JP2013162558A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge air mixed into a circulation path of a cooling device when turning a system off while traveling.SOLUTION: When a braking operation or a steering operation is detected (S120, S130) when a system is turned off (S110) while traveling, first control is executed (S140, S150) such that an electric pump operates over a predetermined time t1 and one phase energization of an inverter is performed, when an element temperature of the inverter exceeds a temperature threshold value ( S160, S170) while the first control is being executed, second control is executed (S180, S190) such that one phase energization of the inverter is stopped and the electric pump operates over a predetermined time t2. That is, mixing of air into the circulation path is decided by observing a rise in element temperature of the inverter while the first control is being executed, and the mixed air is discharged via a reserve tank by executing the second control.

Description

  The present invention relates to an automobile, and more specifically, cooling so that a coolant circulates in a circulation path including a traveling motor, an inverter having a switching element and driving the motor, and a reserve tank for cooling the motor and the inverter. The present invention relates to an automobile including a cooling device having an electric pump for pumping liquid, and control means that can be controlled so that energization of an inverter and operation of the electric pump are performed regardless of whether the system is off.

  Conventionally, as this type of automobile, cooling water is circulated in a circulation passage including a reserve tank for cooling a traveling motor and the motor and a PCU (Power Control Unit) for driving the motor. A cooling system having a water pump, and when it is determined that there is a history that the electrical connection between the in-vehicle battery and the ECU (Electronic Control Unit) of the vehicle is in a disconnected state, There has been proposed one that detects that cooling water has been introduced and operates a water pump (see, for example, Patent Document 1). In this automobile, therefore, cooling water is introduced at the time of manufacturing or maintenance of the vehicle, and the air remaining in the circulation path is removed through the vent hole of the reserve tank.

JP 2005-57953 A

  In the above-mentioned automobile, when the vehicle system is turned off due to, for example, a user's erroneous switch operation during traveling, air may be mixed into the circulation flow path due to a sudden braking operation or steering wheel operation. In this case, if the state where air is mixed in the circulation flow path when the system is turned on again, the cooling performance by the cooling water may deteriorate, or the wear of the rotating shaft of the water pump may progress. there were. For this reason, it is desirable to be able to discharge air mixed in the circulation channel when the system is turned off during traveling.

  The main object of the automobile of the present invention is to discharge air mixed in the circulation path of the cooling device when the system is turned off during traveling.

  The automobile of the present invention has taken the following means in order to achieve the main object described above.

The automobile of the present invention
An electric pump that pumps the coolant so that the coolant circulates in a circulation path including a reserve tank for cooling the motor and an inverter having a switching element and driving the motor, and the motor and the inverter In a motor vehicle comprising: a cooling device having control means; and control means that can be controlled so that energization of the inverter and operation of the electric pump are performed regardless of system off,
The control means is configured such that when the system is turned off during traveling, when the brake operation or the steering operation is detected, the electric pump is operated for a first predetermined time and the inverter is energized. And when the temperature of the switching element becomes equal to or higher than a predetermined temperature threshold during the execution of the first control, the energization of the inverter is stopped and Means for executing a second control for controlling the inverter and the electric pump so that the electric pump is operated over a second predetermined time;
It is characterized by that.

  In the automobile of the present invention, when the system is turned off during traveling and the brake operation or the steering operation is detected, the inverter is operated so that the electric pump is operated and the inverter is energized for a first predetermined time. When the temperature of the switching element becomes equal to or higher than a predetermined temperature threshold during the execution of the first control, the energization of the inverter is stopped and the second predetermined control is performed. The second control is performed to control the inverter and the electric pump so that the electric pump operates over time. That is, it is possible to determine the possibility that air has entered the circulation path of the cooling device by detecting a brake operation or a steering operation when the system is turned off during traveling, and during the execution of the first control, the switching element of the inverter By determining the temperature rise, it is determined that air has entered the circulation path of the cooling device, and by executing the second control, the air mixed in the cooling device is discharged through the reserve tank. Thereby, the air mixed in the circulation path of the cooling device when the system is turned off during traveling can be discharged.

  Here, the “first predetermined time” may be a predetermined time or the like for determining the possibility that air has entered the circulation path of the cooling device by a brake operation or a steering operation. The time required for the coolant of the cooling device to go around the circulation path can be used. The “energization of the inverter” can be performed, for example, by turning on a one-phase switching element of the inverter. The “temperature threshold value” may be a predetermined threshold value for determining that air has entered the circulation path of the cooling device. The “second predetermined time” can be a predetermined time for discharging the air mixed in the circulation path of the cooling device, for example, the cooling liquid of the cooling device goes around the circulation path. It is possible to use the time required for The “second control” may be executed after the first control for the first predetermined time (after the first predetermined time elapses), or the first control for the first predetermined time. May be executed (before the first predetermined time has elapsed). The “traveling motor” includes a motor that outputs traveling power, a motor as a generator that generates electric power used as traveling power, and the like.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 3 is a flowchart showing an example of a system-off time control routine executed by an HVECU 70. It is explanatory drawing which shows an example of the mode of the time change of the drive state of the inverter 42, and its element temperature when forced operation of the electric pump 66 and the one-phase electricity supply of the inverter 42 are performed over predetermined time t1. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. It is a block diagram which shows the outline of a structure of the electric vehicle 220 of a modification.

  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 drawing, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline or light oil as a fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, an engine, and the like. A planetary gear 30 having a carrier connected to the crankshaft 26 and a ring gear connected to a drive shaft 36 connected to the drive wheels 38a and 38b via a differential gear 37, and a rotor configured as a synchronous generator motor. Motor MG1 connected to the sun gear of planetary gear 30, motor MG2 configured as a synchronous generator motor and having a rotor connected to drive shaft 36, and an inverter that drives motors MG1 and MG2 by switching of a plurality of switching elements (not shown) 41, 42 and Inva A motor electronic control unit (hereinafter referred to as a motor ECU) 40 for driving and controlling the motors MG1 and MG2 by switching control of the plurality of switching elements 41 and 42, and an inverter 41 configured as, for example, a lithium ion secondary battery. , 42, the battery 50 that exchanges power with the motors MG1, MG2, the battery electronic control unit (hereinafter referred to as battery ECU) 52 that manages the battery 50, and the motors MG1, MG2 and the inverters 41, 42 are cooled. A cooling device 60 and a hybrid electronic control unit (hereinafter referred to as HVECU) 70 for controlling the entire vehicle are provided.

  Here, the inverter 41 has a total of six switching elements (for example, transistors), two for each of the U-phase, V-phase, and W-phase of the motor MG1, and 6 connected in parallel to the six switching elements in the reverse direction. The six switching elements are arranged in pairs so that they are on the source side and the sink side with respect to the positive and negative buses of the power line from the battery 50, and Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor MG1 is connected to each connection point of the switching elements. Inverter 42 also includes six switching elements (for example, transistors), two for each of the U-phase, V-phase, and W-phase of motor MG2, and six switching elements connected in parallel in the reverse direction. Each of the six switching elements is arranged in pairs so as to be a source side and a sink side with respect to a positive electrode bus and a negative electrode bus of the power line from the battery 50 to form a pair. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor MG2 is connected to each connection point between the switching elements.

  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. . The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a water temperature sensor that detects the crank position θcr from the crank position sensor that detects the rotational position of the crankshaft 26 and the coolant temperature of the engine 22. Cooling water temperature Twe from the cylinder, in-cylinder pressure Pin from a pressure sensor installed in the combustion chamber, cam from a cam position sensor that detects the rotational position of an intake valve that performs intake and exhaust to the combustion chamber and a camshaft that opens and closes the exhaust valve Position θca, throttle position TP from a throttle valve position sensor that detects the position of the throttle valve, intake air amount Qa from an air flow meter attached to the intake pipe, intake air temperature Ta from a temperature sensor also attached to the intake pipe, Take the exhaust system The air-fuel ratio AF from the attached air-fuel ratio sensor, the oxygen signal O2 from the oxygen sensor attached to the exhaust system, and the like are input via the input port, and the engine ECU 24 is for driving the engine 22. Various control signals, such as the drive signal to the fuel injection valve, the drive signal to the throttle motor that adjusts the throttle valve position, the control signal to the ignition coil integrated with the igniter, and the opening / closing timing of the intake valve can be changed A control signal to the variable valve timing mechanism is output via the output port. The engine ECU 24 is in communication with the HVECU 70, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data related to the operation state of the engine 22 to the HVECU 70 as necessary. 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 signal from a crank position sensor (not shown) attached to the crankshaft 26.

  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. . The motor ECU 40 has temperature sensors 41u, 41v, which detect signals necessary for driving and controlling the motors MG1, MG2, for example, the temperatures of the switching elements of the respective phases (U phase, V phase, W phase) of the inverter 41. The element temperatures Tsu1, Tsv1, Tsw1 from the element 41w and the element temperatures Tsu2, Tsv2, Tsw2 from the temperature sensors 42u, 42v, 42w for detecting the temperature of the switching element of each phase (U phase, V phase, W phase) of the inverter 42 , Rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 for detecting the rotational positions of the rotors of the motors MG1 and MG2, phase currents applied to the motors MG1 and MG2 detected by a current sensor (not shown), and the like are input. It is input via the port, and the motor ECU 40 switches on the inverters 41 and 42 (not shown). A switching control signal to the switching element is output via the output port. The motor ECU 40 is in communication with the HVECU 70, controls the driving of the motors MG1 and MG2 by a control signal from the HVECU 70, and outputs data related to the operating state of the motors MG1 and MG2 to the HVECU 70 as necessary. The motor ECU 40 also calculates the rotational angular velocities ωm1, ωm2 and 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 from the rotational position detection sensors 43, 44. ing.

  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. . The battery ECU 52 receives signals necessary for managing the battery 50, for example, an inter-terminal voltage Vb from a voltage sensor (not shown) installed between the terminals of the battery 50 and a power line connected to the output terminal of the battery 50. The charging / discharging current Ib from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor (not shown) attached to the battery 50, and the like are input. Send to. Further, in order to manage the battery 50, the battery ECU 52 is a power storage that is a ratio of the capacity of the electric power that can be discharged from the battery 50 at that time based on the integrated value of the charge / discharge current Ib detected by the current sensor. 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.

  Cooling device 60 is disposed at the foremost part of an engine room (not shown), radiator 62 that performs heat exchange between cooling water (LLC (long life coolant)) and outside air, radiator 62 is disposed, and motors MG1, MG2 and inverter 41, A circulating flow path 64 through which cooling water circulates for cooling with 42, an electric pump 66 that pumps the cooling water so that the cooling water circulates in the circulating flow path 64, and air mixed in the circulating flow path 64 (air ) To the outside, a reserve tank 67 provided at a predetermined height position in the circulation flow path 64 (for example, the highest position of the circulation flow path 64), the electric pump 66, and the like are not shown. A relay 68 that electrically connects and disconnects the auxiliary battery. The auxiliary battery is connected to the battery 50 via a DC / DC converter (not shown) that steps down the power of the battery 50.

  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. The HVECU 70 has a cooling water temperature Twm from the temperature sensor 69 that detects the rotation speed Np of the electric pump 66 from the rotation speed sensor 66 a that detects the rotation speed of the electric pump 66 of the cooling device 60 and the cooling water temperature of the cooling device 60. In addition, the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, the 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 depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, the steering angle θs from the steering angle sensor 89 that detects the steering amount of the steering wheel (steering wheel), etc. Input port To have been input. Further, from the HVECU 70, a control signal to the electric pump 66 of the cooling device 60, a drive signal to the relay 68, and the like are output 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, and 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 thus configured, the required torque Tr * to be output to the drive shaft 36 is calculated based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver. 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 Tr * is output to the drive shaft 36. As the 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 the power output from the engine 22 is transmitted to the planetary gear 30 and the motor. The torque conversion operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the torque is converted by the MG1 and the motor MG2 and output to the drive shaft 36, and the sum of the required power and the power required for charging and discharging the battery 50 is met. Operation of the engine 22 is controlled so that power is output from the engine 22, and all or part of the power output from the engine 22 with charge / discharge of the battery 50 is torque generated by the planetary gear 30, the motor MG1, and the motor MG2. The required power is output to the drive shaft 36 with conversion. Charge-discharge drive mode for driving and controlling the motors MG1 and MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 36. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22, the motor MG1, and the motor MG2 are controlled so that the required power is output to the drive shaft 36 with the operation of the engine 22. Since there is no substantial difference in control, both are hereinafter referred to as the engine operation mode.

  In the engine operation mode, the HVECU 70 sets the required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88, and the set required torque The travel power Pdrv * required for travel is calculated by multiplying Tr * by the rotational speed Nr of the drive shaft 36 (for example, the rotational speed obtained by multiplying the rotational speed Nm2 of the motor MG2 and the vehicle speed V by the conversion factor). The power to be output from the engine 22 by subtracting the charge / discharge required power Pb * (positive value when discharging from the battery 50) of the battery 50 obtained from the calculated traveling power Pdrv * based on the storage ratio SOC of the battery 50 Is set as the required power Pe *. Then, the target rotational speed Ne of the engine 22 is obtained using an operation line (for example, a fuel efficiency optimal operation line) as a relationship between the rotational speed Ne of the engine 22 and the torque Te that can efficiently output the required power Pe * from the engine 22. * And the target torque Te * are set, and the motor is controlled by the rotational speed feedback control so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne * within the range of the input / output limits Win and Wout of the battery 50. A torque command Tm1 * as a torque to be output from MG1 is set, and when the motor MG1 is driven by the torque command Tm1 *, the torque acting on the drive shaft 36 via the planetary gear 30 is subtracted from the required torque Tr * to reduce the motor MG2. Torque command Tm2 * is set, and the target rotational speed Ne * and target torque Te * are set. In its sent to the engine ECU 24, the torque command Tm1 *, the Tm2 * is sent to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te *, controls the intake air amount, fuel injection control, and ignition of the engine 22 so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te *. The motor ECU 40 that performs the control and receives the torque commands Tm1 * and Tm2 * performs switching control of the plurality of switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. .

  In the motor operation mode, the HVECU 70 sets a required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V, sets a value 0 to the torque command Tm1 * of the motor MG1, and sets the battery 50. The torque command Tm2 * of the motor MG2 is set and transmitted to the motor ECU 40 so that the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win, Wout. The motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the plurality of switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  In the hybrid vehicle 20 of the embodiment configured as described above, the target rotational speed at which the electric pump 66 should be rotated based on the cooling water temperature Twm as the temperature of the cooling water in the circulation passage 64 of the cooling device 60 during traveling. In addition to setting Np *, a drive command value D (for example, a duty ratio) corresponding to the target rotation speed Np * is set, and the electric pump 66 is driven at the drive command value D so that the electric pump 66 rotates at the target rotation speed Np *. By controlling, the cooling water is circulated in the circulation flow path 64 to cool the motors MG1, MG2 and the inverters 41,. Here, the drive command value D of the electric pump 66 can be set using a map in which the relationship between the target rotational speed Np * and the drive command value D is determined in advance and stored in a ROM (not shown). As for the target rotational speed Np * of 66, a predetermined map is stored in a ROM (not shown) so that the target rotational speed Np * becomes higher as the cooling water temperature Twm becomes higher as the relationship between the cooling water temperature Twm and the target rotational speed Np *. If the cooling water temperature Twm is given, it can be set by deriving the corresponding target rotational speed Np * from the stored map. In this embodiment, the target rotational speed Np * is set to increase in three stages in the order of the minimum rotational speed Npmin, the intermediate rotational speed Npmid, and the maximum rotational speed Npmax as the cooling water temperature Twm increases.

  Next, the operation of the hybrid vehicle 20 of the embodiment, particularly the operation when the system is turned off during traveling will be described. FIG. 2 is a flowchart showing an example of a system-off time control routine executed by the HVECU 70. This routine is executed when the system of the vehicle is turned off, for example, when the driver turns off the ignition by operating the ignition switch 80. In the embodiment, when the vehicle is turned off, the connection between the battery 50 and the inverters 41 and 42 is released when the operation of the engine 22 is stopped and the motors MG1 and MG2 (inverters 41 and 42) are stopped. This is done by turning off the system main relay and turning off the relay 68 so that the power supply from the auxiliary battery to the electric pump 66 is cut off. Prior to execution of this routine, the system main relay and the relay 68 are turned on. In addition, the system main relay and the relay 68 are turned off when the execution of this routine is finished. Further, when the system is turned off in this way, the HVECU 70 and the motor ECU 40 can be operated so as to be able to input and output various signals upon receiving power supply from the auxiliary battery.

  When the system off time control routine is executed, the CPU of the HVECU 70 first performs control such as the brake pedal position BP from the brake pedal position sensor 86, the vehicle speed V from the vehicle speed sensor 88, and the steering angle θs from the steering angle sensor 89. Necessary data is input (step S100), it is determined whether the input vehicle speed V is greater than 0 (step S110), and a brake operation is performed based on the input brake pedal position BP and the steering angle θs. Whether or not there is a steering operation is executed (step S120). The determination of the vehicle speed V is for determining whether or not the vehicle is traveling. The determination of the brake operation and the determination of the steering operation are for determining (detecting) whether or not the brake operation or the steering operation has been performed when the system is turned off during traveling. It is determined (detected) that the brake operation has been performed when the pedal position BP is greater than 0, and it is determined (detected) that the steering operation has been performed when the absolute value of the steering angle θs is greater than 0.

  When the vehicle speed V is 0, it is determined that the vehicle is stopped. When the brake operation and the steering operation are not detected even when the vehicle speed V is greater than 0, this routine is terminated.

  When the vehicle speed V is greater than 0 and a brake operation or steering operation is detected, the system is turned off during traveling, and air is passed through the reserve tank 67 into the circulation passage 64 of the cooling device 60 by the brake operation or steering operation. The motor MG2 side inverter is started by forcibly starting the electric pump 66 to rotate at the maximum rotation speed Npmax (step S140) and transmitting an instruction signal to the motor ECU 40. One-phase energization is started to turn on two switching elements of one phase (for example, U phase) 42 (step S150).

  Subsequently, when the predetermined time t1 has not elapsed, the element temperatures of the two switching elements in the phase in which the one-phase energization of the inverter 42 is performed (for example, the element temperature Tsu2 of the U phase detected by the temperature sensor 42U). Is input from the motor ECU 40 to monitor (monitor) the element temperature for a predetermined time t1 after starting the forced operation of the electric pump 66 and the one-phase energization of the inverter 42 (step S160). A predetermined temperature threshold value (for example, 120 ° C. or 130 ° C.) determined in advance by an experiment or the like to determine that the element temperature monitored over t1 is mixed in the circulation flow path 64. It is determined whether or not the above has been reached (step S170). Here, the predetermined time t1 is for determining the possibility that air is mixed into the circulation flow path 64 of the cooling device 60 by the brake operation or the steering operation. In the embodiment, the electric pump 66 is operated at the maximum rotational speed. As the time required for the cooling water of the cooling device 60 to make a round of the circulation flow path 64 when rotating at Npmax, a time (for example, several tens of seconds) obtained in advance by experiments or the like is used.

  When the element temperature monitored over the predetermined time t1 is less than the temperature threshold (when it has never been higher than the temperature threshold), it is determined that air is not mixed in the circulation flow path 64, and this routine is performed. Exit. At this time, the forced operation of the electric pump 66 and the one-phase energization of the inverter 42 are stopped.

  When the element temperature monitored over the predetermined time t1 is equal to or higher than the temperature threshold (when it is equal to or higher than the temperature threshold even once), it is determined that air is mixed in the circulation flow path 64; By transmitting an instruction signal to the motor ECU 40, one-phase energization of the inverter 42 is stopped (step S180), and the electric pump 66 is forced to operate at a maximum rotation speed Npmax for a predetermined time t2 ( Step S190), this routine is finished. Here, the predetermined time t2 is for discharging air mixed in the circulation flow path 64 of the cooling device 60. In the embodiment, the cooling water of the cooling device 60 goes around the circulation flow path 64 once. As the necessary time, the same time (for example, several tens of seconds) as the predetermined time t1 obtained in advance by experiments or the like is used.

  FIG. 3 is an explanatory diagram showing an example of a time change state of the drive state of the inverter 42 and its element temperature when the forced operation of the electric pump 66 and the one-phase energization of the inverter 42 are executed over a predetermined time t1. It is. As shown in the figure, when the forced operation of the electric pump 66 and the one-phase energization of the inverter 42 are started at time t11, the cooling water circulates in the circulation flow path 64 by the forced operation of the electric pump 66 and enters the circulation flow path 64. When air is mixed, the cooling of the inverter 42 is performed at a timing when the air mixed in the circulation flow path 64 passes through the inverter 42 before a predetermined time t1 when the cooling water goes around the circulation flow path 64 elapses. Since the performance temporarily decreases, the element temperature of the phase in which the one-phase energization of the inverter 42 is performed becomes equal to or higher than the temperature threshold. Thereafter, the one-phase energization of the inverter 42 is stopped at time t12, and the element temperature of the inverter 42 decreases.

  As described above, when it is determined that there is a possibility that air is mixed in the circulation flow path 64 of the cooling device 60 by performing a brake operation or a steering operation when the system is turned off during traveling, the electric pump The first control is executed for the predetermined time t1 required for the cooling water to circulate in the circulation passage 64 by circulating the cooling water in the circulation passage 64 by the forced operation of 66 and the one-phase energization of the inverter 42. , And whether or not the element temperature of the phase in which the one-phase energization of the inverter 42 is performed during the execution of the first control has become equal to or higher than the temperature threshold value, Can be determined. If it is determined that air has entered the circulation flow path 64, the forced operation of the electric pump 66 is further performed for a predetermined time t2 required for the circulation of the cooling water in the circulation flow path 64 ( Since the second control is continued, the air mixed in the circulation flow path 64 is separated into gas and liquid via the reserve tank 67 and discharged to the outside at the timing when the air passes through the reserve tank 67. it can. Moreover, by executing the second control over the predetermined time t2, the cooling water makes two rounds in the circulation flow path 64, so that the mixed air can be discharged more reliably.

  According to the hybrid vehicle 20 of the embodiment described above, when the system is turned off during traveling and the brake operation or the steering operation is detected, the electric pump 66 is operated for a predetermined time t1 and the inverter 42 is turned on. When the first control for controlling the inverter 42 and the electric pump 66 is performed so that the one-phase energization is performed, and the element temperature of the inverter 42 becomes equal to or higher than the temperature threshold during the execution of the first control, the inverter 42 The second control is executed to control the inverter 42 and the electric pump 66 so that the electric pump 66 is operated for a predetermined time t2 while the one-phase energization is stopped. That is, by detecting a brake operation or a steering operation when the system is turned off during traveling, it is possible to determine the possibility that air has entered the circulation flow path 64 of the cooling device 60, and during the execution of the first control. By observing the temperature rise of the switching element of the inverter 42, it is determined that air has entered the circulation flow path 64 of the cooling device 60, and the second control is executed, thereby mixing in the circulation flow path 64. Since the air is discharged through the reserve tank 67, the air mixed in the circulation flow path 64 of the cooling device 60 when the system is turned off during traveling can be discharged. As a result, for example, when the system is turned on again by a driver's switch operation or the like during traveling, the cooling performance of the cooling device 60 decreases due to air being mixed in the circulation flow path 64 or the electric pump 66. The progress of wear of the rotating shaft can be suppressed.

  In the hybrid vehicle 20 of the embodiment, it is determined whether the brake operation or the steering operation has been performed based on the brake pedal position BP and the steering angle θ input when the system is turned off. Whether or not a brake operation or a steering operation has been performed based on the maximum value of the brake pedal position BP and the maximum absolute value of the steering angle θ input during a certain period of time (for example, several seconds). It may be determined.

  In the hybrid vehicle 20 of the embodiment, one-phase energization of the inverter 42 is performed, but two-phase energization or three-phase energization of the inverter 42 may be performed. In this case, it is possible to monitor the element temperatures of all the energized phases, and to execute the second control described above when any element temperature is equal to or higher than the temperature threshold.

  In the hybrid vehicle 20 of the embodiment, the one-phase energization of the inverter 42 on the motor MG2 side is performed. However, the element temperature of the inverter 41 may be monitored by performing the one-phase energization of the inverter 41 on the motor MG1 side. .

  In the hybrid vehicle 20 of the embodiment, the temperature sensor is provided for each of the two switching elements of each phase of the inverters 41 and 42. However, the temperature of the switching element is detected one by one for each of the inverters 41 and 42. A temperature sensor may be provided.

  In the hybrid vehicle 20 of the embodiment, as the predetermined time t1 and the predetermined time t2, the time necessary for the cooling water to go around the circulation channel 64 is used, but a longer time may be used.

  In the hybrid vehicle 20 of the embodiment, the forcible operation of the electric pump 66 and the one-phase energization of the inverter 42 are executed (continued) for a predetermined time t1, but the forcible operation of the electric pump 66 and one of the inverters 42 are performed. When the element temperature of the inverter 42 becomes equal to or higher than the temperature threshold before the predetermined time t1 has elapsed since the start of phase energization, the one-phase energization of the inverter 42 is stopped (that is, the first control described above). And the forced operation over the predetermined time t2 of the electric pump 66 may be executed (that is, the second control described above is executed).

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 4, a motor MG is attached to the drive shaft 36 connected to the drive wheels 38a and 38b via the transmission 130, and a clutch 129 is attached to the rotation shaft of the motor MG. The engine 22 is connected to the motor 22 through the rotation shaft of the motor MG and the transmission 130 to the drive shaft, and the power from the motor MG is output to the drive shaft through the transmission 130. It may be output. Alternatively, as illustrated in the electric vehicle 220 of the modified example of FIG. 5, the engine MG is output without the engine, and the power from the motor MG is output to the drive shaft connected to the drive wheels 38 a and 38 b via the transmission 230. It is good. In other words, the present invention may be applied to any type of hybrid vehicle or electric vehicle.

  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, when the motor MG2 corresponds to the “motor”, the inverter 42 corresponds to the “inverter”, the cooling device 60 having the electric pump 66 and the reserve tank 67 corresponds to the “cooling device”, and the system is turned off. However, by turning on the system main relay and relay 68, the inverter 42 can be energized and the electric pump 66 can be operated, and when it is determined that the system is off and the vehicle is running, the system main relay and the relay 68 are operated for a predetermined time t1. The forced operation of the electric pump 66 and the instruction of the one-phase energization of the inverter 42 are performed, and when the element temperature of the inverter 42 becomes equal to or higher than the temperature threshold value for a predetermined time t1, the one-phase energization of the inverter 42 is stopped. 2 is executed to execute the forced operation of the electric pump 66 for a predetermined time t2. And VECU70, a motor ECU40 for turning on and off the switching elements of the inverter 42 corresponds to a "control unit".

  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 automobile manufacturing industry.

  20, 120 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 40 motor electronic control unit (motor ECU) ), 41, 42 Inverter, 41u, 41v, 41w, 42u, 42v, 42w Temperature sensor, 43, 44 Rotation position detection sensor, 50 Battery, 52 Electronic control unit for battery (battery ECU), 60 Cooling device, 62 Radiator, 64 Circulating flow path, 66 Electric pump, 66a Rotational speed sensor, 67 Reserve tank, 68 Relay, 69 Temperature sensor, 70 Electronic control unit for hybrid (HVECU), 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 Steering angle sensor, 129 Clutch, 130, 230 Transmission, 220 Electric vehicle, MG , MG1, MG2 motor.

Claims (1)

A motor for traveling, an inverter having a switching element and driving the motor, an electric pump for pumping the coolant so that the coolant circulates in the circulation path for cooling the motor and the inverter, and the circulation path In a motor vehicle comprising a cooling device having a reserve tank disposed in the control unit, and control means that can be controlled so that energization of the inverter and operation of the electric pump are performed regardless of system off,
The control means is configured such that when the system is turned off during traveling, when the brake operation or the steering operation is detected, the electric pump is operated for a first predetermined time and the inverter is energized. And when the temperature of the switching element becomes equal to or higher than a predetermined temperature threshold during the execution of the first control, the energization of the inverter is stopped and Means for executing a second control for controlling the inverter and the electric pump so that the electric pump is operated over a second predetermined time;
A car characterized by that.