JP4324457B2 - Vehicle power supply system, vehicle power supply control device, and vehicle power supply control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To utilize a generator for driving a vehicle effectively by supplying power to an electric load different from a motor for driving the vehicle when the vehicle stops or the vehicle is not driven by the motor. <P>SOLUTION: The power supply system for a vehicle having a pair of wheels being driven through an engine, and a pair of wheels driven by a motor comprises a first generator driven by the engine to charge a battery, a second generator for supplying power to the motor, and a switch for switching electrical connection between electrical connection passages of the second generator and the motor wherein the switch can connect the second generator with an electric load other than the motor. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a vehicle power supply system mounted on a vehicle, and more particularly to a vehicle power supply system in which one wheel is driven by an engine and the other wheel is driven by an electric motor, a vehicle power supply control device, and a vehicle power supply control method. About.

  As a conventional vehicle drive device, for example, as described in JP-A-2001-253256, it is driven by an engine, and a first generator that charges a battery, an electric motor that drives wheels, and an engine And a second generator for driving and supplying electric power to the electric motor, wherein the electric motor is disposed in the vicinity of a differential gear integrated with a speed reduction mechanism located at a substantially central portion of the rear wheel. is there.

JP 2001-253256 A

  However, the vehicle drive device described in Japanese Patent Application Laid-Open No. 2001-253256 is used only for driving a vehicle as a power generator of a vehicle drive motor. Therefore, when the vehicle is stopped while operating the engine, the generator does not exhibit its power generation capability even though it has the capability of generating power.

  This means that in order to use a battery charged by a generator as a power source for, for example, an electric heating catalyst system or a vehicle window heating system, a DC-DC converter or an inverter for boosting the voltage is required. Due to the problems of reduced reliability and increased cost due to the complexity, it has not been widely spread to date.

  In addition, the electric heating catalyst system and the vehicle window heating system are relatively limited in use frequency such as when the engine is started and when the vehicle window is frozen in a cold region.

  However, despite the limited use frequency, the problem of cost to increase the power generation capacity of the battery and the battery charging generator for the establishment of an electric heating catalyst system and a vehicle window heating system. The reason is that the electric heating catalyst system and the vehicle window heating system are not widely spread.

  The object of the present invention is to supply a generator for driving a vehicle as a power source for an electric load different from the motor for driving the vehicle when the vehicle is stopped or when the vehicle is not driven by the motor. An object of the present invention is to provide a vehicle power supply system, a vehicle power supply control device, and a vehicle power supply control method capable of effectively utilizing a vehicle driving generator.

  In order to achieve the above object, the present invention provides a power supply system for a vehicle having a pair of wheels driven by an engine and a pair of wheels driven by an electric motor, which is driven by the engine and charges a battery. It is possible to switch the electrical connection between the first generator, the second generator that supplies power to the motor, and the electrical connection path of the second generator and the motor. The switch includes a switch, and the switch enables the second generator to be connected to an electric load other than the electric motor.

  By configuring in this way, the generator for driving the vehicle is supplied as a power source for an electric load different from the motor for driving the vehicle when the vehicle is stopped or when the vehicle is not driven by the motor. Thus, the generator for driving the vehicle can be used effectively.

  Preferably, the electric load is an electric heating catalyst system or a vehicle window heating device.

  Preferably, the electric load can be an electric load operable at a voltage different from the voltage generated by the first generator or the battery terminal voltage.

  Preferably, when the second generator is connected to an electric load other than the electric motor, the pair of wheels driven by the electric motor are not driven.

  Preferably, when the second generator is connected to an electric load other than the electric motor, a means for warning that a pair of wheels driven by the electric motor is not driven is provided.

  Preferably, when the vehicle starts when the second generator is connected to an electric load other than the electric motor, power supply to the electric load is stopped and electric power is supplied to the electric motor. Constitute.

  Further, preferably, the output voltage of the second generator is measured, and when the output voltage becomes a predetermined value or less, the power generation of the generator is stopped.

  In order to achieve the above object, according to the present invention, there is provided a power supply control device for a vehicle having a pair of wheels driven by an engine and a pair of wheels driven by an electric motor, the generator being connected to the electric motor. Control connection and switching of the generator to an electrical load other than the motor.

  In order to achieve the above object, according to the present invention, there is provided a power control method for a vehicle having a pair of wheels driven by an engine and a pair of wheels driven by an electric motor, the generator being connected to the electric motor. Switching between connection and connection of the generator to an electrical load other than the motor is performed.

  According to the present invention, by supplying a generator for driving a vehicle as a power source of an electric load different from the motor for driving the vehicle when the vehicle is stopped or when the vehicle is not driven by the motor, It is possible to provide a vehicular power supply system, a vehicular power supply control device, and a vehicular power supply control method that can effectively use a vehicular drive generator.

  The configuration and operation of the embodiment of the present invention will be described below with reference to FIG.

  The four-wheel drive vehicle 1 includes an engine 2, and the driving force of the engine 2 is transmitted to the front wheels 6 and 7 via the transmission 3 and the front axles 4 and 5, whereby the front wheels 6 and 7 are rotationally driven, and the entire vehicle Performs operations such as moving forward and backward.

  On the other hand, the driving force of the rear wheels is rotationally driven by the operation of the DC motor 8 by being transmitted to the rear wheels 13 and 14 via the speed reducer 9, the clutch 10, the rear wheel axles 11 and 12, and the like. Here, the DC motor is driven by electric power generated by a second generator 17 different from the first generator 16 for charging the battery 15 and lighting a headlamp (not shown).

  However, the rear wheel drive by the electric motor 8 is not performed unless the driver requests the operation by turning on the switch 18. This is necessary only when the rear wheels are driven in the same way as the front wheels when the vehicle operates safely, such as when driving on rear roads on snowy roads or when driving on slippery roads in rainy weather. This is because it is not necessary to always operate.

  On the other hand, by disengaging the clutch 10 and separating the rear wheel axles 11, 12 and the speed reducer 9, and the electric motor 8 from the rear wheels 13, 14, for example, when traveling at high speed in a good road surface condition such as a paved road in fine weather. By reducing friction loss, the fuel consumption rate can be reduced.

  The output of the engine 2 is controlled by an electronic control throttle (not shown) that is driven by a command from an engine control unit (ECU) 19. The electronically controlled throttle is provided with an accelerator opening sensor (not shown), and detects the accelerator opening. The transmission 3 is an automatic transmission, and is controlled by an automatic transmission control unit (ATCU) 20 so as to achieve a gear ratio selected by a select lever (not shown). (Not shown).

  Further, the brakes 21, 22, 23 and 24 provided on the front wheels 6 and 7 and the rear wheels 13 and 14 have anti-lock brakes (ABSCU) 25 controlled by an anti-lock brake (ABSCU) 25, respectively. ABS) actuators 26, 27, 28, 29 are provided.

  The front wheels 6 and 7 and the rear wheels 13 and 14 are provided with rotation sensors 30, 31, 32 and 33 for detecting the rotation speed and the rotation direction. The ABS control unit 25 calculates the friction coefficient Μ of the road surface based on the output of the rotation sensors 30, 31, 32, 33, etc., and applies the braking force according to the value of the friction coefficient ブ レ ー キ to the brakes 21, 22, 23, Actuators 26, 27, 28, and 29 are operated so as to be supplied to 24.

Signals are input from an engine control unit (ECU) 19, ABSCU 25, and ATCU 20 to a power supply control unit (PCU) 34 serving as a vehicle power supply control device. For example, rotation sensors 30, 31, 32, and 33 are input through the ABSCU 25. The vehicle speed is calculated from the detected rotational speed information, and the vehicle is operated by the electric motor by controlling the field current of the second generator 17 and the electric motor 8 based on the calculated vehicle speed. However, in this case, information from each control unit may be obtained via an in-vehicle LAN (CAN) bus.

  Here, the PCU 34 determines the state of the vehicle based on the input information, and determines which electric load the power from the generator is supplied by switching the switch 35. For example, if an electric heating catalyst system (EHC) 36 is provided, the switch 35 is switched at the time of start-up, and the output of the second generator 17 is supplied to the EHC 36.

At this time, since the output of the second generator 17 cannot be supplied to the electric motor 8, when the switch 18 is ON, the PCU 34 should make the vehicle driver recognize that the rear wheel drive by the electric motor 8 is impossible. A warning light 37 such as a position below the speedometer, for example, that can be recognized by the driver in the passenger compartment is turned on. Thus, the driver can recognize that the rear wheel drive by the electric motor 8 does not operate, and can drive the vehicle safely. Thereafter, if the power supply to the EHC 36 becomes unnecessary, the PCU 31 can turn off the warning lamp 36 and switch the switch 35 to supply the output of the second generator 17 to the electric motor 8.

  Here, an example in which the driver recognizes whether or not the rear wheel drive by the electric motor 8 can be performed with a warning lamp has been described. However, for example, an indicator lamp for recognizing that the EHC 36 is operating may be turned on.

  Further, when the switch 35 is switched to the EHC 36 side in order to supply power to the EHC 36 with the switch 18 turned ON, even if the driver issues a command to the ECU 19 to depress the accelerator, the electronic control By preventing the engine speed from increasing by controlling the throttle, the vehicle can be prevented from starting.

In addition, when power is supplied to the EHC 36 with the switch 18 turned on, considering a case where a relatively steep slope is started on a slippery road surface, even if the warning light 37 is turned on, the driver can If not noticed, the driver may misunderstand that the rear wheels are driven by an electric motor, and the vehicle may enter a starting operation, so that the driver's sense does not match the behavior of the vehicle. In this case, it is conceivable that the vehicle moves in the direction opposite to the traveling direction. In order to avoid such a situation, for example, when the switch 18 is ON and the switch 35 is in a state of supplying a current to the EHC 36, the progress of the vehicle selected by the selection lever (not shown) of the automatic transmission. The direction is input from the ATCU 20 to the PCU 34 through a gear position detection sensor (not shown), and at the same time, the vehicle speed information from the vehicle speed sensors 32 and 33 of the rear wheels is input to the ABSCU.
25 to the PCU 34.

  When the gear position and the vehicle speed are opposite, the PCU issues an instruction to the ABSCU 25 to operate the rear wheel actuators 28 and 29 and apply the brakes to prevent the vehicle from moving backward.

  A program of the control operation as described above is stored in the memory of a series of control units, signals of sensors are input to the microprocessor in each unit, and communication is performed between each control unit. The safety of the vehicle can be ensured while ensuring the operation of the parts related to the laws and regulations.

The above vehicle operation control is an example of the operation in a state in which the switch 18 for determining whether or not the DC motor 8 for driving the rear wheels is operated is ON, and the switch 18 is OFF. In this case, it is possible to start by driving the front wheels by the engine 2 while the second generator 17 supplies power to the EHC 36.

  As described above, the EHC 36 is described as an example of the electric load for the second generator 17 to supply electric power in addition to the electric motor 8, but the same applies to the case of the vehicle window heating device (QCG) 38. By switching 35, the electric load supplied by the second generator 17 can be selected.

  Here, the priority of the power supply to the electric load can be arbitrarily selected by storing the program in the memory in the PCU 34. Therefore, for example, it is possible to select to always give priority to the rear wheel drive by the electric motor 8 as compared with the power supply to other electric loads.

  Also, even in the case of an electrical load, such as the EHC 36 or the QCG 38, it is desirable to operate at a higher voltage than the reference voltage of the battery mounted on the vehicle, for example, around 14V, for example. By controlling the field current from the PCU 34 in the same manner as the control of the electric motor 8, the generated voltage of the second generator 17 can be controlled. Of course, even if the electrical load connected to the switch 35 operates at substantially the same voltage as the battery mounted on the vehicle, the power is supplied from the second generator 17 by the command value from the PCU 34 without any problem. It becomes possible to do.

  Further, if necessary, the PCU 34 gives an instruction to the electronic control throttle via the ECU 19 to increase the engine speed during idling, thereby causing the second generator 17 to rotate. It is also possible to increase the generated power.

  Further, when the vehicle transmits while supplying power to the EHC 36 by a program stored in the PCU 34, for example, the behavior is judged from the signal of the rotation sensor, the power supply to the EHC is stopped, and the electric motor 8 is stopped. It is also possible to switch the switch 35 so as to supply electric power, and by determining the priority of the operation of the electric motor 8 involved in the operation of the vehicle and other electric loads in consideration of the state of operation of the vehicle in advance. Highly safe and practical vehicle operation can be obtained.

FIG. 2 shows another embodiment. In the present embodiment, the same number of junction boxes 39, 40, 41 as the electric loads connected in parallel to the output terminal of the second generator 17 are connected in series to each electric load. The junction boxes 39, 40, and 41 can have their capacities and component configurations changed according to the load. Basically, the relays 42, 43, and 44, sensors 45 for monitoring the power generation voltage of the generator, 46, 47, voltage sensors 48, 49, 50 for monitoring the voltage applied to each electric load, and current sensors 51, 52, 53 for monitoring the current flowing through each electric load. According to the instruction of the PCU 34, the relays 42, 43,
By opening and closing 44, the electric power of the second generator 17 is supplied to each electric load. Here, the PCU 34 operates only one of the relays 42, 43, 44 to operate only one of the electric loads connected in parallel to the output end of the second generator 17. There is no problem even if the operating voltage of each electric load is different.

  Also, if the electrical load connected in parallel to the output end of the second generator 17 operates at the same voltage, if the second generator can supply sufficient power, by operating a plurality of relays, It is possible to supply power to each.

The operation of the embodiment shown in FIG. 2 will be described in detail with reference to FIG. 3. The PCU 54 controls the relays 55, 56 and 57. Here, the relay 55 controls the operation of the rear wheel motor 58, the relay 56 controls the QCG 59, and the relay 57 controls the operation of the EHC 60. For example, when the 55 relay is turned on, the 12V power supply (battery) 61 to the BB terminal 63 of the generator 62 are provided. 12V power is supplied to the generator 62 through the PC, and a duty signal is supplied from the PCU 54 to the CL terminal 64 of the generator 62, so that the power switch 65 built in the generator 62 operates, whereby the generator An exciting current flows through the field coil 66 of the rotor 62, and the generator 62 is charged.

  At the same time, the relay 71 connected to the power supply circuit of the electric motor 58 is also turned ON, and the electric power from the generator 62 is supplied to the electric motor 58. When the rotational speed further increases and the output voltage of the generator 62 becomes higher than the voltage of the 12V power supply 61, the supply of excitation current from the 12V power supply 61 through the BB terminal 63 is stopped, and the generator 62 is switched to self-excited power generation. Here, 67 is a stator of the generator, around which a stator winding is wound. 68 represents a rectifier.

The above description is for the case where the electric motor 58 is operated. The same applies to the case where the QCG 59 and the EHC 60 are operated. Can be supplied to each electric load. By the way, the second generator 62 is variable in voltage, and when generating at a high voltage, when the generated voltage exceeds a certain level, the supply from the battery 61 is stopped, and a part of the current generated by itself is reduced to the field coil. Power is generated by energizing 66. Therefore, when the generated voltage is on the relatively high voltage side, the voltage applied to the field coil is also high, so that the current flowing in the field coil whose resistance value is not variable becomes relatively large, The temperature of the field coil rises, and in the worst case, the insulation of the field coil is broken and a short circuit is caused.

  Therefore, for example, from the values of the current sensor 51 and the voltage sensor 48 that measure the value of the current supplied to the motor 8 shown in FIG. 2 and the field current control signal of the second generator that is output from the PCU 34, The generator can be protected by predicting the temperature of the generator and shutting off the power generation as necessary.

  In other words, the rotational speed of the second generator, the field current flowing through the field coil (duty%), the generated current, the relationship between the voltage and the temperature of the field coil are obtained by experiments on the desk, and the field is determined from the relationship. By storing the threshold value of the generated current in consideration of the temperature of the magnetic coil in the power supply control unit, the actual power generation is lower than the threshold value stored in advance for the field current command of a certain power supply control unit. In this case, it is possible to protect the generator by determining that the field coil is heated and stopping the power generation.

  However, the above-described control that is relatively complicated and requires a large amount of information to be stored in the power supply control unit is performed by controlling the output current and voltage of the second generator, particularly when power is supplied to the motor. Because the output torque of the generator is always controlled, the generator does not always generate 100%, that is, the duty of the field current control is not 100%. The field current control signal of the current generator is monitored, and the relationship between the generated current, voltage and the field current control signal of the second generator from the power supply control unit and the temperature of the field current can be investigated and stored in advance. Although it is necessary, as described above, for example, when an electric heating catalyst or a vehicle window heating system is operated, the second generator always generates electric power at its full capacity. And the not the duty of the field current control of the second generator is always 100%.

  Therefore, even if the power control unit does not store the complicated relationship between the field current control signal of the second generator, the generated current, and the generated voltage, the generated current is calculated in consideration of the generated voltage and the temperature of the field coil. It is possible to control and protect the generator only with the threshold.

  As described above, according to the embodiments of the present invention, it is desirable to use an electric load such as EHC or QCG that is desirably operated at a higher voltage than a voltage around 14 V widely used in ordinary vehicles, and a terminal voltage around 14 V. A DC-DC converter or inverter is connected by connecting to a generator that can vary the voltage and current to control the operation of the motor for driving the rear wheels, not the generator for charging the battery Such an expensive and complicated device is not required.

  In addition, for example, in the case of a system for deicing by heating the window glass in front of the driver seat with QCG or the like, it is mainly used when the vehicle is stopped, and power is supplied to the motor for driving the rear wheels. There is no need to supply. Therefore, basically, when the vehicle is stopped, the generator that supplies power to the rear-wheel drive motor does not generate power, and the generator can be used effectively according to the present invention. .

  In addition, it is possible to operate a generator that charges the battery and an electric load that may operate at a voltage different from that of the battery with a simple and inexpensive system. Furthermore, it is possible to sufficiently ensure the safety and the original function of the vehicle equipped with the system.

  In particular, the present invention relates to a vehicle power supply system in which one wheel is driven by an engine and the other wheel is driven by an electric motor, a vehicle power supply control device, and a vehicle power supply control method. When the vehicle is driven or not driven by the electric motor, it can be supplied as a power source of an electric load different from the electric motor for driving the vehicle, and the electric power of the generator for driving the vehicle can be used effectively.

1 is a system configuration diagram illustrating configurations of a vehicle drive device and a vehicle power supply system according to an embodiment of the present invention. It is a system block diagram which shows the structure of the vehicle drive device which is another Example of this invention, and a vehicle power supply system. FIG. 3 is a system diagram supplementing the embodiment of the invention shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Four-wheel drive vehicle, 2 ... Engine (internal combustion engine), 3 ... Transmission, 4, 5 ... Front axle, 6, 7 ... Front wheel, 8 ... DC motor, 9 ... Reduction gear, 10 ... Clutch, 11, 12 ... Rear wheel axle, 13, 14 ... rear wheel, 15 ... battery, 16 ... first generator, 17 ... second generator, 18 ... rear wheel drive switch, 34 ... power control unit (PCU), 35 ... switch 37 ... Warning light, 55, 56, 57 ... Relay, 58 ... Rear wheel motor, 59 ... Vehicle window heating system (QCG), 61 ... 12V power supply (battery), 63 ... BB terminal, 64 ... CL terminal, 65 ... Power switch, 66 ... Field coil of the second generator, 67 ... Stator of the second generator.

Claims (16)

A power supply system for a vehicle having a pair of wheels driven by an engine and a pair of wheels driven by an electric motor,
A first generator driven by the engine to charge a battery;
A second generator driven by the engine and capable of supplying a voltage higher than the voltage of the battery to the electric motor;
A switch that enables switching of electrical connection between the electrical connection path of the second generator and the electric motor,
The switch is an electric load desired to operate the second generator at a voltage higher than the voltage of the battery other than the electric motor, and the output of the second generator is connected to the battery. A vehicle power supply system that is connectable to an electric load supplied directly without being connected.   2. The vehicle power supply system according to claim 1, wherein the electric load is an electric heating catalyst system or a vehicle window heating device. The vehicle power supply system according to claim 1, wherein when the second generator is connected to an electric load other than the electric motor, the pair of wheels driven by the electric motor are not driven by the electric motor. A power supply system for a vehicle characterized by comprising. 4. The vehicle power supply system according to claim 3, wherein when the second generator is connected to an electric load other than the electric motor, a pair of wheels driven by the electric motor are not driven by the electric motor. A vehicle power supply system comprising a warning means. 2. The power supply system for a vehicle according to claim 1, wherein when the second generator is connected to an electric load other than the electric motor and the vehicle starts, power supply to the electric load is stopped and the electric motor is stopped. A vehicle power supply system configured to supply electric power to a vehicle.   2. The vehicle power supply system according to claim 1, wherein the output voltage of the second generator is measured, and the generator is stopped when the output voltage becomes a predetermined value or less. A vehicle power supply system characterized by the above. A pair of wheels driven by an engine, a pair of wheels driven by an electric motor, a first generator driven by the engine to charge a battery, and a voltage of the battery on the electric motor driven by the engine A power supply control device for a vehicle having a second generator capable of supplying a higher voltage ,
Said second generator, and connected to the electric motor, a front Symbol electrical load it is desired to operate at a higher voltage than the voltage of the battery other than the electric motor, the output of the second generator power control apparatus for a vehicle and controlling the switching of the connection to the electrical load to be supplied directly without the battery. 8. The power control apparatus for a vehicle according to claim 7, wherein when the second generator is connected to an electric load other than the electric motor, the pair of wheels driven by the electric motor are not driven by the electric motor. A power supply control device for a vehicle, characterized in that 9. The power control apparatus for a vehicle according to claim 8, wherein when the second generator is connected to an electric load other than the electric motor, the pair of wheels driven by the electric motor are not driven by the electric motor. A power control apparatus for a vehicle, characterized in that control is performed to warn the vehicle. The power supply control device for a vehicle according to claim 7, wherein when the vehicle starts when the second generator is connected to an electric load other than the electric motor, the power supply to the electric load is stopped to A power supply control device for a vehicle, wherein control is performed so as to supply electric power to the electric motor. 8. The power control apparatus for a vehicle according to claim 7, wherein the output voltage of the second generator is measured, and when the output voltage becomes a predetermined value or less, the power generation of the second generator is stopped. A power supply control device for a vehicle, characterized by being controlled as described above. A pair of wheels driven by an engine, a pair of wheels driven by an electric motor, a first generator driven by the engine to charge a battery, and a voltage of the battery on the electric motor driven by the engine A power supply control method for a vehicle having a second generator capable of supplying a higher voltage than
Said second generator, and connected to the electric motor, a front Symbol electrical load it is desired to operate at a higher voltage than the voltage of the battery other than the electric motor, the output of the second generator power supply control method for a vehicle, characterized in that for switching between the connection to the electrical load to be supplied directly without the battery. The power control method for a vehicle according to claim 12, wherein when the second generator is connected to an electric load other than the electric motor, the pair of wheels driven by the electric motor are not driven by the electric motor. A power control method for a vehicle, characterized by: The power control method for a vehicle according to claim 13, wherein when the second generator is connected to an electric load other than the electric motor, a pair of wheels driven by the electric motor are not driven by the electric motor. A power control method for a vehicle, characterized in that control is performed to warn the vehicle. 13. The power control method for a vehicle according to claim 12, wherein when the vehicle starts when the second generator is connected to an electric load other than the electric motor, the power supply to the electric load is stopped and the electric power is stopped. A power supply control method for a vehicle, characterized in that control is performed so as to supply electric power to an electric motor. 13. The vehicle power supply control method according to claim 12, wherein an output voltage of the second generator is measured, and when the output voltage becomes a predetermined value or less, the power generation of the second generator is stopped. A power supply control method for a vehicle, characterized in that

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