveling while the internal combustion engine is intermittently operated is used. The internal combustion engine and the electric motor are controlled to run, and when the temperature of the electric motor is equal to or higher than a predetermined temperature, the internal combustion engine and the electric motor are controlled to run with the required driving force while the internal combustion engine is continuously operated. Therefore, when the temperature of the electric motor is equal to or higher than the predetermined temperature, it is possible to suppress an excessive increase in the temperature of the electric motor by continuously operating the internal combustion engine. Further, when the temperature of the electric motor is low, by intermittently operating the internal combustion engine, fuel consumption can be suppressed as compared with the case where the operation of the internal combustion engine is continued, and the energy efficiency of the entire vehicle is reduced. Can be suppressed.

  In such a hybrid vehicle of the present invention, the control means is means for starting the internal combustion engine when the temperature of the electric motor becomes equal to or higher than the predetermined temperature in a state where the operation of the internal combustion engine is stopped. You can also

  In the hybrid vehicle of the present invention, when the driving force is output from the electric motor and the rotor of the electric motor stops rotating, the control means has the temperature of the electric motor equal to or higher than the predetermined temperature. It can also be a means for controlling the internal combustion engine to be continuously operated. In this aspect of the hybrid vehicle of the present invention, the control means is configured such that when the driving force is output from the motor on an uphill road and the rotor of the motor stops rotating, the temperature of the motor exceeds the predetermined temperature. At this time, the internal combustion engine may be a means for controlling the engine to be continuously operated.

  Further, in the hybrid vehicle of the present invention, there are three generators that can input and output power, a drive shaft connected to the first axle, an output shaft of the internal combustion engine, and a rotary shaft of the generator. It can also be a planetary gear mechanism in which two rotating elements are connected.

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 explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the collinear diagram which shows the dynamic relationship between the rotation speed and torque in the rotation element of the power distribution integration mechanism 30 when drive | working in motor operation mode. 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. It is explanatory drawing which shows an example of the collinear diagram which shows the dynamic relationship between the rotation speed and torque in the rotation element of the power distribution integration mechanism 30 when drive | working by engine operation mode. 5 is a flowchart showing an example of an operation stop prohibition flag setting routine executed by a hybrid electronic control unit 70. 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. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example.

  Next, the form for implementing this invention is demonstrated using an Example.

  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 configured as an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and a crankshaft 26 serving as an output shaft of the engine 22. A carrier 34 that connects a plurality of pinion gears 33 is connected via a damper 28, and a ring gear 32 is connected to a ring gear shaft 32a as a drive shaft that is connected to drive wheels 63a and 63b via a differential gear 62 and a gear mechanism 60. As a well-known synchronous generator motor having a three-shaft power distribution and integration mechanism 30 connected and configured as a planetary gear mechanism, and a rotor in which a permanent magnet is embedded and a stator around which a three-phase coil is wound, for example. A motor MG1 having a rotor connected to the sun gear 31 of the power distribution and integration mechanism 30; For example, the rotor is connected to a ring gear shaft 32a as a drive shaft via a reduction gear 35, which is configured as a known synchronous generator motor having a rotor embedded with permanent magnets and a stator wound with a three-phase coil. Motor MG2 and inverters 41 and 42 for driving motors MG1 and MG2, and a battery 50 that is configured as, for example, a lithium ion secondary battery and exchanges power with motors MG1 and MG2 via inverters 41 and 42. And a hybrid electronic control unit 70 for controlling the entire vehicle.

  A mechanical oil pump 23 is attached to the crankshaft 26 of the engine 22. The mechanical oil pump 23 is driven by the engine 22 and supplies cooling oil (automatic transmission fluid: ATF) stored in an oil pan below the vehicle to cooling targets such as the power distribution and integration mechanism 30 and the motors MG1 and MG2. To do. The cooling oil supplied to the object to be cooled returns to the oil pan by gravity.

  The engine 22 is subjected to operation control such as intake air amount adjustment control, fuel injection control, and ignition control by an engine electronic control unit (hereinafter referred to as engine ECU) 24. 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 outputs various control signals for controlling the operation of the engine 22, for example, a drive control signal for a throttle valve, a fuel injection valve, a spark plug, and a variable valve timing mechanism. 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 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 has a signal necessary for managing the battery 50, for example, an inter-terminal voltage from a voltage sensor (not shown) installed between terminals of the battery 50, and an illustration attached to an output terminal on the positive side of the battery 50. The charging / discharging current from the current sensor, the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input, and data regarding the state of the battery 50 is communicated to the hybrid electronic control unit 70 as necessary. Output. In addition, the battery ECU 52 manages the battery 50, and the power storage that is the ratio of the stored power amount stored in the battery 50 based on the integrated value of the charge / discharge current detected by the current sensor to the total capacity (power storage capacity). The ratio SOC is calculated, and the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limiting limit are set based on the storage ratio 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 a shift position from a shift position sensor 82 that detects the motor temperature Tmo from the temperature sensor 48 that detects the temperature of the motor MG2, the ignition signal from the ignition switch 80, and the operation position of the shift lever 81. SP, accelerator pedal position Acc from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83, brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, and vehicle speed from the vehicle speed sensor 88 V or the like is input through 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 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 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 sum of the required power and the power required for charging and discharging the battery 50 The engine 22 is operated and controlled so that power corresponding to the 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 performed by the power distribution and integration mechanism 30 and the motor MG1. The required power is converted to the ring gear shaft 3 by torque conversion with the motor MG2. a charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to a, and a motor operation 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. There are modes. Note that both the torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the ring gear shaft 32a with the operation of the engine 22. Can be considered as an engine operation mode.

  Next, the operation of the thus configured hybrid vehicle 20 of the embodiment 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 milliseconds) except when the engine 22 is started.

  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, a value 0 is set when the engine 22 may be intermittently operated, and an operation stop prohibition flag is set when a value 1 is set when the operation stop of the engine 22 should be prohibited (the operation of the engine 22 should be continued) A process of inputting data necessary for control such as F is executed (step S100). 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. Further, the operation stop prohibition flag F is read and inputted by the one set by the operation stop prohibition flag setting routine described later.

  When the data is thus input, the required torque Tr * 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 input accelerator opening Acc and the vehicle speed V. And the required power Pe * required for the vehicle is set (step S110). 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. 3 shows an example of the required torque setting map. The required power Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * required by the battery 50 and the loss Loss. 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, the value of the operation stop prohibition flag F is checked (step S120). Hereinafter, the case where the operation stop prohibition flag F is 0, that is, the case where the engine 22 may be intermittently operated, will be described. Explain when. When the operation stop prohibition flag F is 0, it is determined whether the engine 22 is operating or stopped (step S130). When the engine 22 is stopped, the required power Pe * is determined as the engine power. Compared with a threshold value Pstart determined as a lower limit of the range of the required power Pe * that should be started to efficiently operate the engine 22 (step S140), when the required power Pe * is less than the threshold value Pstart, 22 is determined to be continued, and a value 0 is set for the torque command Tm1 * of the motor MG1 (step S150), and the required torque Tr * is divided by the gear ratio Gr of the reduction gear 35. The torque command Tm2 * of the motor MG2 is set (step S160), and the set torque command T of the motors MG1 and MG2 is set. 1 *, and sends the Tm2 * to the motor ECU 40 (step S170), the routine ends. The motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. By such control, it is possible to travel by outputting the required torque Tr * from the motor MG2 to the ring gear shaft 32a as the drive shaft. FIG. 4 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30 when traveling in the motor operation mode. 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.

  When the required power Pe * is greater than or equal to the threshold value Pstart in step S140, it is determined that the engine 22 should be started, and the engine 22 is started (step S180). Here, the engine 22 is started by outputting torque from the motor MG1 and outputting torque from the motor MG2 for canceling torque output to the ring gear shaft 32a as a drive shaft in accordance with the output of this torque. This is performed by cranking the engine 22 and starting fuel injection control, ignition control, etc. when the rotational speed Ne of the engine 22 reaches a predetermined rotational speed (for example, 1000 rpm). During the start of the engine 22, the drive control of the motor MG2 is performed so that the required torque Tr * is output to the ring gear shaft 32a. That is, the torque to be output from the motor MG2 is to cancel the torque for outputting the required torque Tr * to the ring gear shaft 32a and the torque acting on the ring gear shaft 32a when the engine 22 is cranked by the motor MG1. This is the sum of the torque and the torque.

  When the engine 22 is started, a target rotational speed Ne * and a target torque Te * are set as operating points at which the engine 22 should be operated based on the required power Pe * and an operation line for operating the engine 22 efficiently (step S200), 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 by the following equation (1): Formula (2) is calculated 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. To calculate the torque command Tm1 * to be output from the motor MG1 (step S210). 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 *). Expression (1) is a dynamic relational expression for the rotating elements of the power distribution and integration mechanism 30. FIG. 6 shows an example of a collinear diagram showing the dynamic relationship between the rotation speed and torque in the rotating elements of the power distribution and integration mechanism 30 when traveling in the engine operation mode. In the figure, two thick arrows on the R axis indicate that torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and torque Tm2 output from the motor MG2 is applied to the ring gear shaft 32a via the reduction gear 35. And acting torque. Expression (1) can be easily derived by using this alignment chart. 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, a torque command Tm2 * to be output from the motor MG2 by adding the torque command Tm1 * divided by the gear ratio ρ of the power distribution and integration mechanism 30 to the required torque Tr * and further dividing by the gear ratio Gr of the reduction gear 35. Is calculated by the following equation (3) (step S220), the target rotational speed Ne * and the target torque Te * of the engine 22 are determined by the engine ECU 24, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are determined by the motor ECU 40. Each is transmitted (step S230), and this routine is finished. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * adjusts 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 control, fuel injection control, and ignition control are performed. By such control, the required power Pe * can be efficiently output from the engine 22, and the required torque Tr * can be output to the ring gear shaft 32a as the drive shaft for traveling. Here, Expression (3) can be easily derived from the alignment chart of FIG.

  Tm2 * = (Tr * + Tm1 * / ρ) / Gr (3)

  When traveling using the power from the engine 22 is started in this way, the next time this routine is executed, if the operation stop prohibition flag F is 0 in step S120, the engine 22 is in operation in step S130. The determined power Pe * is compared with the threshold value Pstop defined as the upper limit of the required power Pe * that is better to stop the engine 22 in order to operate the engine 22 efficiently (step S190), and the required power Pe. When * is larger than the threshold value Pstop, it is determined that it is better to continue the operation of the engine 22, and the target rotational speed Ne *, the target torque Te *, the motor MG1, MG2 of the engine 22 are determined by the processing of steps S200 to S230 described above. Torque commands Tm1 *, Tm2 * of the engine ECU 24 and motor ECU 4 When the required power Pe * is equal to or less than the threshold value Pstop, it is determined that it is better to stop the operation of the engine 22, and the operation of the engine 22 is stopped (step S240). Through the processing of S150 to S170, torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are set and transmitted to the motor ECU 40, and this routine is terminated. Note that a value slightly smaller than the threshold value Pstart is used as the threshold value Pstop.

  When the operation stop prohibition flag F is 1 in step S120, that is, when the operation stop of the engine 22 should be prohibited, it is determined whether the engine 22 is operating or operation stopped (step S250). When the operation is stopped, the engine 22 is started in the same manner as in step S180 described above (step S260). The starting of the engine 22 has been described above.

  When the engine 22 is started, or when it is determined in step S250 that the engine 22 is in operation, the required power Pe * is compared with a threshold value Pstop (step S270), and when the required power Pe * is greater than the threshold value Pstop, Through the processing of steps S200 to S230 described above, the target rotational speed Ne *, target torque Te *, and torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set and transmitted to the engine ECU 24 and the motor ECU 40, When this routine is finished and the required power Pe * is equal to or less than the threshold value Pstop, the idle speed Nidl is set to the target speed Ne * of the engine 22 so that the engine 22 operates independently, and the target torque Te * of the engine 22 is set. A value of 0 is set (step S280) and the motor MG1 torque is 0 is set to the torque command Tm1 * (step S290), the torque command Tm2 * of the motor MG2 is set (step S220), and the target engine speed Ne * and the target torque Te * of the engine 22 are set to the engine ECU 24. The torque commands Tm1 * and Tm2 * for MG1 and MG2 are transmitted to the motor ECU 40 (step S230), and this routine ends.

  The drive control has been described above. Next, processing for setting the operation stop prohibition flag F used in this drive control will be described. FIG. 7 is a flowchart showing an example of an operation stop prohibition flag setting routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec) in parallel with the drive control routine of FIG.

  When the operation stop prohibition flag setting routine is executed, the CPU 72 of the hybrid electronic control unit 70 inputs the motor temperature Tmo that is the temperature of the motor MG2 from the temperature sensor 48 (step S300), and the value of the operation stop prohibition flag F (Step S310), and when the operation stop prohibition flag F is 0, the motor temperature Tmo is compared with a predetermined temperature Tmoref determined as the lower limit of the temperature range lower than the allowable temperature Tmomax (step S320). Here, the predetermined temperature Tmoref is determined as the lower limit of the temperature range in which the temperature increase of the motor MG2 is to be suppressed so that the motor temperature Tmo does not exceed the allowable temperature Tmomax. For example, the allowable temperature Tmomax is 220 ° C. or 230 ° C. 180 ° C., 190 ° C., 200 ° C., etc. can be used when the temperature is 240 ° C., etc. When the motor temperature Tmo is lower than the predetermined temperature Tmoref, this routine is terminated as it is. When the motor temperature Tmo is equal to or higher than the predetermined temperature Tmoref, the operation stop prohibition flag F is set to 1 (step S330), and this routine is terminated. When the value 1 is set in the operation stop prohibition flag F in this way, as described above, the engine 22 is continuously operated regardless of the required power Pe *, so that the mechanical oil pump 23 is driven to integrate power distribution. Cooling oil is supplied to cooling objects such as the mechanism 30 and the motors MG1, MG2. Thereby, the excessive temperature rise of motor temperature Tmo can be suppressed.

  When the operation stop prohibition flag F is a value 1 in step S310, the motor temperature Tmo is compared with a temperature that is lower than the predetermined temperature Tmoref by a margin α (for example, 5 ° C., 10 ° C., 15 ° C., etc.) (step S340). When Tmo is equal to or higher than the temperature (Tmoref-α), this routine is terminated. When the motor temperature Tmo is lower than the temperature (Tmoref-α), the operation stop prohibition flag F is set to 0 (step S350). End the routine. If the operation stop prohibition flag F is frequently switched, the start / stop frequency of the engine 22 is likely to increase when the required power Pe * is in the vicinity of the threshold value Pstart and the threshold value Pstop. The margin α is for providing hysteresis so that the value of the operation stop prohibition flag F is not frequently switched.

  Now, when the accelerator pedal 83 is depressed and held on the uphill road and the vehicle is stopped, a certain amount of torque is output from the motor MG2 on the uphill road, and the rotor of the motor MG2 stops rotating. Think about the time. At this time, a large current flows only in a specific phase of the three-phase coil wound around the stator of the motor MG2, so that the motor temperature Tmo is likely to rise. Therefore, if the engine 22 is continuously operated when the motor MG2 is stopped rotating, the cooling oil is continuously supplied to the motor MG2 and the like by the mechanical oil pump 23, and the motor temperature Tmo is increased. Can be suppressed. However, at this time, if the engine 22 is continuously operated regardless of the motor temperature Tmo, when the motor temperature Tmo is low and the required power Pe * is also small, that is, it is not necessary to cool the motor MG2 and the engine 22 When the engine can be stopped, the engine is wasted, and the energy efficiency of the entire vehicle is deteriorated. Therefore, in the embodiment, it is not determined whether the motor MG2 has stopped rotating, but the motor temperature Tmo is used to prohibit the engine 22 from being stopped when the motor temperature Tmo reaches a predetermined temperature Tmoref (the engine 22 Subsequently, the engine 22 is allowed to intermittently operate when the motor temperature Tmo reaches a temperature (Tmoref-α). As a result, an excessive increase in the motor temperature Tmo can be suppressed and a decrease in energy efficiency of the entire vehicle can be suppressed. In the present invention, a case where a certain amount of torque is output from the motor MG2 on the uphill road and the rotor of the motor MG2 stops rotating has been described. However, a certain amount of torque is output from the uphill road or the motor MG2. However, the present invention is not limited to the case where the rotor of the motor MG2 stops rotating, and may be any engine that continuously operates the engine 22 when the motor temperature Tmo is equal to or higher than the predetermined temperature Tmoref.

  According to the hybrid vehicle 20 of the embodiment described above, when the motor temperature Tmo is lower than the predetermined temperature Tmoref, the engine 22 and the motor are driven so as to run with the required torque Tr * while the engine 22 is intermittently operated according to the required power Pe *. When MG1 and MG2 are controlled and the motor temperature Tmo rises above the predetermined temperature Tmoref, the engine 22 and the motor MG1 are driven so as to run with the required torque Tr * while the engine 22 is continuously operated regardless of the required power Pe *. Since MG2 is controlled, an excessive increase in motor temperature Tmo can be suppressed and a decrease in energy efficiency of the entire vehicle can be suppressed.

  In the hybrid vehicle 20 of the embodiment, the hysteresis is given to the motor temperature Tmo when the value of the operation stop prohibition flag F is switched from the value 0 to the value 1 and when the value is switched from the value 1 to the value 0. Such hysteresis may not be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the motor MG2 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b. As described above, the power output from the motor MG2 is output to an axle (an axle connected to the wheels 64a and 64b in FIG. 8) different from an axle (an axle connected to the driving wheels 63a and 63b) to which the driving shaft is connected. It is good.

  In the hybrid vehicle 20 of the embodiment, the power from 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, and the power from the motor MG2 is output to the ring gear shaft. The motor MG is attached to the drive shaft connected to the drive wheels 63a and 63b via the transmission 230 as illustrated in the hybrid vehicle 220 of the modified example of FIG. The engine 22 is connected to the rotation shaft via the clutch 229, and the power from the engine 22 is output to the drive shaft via the rotation shaft of the motor MG and the transmission 230 and the power from the motor MG is transmitted to the transmission 230. It is good also as what outputs to a drive shaft via. Further, as illustrated in the hybrid vehicle 320 of the modification of FIG. 10, the power from the engine 22 is output to the axle connected to the drive wheels 63a and 63b via the transmission 330 and the power from the motor MG is driven. It is good also as what outputs to the axle different from the axle connected to wheel 63a, 63b (the axle connected to wheel 64a, 64b in FIG. 10).

  The correspondence between the main elements of the embodiment 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 MG2 corresponds to the “electric motor”, the battery 50 corresponds to the “secondary battery”, and the mechanical oil pump 23 corresponds to the “mechanical oil pump”. Correspondingly, the hybrid electronic control that executes the processing of step S110 of the drive control routine of FIG. 2 for setting the required torque Tr * to be output to the ring gear shaft 32a as the struggle shaft based on the accelerator opening Acc and the vehicle speed V The unit 70 corresponds to “required driving force setting means”. When the motor temperature Tmo, which is the temperature of the motor MG2, is less than the predetermined temperature Tmoref, the operation stop prohibition flag F is set to 0, and the motor temperature Tmo is equal to or higher than the predetermined temperature Tmoref. After that, the motor temperature Tmo is lower than the predetermined temperature Tmoref by a margin α (Tmoref−α). The operation stop prohibition flag setting routine of FIG. 7 for setting the value 1 to the operation stop prohibition flag F is executed until it reaches less than the value, and when the operation stop prohibition flag F is the value 0, the requested torque Tr while the engine 22 is intermittently operated. * The target engine speed Ne * and target torque Te * of the engine 22 and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set as necessary and transmitted to the engine ECU 24 and the motor ECU 40 to stop the operation. When the prohibition flag F is 1, the target engine speed Ne *, the target torque Te *, the motor MG1, and the motor MG1, so that the engine 22 runs with the required torque Tr * while continuously operating regardless of the required power Pe *. The drive control routine shown in FIG. 2 is executed in which MG2 is set and transmitted to the engine ECU 24 and the motor ECU 40. The hybrid electronic control unit 70, an engine ECU 24 that controls the engine 22 based on the target rotational speed Ne * and the target torque Te * when receiving the target rotational speed Ne * and the target torque Te *, and a torque command Tm1 The motor ECU 40 that controls the motors MG1 and MG2 based on the torque commands Tm1 * and Tm2 * when receiving * and Tm2 * corresponds to “control means”.

  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, but can output power to the first axle such as a hydrogen engine. Any type of internal combustion engine may be used. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and can output power to the first axle or a second axle different from the first axle, such as an induction motor. Any type of electric motor may be used. The “secondary battery” is not limited to the battery 50 configured as a lithium ion secondary battery, and can exchange electric power with an electric motor such as a nickel hydride secondary battery, a nickel cadmium secondary battery, or a lead storage battery. Any type of secondary battery may be used. 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 the required torque Tr * based only on the accelerator opening Acc. Any device may be used as long as it sets a required torque required for traveling, such as a setting device. 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. As the “control means”, when the motor temperature Tmo, which is the temperature of the motor MG2, is less than the predetermined temperature Tmoref, the operation stop prohibition flag F is set to 0, and when the motor temperature Tmo reaches or exceeds the predetermined temperature Tmoref Until the motor temperature Tmo reaches a temperature lower than the predetermined temperature Tmoref by a margin α (Tmoref−α), a value of 1 is set in the operation stop prohibition flag F. When the set operation stop prohibition flag F is a value of 0, the engine 22 The target rotational speed Ne * and target torque Te * of the engine 22 and torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set as necessary so that the engine 22 travels with the required torque Tr * while intermittently operating. When the motors MG1 and MG2 are controlled and the operation stop prohibition flag F is a value 1, the required power Regardless of Pe *, the engine 22 and the motor MG1, the engine 22 and the motor MG1, are set by setting the target rotational speed Ne *, the target torque Te *, and the motors MG1 and MG2 so that the engine 22 travels with the required torque Tr *. It is not limited to the one that controls MG2, and when the temperature of the electric motor is lower than a predetermined temperature, the internal combustion engine and the electric motor are controlled so that the internal combustion engine travels with the required driving force while being intermittently operated. When the temperature of the electric motor is equal to or higher than the predetermined temperature, the internal combustion engine and the electric motor may be controlled as long as the internal combustion engine is continuously operated and travels with the required driving force.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, 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.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

  20, 120, 220, 320 Hybrid vehicle, 22 engine, 23 mechanical oil pump, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution and 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, 48 temperature 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 hybrid electronic control unit, 72 CPU, 7 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, 229 Clutch, 230, 330 Transmission , MG, MG1, MG2 motors.

Claims (5)

An internal combustion engine capable of outputting power to a first axle, an electric motor capable of outputting power to the first axle or a second axle different from the first axle, and exchange of electric power with the motor are possible. A hybrid vehicle comprising: a secondary battery; and a mechanical oil pump that is driven by the internal combustion engine and supplies a cooling liquid to a cooling target including the electric motor,
Required driving force setting means for setting required driving force required for traveling;
When the temperature of the electric motor is lower than a predetermined temperature set as a lower limit of a temperature range in which the temperature rise of the electric motor is to be suppressed, the internal combustion engine is caused to travel with the set required driving force while being intermittently operated. When the temperature of the electric motor is equal to or higher than the predetermined temperature, the internal combustion engine and the electric motor are controlled so as to run with the set required driving force while the internal combustion engine is continuously operated. Control means for
A hybrid car with The hybrid vehicle according to claim 1,
The control means is means for starting the internal combustion engine when the temperature of the electric motor becomes equal to or higher than the predetermined temperature in a state where the operation of the internal combustion engine is stopped.
Hybrid car. A hybrid vehicle according to claim 1 or 2,
The control means is configured to continuously operate the internal combustion engine when a driving force is output from the electric motor and the temperature of the electric motor is equal to or higher than the predetermined temperature when the rotor of the electric motor stops rotating. Is a means to control,
Hybrid car. A hybrid vehicle according to claim 3,
The control means is configured to continue the internal combustion engine when a driving force is output from the motor on an uphill road and the motor temperature is equal to or higher than the predetermined temperature when the rotor of the motor stops rotating. Means to control to be driven,
Hybrid car. A hybrid vehicle according to any one of claims 1 to 4,
A generator capable of inputting and outputting power;
A planetary gear mechanism in which three rotating elements are connected to three axes of a driving shaft coupled to the first axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator;
A hybrid car with

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