JP6133721B2 - Automobile - Google Patents

Description

  The present invention relates to an automobile, and more particularly, to an automobile provided with a motor capable of outputting regenerative torque to a drive shaft connected to an axle, and a battery that exchanges electric power with the motor.

  Conventionally, this type of automobile is equipped with a motor that rotates by receiving power supplied from a battery. When the motor speed is reduced, the value is 0 when the motor speed is not less than the first speed and not more than the second speed. It is proposed that the motor is controlled so that the regenerative torque that gradually decreases (becomes larger as an absolute value) is output and the regenerative torque that becomes a constant value when the second rotational speed is exceeded is output from the motor ( For example, see Patent Document 1). In this automobile, when the voltage of the battery is equal to or higher than a certain value and the rotation speed of the motor is equal to or higher than the third rotation speed higher than the second rotation speed, the regenerative torque that decreases as the motor rotation speed increases from the motor. By controlling the motor so that it is output, the battery is prevented from being overcharged.

JP 2002-34106 A

  However, in the above-mentioned automobile, when the rotation speed of the motor is equal to or higher than the third rotation speed, when the voltage of the battery is equal to or higher than a certain value and when the voltage of the battery is lower than the certain value, Since the change in the regenerative torque with respect to the rotational speed is different, the driver may feel uncomfortable.

  The main object of the automobile of the present invention is to suppress the battery from being charged with excessive power when the accelerator is turned off, and to suppress the driver from feeling uncomfortable.

  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
A motor comprising a motor capable of outputting regenerative torque to a drive shaft connected to an axle, and a battery that exchanges electric power with the motor,
When the accelerator is turned off, when the charging of the battery is restricted and the vehicle speed is equal to or higher than a predetermined low vehicle speed, the vehicle is driven so as to travel while outputting a regenerative torque not less than a required regenerative torque lower limit to the drive shaft A control means for controlling the motor,
The gist of the invention is that the control means uses the torque obtained by subtracting a predetermined amount from the required regenerative torque when the accelerator is turned off and charging of the battery is not limited as the required regenerative torque lower limit value. .

  In the automobile of the present invention, when the accelerator is turned off, when the battery charging is restricted and the vehicle speed is equal to or higher than a predetermined low vehicle speed, a regenerative torque equal to or higher than the required regenerative torque lower limit value is output to the drive shaft. The torque is calculated by subtracting a predetermined amount from the required regenerative torque when the motor is controlled to travel while the accelerator is off and the charging of the battery is not restricted. As a result, even when the charging of the battery is restricted, it is possible to produce a feeling of deceleration close to that when the charging of the battery is not restricted, the battery is prevented from being charged with excessive power, and the driver feels strange. Can be suppressed. Here, the “required regenerative torque” is a regenerative torque required for the motor.

  In such an automobile of the present invention, the control means may be means for setting the value 0 to the required regenerative torque lower limit value when the required regenerative torque lower limit value is smaller than the value 0.

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 an emblem guarantee torque setting process routine for setting an emblem guarantee torque executed by a CPU 72 of the HVECU 70; It is explanatory drawing which shows an example of the relationship between request | requirement torque Tr *, emblem guarantee torque Teb, and vehicle speed V when shift position SP exists in D range and B range at the time of accelerator off. When the accelerator position is off and the shift position is in the D range, the charging of the battery 50 is not restricted and the required torque Tr * is set as it is to the torque command Tm2, and output to the drive shaft 36 in the comparative example and this embodiment. It is explanatory drawing which shows an example of the time change of the torque and the power which charges / discharges the battery 50 (it is a negative value when charging the battery 50).

  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. In the hybrid vehicle 20 of the embodiment, as shown in the figure, a carrier is connected to an engine 22 that outputs power using gasoline or light oil as a fuel, a crankshaft 26 of the engine 22, and a differential gear 32 is connected to drive wheels 34 a and 34 b. A planetary gear 30 in which a ring gear is connected to a drive shaft 36 connected via a motor, a motor MG1 configured as a synchronous generator motor, for example, and a rotor connected to a sun gear of the planetary gear 30, and configured as a synchronous generator motor, for example. A motor MG2 having a rotor connected to the drive shaft 36, inverters 41 and 42 that drive the motors MG1 and MG2 by switching of a plurality of switching elements (not shown), and inverters 41 and 42 configured as, for example, lithium ion secondary batteries. Through the motor MG1 Comprising the MG2 and the battery 50 to exchange power, the hybrid electronic control unit which controls the entire vehicle (hereinafter, HVECU hereinafter) 70, a.

  The HVECU 70 is configured as a microprocessor centered on the CPU 72, and includes a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 72. The HVECU 70 includes 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, and an accelerator opening degree from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Operation control of the engine 22 such as Acc, 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, and signals from various sensors that detect the state of the engine 22 Installed between the terminals of the battery 50, signals necessary for driving and controlling the motors MG1, MG2, such as signals from a rotational position detection sensor (not shown) for detecting the rotational position of the rotor of the motors MG1, MG2. Voltage not shown Such as signals required for control of the inter-terminal voltage such as a battery 50 from capacitors is input via the input port. The HVECU 70 outputs an operation control signal for controlling the operation of the engine 22 and a switching control signal for the inverters 41 and 42.

  Further, in the hybrid vehicle 20 of the embodiment, as the shift position SP of the shift lever 81, a parking range (P range) used during parking, a reverse range for reverse travel (R range), a neutral neutral range (N range), forward In addition to the normal driving range (D range) for driving, the setting of the driving force when the accelerator is on is the same as the D range, but the braking force that is applied to the vehicle when the accelerator is off during driving is set larger than the D range. A sequential shift range (S range) having a brake range (B range), an upshift instruction range, and a downshift instruction range is prepared. Here, the S range is a range in which the driving force when the accelerator is on and the braking force when the accelerator is off during traveling are changed to, for example, six steps (S1 to S6), and the upshift instruction range is operated to upshift. The driving force when the accelerator is on and the braking force when the accelerator is off during traveling are reduced each time, and the driving force when the accelerator is on and the braking when the accelerator is off during traveling each time a downshift is performed by operating the downshift instruction range. The power increases.

  In the hybrid vehicle 20 of the embodiment thus configured, the required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc, the vehicle speed V, and the shift position SP corresponding to the amount of depression of the accelerator pedal by the driver. The engine 22, the motor MG 1, and the motor MG 2 are controlled so that the calculated 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 requests torque Tr * (shift position SP) to be output to the drive shaft 36 based on the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, and the shift position SP. Is a forward travel range, a negative value is set when the braking force is applied, and the rotation speed Nr of the drive shaft 36 (for example, the rotation speed Nm2 of the motor MG2 or the vehicle speed V is set to the set required torque Tr *. The traveling power Pdrv * required for traveling is calculated by multiplying the number of revolutions obtained by multiplying the conversion factor), and the charging of the battery 50 obtained from the calculated traveling power Pdrv * based on the storage ratio SOC of the battery 50 is calculated. The power to be output from the engine 22 by reducing the required discharge power Pb * (a positive value when discharging from the battery 50) It sets the required power Pe * of Te. 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 a target torque Te * are set, and a torque command Tm1 * as a torque to be output from the motor MG1 is set by the rotational speed feedback control for setting the rotational speed Ne of the engine 22 to the target rotational speed Ne *. . 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, and the set target rotational speed Ne * and target torque are set. The intake air amount control, fuel injection control, ignition control, etc. of the engine 22 are performed so that the engine 22 is operated by Te *, and the inverter 41 is driven so that the motors MG1, MG2 are driven by the torque commands Tm1 *, Tm2 * set. , 42 is switched.

  In the motor operation mode, the HVECU 70 sets the required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc, the vehicle speed V, and the shift position SP, and sets a value 0 to the torque command Tm1 * of the motor MG1. At the same time, 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, switching control of the plurality of switching elements of the inverters 41 and 42 is performed so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  When the accelerator pedal 83 is turned off in a state where the engine 22 and the motors MG1, MG2 are controlled by the engine operation mode and the motor operation mode, the CPU 72 of the HVECU 70 basically includes the vehicle speed V from the vehicle speed sensor 88, The required torque Tr * to be output to the drive shaft 36 based on the shift position SP, the accelerator off-time required torque setting map that defines the relationship between the vehicle speed V, the shift position SP, and the required torque Tr * when the accelerator is off. Set. In the map for setting required torque when the accelerator is off, when the shift range is the D range, B range, and S range for forward travel, the required torque Tr * is 0 when the vehicle speed V is equal to or higher than a predetermined vehicle speed Vref (for example, 20 km / hour). It was assumed that: Further, when the shift position SP is in the B range, the required torque Tr * becomes smaller (as the braking force increases) than in the D range, and when the shift position SP is in the S range, the smaller the number of steps from S6 to S1. It becomes (it becomes large as braking force). Furthermore, when the shift range is the R range for reverse travel, the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref and the required torque Tr * is equal to or higher than 0.

  Subsequently, based on the input vehicle speed V and the shift position SP, the target engine speed Nettag, which is a target value of the engine speed when the engine 22 forcibly stopped (fuel cut) is forcibly rotated by motoring. Is set, and a torque command Tm1 * as a torque to be output from the motor MG1 is set by the rotation speed feedback control for setting the rotation speed Ne of the engine 22 to the target rotation speed Netag.

  Then, the torque command Tm2 * of the motor MG2 is set as a torque for outputting the required torque Tr * to the drive shaft 36 within the range of the input limit Win of the battery 50, and the fuel injection control and ignition control of the engine 22 are stopped and the motor is stopped. Switching control of the plurality of switching elements of the inverters 41 and 42 is performed so that the MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 * set. By such control, when the accelerator is off, the regenerative torque can be output from the motor MG2 to the drive shaft 36 within the range of the input limit Win of the battery 50 to produce an engine brake feeling.

  In such a hybrid vehicle 20, if the regenerative torque is output from the motor MG <b> 2 to the drive shaft 36 within the range of the input limit Win when the accelerator is turned off when the charging of the battery 50 is relatively largely restricted, the drive shaft 36. The regenerative torque that is output to is reduced and the driver may feel idle. In order to avoid this, when the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref, that is, when the required torque Tr * when the accelerator is off is the braking force, the torque that can produce the engine braking feeling that the driver expects. Emblem guarantee torque Teb (absolute value is required regenerative torque lower limit value) as a lower limit value is set, and temporary torque of motor MG2 is output as required torque Tr * to drive shaft 36 within the range of input limit Win of battery 50. Tm2tmp is set, the torque having the larger absolute value of the temporary torque Tm2tmp and the emblem guarantee torque Teb is set in the torque command Tm2 * of the motor MG2, and the fuel injection control and ignition control of the engine 22 are stopped and the motor MG1 , MG2 is driven by the torque commands Tm1 * and Tm2 * set by the inverter 4 , It performs switching control of the plurality of switching elements 42. The setting of the emblem guarantee torque Teb will be described later.

  Here, when the charging of the battery 50 is relatively largely restricted, for example, the temperature of the battery 50 is equal to or higher than a predetermined temperature (for example, 65 ° C., 70 ° C., 80 ° C.) that restricts the charging of the battery 50. The input limit Win of the battery 50 is relatively large (absolutely, for example, when the ratio SOC of the stored capacity to the total capacity that the battery 50 can store is a predetermined ratio (for example, 70%, 75%, 80%) or more) Or when the temperature of the motor MG2 is high (for example, 155 ° C., 160 ° C., 165 ° C. or more) and the driving of the motor MG2 is relatively large.

  By such control, when the absolute value of the torque (temporary torque Tm2tmp) for outputting the required torque Tr * to the drive shaft 36 within the range of the input limit Win of the battery 50 becomes less than the absolute value of the emblem guarantee torque Teb, the emblem guarantee The torque Teb is set to the torque command Tm2 * of the motor MG2. As a result, a regenerative torque equal to or greater than the absolute value of the emblem guarantee torque Teb can be output from the motor MG2 to the drive shaft 36, and the engine brake feeling expected by the driver can be produced.

  Here, the setting of the emblem guarantee torque Teb will be described. FIG. 2 is a flowchart showing an example of an emblem guarantee torque setting processing routine for setting the emblem guarantee torque executed by the CPU 72 of the HVECU 70. This routine is executed when the vehicle speed V becomes equal to or higher than the predetermined vehicle speed Vref.

  When the emblem guarantee torque setting processing routine is executed, the CPU 72 of the HVECU 70 first determines whether the shift position SP is in the D range or the B range (step S100) and whether the shift position SP is in the R range. The examination process is executed (step S110). When the shift range is the D range or the B range, a value obtained by multiplying a value obtained by subtracting the predetermined torque Tα from the absolute value of the required torque Tr * (required regenerative torque) by the value −1 is set as the temporary Tetpmp (step 120). The smaller value of the temporary Tetpmp and the value 0 is set as the engine guarantee torque Teb (step S130), and this routine is finished. The predetermined torque Tα is obtained by experiment or analysis as a value that does not cause the driver to feel idle even if the regenerative torque output to the drive shaft 36 is a value smaller than the required regenerative torque by the predetermined torque Tα. It was supposed to be used.

  FIG. 3 is an explanatory diagram showing an example of the relationship among the required torque Tr *, the emblem guarantee torque Teb, and the vehicle speed V when the shift position SP is in the D range and the B range when the accelerator is off. In the figure, the solid line indicates the emblem guarantee torque Teb, and the broken line indicates the required torque Tr * when the accelerator is off. Thus, the emblem guarantee torque Teb has a value that follows the change in the required torque Tr *, and the torque command Tm2 * of the motor MG2 is set as a regenerative torque that is greater than or equal to the absolute value of the emblem guarantee torque Teb. Become.

  When the shift position SP is in the R range (steps S100 and S110), a value obtained by subtracting the predetermined torque Tα from the absolute value (requested regenerative torque) of the required torque Tr * is set as the temporary Tetmp (step 140), and the temporary Tetmp and the value are set. The larger value of 0 is set as the engine guarantee torque Teb (step S150), and this routine is terminated. By such processing, the emblem guarantee torque Teb can be set to a value slightly smaller than the required torque Tr * and following the change in the required torque Tr *.

  When the shift position SP is not in any of the D, B, and R ranges, that is, when the shift position SP is in the S range (steps S100 and S110), the required torque Tr * is set to the engine guaranteed torque Teb (step S160). ), This routine is terminated. By such processing, the emblem guarantee torque Teb can be set to the same value as the required torque Tr *.

  When the emblem guarantee torque is set in this manner, the torque command Tm2 * of the motor MG2 is set as a regenerative torque greater than the absolute value of the emblem guarantee torque Teb, and the regenerative torque greater than the absolute value of the emblem guarantee torque Teb is driven from the motor MG2. The motor MG2 is controlled so as to be output to the shaft 36.

  FIG. 4 shows the driving in the comparative example and the present embodiment when charging of the battery 50 is not restricted when the shift position is in the D range when the accelerator is off, and the required torque Tr * is set to the torque command Tm2 as it is. It is explanatory drawing which shows an example of the time change of the torque output to the axis | shaft 36, and the power which charges / discharges the battery 50 (it is a negative value when charging the battery 50). In the drawing, the example is represented by a solid line, the comparative example is represented by a broken line, and the input restriction Win is represented by a one-dot chain line. In the embodiment, as shown, the regenerative torque output to the drive shaft 36 is small, and the charging power of the battery 50 is also small. Further, in the example and the comparative example, the torque output to the drive shaft 36 changes substantially in the same manner with respect to the time change although the absolute value is different. In other words, it is possible to prevent the battery 50 from being charged with excessive power, and to produce an engine brake feeling close to that when the charging of the battery 50 is not restricted even when the charging of the battery 50 is restricted. Even when the charging of the battery 50 is restricted, the feeling of engine braking is different from that when the charging of the battery 50 is not restricted, and the driver can be prevented from feeling uncomfortable.

  In the hybrid vehicle 20 of the embodiment described above, when the accelerator is turned off, when the charging of the battery 50 is restricted and the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref, fuel injection and ignition control in the engine 22 are stopped. Then, the motors MG1 and MG2 are controlled to run while outputting a regenerative torque equal to or greater than the absolute value (required regenerative torque lower limit value) of the emblem guarantee torque Tbe from the motor MG2 to the drive shaft 36. Thereby, it can suppress that the battery 50 is charged with excessive electric power, and can suppress that a driver feels uncomfortable.

  In the hybrid vehicle 20 of the embodiment, the predetermined vehicle speed Vref is a vehicle speed at which the required torque Tr * when the accelerator is off is 0. However, the predetermined vehicle speed Vref is not limited to such a vehicle speed, and the shift position SP is in the D range. In the B range, the vehicle speed at which the required torque Tr * is increased by the predetermined torque Tα, or when the shift position SP is in the R range, the vehicle speed is decreased by the predetermined torque Tα, or according to the required engine braking feeling. Can be determined as appropriate.

  The hybrid vehicle 20 of the embodiment includes two motors MG1 and MG2 and a planetary gear 30, but the vehicle to which the present invention is applied has a first motor driven by an engine, traveling power and regenerative torque. It may be a series-type hybrid vehicle including a second motor for output, or may be a parallel-type (one-motor type) hybrid vehicle including an engine and a motor capable of outputting at least regenerative torque. May be an electric vehicle provided with as a power generation source for traveling.

  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 battery 50 corresponds to the “battery”, and the accelerator is turned off, the charging of the battery 50 is restricted and the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref. In some cases, fuel injection and ignition control in the engine 22 is stopped, and a regenerative torque equal to or greater than the emblem guarantee torque Teb (required regenerative torque lower limit value) set by the emblem guarantee torque setting processing routine illustrated in FIG. 2 is driven from the motor MG2. The HVECU 70 that controls the motors MG1 and MG2 to travel while being output to the shaft 36 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. 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 hybrid vehicle, 22 engine, 26 crankshaft, 30 planetary gear, 32 differential gear, 34a, 34b drive wheel, 35a, 35b wheel, 36 drive shaft, 41, 42 inverter, 50 battery, 70 HVECU, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal range sensor, 88 vehicle speed sensor, MG1, MG2 motor.

Claims (1)

A motor comprising a motor capable of outputting regenerative torque to a drive shaft connected to an axle, and a battery that exchanges electric power with the motor,
When the accelerator is turned off, when the charging of the battery is restricted and the vehicle speed is equal to or higher than a predetermined low vehicle speed, the vehicle is driven so as to travel while outputting a regenerative torque not less than a required regenerative torque lower limit to the drive shaft A control means for controlling the motor,
The control means is a vehicle that uses a torque obtained by subtracting a predetermined amount from a required regenerative torque when charging of the battery is not restricted when the accelerator is turned off as the required regenerative torque lower limit value.

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