JP2008167633A - Vehicle and control method therefor - Google Patents

Abstract

In a vehicle including a motor connected to a drive wheel via a clutch and an inverter for driving the motor, overheating of the motor and the inverter is suppressed.
When the absolute value of the rotational speed Nm of the motor is less than or equal to a threshold value Nref (S130), an excess prediction time tref is set so as to decrease as the required torque Td * increases (S190), and the absolute value of the rotational speed Nm. When the rotation stop duration tms, which is a time equal to or less than the threshold value Nref, becomes equal to or greater than the excess predicted time tref (S210), the clutch is turned off (S220), and then the motor rotation shaft rotates and the three-phase coil of the motor When the state of the phase current is changed, the clutch is turned on (S250).
[Selection] Figure 3

Description

  The present invention relates to a vehicle and a control method thereof.

Conventionally, this type of vehicle includes a motor connected to drive wheels and an inverter that drives the motor, and the vehicle stops on an uphill and the traveling motor outputs torque but rotates. There has been proposed one that changes the phase of the phase current to the motor by gradually reducing the torque from the motor and moving the vehicle backward when the locked state is reached (see, for example, Patent Document 1). In this vehicle, by changing the phase of the phase current to the motor in this way, the switching elements of the motor and the inverter are prevented from overheating.
JP 11-215687 A

  In addition to the hardware configuration of the vehicle described above, even in a vehicle including a clutch between the motor and the drive wheel, it is a problem to suppress overheating of the motor and the inverter when the vehicle is locked, as in the vehicle described above. It is considered as one of

  A vehicle and a control method thereof according to the present invention include a connection release device for connecting and releasing a connection between a rotating shaft of a motor and a drive shaft connected to a drive wheel, and overheating a motor and a drive circuit that drives the motor. It aims at suppressing.

  The vehicle and the control method thereof according to the present invention employ the following means in order to achieve the above-described object.

The vehicle of the present invention
An electric motor that outputs driving force;
Connection release means for connecting and releasing the connection between the rotating shaft of the electric motor and the drive shaft connected to the drive wheel;
Drive control means for controlling the electric motor so that a driving force based on a required driving force required for traveling is output from the electric motor;
Based on the driving force output from the motor when the rotating shaft of the motor is connected to the driving shaft and the absolute value of the rotating speed of the motor is not more than a predetermined rotating speed including a value of 0. Excess prediction time setting means for setting an excess prediction time which is a time predicted that the temperature of the electric motor exceeds a predetermined temperature;
When the rotation stop state continues for the set estimated excess time, the connection release control is executed to control the connection release means so that the connection between the rotating shaft and the drive shaft is released, and the connection A connection release control means for executing connection control for controlling the connection release means so that the rotating shaft and the drive shaft are connected when a predetermined connection release end condition is satisfied after executing the release control;
It is a summary to provide.

  In the vehicle of the present invention, the motor is controlled so that the driving force based on the required driving force required for traveling is output from the motor, and the rotation shaft of the motor and the driving shaft are connected, so that the absolute number of rotations of the motor can be reduced. When the value is equal to or less than a predetermined number of revolutions including the value 0, an excess predicted time is set based on the driving force output from the motor and the motor temperature is predicted to exceed the predetermined temperature. When the stop state continues for the estimated excess time, a connection release control is performed to control the connection release means so that the connection between the rotating shaft and the drive shaft is released, and after the connection release control is executed, a predetermined connection is established. When the release end condition is satisfied, connection control is executed to control the connection release means so that the rotating shaft and the drive shaft are connected. That is, when the rotation stop state continues for the excess estimated time based on the driving force output from the electric motor, the connection between the rotating shaft and the driving shaft is released, and then the predetermined disconnection termination condition is satisfied. The rotary shaft and the drive shaft are reconnected. If the connection between the rotating shaft and the drive shaft is released while outputting the driving force from the motor while the rotation is stopped, the rotating shaft of the motor will rotate, so the state of the phase current flowing through the motor will change. In addition, overheating of the electric motor and the drive circuit that drives the electric motor can be suppressed. In addition, since the excess prediction time is set according to the driving force output from the electric motor, the drive output from the electric motor is compared with that using a certain time as the excessive prediction time regardless of the driving force output from the electric motor. It is possible to set an estimated excess time that reflects power. Here, the “predetermined temperature” includes a temperature lower than the allowable temperature of the electric motor and the drive circuit.

  In such a vehicle of the present invention, the excess predicted time setting means may be a means for setting the excess predicted time so that the greater the driving force output from the electric motor, the shorter the tendency. This is based on the reason that the greater the driving force output from the motor, the greater the current that is passed through the motor so that the driving force is output, and the temperature of the motor and the drive circuit that drives the motor is likely to rise. .

  In the vehicle of the present invention, the electric motor is a multiphase AC electric motor, and the predetermined disconnection termination condition is that the rotation shaft of the electric motor performs the disconnection control when the phase current of the electric motor is in the state. It can also be the conditions which rotated more than the minimum rotation amount used as the state different from the state of the previous phase current. If it carries out like this, overheating of the drive circuit which drives an electric motor and an electric motor can be suppressed more appropriately.

  Further, in the vehicle of the present invention, a braking force applying means for applying a braking force to the driving wheel, and a braking force is applied to the driving wheel from the execution of the connection release control to the execution of the connection control. And braking force application control means for controlling the braking force application means. If it carries out like this, when connection cancellation | release control is performed in the state which the vehicle has stopped on the slope, it can suppress that a vehicle moves to the reverse direction to the advancing direction.

The vehicle control method of the present invention includes:
A vehicle control method comprising: an electric motor that outputs a driving force; and a connection release unit that performs connection and release of a connection between a rotating shaft of the electric motor and a drive shaft coupled to a drive wheel,
Controlling the electric motor so that a driving force based on a required driving force required for traveling is output from the electric motor;
Based on the driving force output from the motor when the rotating shaft of the motor is connected to the driving shaft and the absolute value of the rotating speed of the motor is not more than a predetermined rotating speed including a value of 0. And setting an excess prediction time, which is a time when the temperature of the motor is predicted to exceed a predetermined temperature,
When the rotation stop state continues for the set estimated excess time, the connection release control is executed to control the connection release means so that the connection between the rotating shaft and the drive shaft is released, and the connection Executing a connection control for controlling the connection release means so that the rotating shaft and the drive shaft are connected when a predetermined connection release end condition is satisfied after the release control is executed;
This is the gist.

  In the vehicle of the present invention, the motor is controlled so that the driving force based on the required driving force required for traveling is output from the motor, and the rotation shaft of the motor and the driving shaft are connected, so that the absolute number of rotations of the motor can be reduced. When the value is equal to or less than a predetermined number of revolutions including the value 0, an excess predicted time is set based on the driving force output from the motor and the motor temperature is predicted to exceed the predetermined temperature. When the stop state continues for the estimated excess time, a connection release control is performed to control the connection release means so that the connection between the rotating shaft and the drive shaft is released, and after the connection release control is executed, a predetermined connection is established. When the release end condition is satisfied, connection control is executed to control the connection release means so that the rotating shaft and the drive shaft are connected. That is, when the rotation stop state continues for the excess estimated time based on the driving force output from the electric motor, the connection between the rotating shaft and the driving shaft is released, and then the predetermined disconnection termination condition is satisfied. The rotary shaft and the drive shaft are reconnected. If the connection between the rotating shaft and the drive shaft is released while outputting the driving force from the motor while the rotation is stopped, the rotating shaft of the motor will rotate, so the state of the phase current flowing through the motor will change. In addition, overheating of the electric motor and the drive circuit that drives the electric motor can be suppressed. In addition, since the excess prediction time is set according to the driving force output from the electric motor, the drive output from the electric motor is compared with that using a certain time as the excessive prediction time regardless of the driving force output from the electric motor. It is possible to set an estimated excess time that reflects power. Here, the “predetermined temperature” includes a temperature lower than the allowable temperature of the electric motor and the drive circuit.

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

  FIG. 1 is a configuration diagram showing an outline of a configuration of an electric vehicle 20 as an embodiment of the present invention. As shown in the drawing, the electric vehicle 20 according to the embodiment includes a motor 22, an inverter 24 that drives the motor 22 using electric power from the battery 26, and power output to the rotating shaft 23 of the motor 22 as drive wheels 30 a, A clutch 38 that transmits to a drive shaft 36 that is connected to 30b via a differential gear 32, and an electronic control unit 40 that controls the entire vehicle are provided.

  FIG. 2 is a configuration diagram showing an outline of the configuration of the electric drive system centered on the motor 22. As shown in the figure, the motor 22 includes a rotor with a permanent magnet attached and a stator around which a three-phase coil is wound, and is configured as a known synchronous generator motor that can be driven as a generator and can be driven as an electric motor. ing. The inverter 24 includes six transistors T1 to T6 and six diodes D1 to D6 connected in reverse parallel to the transistors T1 to T6. The six transistors T1 to T6 are arranged in pairs so that they are on the source side and the sink side with respect to the positive electrode bus connected to the positive electrode of the battery 26 and the negative electrode bus connected to the negative electrode of the battery 26. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor 22 is connected to the connection point. Therefore, a rotating magnetic field can be formed in the three-phase coil by adjusting the ratio of the ON times of the paired transistors T1 to T6, and the motor 22 can be driven to rotate.

  The electronic control unit 40 is configured as a microprocessor centered on the CPU 42, and includes a ROM 44 for storing a processing program, a RAM 46 for temporarily storing data, and an input / output port (not shown) in addition to the CPU 42. The electronic control unit 40 includes an ignition signal from the ignition switch 50, a shift position SP from the shift position sensor 52 that detects the operation position of the shift lever 51, and an accelerator pedal position sensor 54 that detects the amount of depression of the accelerator pedal 53. From the accelerator position Acc, the brake pedal position BP from the brake pedal position sensor 56 that detects the depression amount of the brake pedal 55, the vehicle speed V from the vehicle speed sensor 58, and the rotational position detection sensor 22a that detects the rotational position of the rotor of the motor 22. , The element temperature from a temperature sensor (not shown) that detects the temperature of the transistors T1 to T6 of the inverter 24, the phase current from a current sensor (not shown) that detects the phase current flowing in each phase of the three-phase coil of the motor 22, etc. Entered It is input via the port. From the electronic control unit 40, a switching control signal to the transistors T1 to T6 of the inverter 24, a drive signal to the actuator (not shown) of the clutch 38, and an actuator (not shown) of the brakes 31a and 31b for applying a braking force to the drive wheels 30a and 30b. A drive signal is output through an output port. As the shift position SP, in the embodiment, a parking position for parking (P position), a neutral position for neutral (N position), a drive position for forward travel (D position), and a reverse position for reverse travel (R Position).

  Next, the operation of the electric vehicle 20 of the embodiment configured as described above, particularly the operation when the vehicle is stopped in a state where the accelerator pedal 53 is depressed on the uphill road will be described. FIG. 3 is a flowchart showing an example of a drive control routine executed by the electronic control unit 40. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, the CPU 42 of the electronic control unit 40 first needs to control the accelerator opening Acc from the accelerator pedal position sensor 54, the vehicle speed V from the vehicle speed sensor 58, the rotational speed Nm of the motor 22, and the like. Correct data is input (step S100). Here, the rotational speed Nm of the motor 22 is calculated based on the rotational position of the rotor of the motor 22 from the rotational position detection sensor 22a by a motor rotational speed calculation routine (not shown) and written to a predetermined address in the RAM 46. It was supposed to be input by reading.

  When the data is input in this way, the required torque Td * to be output to the drive shaft 36 connected to the drive wheels 30a, 30b is set as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V ( Step S110). In the embodiment, the required torque Td * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Td * in the ROM 44 as a required torque setting map. , The corresponding required torque Td * is derived from the stored map and set. FIG. 4 shows an example of the required torque setting map.

  Subsequently, a value of a clutch state flag F described later is checked (step S120). This clutch state flag is a flag that is set to a value of 1 when the clutch is on, and a value of 0 when the clutch is off. When the clutch state flag F is 1, that is, when the clutch 38 is on, the absolute value of the rotational speed Nm of the motor 22 is compared with a threshold value Nref (step S130). Here, the threshold value Nref is used as an upper limit of the rotational speed Nm of the motor 22 that can be determined that the motor 22 has substantially stopped rotating, and is determined by the characteristics of the motor 22 and the rotational position detection sensor 22a. It is done. Therefore, the comparison between the rotation speed Nm of the motor 22 and the threshold value Nref in step S130 is a process for determining whether or not the motor 22 has substantially stopped rotating. When the absolute value of the rotational speed Nm of the motor 22 is greater than the threshold value Nref, it is determined that the motor 22 has not substantially stopped rotating, the clutch 38 is kept on (step S140), and the clutch state flag F has a value of 1 (Step S150), the brakes 31a and 31b are kept off (step S160), and the transistors T1 to T6 of the inverter 24 are subjected to switching control so that the torque corresponding to the required torque Td * is output from the motor 22. (Step S170), the drive control routine is terminated.

  On the other hand, when the absolute value of the rotational speed Nm of the motor 22 is less than or equal to the threshold value Nref, it is determined that the motor 22 has stopped substantially, and the absolute value of the previous rotational speed of the motor 22 (previous Nm) is compared with the threshold value Nref. If the absolute value of the previous rotation speed (previous Nm) of the motor 22 is larger than the threshold value Nref, the temperature of the motor 22 and the inverter 24 will be increased if the torque corresponding to the required torque Td * is continuously output from the motor 22. Is set to an excess predicted time tref that is predicted to exceed the predetermined temperature (step S190), and the rotation stop duration is a time during which the absolute value of the rotation speed Nm of the motor 22 continues below the threshold value Nref. Time measurement of tms is started (step S200). Here, the predetermined temperature is determined as a temperature lower than a predetermined allowable temperature of the motor 22 or the inverter 24 and can be set based on characteristics of the motor 22 or the inverter 24. In addition, in the embodiment, the excess predicted time tref is determined in advance by experimentation or the like as a relationship between the required torque Td * and the excess predicted time tref and stored in the ROM 44 as an excess predicted time setting map. When given, the excess prediction time tref is derived and set from the stored map. An example of the excess prediction time setting map is shown in FIG. As shown in the figure, the estimated excess time tref is set to be shorter as the required torque Td * is larger. This is based on the following reason. The vehicle stops when the accelerator pedal 53 is depressed on an uphill road, or when the accelerator pedal 53 is depressed to get rid of these when it is caught by a curb or fitted into a groove or hole. Is considered (when the rotating shaft 23 of the motor 22 is substantially stopped rotating). Since the motor 22 is controlled so that torque is output based on the rotational position of the rotor, an attempt is made to output torque from the motor 22 even though the rotation shaft 23 of the motor 22 is substantially stopped. A large current flows in a specific phase among the three-phase coils of the motor 22, and the specific transistor among the transistors T1 to T6 may be overheated. At this time, as the torque to be output from the motor 22 increases, the current passed through the specific transistor increases, and the time until the transistor overheats decreases. For these reasons, in the embodiment, the excess prediction time tref is set so as to decrease as the required torque Td * increases.

  Subsequently, the rotation stop duration tms is compared with the excess prediction time tref (step S210). Immediately after starting the timing of the rotation stop duration tms, the rotation stop duration tms is shorter than the predicted heating time tref, and the above-described steps. The processes after S140 are executed.

  When this routine is executed after the next time, the rotation speed (previous Nm) of the previous motor 22 is equal to or less than the threshold value Nref in step S180, the processing of steps S190 and S200 is not executed, and the rotation stop duration time in step S210. When tms is less than the excess prediction time tref, that is, when the state where the motor 22 has substantially stopped rotating has not continued for the excess prediction time tref, the processing after step S140 is executed, and the rotation is performed at step S210. When the stop continuation time tms is equal to or longer than the estimated excess time tref, the clutch 38 is turned off (step S220), the clutch state flag F is set to 0 (step S230), and the brakes 31a and 31b are turned on (step S220). Step S240), whether the torque corresponding to the required torque Td * is the motor 22 The transistor T1~T6 inverter 24 to be output by performing a switching control (step S170), and terminates the drive control routine. That is, when the rotation stop duration tms continues for the excess prediction time tref, the clutch 38 is turned off to release the connection between the rotary shaft 23 and the drive shaft 36 of the motor 22, and the brakes 31a and 31b are turned on to drive wheels. 30a and 30b are locked. Thereby, when the vehicle is stopped in a state where the accelerator pedal 53 is depressed on the uphill road, the rotating shaft 23 of the motor 22 is not moved in the direction opposite to the traveling direction corresponding to the shift position SP. Can be rotated. As a timing for turning off the clutch 38, the temperature of the motor 22 or the inverter 24 may be used instead of the excess prediction time tref. However, when the rotation shaft 23 of the motor 22 is substantially stopped, Since the temperature rise is different for each phase of the three-phase coil of the motor 22, if the temperature of the motor 22 or the inverter 24 is to be used, it is necessary to provide a plurality of temperature sensors, resulting in an increase in the number of parts. Considering these reasons, in the embodiment, the excess predicted time tref set based on the required torque Td * is used as the timing for turning off the clutch 38.

  When the clutch state flag F is 0 in step S120, it is determined whether or not the state of the phase current energized in each phase of the three-phase coil of the motor 22 has been changed (step S250). This determination is made by, for example, a current sensor (not shown) to determine whether or not the phase current of a phase in which a relatively large current flows among the three-phase coils of the motor 22 is within a relatively small predetermined range including a value of 0. The rotational position detection sensor 22a determines whether or not the rotational shaft 23 of the motor 22 has rotated more than the rotational angle corresponding to the electrical angle (2π / 3). The determination can be made based on the rotational position of the rotor of the motor 22. The electrical angle (2π / 3) is an electrical angle corresponding to one phase of the phase current of the motor 22. When it is determined that the state of the phase current energized in each phase of the three-phase coil of the motor 22 has not been changed, the processing after step S220 is executed. On the other hand, when it is determined that the state of the phase current applied to each phase of the three-phase coil of the motor 22 has been changed, the clutch 38 is turned on (step S140), and a value 1 is set in the clutch state flag F. (Step S150), the brakes 31a and 31b are turned off (Step S160), and the switching control of the transistors T1 to T6 of the inverter 24 is performed so that the torque corresponding to the required torque Td * is output from the motor 22 (Step S170). Then, the drive control routine ends. Thus, when the state where the rotation shaft 23 of the motor 22 has stopped rotating continues for the excess prediction time tref, the clutch 38 is turned off and the rotation shaft 23 of the motor 22 is rotated. By turning on the clutch 38 when the state of the phase current applied to each phase of the phase coil is changed, it is possible to suppress overheating of a specific transistor among the transistors T1 to T6 of the inverter 24. .

  According to the electric vehicle 20 of the embodiment described above, the state in which the rotation shaft 23 of the motor 22 is substantially stopped is continued for the excess prediction time tref set to be shorter as the required torque Td * is larger. Since the clutch 38 is turned off and the rotation shaft 23 of the motor 22 is rotated thereafter and the state in which each phase of the three-phase coil of the motor 22 is energized is changed, the clutch 38 is turned on. It is possible to suppress overheating of a specific transistor among the transistors T1 to T6 of the inverter 24. Moreover, since the brakes 31a and 31b are turned on while the clutch 38 is turned off, when the vehicle is stopped with the accelerator pedal 53 being depressed on a slope, It is possible to suppress movement in the reverse direction.

  In the electric vehicle 20 of the embodiment, the excess prediction time tref is set so as to decrease linearly as the required torque Td * increases as illustrated in FIG. 5, but is not limited thereto, and the required torque is not limited thereto. The excess prediction time tref may be set such that the larger the Td * is, the shorter the curve becomes shorter, and the larger the required torque Td * is, the more the predicted time tref tends to decrease stepwise with one or more stages. It may be set.

  In the electric vehicle 20 of the embodiment, while the state where the rotation shaft 23 of the motor 22 is substantially stopped is continued for the excess estimated time tref and the clutch 38 is turned off, the brake is applied regardless of the road surface gradient. 31a and 31b are turned on, but the brakes 31a and 31b may not be turned on regardless of the road surface gradient. When the road surface gradient is equal to or higher than the predetermined gradient, the brakes 31a and 31b are turned on and the road surface gradient is When it is less than the predetermined gradient, the brakes 31a and 31b may be turned off. In the latter case, the predetermined gradient is set to an upper limit gradient that can determine that the vehicle does not move in the direction opposite to the traveling direction without turning on the brakes 31a and 31ba while the clutch 38 is turned off. can do.

  In the electric vehicle 20 of the embodiment, after the clutch 38 is turned off, the clutch 38 is turned on when the state of the phase current applied to each phase of the three-phase coil of the motor 22 is changed. The clutch 38 may be turned on when a certain amount of time has passed since the clutch 38 was turned off. Here, as the certain time, for example, a time when the state of the phase current of the motor 22 is considered to be changed before the clutch 38 is turned off can be used, and the shorter the required torque Td *, the shorter the time. Time can be used, or a predetermined time can be used.

  In the electric vehicle 20 of the embodiment, the motor 22 and the clutch 38 for connecting and releasing the rotating shaft 23 of the motor 22 and the driving shaft 36 coupled to the driving wheels 30a and 30b are provided. In place of the clutch 38, the stepped gear can transmit power between the rotating shaft 23 of the motor 22 and the drive shaft 36 along with the change of the gear position and can release the connection between the rotating shaft 23 of the motor 22 and the drive shaft 36. A transmission may be provided.

  In the embodiment, the electric vehicle 20 including the motor 22 and the clutch 38 for connecting and releasing the driving shaft 36 coupled to the rotating shaft 23 of the motor 22 and the driving wheels 30a and 30b has been described. In addition to the motor 22 and the clutch 38, the electric vehicle 120 includes an engine 122 and a motor 124 connected to the drive shaft 36 via a planetary gear mechanism 126, as illustrated in the electric vehicle 120 of the modified example of FIG. Alternatively, as illustrated in the electric vehicle 220 of the modification of FIG. 7, the power shaft 34 connected to the rotating shaft 23 of the motor 22 and the clutch 38 is connected via the planetary gear mechanism 226. The present invention may be applied to an electric vehicle 220 including an engine 222 and a motor 224, or as illustrated in an electric vehicle 320 of a modification example in FIG. The engine 322, the inner rotor 332 connected to the crankshaft of the engine 322, and the outer rotor 334 connected to the rotary shaft 23 of the motor 22 and the power shaft 34 connected to the clutch 38. It is good also as what is applied to the electric vehicle 320 provided with the counter-rotor motor 330 which transmits a part of power to the power shaft 34 and converts the remaining power into electric power.

  Here, the correspondence between the main elements of the embodiments and the modified examples and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor 22 that outputs torque corresponds to an “electric motor”, and a clutch 38 that connects and disconnects the rotary shaft 23 of the motor 22 and the drive shaft 36 connected to the drive wheels 30a and 30b is “ It corresponds to the “disconnecting means”, sets the required torque Td * based on the accelerator opening Acc and the vehicle speed V, and outputs the torque corresponding to the required torque Td * from the motor 22 so that the transistors T1 to T6 of the inverter 24 The electronic control unit 40 for performing the switching control corresponds to “drive control means”, and the rotation shaft 23 and the drive shaft 36 of the motor 22 are connected, and the absolute value of the rotation speed Nm of the motor 22 is equal to or less than the threshold value Nref. The electronic control unit 40 that sets the predicted excess time tref in a tendency to become shorter as the required torque Td * increases is “excess predicted time setting means”. Correspondingly, the clutch 38 is turned off when the rotation stop duration tms, which is the time when the absolute value of the rotational speed Nm of the motor 22 is less than or equal to the threshold value Nref, exceeds the estimated excess time tref, and then the phase currents of the transistors T1-T6 The electronic control unit 40 that executes the process of turning on the clutch 38 when the state is changed corresponds to the “connection release control means”. Further, the brakes 31a and 31b for applying the braking force to the drive wheels 30a and 30b correspond to “braking force applying means”, and the brakes 31a and 31b are turned on until the clutch 38 is turned on after the clutch 38 is turned off. The electronic control unit 40 that executes the processing is equivalent to “braking force application control means”. Note that the correspondence between the main elements of the embodiment and the modified example and the main elements of the invention described in the column of means for solving the problem is described in the column of means for the embodiment to solve the problem. Since this is an example for specifically describing the best mode for carrying out the invention, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

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

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

It is a block diagram which shows the outline of a structure of the electric vehicle 20 as one Example of this invention. 2 is a configuration diagram showing an outline of a configuration of an electric drive system centered on a motor 22. FIG. 4 is a flowchart showing an example of a drive control routine executed by the electronic control unit 40. 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 map for excess prediction time setting. It is a block diagram which shows the outline of a structure of the electric vehicle 120 of a modification. It is a block diagram which shows the outline of a structure of the electric vehicle 220 of a modification. FIG. 11 is a configuration diagram illustrating an outline of a configuration of a modified example of an electric vehicle 320.

Explanation of symbols

  20, 120, 220, 320 Electric vehicle, 22 motor, 22a rotational position detection sensor, 23 rotational shaft, 24 inverter, 26 battery, 30a, 30b drive wheel, 31a brake, 32 differential gear, 36 drive shaft, 38 clutch, 40 Electronic control unit, 42 CPU, 44 ROM, 46 RAM, 50 ignition switch, 51 shift lever, 52 shift position sensor, 53 accelerator pedal, 54 accelerator pedal position sensor, 55 brake pedal, 56 brake pedal position sensor, 58 vehicle speed sensor, 122 engine, 124 motor, 126 planetary gear mechanism, 222 engine, 224 motor, 330 pair rotor motor, 332 inner rotor, 334 outer rotor, D1 to D Diode, T1~T6 transistor.

Claims (5)

An electric motor that outputs driving force;
Connection release means for connecting and releasing the connection between the rotating shaft of the electric motor and the drive shaft connected to the drive wheel;
Drive control means for controlling the electric motor so that a driving force based on a required driving force required for traveling is output from the electric motor;
Based on the driving force output from the motor when the rotating shaft of the motor is connected to the driving shaft and the absolute value of the rotating speed of the motor is not more than a predetermined rotating speed including a value of 0. Excess prediction time setting means for setting an excess prediction time which is a time predicted that the temperature of the electric motor exceeds a predetermined temperature;
When the rotation stop state continues for the set estimated excess time, the connection release control is executed to control the connection release means so that the connection between the rotating shaft and the drive shaft is released, and the connection A connection release control means for executing connection control for controlling the connection release means so that the rotating shaft and the drive shaft are connected when a predetermined connection release end condition is satisfied after executing the release control;
A vehicle comprising:   2. The vehicle according to claim 1, wherein the excess predicted time setting means is a means for setting the excess predicted time so as to be shorter as the driving force output from the electric motor is larger. The vehicle according to claim 1 or 2,
The electric motor is a multiphase AC electric motor;
The predetermined disconnection termination condition is a condition in which the rotating shaft of the electric motor rotates more than a minimum amount of rotation at which the state of the phase current of the electric motor is different from the state of the phase current before executing the disconnection control. Is a vehicle. A vehicle according to the present invention,
Braking force applying means for applying a braking force to the drive wheel;
A braking force application control unit that controls the braking force application unit so that a braking force is applied to the driving wheel from the execution of the connection release control to the execution of the connection control;
A vehicle comprising: A vehicle control method comprising: an electric motor that outputs a driving force; and a connection release unit that performs connection and release of a connection between a rotating shaft of the electric motor and a drive shaft coupled to a drive wheel,
Controlling the electric motor so that a driving force based on a required driving force required for traveling is output from the electric motor;
Based on the driving force output from the motor when the rotating shaft of the motor is connected to the driving shaft and the absolute value of the rotating speed of the motor is not more than a predetermined rotating speed including a value of 0. And setting an excess prediction time, which is a time when the temperature of the motor is predicted to exceed a predetermined temperature,
When the rotation stop state continues for the set estimated excess time, the connection release control is executed to control the connection release means so that the connection between the rotating shaft and the drive shaft is released, and the connection Executing a connection control for controlling the connection release means so that the rotating shaft and the drive shaft are connected when a predetermined connection release end condition is satisfied after executing the release control;
Vehicle control method.

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