JP2016159707A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a rise in the temperature of a motor.SOLUTION: When a traveling mode is set to a CS mode in which HV traveling in which an engine is run for traveling is given higher priority than EV traveling in which the engine is stopped and power from a motor is used for traveling, an electric W/P is controlled so that the electric W/P is driven at a driving level L designated using an HV unit water temperature Thv and ordinal driving map (steps S100, S110, and S130). When the traveling mode is set to a CD mode in which the EV traveling is given higher priority than the HV traveling, the electric W/P is controlled so that the electric W/P is driven at a driving level L designated to be higher at the same HV unit water temperature Thv than it is in the CS mode (steps S100, S120, and S130). Accordingly, a rise in the temperature of the motor in the CD mode can be suppressed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hybrid vehicle, and more specifically, an engine capable of outputting power for traveling, a motor capable of outputting power for traveling, a battery capable of supplying power to the motor, and pumping cooling water to the motor. And a cooling device having a cooling water pump.

  Conventionally, as this kind of vehicle, what is provided with a motor, a battery, and a cooling system is proposed (for example, refer to patent documents 1). The cooling system includes a pump that pumps cooling water to the motor. In this vehicle, when the operating point of the motor is in the second operating region where the output is larger than that in the first operating region, the cooling capacity of the cooling system is higher than when the operating point is in the first operating region. Increase the drive. Thereby, compared with what improves the cooling capacity of a motor uniformly, it is supposed that the power consumption of a pump can be reduced and the driving efficiency of the whole vehicle can be improved.

JP 2011-93424 A

  By the way, in a hybrid vehicle including a traveling engine and a motor, priority is given to hybrid traveling that travels using power from the engine and motor over electric traveling that travels using power from the motor with the engine stopped. The engine and the motor may be controlled to run in the hybrid travel priority mode, or the engine and the motor may be controlled to travel in the electric travel priority mode that prioritizes the electric travel over the hybrid travel. In the electric travel priority mode, since electric travel becomes frequent, the temperature of the motor tends to rise. As a technique for suppressing the temperature rise of the motor, a technique for enlarging the drive of the pump when actually carrying out electric driving can be considered. However, since it takes time until the cooling capacity actually increases after the drive of the pump is increased, if the drive of the pump of the cooling system is increased during actual electric running, the temperature of the motor will increase. There is a case.

  The main purpose of the hybrid vehicle of the present invention is to suppress an increase in the temperature of the motor.

  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 engine capable of outputting power for traveling;
A motor capable of outputting driving power;
A battery capable of supplying power to the motor;
A cooling system having a cooling water pump for pumping cooling water to the motor;
Control means for controlling the cooling water pump to be driven by a pump output based on at least one of a motor driving force output from the motor and the motor temperature;
A hybrid vehicle comprising:
The control means is in an electric travel priority mode that prioritizes an electric travel that travels using the power from the motor while stopping the engine over a hybrid travel that travels using the power from the engine and the motor. The means for increasing the pump output with respect to the same motor driving force and / or the motor temperature than in the hybrid traveling priority mode in which the hybrid traveling is prioritized over the electric traveling.
It is characterized by that.

  In the hybrid vehicle of the present invention, when in the electric travel priority mode that prioritizes the electric travel that travels using the power from the motor by stopping the operation of the engine rather than the hybrid travel that travels using the power from the engine and the motor, The pump output for the same motor driving force and / or motor temperature is increased compared to the hybrid travel priority mode in which hybrid travel is prioritized over electric travel. In the electric travel priority mode, the pump output is increased compared to the hybrid travel priority mode, regardless of whether the motor driving force has actually increased. Even when it takes time until the temperature increases, the increase in the temperature of the motor can be suppressed.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 5 is a flowchart showing an example of a cooling water flow rate control routine executed by the HVECU 70 in order to adjust the flow rate of cooling water flowing through the circulation flow path 64 of the HV unit cooling system 60.

  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, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, a charger 56, a hybrid electronic control unit (hereinafter referred to as a hybrid electronic control unit). 70).

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as a fuel. The engine 22 sucks the air cleaned by the air cleaner through the throttle valve and injects fuel from the fuel injection valve to mix the air and gasoline. Then, the air-fuel mixture is sucked into the combustion chamber via the intake valve. The engine 22 explodes and burns the sucked air-fuel mixture with an electric spark from the spark plug, and converts the reciprocating motion of the piston pushed down by the energy into the rotational motion of the crankshaft 26. Operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as engine ECU) 24.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 from an input port. Examples of signals from various sensors include the following. A crank angle θcr from a crank position sensor 23 that detects the rotational position of the crankshaft 26 of the engine 22. The throttle opening TH from the throttle valve position sensor that detects the throttle valve position. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through an output port. Examples of various control signals include the following. Drive signal to the fuel injection valve. Drive signal to the throttle motor that adjusts the throttle valve position. Control signal to the ignition coil integrated with the igniter. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 controls the operation of the engine 22 by a control signal from the HVECU 70. Further, the engine ECU 24 outputs data relating to the operating state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank angle θcr detected by the crank position sensor 23.

  The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of planetary gear 30 is connected to the rotor of motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37 and a rotor of the motor MG2. A crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30.

  The motor MG1 is configured as a synchronous generator motor, for example. As described above, the motor MG1 has a rotor connected to the sun gear of the planetary gear 30. The motor MG2 is configured as, for example, a synchronous generator motor. In the motor MG2, the rotor is connected to the drive shaft 36 as described above. The inverters 41 and 42 are connected to the power line 54 together with the battery 50. Motors MG1 and MG2 are rotationally driven by switching control of switching elements (not shown) of inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as motor ECU) 40.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for driving and controlling the motors MG1, MG2 are input to the motor ECU 40 via the input port. Examples of signals from various sensors include the following. Rotation positions θm1 and θm2 from rotation position detection sensors 43 and 44 that detect the rotation positions of the rotors of the motors MG1 and MG2. Phase current from a current sensor that detects current flowing in each phase of motors MG1 and MG2. The motor ECU 40 outputs a switching control signal to a switching element (not shown) of the inverters 41 and 42 through an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 controls driving of the motors MG1 and MG2 by a control signal from the HVECU 70. In addition, motor ECU 40 outputs data relating to the driving state of motors MG1 and MG2 to HVECU 70 as necessary. The motor ECU 40 calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 detected by the rotational position detection sensors 43, 44.

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the power line 54 together with the inverters 41 and 42 as described above. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52.

  The charger 56 is connected to the power line 54. The charger 56 is configured to charge the battery 50 using power from the external power source when the power plug 57 is connected to an external power source such as a household power source. The charger 56 includes an AC / DC converter and a DC / DC converter. The AC / DC converter converts AC power from an external power source supplied via the power plug 57 into DC power. The DC / DC converter converts the voltage of the DC power from the AC / DC converter and supplies it to the battery 50 side.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals from various sensors include the following. The battery voltage Vb from the voltage sensor 51a installed between the terminals of the battery 50. The battery current Ib from the current sensor 51b attached to the output terminal of the battery 50. The battery temperature Tb from the temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 outputs data relating to the state of the battery 50 to the HVECU 70 as necessary. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the battery current Ib detected by the current sensor 51b. The storage ratio SOC is a ratio of the capacity of power that can be discharged from the battery 50 to the total capacity of the battery 50. Further, the battery ECU 52 calculates the input / output limits Win and Wout based on the calculated storage ratio SOC and the battery temperature Tb detected by the temperature sensor 51c. The input / output limits Win and Wout are the maximum allowable power that may charge / discharge the battery 50.

  The HV unit cooling system 60 circulates the cooling water in this order through the radiator 62 that performs heat exchange between the cooling water (LLC (long life coolant)) and the outside air, the radiator 62, the inverters 42 and 41, and the motors MG1 and MG2. A flow path 64 and an electric water pump (W / P) 66 that pumps cooling water are provided. The radiator 62 is disposed at the forefront of an engine room (not shown).

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the HVECU 70 via input ports. Examples of signals from various sensors include the following. The HV unit water temperature Thv from the temperature sensor 69 that detects the temperature of the cooling water of the HV unit cooling system 60. An ignition signal from the ignition switch 80. A shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Accelerator opening degree Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83. The brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85. Vehicle speed V from the vehicle speed sensor 88. A drive signal to the electric W / P 66 of the HV unit cooling system 60 is output from the HVECU 70 via an output port. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port. The HVECU 70 exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

  In the hybrid vehicle 20 of the embodiment configured as described above, the vehicle travels by hybrid travel (HV travel) or travels by electric travel (EV travel). In HV traveling, the vehicle travels with the operation of the engine 22. In EV travel, the engine 22 is stopped and travels.

  When traveling in HV traveling, the HVECU 70 is first requested for traveling based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88 (should be output to the drive shaft 36). Set the required torque Tr *. Subsequently, the required torque Tr * is multiplied by the rotational speed Nr of the drive shaft 36 to calculate the traveling power Pdrv * required for traveling. Here, as the rotational speed Nr of the drive shaft 36, the rotational speed Nm2 of the motor MG2 and the rotational speed obtained by multiplying the vehicle speed V by a conversion factor can be used. Then, the required power Pe * required for the vehicle is calculated by subtracting the required charge / discharge power Pb * of the battery 50 (a positive value when discharging from the battery 50) from the travel power Pdrv *.

  Next, the target rotational speed Ne of the engine 22 is output so that the required power Pe * is output from the engine 22 and the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. * And target torque Te * and torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are set. Then, the target rotational speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40. When the engine ECU 24 receives the target rotational speed Ne * and the target torque Te * of the engine 22, the intake air of the engine 22 is operated so that the engine 22 is operated based on the received target rotational speed Ne * and the target torque Te *. Perform quantity control, fuel injection control, ignition control, etc. When motor ECU 40 receives torque commands Tm1 * and Tm2 * of motors MG1 and MG2, motor ECU 40 performs switching control of switching elements of inverters 41 and 42 so that motors MG1 and MG2 are driven by torque commands Tm1 * and Tm2 *. . During traveling in HV traveling, when the required power Pe * reaches less than the threshold value Pref, it is determined that the stop condition for the engine 22 has been established, and the operation of the engine 22 is stopped to shift to traveling in EV traveling. .

  During travel in EV travel, the HVECU 70 first sets the required torque Tr *, as in travel in HV travel. Subsequently, a value 0 is set in the torque command Tm1 * of the motor MG1. Then, the torque command Tm2 * of the motor MG2 is set so that the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. Then, torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40. When motor ECU 40 receives torque commands Tm1 * and Tm2 * of motors MG1 and MG2, motor ECU 40 performs switching control of switching elements of inverters 41 and 42 so that motors MG1 and MG2 are driven by torque commands Tm1 * and Tm2 *. . During this EV traveling, when the required power Pe * calculated in the same manner as during HV traveling reaches or exceeds the threshold value Pref, it is determined that the engine 22 start condition is satisfied, and the engine 22 is started. To shift to HV traveling.

  In the hybrid vehicle 20 according to the embodiment, the HVECU 70 receives a connection detection signal from the connection detection sensor (the power plug 57 is connected to an external power source) while the system is off at home or at a preset charging point. And) using the power from the external power source, the charger 56 is controlled so that the battery 50 is in a fully charged state or a predetermined charged state slightly lower than that. Then, when the system is started after the battery 50 is charged, the EV travel that prioritizes the EV travel over the HV travel until the storage ratio SOC of the battery 50 reaches a threshold value Shv (for example, 25%, 30%, 35%, etc.) After traveling in the priority mode (CD (Charge Depleting) mode) and the storage ratio SOC of the battery 50 reaches the threshold value Shv or less, the HV traveling priority mode (CS (Charge Sustaining) mode) giving priority to the HV traveling over the EV traveling. ). In the embodiment, in the CD mode, the threshold value Pref is made sufficiently larger than in the CS mode, so that the EV driving is prioritized over the HV driving in the CD mode. In this case, HV driving is given priority over EV driving. Also, in the CD mode, the upper limit of the power that can be output during EV traveling is increased by increasing the output limit Wout compared to the CS mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation of the HV unit cooling system 60 will be described. FIG. 2 is a flowchart showing an example of a cooling water flow rate control routine executed by the HVECU 70 in order to adjust the flow rate of the cooling water flowing through the circulation flow path 64 of the HV unit cooling system 60. This routine is repeatedly executed every predetermined time (for example, every several hundred msec).

  When this routine is executed, the HVECU 70 first executes a process for checking the travel mode (step S100). When the traveling mode is the CS mode, the drive level L of the electric W / P 66 is set using the HV unit water temperature Thv from the temperature sensor 69 and a normal operation map (not shown) (step S110). The normal operation map is a map that defines the relationship between the HV unit water temperature Thv and the drive level L, and is stored in advance in the ROM of the HVECU 70. In the normal operation map, when the HV unit water temperature Thv is lower than the threshold value TH1, the drive level L is set to “low”. Further, when the HV unit water temperature Thv is equal to or higher than the threshold TH1 and lower than the threshold TH2, which is higher than the threshold TH1, the drive level L is set to “medium” where the output is larger than “low”. When the HV unit water temperature Thv is equal to or higher than the threshold value TH2, the drive level L is set to “high”, which is larger in output than “medium”.

  When the drive level L is set in this way, the electric W / P 66 is controlled to drive at the drive level L (step S130), and this routine is terminated. Since the cooling water having a flow rate corresponding to the HV unit water temperature Thv can be circulated through the circulation flow path 64, the motors MG1, MG2, and the inverters 41, 42 can be favorably cooled.

  When the running mode is the CD mode (step S100), the temporary drive level Ltmp set using the HV unit water temperature Thv from the temperature sensor 69 and the normal operation map is set to the upper limit Lmax ( A level that does not exceed “high”) is set to the drive level L of the electric W / P 66 (step S120), and the electric W / P 66 is controlled to drive at the drive level L (step S130). This routine is terminated. That is, the drive level L is set to “medium” when the temporary drive level Ltmp is “low”, is set to “high” when the temporary drive level Ltmp is “medium”, and the temporary drive level Ltmp is “high”. Sometimes set to “high”. The temporary drive level is the same as the drive level in the CS mode for the same HV unit water temperature Thv. Therefore, in the process of step S120, when the CS mode drive level L for the same HV unit water temperature Thv is not “high”, the cooling water amount is larger for the same HV unit water temperature Thv than in the CS mode. This is a process of setting the drive level L. Further, when the drive level L in the CS mode for the same HV unit water temperature Thv is “high”, the process is to maintain the drive level L at “high”. Next, the reason for setting the drive level L in this way will be described.

  In the CD mode, the upper limit of power that can be output during EV traveling is increased by sufficiently increasing the output limit Wout. Therefore, the temperatures of the motor MG2 and the inverter 42 are likely to rise as compared with the CS mode. By the way, in the HV unit cooling system 60, even if the output of the electric W / P 66 is increased, it takes time until the cooling capacity is actually increased. Therefore, when the driving force of the motor MG2 or the inverter 42 actually increases, the electric W Even if the output of / P66 is increased, the temperature of the motor MG2 and the inverter 42 may increase. In the embodiment, in the CD mode, regardless of whether or not the driving force of the motor MG2 and the inverter 42 is actually increased, the pump output is increased with respect to the same HV unit water temperature Thv than in the CS mode. Thus, the increase in the temperature of the motor MG2 and the inverter 42 can be suppressed by increasing the amount of cooling water.

  According to the hybrid vehicle 20 of the embodiment described above, in the CD mode, the electric W / P 66 is driven for the same HV unit water temperature Thv so that the output of the pump is larger than in the CS mode. The temperature rise of the motor MG2 and the inverter 42 can be suppressed.

  In the hybrid vehicle 20 of the embodiment, the temporary drive level Ltmp set using the HV unit water temperature Thv and the normal operation map in the process of step S120 is the upper limit Lmax (“high”) of the drive level L for normal operation. However, the provisional drive level Ltmp is fixed to the upper limit Lmax (“high”) of the drive level L for normal operation. Alternatively, a drive level L that exceeds the upper limit Lmax of the drive level L for normal operation may be set.

  In the hybrid vehicle 20 of the embodiment, in the processing of steps S110 and S120, the driving level L is set to three stages of “low”, “medium”, and “high” using the HV unit water temperature Thv. It is good also as what sets to a stage more than a stage, and it is good also as what sets the drive amount of electric W / P66 so that the HV unit water temperature Thv becomes high.

  In the hybrid vehicle 20 of the embodiment, the drive level L is set using the HV unit water temperature Thv in the processing of steps S110 and S120. However, the temperature of the motor MG2, the temperature of the inverter 42, and the torque command Tm2 of the motor MG2 The drive level L may be set using *. In this case, the temperature may be set so as to increase as the temperature of the motor MG2, the temperature of the inverter 42, and the torque command Tm2 * increase.

  In the hybrid vehicle 20 of the embodiment, when the traveling mode is the CS mode, the electric W / P 66 is controlled so that the electric W / P 66 is driven at the driving level L set using the HV unit water temperature Thv and the normal operation map. When the driving mode is the CD mode, the electric W / P 66 is controlled so that the electric W / P 66 is driven at the driving level L set to be higher than that in the CS mode with respect to the same HV unit water temperature Thv. It was. However, when the traveling mode is the CS mode, the electric W / P 66 is driven so that the HV unit water temperature Thv becomes the target water temperature Thvtag1, and when the traveling mode is the CD mode, the target water temperature Thvtag2 where the HV unit water temperature Thv is lower than the target water temperature Thvtag1. The electric W / P 66 may be driven so that In this way, in the CD mode, the drive amount of the electric W / P 66 can be made larger for the same HV unit water temperature Thv than in the CS mode.

  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 “engine”, the motor MG2 corresponds to “motor”, the battery 50 corresponds to “battery”, the HV unit cooling system 60 corresponds to “cooling system”, and the HVECU 70 It corresponds to “control means”.

  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. In other words, the interpretation of the invention described in the column of means for solving the problem 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 problem. 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 is applicable to the hybrid vehicle manufacturing industry and the like.

  20 Hybrid Vehicle, 22 Engine, 23 Crank Position Sensor, 24 Electronic Control Unit for Engine (Engine ECU), 26 Crankshaft, 30 Planetary Gear, 36 Drive Shaft, 37 Differential Gear, 38a, 38b Drive Wheel, 40 Electronic Control Unit for Motor (Motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line, 56 charging , 57 Power plug, 60 HV unit cooling system, 62 Radiator, 64 Circulating flow path, 66 Electric water pump, 69 Temperature sensor, 70 Hybrid electronic control unit (HVECU), 8 0 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, MG1, MG2 motor.

Claims (1)

An engine capable of outputting power for traveling;
A motor capable of outputting driving power;
A battery capable of supplying power to the motor;
A cooling system having a cooling water pump for pumping cooling water to the motor;
Control means for controlling the cooling water pump to be driven by a pump output based on at least one of a motor driving force output from the motor and the motor temperature;
A hybrid vehicle comprising:
The control means is in an electric travel priority mode that prioritizes an electric travel that travels using the power from the motor while stopping the engine over a hybrid travel that travels using the power from the engine and the motor. The means for increasing the pump output with respect to the same motor driving force and / or the motor temperature than in the hybrid traveling priority mode in which the hybrid traveling is prioritized over the electric traveling.
A hybrid vehicle characterized by that.

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