JP2018118578A - Hybrid vehicle - Google Patents

Abstract

The present invention suppresses deterioration of fuel consumption and emission when an alternator is driven due to an abnormality in a DC / DC converter. In a hybrid vehicle, an engine and a motor are controlled so that the engine runs while driving in a fuel-efficient region where fuel efficiency is good based on a driver's operation. When an abnormality occurs in the DC / DC converter that supplies power to the auxiliary power line to which the auxiliary power storage device is connected, the driving of the DC / DC converter is stopped and the power generated by the alternator is used as the auxiliary power line. The alternator and the engine are controlled so as to be supplied to the engine. At that time, the engine and the motor are controlled so as to increase the power output from the motor so that the engine operation point is changed to the fuel efficiency good region side when the engine operation point exceeds the fuel efficiency good region. [Selection] Figure 2

Description

  The present invention relates to a hybrid vehicle.

  Conventionally, as this type of hybrid vehicle, in a so-called series hybrid vehicle, the power of the power line from the main battery to the driving motor is stepped down and supplied to the power line to which the auxiliary battery that supplies power to the auxiliary machine is connected. A device including a DC / DC converter and an alternator that generates electric power using engine power to supply power to a power line to which an auxiliary battery is connected has been proposed (for example, see Patent Document 1). In this hybrid vehicle, when an abnormality occurs in the DC / DC converter, the alternator is driven to supply power to the power line to which the auxiliary battery is connected.

JP 2000-224709 A

  In a hybrid vehicle that travels using the power from the engine and motor, the power required for driving based on the amount of operation of the driver and the driving state, and the power that is input and output from the motor, taking into account fuel efficiency and emissions, and the engine It distributes to the motive power output from. When an abnormality occurs in the above-described DC / DC converter for such a hybrid vehicle and power is supplied to the power line to which the auxiliary battery is connected, the power necessary for driving the alternator is output from the engine. Since the power is added to the power, the power output from the engine becomes large, the engine operation focus deviates from the region where the engine operates efficiently, and the fuel consumption may deteriorate or the emission may deteriorate.

  The main purpose of the hybrid vehicle of the present invention is to suppress the deterioration of fuel consumption and emission when the alternator is driven due to an abnormality in the DC / DC converter.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An engine capable of outputting power to a drive shaft connected to an axle;
A motor capable of inputting and outputting power to the drive shaft;
A drive power storage device that exchanges power with the motor via a drive power line;
Auxiliary power storage device that supplies power to the auxiliary machine via the auxiliary power line,
A DC / DC converter that steps down the power of the driving power line and supplies the power to the auxiliary power line;
An alternator that generates power using the power of the engine to supply power to the auxiliary power line;
Based on the operation of the driver, the engine and the motor are controlled so that the engine runs in a fuel-efficient region where fuel efficiency is good, and power is supplied to the auxiliary power line. A control device for controlling the DC / DC converter and the alternator;
A hybrid vehicle comprising:
When an abnormality occurs in the DC / DC converter, the control device stops driving the DC / DC converter and supplies the power generated by the alternator to the auxiliary power line. The engine and the engine to increase the power output from the motor so that the engine operating point is changed to the fuel efficiency good region side when the engine operating point exceeds the fuel efficiency good region. Control the motor,
It is characterized by that.

  In the hybrid vehicle according to the present invention, the engine and the motor are controlled so as to run while driving the engine in a fuel-efficient region where fuel efficiency is good based on the operation of the driver. The good fuel economy region is a region represented by the engine speed and torque, and may be a linear operation line, or may be a region of a slight torque width including the linear operation line. When an abnormality occurs in the DC / DC converter, the driving of the DC / DC converter is stopped, and the alternator and the engine are controlled so that the electric power generated by the alternator is supplied to the auxiliary power line. At this time, the engine is controlled so as to output a torque obtained by adding a torque necessary for driving the alternator. At that time, the engine and the motor are controlled so as to increase the power output from the motor so that the engine operation point is changed to the fuel efficiency good region side when the engine operation point exceeds the fuel efficiency good region. Thereby, the driving point of the engine can be changed to the fuel efficiency good region side, and deterioration of fuel efficiency and emission can be suppressed.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 4 is a flowchart showing an example of a control routine executed by the electronic control unit 70 when the DC / DC converter is abnormal. It is explanatory drawing which shows an example of a fuel consumption operation line and a fuel consumption favorable area | region.

  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 illustrated, the hybrid vehicle 20 of the embodiment includes an engine 22, an alternator 24, a motor 30, an inverter 32, a clutch 36, an automatic transmission 40, a battery 60, a DC / DC converter 64, An auxiliary battery 66 and an electronic control unit 70 are provided.

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as a fuel, and the crankshaft 23 is connected to the rotating shaft of the motor 30 and the automatic transmission 40 via a clutch 36. The alternator 24 is connected to the crankshaft 23 by a belt 25, and the generated power is connected to an auxiliary power line 67 to which an auxiliary battery 66 for driving the auxiliary machine is connected. The motor 30 is configured as a synchronous generator motor, for example, and is driven by an inverter 32. The inverter 32 is configured as a well-known inverter circuit including six switching elements and six diodes, and is connected to the battery 60 via the driving power line 61. The battery 60 is configured as a lithium ion secondary battery, for example. The DC / DC converter 64 is configured as a well-known DC / DC converter, and is connected to the drive power line 61 and the auxiliary power line 67, and steps down the DC power voltage of the drive power line 61. To the auxiliary machine power line 67.

  The automatic transmission 40 is configured as a hydraulically driven 8-speed or 10-speed automatic transmission, and includes an input shaft 41 connected to the rotating shaft of the motor 30, an axle 56 and a differential on the drive wheels 55 a and 55 b. It has an output shaft 42 connected to a drive shaft 46 coupled via a gear 57, a plurality of planetary gears, and a plurality of hydraulically driven friction engagement elements (clutch, brake). The automatic transmission 40 forms a forward gear and a reverse gear from the first speed to the eighth speed or the tenth speed by engaging and disengaging a plurality of friction engagement elements, and between the input shaft 41 and the output shaft 42. Transmit power.

  Although not shown, the electronic control unit 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, and an input / output port in addition to the CPU. Signals from various sensors are input to the electronic control unit 70 via input ports. Examples of the signal input to the electronic control unit 70 include a crank angle θcr from a crank position sensor 23 a that detects the rotational position of the crankshaft 23 of the engine 22, and a rotational position that detects the rotational position of the rotor of the motor 30. The rotational position θm of the rotor of the motor 30 from the detection sensor (for example, resolver) 30a, and the rotational speed Np of the drive shaft 46 from the rotational speed sensor 46a attached to the drive shaft 46 can be mentioned. Moreover, the voltage Vb of the battery 60 from the voltage sensor attached between the terminals of the battery 60 and the current Ib of the battery 60 from the current sensor attached to the output terminal of the battery 60 can also be mentioned. Further, the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and the accelerator opening degree Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83 are detected. The brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed V from the vehicle speed sensor 88 can also be mentioned. Here, the shift position SP includes a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), and the like. Various control signals are output from the electronic control unit 70 via an output port. Examples of the signal output from the electronic control unit 70 include a control signal to the engine 22. Further, a control signal to the inverter 32, a control signal to the clutch 36, and a control signal to the automatic transmission 40 can be cited. The electronic control unit 70 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 23a, or based on the rotational position θm of the rotor of the motor 30 from the rotational position detection sensor 30a. The rotational speed Nm of the motor 30 (the rotational speed Natin of the input shaft 41 of the automatic transmission 40) is calculated.

  In the hybrid vehicle 20 of the embodiment configured in this way, the electric traveling (EV traveling) mode in which traveling is performed using the power from the motor 30 without the operation of the engine 22 in the state where the clutch 36 is off, or the clutch 36 is on. In this state, the vehicle travels in a hybrid travel (HV travel) mode that travels using the power from the engine 22 and the motor 30.

  In the HV traveling mode, the automatic transmission 40 is set so that the target gear stage S * of the automatic transmission 40 is set based on the accelerator opening Acc and the vehicle speed V, and the gear stage of the automatic transmission 40 becomes the target gear stage S *. 40 is controlled. Further, the required torque Tp * of the drive shaft 46 (the output shaft 42 of the automatic transmission 40) is set based on the accelerator opening Acc, the vehicle speed V, and the brake pedal position BP, and the required torque Tp * of the drive shaft 46 is automatically set. Based on the gear ratio Gr of the transmission 40, the required torque Tin * of the input shaft 41 of the automatic transmission 40 is calculated. The gear ratio Gr of the automatic transmission 40 is calculated by dividing the rotational speed Nm of the motor 30 (the rotational speed Natin of the input shaft 41 of the automatic transmission 40) by the rotational speed Np of the drive shaft 46, or the automatic transmission 40 A value corresponding to the current gear position can be used. Then, the target torque Te * of the engine 22 is set based on the rotational speed Ne of the engine 22 (= the rotational speed Nm of the motor 30) and the fuel consumption operation line. Here, the fuel efficiency operation line of the engine 22 is a line that defines the relationship among the power Pe, the rotational speed Ne, and the torque Te of the engine 22 that can efficiently drive the engine 22. Further, the torque command Tm * of the motor 30 is set so that the required torque Tin * is output to the input shaft 41. Then, the engine 22 is controlled so that the engine 22 is operated with the target torque Te *, and at the same time, switching control of a plurality of switching elements of the inverter 32 is performed so that the motor 30 is driven with the torque command Tm *.

  In the HV traveling mode, the alternator 24 can be driven. In this case, the torque Talt necessary for the alternator 24 is added to the target torque Te * of the engine 22 as necessary. That is, the engine 22 is driven and controlled by setting the target torque Te * to the torque Talt as a new target torque Te *.

  In the EV travel mode, the target speed S * of the automatic transmission 40 is set in the same manner as in the HV travel mode, and the automatic transmission 40 is set so that the speed of the automatic transmission 40 becomes the target speed S *. Control. Further, the required torque Tp * of the drive shaft 46 is set based on the accelerator opening Acc, the vehicle speed V, and the brake pedal position BP in the same manner as in the HV traveling mode, and the required torque Tp * of the drive shaft 46 and the automatic shift are set. The required torque Tin * of the input shaft 41 of the automatic transmission 40 is calculated based on the gear ratio Gr of the machine 40. Further, the torque command Tm * of the motor 30 is set so that the required torque Tin * is output to the input shaft 41. Then, the operation of the engine 22 is stopped, and the switching control of the plurality of switching elements of the inverter 32 is performed so that the motor 30 is driven by the torque command Tm *.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when an abnormality occurs in the DC / DC converter 64 will be described. FIG. 2 is a flowchart illustrating an example of a DC / DC converter abnormality control routine executed by the electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several milliseconds).

  When the DC / DC converter abnormality control routine is executed, the electronic control unit 70 first determines whether or not the DC / DC converter 64 is normally driven (step S100). This determination can be made by reading an abnormality diagnosis result for determining whether or not any abnormality has occurred in the DC / DC converter 64. When it is determined that the DC / DC converter 64 is operating normally, the control at the time of abnormality is unnecessary, and thus this routine is terminated.

  If it is determined in step S100 that the DC / DC converter 64 is not normally driven, the driving of the DC / DC converter 64 is stopped (step S110), and the driving of the alternator 24 is started (step S120). Thus, even when an abnormality occurs in the DC / DC converter 64, power can be supplied to the auxiliary power line 67 to which the auxiliary battery 66 for driving the auxiliary machine is connected.

  Then, it is determined whether or not the operating point of the engine 22 belongs to the fuel efficiency good region (step S130). In the embodiment, the good fuel efficiency region is set as a region having a slight torque width including the fuel efficiency operation line. FIG. 3 is an explanatory diagram showing an example of a fuel efficiency operation line and a fuel efficiency favorable region. In the figure, the hatched portion is the fuel efficiency good region. As described above, when the alternator 24 is driven, the torque necessary for driving the alternator 24 is added to the torque output from the engine 22 as necessary, so that the operating point of the engine 22 may deviate from the fuel efficiency operation line. Arise. Even if the operating point of the engine 22 deviates from the fuel consumption operation line, if the degree is slight, the degree of deterioration of the fuel consumption and emission is not a problem, but if the degree exceeds slightly, the fuel consumption and emission deteriorates. End up. The good fuel efficiency region of the embodiment is set as a region in which the degree of deterioration of the fuel consumption and emission is not a problem. When the operating point of the engine 22 belongs to the fuel efficiency good region, it is determined that deterioration of fuel efficiency or emission is not a problem, and this routine is terminated.

  In step S130, when the operation point of the engine 22 does not belong to the good fuel efficiency region, that is, when the operation point of the engine 22 exceeds the good fuel efficiency region, a command to increase the output of the motor 30 is output (step S140). This routine is terminated. When a command to increase the output of the motor 30 is output, a torque command Tm * that is increased by a predetermined torque Tset within the rated value range with respect to the torque command Tm * of the motor 30 is set as the torque command Tm *, and the torque ΔT is increased. Only the target torque Te * of the engine 22 is reduced. As a result, the operating point of the engine 22 is within the fuel efficiency good region or approaches the fuel efficiency good region, and deterioration of fuel consumption and emissions can be suppressed. Here, as the predetermined torque Tset, a torque corresponding to a torque necessary for driving the alternator 24 or a torque smaller than this can be used.

  In the hybrid vehicle 20 of the embodiment described above, when it is determined that the DC / DC converter 64 is not normally driven, the driving of the DC / DC converter 64 is stopped and the driving of the alternator 24 is started. When the operating point of the engine 22 exceeds the fuel efficiency good region, a command to increase the output of the motor 30 is output. Thereby, the deterioration of fuel consumption and emission can be suppressed by setting the operating point of the engine 22 within the fuel efficiency good region or approaching the fuel efficiency good region side.

  In the hybrid vehicle 20 of the embodiment, when the DC / DC converter 64 is not normally driven and the driving point of the engine 22 exceeds the fuel efficiency good region, a command to increase the output of the motor 30 is output. did. However, when the DC / DC converter 64 is not normally driven and the operating point of the engine 22 exceeds the fuel consumption operation line, a command to increase the output of the motor 30 may be output.

  Although the hybrid vehicle 20 according to the embodiment includes the battery 60, it may be provided with a capacitor instead of the battery 60, for example, as long as it includes a power storage device that stores electric charges.

  In the embodiment, the present invention is applied to a hybrid vehicle including the engine 22, the alternator 24, the motor 30, the battery 60, the auxiliary battery 66, the DC / DC converter 64, and the automatic transmission 40. The case of doing is illustrated. However, an engine that outputs driving power, a motor that inputs and outputs driving power, a driving power storage device that exchanges power with the motor via a driving power line, and an auxiliary power line Auxiliary power storage device that supplies power to the auxiliary machine, a DC / DC converter that steps down the power of the drive power line and supplies it to the auxiliary power line, and to supply power to the auxiliary power line Any configuration may be used as long as it is a hybrid vehicle equipped with an alternator that generates power using the power of the engine.

  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 manufacturing industry of hybrid vehicles.

 20 hybrid vehicle, 22 engine, 23 crankshaft, 23a crank position sensor, 24 alternator, 25 belt, 30 motor, 30a rotational position detection sensor, 32 inverter, 36 clutch, 40 automatic transmission, 41 input shaft, 42 output shaft, 46 Drive shaft, 46a Rotational speed sensor, 55a, 55b Drive wheel, 56 Axle, 57 Differential gear, 60 Battery, 61 Drive power line, 64 DC / DC converter, 66 Auxiliary battery, 67 Auxiliary power line, 70 Electronic control unit, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor Sensor, 88 vehicle speed sensor.

Claims (1)

An engine capable of outputting power to a drive shaft connected to an axle;
A motor capable of inputting and outputting power to the drive shaft;
A drive power storage device that exchanges power with the motor via a drive power line;
Auxiliary power storage device that supplies power to the auxiliary machine via the auxiliary power line,
A DC / DC converter that steps down the power of the driving power line and supplies the power to the auxiliary power line;
An alternator that generates power using the power of the engine to supply power to the auxiliary power line;
Based on the operation of the driver, the engine and the motor are controlled so that the engine runs in a fuel-efficient region where fuel efficiency is good, and power is supplied to the auxiliary power line. A control device for controlling the DC / DC converter and the alternator;
A hybrid vehicle comprising:
When an abnormality occurs in the DC / DC converter, the control device stops driving the DC / DC converter and supplies the power generated by the alternator to the auxiliary power line. The engine and the engine to increase the power output from the motor so that the engine operating point is changed to the fuel efficiency good region side when the engine operating point exceeds the fuel efficiency good region. Control the motor,
A hybrid vehicle characterized by that.

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