JP5516389B2 - Hybrid car - Google Patents

Description

  The present invention relates to a hybrid vehicle.

  Conventionally, this type of hybrid vehicle includes an engine, a motor MG1 capable of inputting / outputting power to / from the engine output shaft, a motor MG2 connected by spline fitting to a drive shaft connected to the axle, and an input shaft. An automatic transmission that is connected to the output shaft of the engine via a torque converter and outputs the power input from the engine to the drive shaft with a shift, and a battery that exchanges electric power with the motor MG1 and the motor MG2, and when starting In order to assist the power from the engine at the time of acceleration, a motor that outputs power from the motor MG2 has been proposed (see, for example, Patent Document 1). In this automobile, in order to suppress a shock caused by the backlash of the spline when power is output from the motor MG2, a pressing torque for pressing the spline in one direction is output from the motor MG2 in advance. When the pressure decreases, the pressing torque is not output.

JP 2007-159360 A

  In the hybrid vehicle described above, in order to suppress the shock at the time of power output by increasing the opportunity to output the pressing torque from the motor MG2 as much as possible, the power storage is as low as possible to a predetermined threshold for determining whether or not the pressing torque can be output. It is required to use a ratio. However, in that case, the power storage ratio used for determining the release of the pressing torque output cannot be a value having sufficient hysteresis with respect to the predetermined threshold value, and the battery power storage ratio is set to the predetermined threshold value. When it fluctuates in the vicinity, the output and release of the pressing torque are repeated. If the output and release of such pressing torque are repeated while the vehicle is stopped, the vehicle may vibrate and give the driver a sense of discomfort.

  The main object of the automobile of the present invention is to suppress frequent repetition of the output and release of the pressing torque while the vehicle is stopped.

  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 internal combustion engine that outputs power to a drive shaft that can transmit power to the axle via a gear mechanism, a rechargeable secondary battery, and power from the secondary battery to output power to the drive shaft In a hybrid vehicle comprising: an electric motor; and allowable discharge power setting means for setting allowable discharge power that is power allowable for discharge of the secondary battery based on a state of the secondary battery.
When the output shaft of the internal combustion engine is rotating while the vehicle is stopped, a push for pressing the gear of the drive system including the gear mechanism toward one direction when the set allowable discharge power is equal to or greater than a predetermined threshold. Pressing control is performed to control the motor so that a contact torque is output from the motor. A pushing control means for releasing the pushing control;
Re-execution limiting means for limiting re-execution of the pressing control by the pressing control means for a predetermined time after the pressing control is released;
It is a summary to provide.

  In the automobile of the present invention, when the allowable discharge power set when the output shaft of the internal combustion engine is rotating while the vehicle is stopped is greater than a predetermined threshold value, the gear of the drive system including the gear mechanism is pushed in one direction. Pushing control is performed to control the motor so that the pushing torque to be applied is output from the motor, and the pushing control is performed when the allowable discharge power set during the pushing control is less than the predetermined threshold. And the re-execution of the pressing control is limited for a predetermined time after the pressing control is canceled. Accordingly, even if the predetermined threshold is set as low as possible to increase the execution opportunity of the pressing control, it is possible to make it difficult to perform the pressing control again after the pressing control is released. As a result, it is possible to suppress frequent output and release of the pressing torque while the vehicle is stopped. Here, the re-execution limiting unit may set only the threshold used for determining the execution of the pressing control over a predetermined time as a threshold larger than the predetermined threshold, or may perform the pressing over a predetermined time. The re-execution of the contact control may be prohibited.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 that is an embodiment of the present invention. It is explanatory drawing which shows an example of the relationship between the battery temperature Tb in the battery 50, and the input / output restrictions Win and Wout. It is a flowchart which shows an example of the pressing torque setting process performed by HVECU70 of an Example.

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

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 that uses gasoline or light oil as fuel, an engine electronic control unit (hereinafter referred to as engine ECU) 24 that controls the drive of the engine 22, and a crank of the engine 22. A planetary gear 30 in which a carrier is connected to the shaft 26 and a ring gear is connected to the drive shaft 32 connected to the drive wheels 63a and 63b via a differential gear 62, and a rotor is configured as a synchronous generator motor, for example. A motor MG1 connected to the sun gear, a motor MG2 configured as a synchronous generator motor and having a rotor connected to the drive shaft 32, inverters 41 and 42 for driving the motors MG1 and MG2, and inverters 41, 42 is controlled by switching control. A motor electronic control unit (hereinafter referred to as a motor ECU) 40 that controls the driving of the MG1 and MG2, and a battery 50 that is configured as, for example, a lithium ion secondary battery and exchanges power with the motors MG1 and MG2 via inverters 41 and 42. And a battery electronic control unit (hereinafter referred to as a battery ECU) 52 for managing the battery 50, an auxiliary device 90 such as an air compressor in the air conditioner in the passenger compartment, and a power line to which the inverters 41 and 42 and the battery 50 are connected. 54 is a hybrid ECU (hereinafter referred to as HVECU) 70 that controls the entire vehicle by exchanging various control signals and data through communication with the drive circuit 92 that is attached to 54 and drives the auxiliary machine 90, and the engine ECU 24, the motor ECU 40, and the battery ECU 52. And comprising. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on a signal from a crank angle sensor (not shown).

  The battery ECU 52 calculates a power storage ratio SOC, which is a ratio of the amount of power stored in the battery 50 to the total capacity (power storage capacity) based on the integrated value of the charge / discharge current detected by the current sensor, or the calculated power storage Based on the ratio SOC and the battery temperature Tb detected by the temperature sensor 51, the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated. FIG. 2 shows an example of the relationship between the battery temperature Tb and the input / output limits Win and Wout.

  The HVECU 70 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port in addition to the CPU. The HVECU 70 includes a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects an amount of depression of the accelerator pedal 83, and an amount of depression of the brake pedal 85. The brake pedal position BP from the brake pedal position sensor 86 for detecting the vehicle speed, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. In addition, a drive signal to the drive circuit 92 is output from the HVECU 70 via an output port.

  The hybrid vehicle 20 of the embodiment configured in this manner generates a required torque to be output to the drive shaft 32 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88 during traveling. The engine 22, the motor MG 1, and the motor MG 2 are controlled so that the calculated power corresponding to the required torque is output to the drive shaft 32. 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 power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. And the motor MG2 convert the torque and output to the drive shaft 32. The torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 are obtained. The operation of the engine 22 is controlled so as to be output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. Accordingly, the required power is output to the drive shaft 32. Charge-discharge drive mode for driving and controlling the motor MG1 and the motor 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 32.

  Further, when the hybrid vehicle 20 is stopped, when the load operation request such that the storage ratio SOC of the battery 50 becomes less than a predetermined ratio is satisfied, the engine 22 is loaded in a stop load operation mode or the engine 22 is cooled. There is a stand-alone operation mode when the engine 22 is operated autonomously when a self-sustained operation request is established such that the water temperature is lower than a predetermined temperature. Further, in these stationary load operation mode and stationary autonomous operation mode, the gears such as the planetary gear 30 and the differential gear 62 (hereinafter referred to as the drive system) are caused by a pumping loss associated with starting and stopping of the engine 22 and torque pulsation of the engine 22. In order to suppress the occurrence of rattling noise), the pressing control for outputting a pressing torque Tp from the motor MG2 as a torque for pressing the driving system gear in one direction to reduce backlash is performed. Done. The initial value of the pressing torque Tp is 0, and a predetermined value Tset is set in the pressing torque setting process described later, and when the predetermined value Tset is set is referred to as execution of the pressing control, When the value 0 is set, the pushing control is canceled.

  As the operation control of the engine 22, the motor MG1, and the motor MG2 in the stop-time load operation mode, the charging speed set in advance for charging the battery 50 is set to the target rotation speed of the engine 22, and the target torque is charged. The engine 22 is operated and controlled, and the torque command of the motor MG1 is set by the rotation speed feedback control for setting the rotation speed of the engine 22 to the target rotation speed, and the motor MG1 is driven by the set torque command. The motor MG1 and MG2 are driven and controlled by setting a torque command for the motor MG2 based on the sum of the cancel torque for canceling the torque acting on the drive shaft 32 via the planetary gear 30 and the pressing torque Tp.

  As the operation control of the engine 22, the motor MG1, and the motor MG2 in the stand-alone operation mode when the vehicle is stopped, the engine 22 is controlled by setting a predetermined idle speed as the target speed of the engine 22 and setting a value 0 as the target torque. Then, a value 0 is set in the torque command of the motor MG1, and a torque command of the motor MG2 is set based on the pressing torque Tp to drive-control the motors MG1 and MG2.

  Further, when a load operation request or a self-sustained operation request is satisfied and the engine 22 is started in a state where the engine 22 is stopped, a predetermined start torque is set in the torque command of the motor MG1, and the set start torque is set. The motor MG1 and MG2 are driven and controlled by setting a torque command for the motor MG2 based on the sum of the cancel torque for canceling the torque acting on the drive shaft 32 when the motor MG1 is driven with torque and the pressing torque Tp. Start control is performed. On the other hand, when the engine 22 is stopped because the load operation request or the independent operation request is not established during the operation of the engine 22 in the stop load operation mode or the stop autonomous operation mode, the torque command of the motor MG1 is predetermined. A torque for the motor MG2 is set based on the sum of the cancel torque and the pressing torque Tp when the motor MG1 is driven with the set stop torque, and the motors MG1 and MG2 are driven and controlled. Stop control is performed.

  Next, the setting of the pressing torque Tp used in drive control while the vehicle is stopped will be described. FIG. 3 is a flowchart showing an example of the pressing torque setting process executed by the HVECU 70. This process is repeatedly executed every predetermined time (for example, every several milliseconds) while the vehicle is stopped.

  When the pressing torque setting process is executed, the CPU of the HVECU 70 first executes a process of inputting data necessary for the process such as the rotational speed Ne of the engine 22 and the output limit Wout of the battery 50 (step S100). Here, the rotational speed Ne of the engine 22 is calculated based on a signal from the crank angle sensor and is input from the engine ECU 24 by communication. Further, the output limit Wout of the battery 50 is set based on the storage ratio SOC of the battery 50 and the battery temperature Tb, and is input from the battery ECU 52 by communication. When the data is input in this way, it is determined whether or not the rotational speed Ne of the engine 22 is greater than 0 (step S110). Here, it is determined that the rotational speed Ne is larger than 0 during start control, stop control, and operation (during load operation or self-sustained operation) of the engine 22, and when the engine 22 is stopped, the rotational speed is determined. It is determined that Ne is not greater than 0. When the rotational speed Ne of the engine 22 is larger than 0, there is a possibility that a rattling noise may be generated in each gear of the drive system due to a pumping loss accompanying the start or stop of the engine 22 or torque pulsation of the engine 22. The determination in S110 is to determine whether or not it is necessary to execute the pressing control in order to suppress the rattling noise.

  When it is determined in step S110 that the rotational speed Ne of the engine 22 is greater than 0, it is determined whether or not the pressing control is being released (step S120). When the pressing control is being released, it is determined whether or not an execution restriction is made as a restriction on the execution of the pressing control (step S130). Here, although details of the execution restriction will be described later, since it is a restriction on the re-execution of the pressing control after the pressing control is released, a case where the execution restriction is not made will be described first. When the execution limit is not made, it is determined whether or not the output limit Wout of the battery 50 is equal to or greater than the threshold value Wref (step S140). When the output limit Wout is equal to or greater than the threshold value Wref, the pressing torque Tp is set to the predetermined torque Tset. Is set (step S150), and this process is terminated. On the other hand, when the output limit Wout is not equal to or greater than the threshold value Wref, the present process is terminated as it is. Since the initial value of the pressing torque Tp is 0, the pressing torque Tp remains 0 when this processing is terminated as it is. Here, the threshold value Wref is within the range of the output limit Wout in which start control, stop control, and operation (load operation and independent operation) of the engine 22 can be appropriately performed even if the pressing torque Tp is output from the motor MG2. As a value as low as possible, for example, set to a value slightly higher than the sum of the power required for the output of the starting torque from the motor MG1 and the power required for the output of the pressing torque Tp from the motor MG2. did. The purpose of setting such a value as the threshold value Wref is to increase the chances of outputting the pressing torque Tp from the motor MG2 as much as possible to suppress the occurrence of rattling noise. On the other hand, if a threshold value having sufficient hysteresis with respect to the threshold value Wref is used to determine whether to release the pressing torque Tp, the engine 22 may not be properly started or stopped. Thus, the threshold value Wref is also used to determine whether to release the pressing torque Tp. In this process, when the predetermined torque Tset is set as the pressing torque Tp, the predetermined torque Tset may be set using the rate process toward the predetermined torque Tset.

  When the predetermined torque Tset is set to the pressing torque Tp in this way, the pressing control is executed. Therefore, when this processing is executed next time, it is determined that the pressing control is not being released in step S120, It is determined whether or not the output limit Wout of the battery 50 is less than the threshold value Wref (step S160). When the output limit Wout is not less than the threshold value Wref, the present process is terminated as it is, and the predetermined torque Tset is held as the pressing torque Tp. On the other hand, when the output limit Wout is less than the threshold value Wref, a value 0 is set to the pressing torque Tp to cancel the pressing control (step S170), and a timer T (not shown) of the HVECU 70 is reset to a value 0. The process is started to limit the execution of the pressing control (step S180), and this process is terminated. It should be noted that when the value 0 is set for the pressing torque Tp in this process, it may be set using the rate process.

  If the execution of the pressing control is restricted after the pushing control is released in this way, the next time this process is executed, it is determined that the execution is restricted in step S130, and the elapsed time of the timer T is less than the predetermined time Tref. Is determined (step S190). Here, it is assumed that the predetermined time Tref is determined as a value of about several seconds, for example. When the timer T is less than the predetermined time Tref, it is determined whether or not the output limit Wout of the battery 50 is equal to or greater than a threshold value (Wref + α) obtained by adding a margin α to the threshold value Wref (step S200), and the output limit Wout is the threshold value (Wref + α). ) At this time, the predetermined torque Tset is set as the pressing torque Tp (step S210), and this process is terminated. On the other hand, when the output limit Wout is not equal to or greater than the threshold value (Wref + α), the process is terminated as it is, and the pressing torque Tp is kept at the value 0.

  Here, the storage ratio SOC of the battery 50 is the change in the charge / discharge state of the battery 50 based on the change in the operation state of the engine 22 and the drive state of the motors MG1 and MG2, the change in the load of the auxiliary machine 90 such as an air compressor, the battery. There may be a slight fluctuation due to a change in the battery temperature Tb of 50 or the like. In such a case, if the output limit Wout is set in the vicinity of the threshold value Wref, the output limit Wout may fluctuate in the vicinity of the threshold value Wref and may be above or below the threshold value Wref. The margin α is determined in advance by experiments or the like as a value that exceeds the fluctuation of the output limit Wout. In the embodiment, the pressing control is not re-executed unless the output limit Wout becomes equal to or greater than the threshold (Wref + α) until the predetermined time Tref elapses after the pressing control is executed. Can be restrained from being re-executed immediately after the pressing control is canceled by changing near the threshold value Wref. Even when the output restriction Wout becomes equal to or greater than the threshold value (Wref + α) when the execution is restricted and the pressing control is re-executed, the threshold value Wref is used as it is for the release determination, and the output restriction Wout is used in step S160. The pressing control is canceled when becomes less than the threshold value Wref. For this reason, it is understood that the margin α also functions as a hysteresis for the re-execution of the pressing control after the pressing control is released and the release after the re-execution. For these reasons, it is possible to suppress frequent execution and release of the pressing control by using the threshold value (Wref + α) instead of the threshold value Wref for the determination of the re-execution of the pressing control. Therefore, even if the threshold Wref is set as low as possible in order to increase the opportunity to output the pressing torque Tp as much as possible, the output hunting of the pressing torque Tp can be suppressed, and the hybrid vehicle 20 can be vibrated. It can be prevented from occurring.

  On the other hand, when it is determined in step S190 that the elapsed time of the timer T is equal to or longer than the predetermined time Tref, the execution restriction of the pressing control is released (step S220). When the execution restriction is released, the threshold value Wref is used again to determine the execution of the pressing control, and the pressing torque Tp in step S150 that follows when it is determined in step S140 that the output limit Wout of the battery 50 is greater than or equal to the threshold value Wref. Thus, the predetermined torque Tset is set and the pressing control is re-executed. In this case, since the predetermined time Tref has already passed and the execution and release of the pressing control are not frequently repeated within a short time, there is little possibility that the hybrid vehicle 20 will vibrate.

  Further, when it is determined in step S110 that the rotational speed Ne of the engine 22 does not exceed the value 0, it can be determined that the engine 22 is stopped and it is not necessary to execute the pressing control. Therefore, it is determined whether or not the pressing control is being executed (step S230). If the pressing control is being executed, a value 0 is set to the pressing torque Tp (step S240) and the pressing is performed. This process is terminated without restricting execution of guess control. Here, when the pushing control is released by stopping the engine 22, the pushing control is not re-executed unless the engine 22 is restarted. Therefore, the pushing control is released and re-executed in a short time. It can be considered that there is little risk of repetition. For this reason, the present process is terminated without restricting execution.

  According to the hybrid vehicle 20 of the embodiment described above, when the engine 22 is started, stopped, or operating while the vehicle is stopped, the pressing torque Tp when the output limit Wout of the battery 50 is equal to or greater than the threshold value Wref. Is set to a predetermined torque Tset, and the pressing control for outputting from the motor MG2 is executed. When the output limit Wout becomes less than the threshold value Wref during the pressing control, the pressing torque Tp is set to a value of 0 and pressed. When the output control Wout becomes equal to or greater than the threshold value (Wref + α) obtained by adding the margin α to the threshold value Wref until the predetermined time Tref elapses after the execution control is restricted by canceling the contact control. Since the predetermined torque Tset is set to the pressing torque Tp and the pressing control is executed again, the output limit Wout is set to the threshold value Wre. Even if it fluctuates in the vicinity of f, it is possible to suppress the repeated execution and release of the pressing control.

  In the hybrid vehicle 20 of the embodiment, the re-execution of the pressing control is limited by setting the threshold value for determining the execution of the pressing control until the predetermined time Tref elapses to a threshold value (Wref + α) larger than the threshold value Wref. However, the re-execution of the pressing control may be restricted by prohibiting the re-execution of the pressing control until the predetermined time Tref elapses. In that case, the processing of steps S200 and S210 may be omitted in the pressing torque setting processing of FIG.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “internal combustion engine”, the battery 50 corresponds to the “secondary battery”, the motor MG2 corresponds to the “motor”, and is based on the calculated storage ratio SOC and the battery temperature Tb. The battery ECU 52 that calculates the output limit Wout as the allowable discharge power allowed for the discharge of the battery 50 corresponds to “allowable discharge power setting means”, and the gears of the drive system such as the planetary gear 30 and the differential gear 62 are “gear mechanisms”. When the engine 22 is started, stopped, or operating, when the output limit Wout of the battery 50 is equal to or greater than the threshold value Wref, the pressing torque Tp is set to the predetermined torque Tset and the pressing control is being executed. When the output limit Wout is less than the threshold value Wref, the pressing torque Tp is set to a value of 0 to limit the execution of the pressing control. When the output limit Wout is equal to or greater than the threshold value (Wref + α), the process of steps S100 to S170, S200, and S210 of the pressing torque setting process of FIG. 3 is performed to set the predetermined torque Tset to the pressing torque Tp. The HMG ECU 70 that sets a torque command based on the pushing torque Tp and the canceling torque or a torque command based on the pushing torque Tp and the inverter 42 based on the set torque command are used to control the drive of the motor MG2. The motor ECU 40 is equivalent to the “pressing control means”, and after the output limit Wout of the battery 50 is less than the threshold value Wref and the value 0 is set to the pressing torque Tp, the timer T is started and the timer T is set to a predetermined value. When the time is less than Tref, the pressing torque Tp The pushing of FIG. 3 is performed to restrict the execution of the pressing control by setting the threshold used for the determination of the setting to a threshold (Wref + α) larger than the threshold Wref, and release the execution restriction of the pressing control when the timer T reaches a predetermined time Tref or more. The HVECU 70 that executes the processes of steps S180, S190, and S220 of the application torque setting process corresponds to the “re-execution restriction 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.

  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 manufacturing industry of hybrid vehicles.

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 32 drive shaft, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 50 battery, 51 temperature Sensor, 52 Battery electronic control unit (battery ECU), 54 Electric power line, 62 Differential gear, 63a, 63b Drive wheel, 70 Hybrid ECU (HVECU), 72 CPU, 74 ROM, 76 RAM, 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, 90 Drive circuit, 92 Auxiliary machine, MG , MG2 motor.

Claims (1)

An internal combustion engine that outputs power to a drive shaft that can transmit power to the axle via a gear mechanism, a rechargeable secondary battery, and power from the secondary battery to output power to the drive shaft In a hybrid vehicle comprising: an electric motor; and allowable discharge power setting means for setting allowable discharge power that is power allowable for discharge of the secondary battery based on a state of the secondary battery.
When the output shaft of the internal combustion engine is rotating while the vehicle is stopped, the drive system gear including the gear mechanism is pressed in one direction when the set allowable discharge power is equal to or greater than a first predetermined value . When the pressing control for controlling the electric motor is performed so that the pressing torque is output from the electric motor, and the set allowable discharge power becomes less than the first predetermined value during the pressing control. A pressing control means for releasing the pressing control;
By setting the threshold value used for determination of execution of the pressing control to a second predetermined value larger than the first predetermined value for a predetermined time after the pressing control is released , the pressing control means Re-execution limiting means for limiting re-execution of the pressing control;
A hybrid car with

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