JP5962305B2 - Power control device - Google Patents

Description

  The present invention relates to a technique for controlling two batteries mounted on a vehicle.

Conventionally, a vehicle having only an internal combustion engine is mounted only with a lead battery (hereinafter referred to as a first battery) that supplies electric power to auxiliary equipment of the vehicle.
However, in recent years, a battery (for example, a lithium ion battery, hereinafter referred to as a second battery) for regenerating and temporarily storing energy during deceleration is mounted, and the power stored in the second battery is used as the power of auxiliary equipment. A vehicle to be reused is proposed.

Such a vehicle can reduce the power consumption of the first battery and improve fuel efficiency. On the other hand, in order to make the arrangement space of the second battery in the vehicle as small as possible, it is desired to make the size of the second battery the minimum necessary size.
Further, as disclosed in Patent Document 1, it is known that in an internal combustion engine with a supercharger, a required voltage of an ignition system increases according to a supercharging pressure and a spark plug cap.

Japanese Patent Laid-Open No. 62-165534

  By the way, since arrangement | positioning of the internal combustion engine (especially internal combustion engine which has a supercharger) in an engine room receives a big restriction | limiting, it is difficult to arrange | position a 2nd battery in an engine room. Therefore, the second battery is disposed outside the engine room, for example, under a seat in the vehicle interior. However, if the second battery is disposed outside the engine room, the wiring resistance increases, and thus the voltage drop increases with respect to the terminal voltage of the second battery. And if such a 2nd battery is made to work as a power supply which supplies electric power to an ignition coil, the electric power supply amount to an ignition coil runs short, As a result, there exists a possibility that vehicle performance may fall.

In addition, in order to stably burn in the internal combustion engine, the secondary voltage supplied from the ignition coil needs to be sufficiently larger than the required voltage for igniting the spark plug. However, when a high efficiency battery such as the second battery is used as a power source for supplying power to the ignition coil, this may not be satisfied. In this case, the amount of power supplied to the ignition coil is insufficient, and as a result, the vehicle performance may deteriorate.
An object of the present invention is to prevent a shortage of power supply to the ignition coil.

  In order to solve the above-mentioned problems, (1) one aspect of the present invention regenerates deceleration energy at the time of deceleration of the vehicle, and a first battery that supplies at least electric power to an ignition coil of the internal combustion engine when the internal combustion engine is started. In the power supply control apparatus for controlling the first battery and the second battery of the vehicle having the second battery having a lower voltage than the first battery and stored as electric power, the second battery includes the ignition As a power supply that is mounted on the vehicle so as to be a power source that supplies power to the coil and that predicts a voltage required by the spark plug, and a power source that supplies power to the ignition coil from the second battery A power determination unit that determines whether or not it is working, and a voltage required by the spark plug by the request voltage prediction unit is less than a preset voltage determination threshold value. And when the power supply determination unit determines that the second battery is acting as a power supply for supplying power to the ignition coil, the power supply for supplying power to the ignition coil is supplied from the second battery to the first power supply. And a switching control unit that switches to one battery.

  (2) In one aspect of the present invention, an accelerator pedal opening detection unit that detects the opening of the accelerator pedal is further provided, and the required voltage prediction unit is configured to open the accelerator pedal detected by the accelerator pedal opening detection unit. The rate of change of a preset period of the accelerator pedal opening detected by the accelerator pedal opening detecting unit is set in advance when the degree is equal to or greater than a preset threshold for accelerator pedal opening determination. It is preferable to predict that the voltage required by the spark plug is equal to or higher than a preset voltage determination threshold when the change rate determination threshold is equal to or higher than the predetermined threshold.

  (3) In one mode of the present invention, it further includes an intake pressure detection unit that detects a pressure in the intake pipe that feeds air into the internal combustion engine, and the required voltage prediction unit includes an intake pipe that is detected by the intake pressure detection unit. It is preferable to predict that the voltage required by the spark plug has become equal to or higher than a preset voltage determination threshold value when the pressure is equal to or higher than a preset pressure determination threshold value.

(4) In one aspect of the present invention, the vehicle includes a supercharger that increases an intake air amount to the internal combustion engine, and an accelerator pedal opening detector that detects an opening of an accelerator pedal; An intake pressure detection unit that detects a pressure in an intake pipe that feeds air into the internal combustion engine, and the supply power prediction unit is at least one of the accelerator pedal opening detection unit and the intake pressure detection unit It is preferable to predict that the voltage required by the spark plug will be equal to or higher than a preset threshold value for voltage determination when it is determined that the region is in the high supercharging region based on the detection result.

  According to the invention of the aspect of (1), when the voltage required by the spark plug is predicted to increase, the power supply source to the ignition coil is switched from the second battery to the first battery. It is possible to prevent the power supply amount from becoming insufficient. Accordingly, in the invention of the aspect (1), for example, it is possible to prevent a decrease in vehicle performance due to a shortage of power supply to the ignition coil.

  According to the invention of the aspect of (2), it can be predicted that the required voltage of the spark plug will be increased by predicting that the vehicle will be accelerated based on the operating state of the accelerator pedal by the occupant.

  According to the invention of aspect (3), it can be predicted that the required voltage of the spark plug will increase based on the pressure in the intake pipe.

According to the invention of the aspect of (4), it can be predicted that the required voltage of the spark plug will increase by determining that it is in the high supercharging region .

FIG. 1 is a diagram illustrating a configuration example of a vehicle according to the present embodiment. FIG. 2 is a block diagram illustrating a configuration example of the power supply control device. FIG. 3 is a flowchart illustrating an example of processing by the switching determination unit of the vehicle ECU. FIG. 4 is a flowchart illustrating an example of processing by the power source determination unit and the switching control unit of the ignition ECU.

Embodiments of the present invention will be described with reference to the drawings.
In this embodiment, the power supply control apparatus which controls two batteries with which a vehicle is mounted is mentioned.
(Constitution)
In FIG. 1, the structural example of the vehicle 1 which concerns on this embodiment is shown.

  As shown in FIG. 1, a vehicle 1 is equipped with an internal combustion engine 10 that is an engine. The internal combustion engine 10 has a spark plug 12 in a cylinder head 11. Here, the ignition plug 12 is ignited by applying a high voltage (so-called secondary voltage) by the ignition coil 13. The ignition coil 13 is a transformer for creating a voltage for discharging the spark plug 12. In the present embodiment, the ignition coil 13 is supplied with power from the first battery 2 or the second battery 3. Here, the first battery 2 is a starting battery for starting the internal combustion engine 10. For example, the first battery 2 is a lead battery. The second battery 3 is a highly efficient regenerative battery that is charged by a regenerative current. The second battery 3 is a battery having a lower voltage than the first battery 2. For example, the second battery 3 is a lithium ion battery.

  In the internal combustion engine 10, an intake port 15 and an exhaust port 16 communicating with the cylinder 14 are formed in the cylinder head 11. Here, the intake port 15 is opened and closed by an intake valve 17, and the exhaust port 16 is opened and closed by an exhaust valve 18. The intake port 15 is provided with a port injector 19 for injecting fuel. The end of the intake port 15 is connected to an intake passage (that is, an intake pipe) 20. A throttle valve 21 that controls the amount of intake air is disposed in the intake passage 20. The vehicle 1 is equipped with a supercharger 4, and when the supercharger 4 is operated, pressurized air is sent to the intake passage 20. On the other hand, the end of the exhaust port 16 is connected to an exhaust passage (that is, an exhaust pipe) 22. A catalyst or the like (not shown) is disposed in the exhaust passage 22.

  The vehicle 1 has various sensors. Specifically, the vehicle 1 includes an accelerator pedal opening sensor 31, an intake pressure sensor 32, a throttle opening sensor 33, and a rotation speed sensor 34. Here, the accelerator pedal opening sensor 31 detects the accelerator pedal opening (that is, the depression amount of the accelerator pedal 23). The accelerator pedal opening sensor 31 outputs the detected value to the vehicle ECU 50 (Electronic Control Unit). The intake pressure sensor 32 is disposed in the intake passage 20 and detects the intake pressure. Then, the intake pressure sensor 32 outputs the detected value to the vehicle ECU 50. The throttle opening sensor 33 detects the opening of the throttle valve 21. The throttle opening sensor 33 outputs the detected value to the vehicle ECU 50. The rotational speed sensor 34 is attached to the crankcase 24 of the internal combustion engine 10 and detects the engine rotational speed of the internal combustion engine 10. Then, the rotational speed sensor 34 outputs the detected value to the vehicle ECU 50.

  The vehicle ECU 50 controls the vehicle 1. Specifically, the vehicle ECU 50 performs ignition control of the spark plug 12 (that is, applied voltage control of the ignition coil 13), injection timing control of the port injector 19, and the like based on detection values of various sensors. Further, the vehicle ECU 50 stores, in the second battery 3, deceleration energy when the vehicle 1 is decelerated as electric power by regenerative control based on detection values of various sensors.

  The vehicle ECU 50 includes, for example, a microcomputer and its peripheral circuits. For example, the vehicle ECU 50 includes a CPU, a ROM, a RAM, and the like. The ROM stores one or more programs that realize various processes. The CPU executes various processes according to one or more programs stored in the ROM.

  In the present embodiment, the vehicle ECU 50 includes a power source that supplies power to the ignition coil 13 from the first battery 2 or the second battery 3 based on detection values of the accelerator pedal opening sensor 31 and the intake pressure sensor 32. The control which switches between the 1st battery 2 and the 2nd battery 3 is performed so that it may become.

FIG. 2 shows a configuration of the vehicle 1 that realizes the control.
As shown in FIG. 2, the vehicle 1 further includes an ignition ECU 60 that controls the ignition system. The ignition ECU 60 includes, for example, a microcomputer and its peripheral circuits, like the vehicle ECU 50. For example, the ignition ECU 60 includes a CPU, a ROM, a RAM, and the like. In the present embodiment, including the ignition ECU 60, the vehicle ECU 50, the accelerator pedal opening sensor 31, and the intake pressure sensor 32 constitute a power supply control device 70. In order to realize the switching control, the vehicle ECU 50 includes a switching determination unit 51. The ignition ECU 60 has a power source determination unit 61 and a switching control unit 62.

As shown in FIG. 2, the second battery 3 is disposed outside the engine room 80, for example, under a seat in the vehicle compartment.
FIG. 3 shows a flowchart of an example of processing by the switching determination unit 51 of the vehicle ECU 50 shown in FIG. FIG. 4 shows a flowchart of an example of processing by the power source determination unit 61 and the switching control unit 62 of the ignition ECU 60 shown in FIG. The processing contents of the switching determination unit 51, the power supply determination unit 61, and the switching control unit 62 will be specifically described below in accordance with the processing procedure shown in FIGS.

As shown in FIG. 3, first, in step S <b> 1, the switching determination unit 51 of the vehicle ECU 50 suddenly changes the accelerator pedal opening based on the detected value of the accelerator pedal opening sensor 31 and the detected value of the intake pressure sensor 32. Or whether it is a high supercharging region.
Specifically, the switching determination unit 51 determines that the accelerator pedal opening has suddenly changed when the change rate of the accelerator pedal opening within a preset period is equal to or greater than the threshold for determining the change rate. Here, the preset period and the threshold value for determining the change rate are values preset experimentally, empirically, or theoretically. For example, the switching determination unit 51 determines that the accelerator pedal opening at the present time (during the current process) is 30% (= threshold for determining change rate) or more with respect to the accelerator pedal opening 100 ms before (for example, during the previous process). If it has increased, it is determined that the accelerator pedal opening has suddenly changed. The accelerator pedal opening of 0% means that the accelerator pedal 23 is not depressed by the passenger.

  Moreover, the switching determination part 51 determines with it being a high supercharging area | region, when an accelerator pedal opening is more than an accelerator pedal opening determination threshold value, or an intake pressure is more than an intake pressure determination threshold value. Here, the threshold value for determining the accelerator pedal opening degree and the threshold value for determining the intake pressure are values set experimentally, empirically, or theoretically in advance. For example, when the accelerator pedal opening is 45% (= accelerator pedal opening determination threshold) or higher or the intake pressure is 150 kpa (= intake pressure determination threshold) or higher, the switching determination unit 51 performs high supercharging. It is determined that the area.

Then, when the switching determination unit 51 determines that the accelerator pedal opening is changing suddenly or is in the high supercharging region, a voltage required by the spark plug 12 (required voltage of the spark plug 12) is preset. The process proceeds to step S2 under the prediction that the voltage determination threshold value is exceeded. If not, the switching determination unit 51 ends the process shown in FIG. 3 (the process is performed again from step S1).
In step S <b> 2, the switching determination unit 51 outputs a coil power supply switching request to the power supply determination unit 61 of the ignition ECU 60. Then, the switching determination unit 51 ends the process shown in FIG.

  On the other hand, as shown in FIG. 4, first, in step S <b> 21, the power source determination unit 61 determines whether a coil power source switching request from the switching determination unit 51 has been input. If the power source determination unit 61 determines that the coil power source switching request from the switching determination unit 51 has been input, the process proceeds to step S22. When determining that the coil power supply switching request from the switching determination unit 51 has not been input, the power supply determination unit 61 terminates the process illustrated in FIG. 4 (re-executes the process of step S21).

  In step S <b> 22, the power source determination unit 61 determines whether the current power source is the second battery 3. That is, the power source determination unit 61 determines whether or not the battery currently working as a power source for supplying power to the ignition coil 13 is the second battery 3. If the power source determination unit 61 determines that the current power source is the second battery 3, the process proceeds to step S23. If the power source determination unit 61 determines that the current power source is not the second battery 3, that is, if the current power source is the first battery 2, the processing shown in FIG. 4 ends (from step S21 again). Process).

  In step S <b> 23, the switching control unit 62 switches the power source (that is, a battery that serves as a power source that supplies power to the ignition coil 13) from the second battery 3 to the first battery 2. And the switching control part 62 complete | finishes the process shown in the said FIG. 4 (it implements a process again from the said step S21).

(Operation, action, etc.)
Next, a series of operations and actions of the power supply control device 70 will be described.
When the power supply control device 70 determines that the accelerator pedal opening has suddenly changed or is in the high supercharging region based on the detection value of the accelerator pedal opening sensor 31 and the detection value of the intake pressure sensor 32, the current control device 70 further It is determined whether the power source is the second battery 3 (steps S1 to S3, step S21). Then, when the current power source is the second battery 3, the power control device 70 switches the power source from the second battery 3 to the first battery 2, and when the current power source is the first battery 2, the power source controller 70 switches the power source to the first battery 2. The battery 2 is maintained (steps S22 to S23).

  As a result, when the accelerator pedal opening degree is suddenly changed and the vehicle 1 is predicted to accelerate, that is, when the voltage required by the spark plug 12 is predicted to increase, the power supply control device 70 applies to the ignition coil 13. Can be switched from the second battery 3 to the first battery 2. Therefore, the power supply control device 70 can quickly switch the power supply source to the ignition coil 13 from the second battery 3 to the first battery 2 immediately before the voltage required by the spark plug 12 increases.

  In particular, in the case of the internal combustion engine 10 with a supercharger, there is a time lag from when the occupant depresses the accelerator pedal 23 until supercharging starts. Therefore, there is a time lag from when the passenger depresses the accelerator pedal 23 until the voltage required by the spark plug 12 increases. For this reason, the power supply control device 70 determines the voltage required by the spark plug 12 before supercharging is started by the determination that it is in the high supercharging region (that is, before the actual supercharging pressure is applied). Can be switched from the second battery 3 to the first battery 2 when the electric power supply to the ignition coil 13 is predicted. Therefore, the power supply control device 70 can quickly switch the power supply source to the ignition coil 13 from the second battery 3 to the first battery 2 immediately before the voltage required by the spark plug 12 increases.

  As described above, the power supply control device 70 can switch the power supply source to the ignition coil 13 from the second battery 3 to the first battery 2 immediately before the voltage required by the spark plug 12 increases. It is possible to prevent the power supply amount to the coil 13 from being insufficient. As a result, the power supply control device 70 can prevent a decrease in vehicle performance due to insufficient power supply to the ignition coil 13.

Further, since the vehicle 1 can use the electric power stored in the second battery 3 as a power source for auxiliary machines until just before the voltage required by the spark plug 12 increases, the frequency of use of the first battery 2 is reduced. And improve fuel efficiency.
In the description of the above-described embodiment, the switching determination unit 51 constitutes a required voltage prediction unit, for example. The accelerator pedal opening sensor 31 constitutes, for example, an accelerator pedal opening detector. The intake pressure sensor 32 constitutes an intake pressure detection unit, for example.

(Modification of this embodiment)
In the present embodiment, the vehicle ECU 50 includes a switching determination unit 51, and the ignition ECU 60 includes a power supply determination unit 61 and a switching control unit 62. However, the present embodiment is not limited to this. That is, for example, in the present embodiment, a single ECU (for example, one of the vehicle ECU 50 and the ignition ECU 60) includes the switching determination unit 51, the power supply determination unit 61, and the switching control unit 62. You can also.

  The present embodiment can also be applied to an internal combustion engine that does not include a supercharger (that is, a non-supercharged internal combustion engine). For example, as the internal combustion engine in this case, an internal combustion engine with a high compression ratio in which the required voltage of the spark plug 12 is large can be cited. In this case, for example, in the switching determination unit 51, the rate of change of the accelerator pedal opening within a preset period is set in advance for acceleration determination (that is, for determination of the required voltage of the spark plug). If the change rate determination threshold value or more, or the accelerator pedal opening is greater than the accelerator pedal opening determination threshold value preset for acceleration determination (that is, for determining the required voltage of the spark plug) If the intake pressure is equal to or higher than the intake pressure determination threshold value preset for acceleration determination (that is, for determining the required voltage of the spark plug), the process proceeds to step S2.

  Further, although the embodiments of the present invention have been specifically described, the scope of the present invention is not limited to the illustrated and described exemplary embodiments, and effects equivalent to those intended by the present invention. All embodiments that provide are also included. Further, the scope of the present invention is not limited to the combination of features of the invention defined by claim 1 but can be defined by any desired combination of specific features among all the disclosed features. .

  DESCRIPTION OF SYMBOLS 1 Vehicle, 2 1st battery, 3 2nd battery, 4 Supercharger, 10 Internal combustion engine, 13 Ignition coil, 31 Accelerator pedal opening sensor, 32 Intake pressure sensor, 50 ECU for vehicle, 51 Switching determination part, 60 Ignition ECU, 61 power supply determination unit, 62 switching control unit, 70 power supply control device

Claims (4)

A first battery that supplies at least electric power to an ignition coil of the internal combustion engine when starting the internal combustion engine; a second battery that regenerates and stores deceleration energy during deceleration of the vehicle as electric power; and a lower voltage than the first battery; In the power supply control device for controlling the first battery and the second battery of the vehicle having
The second battery is mounted on the vehicle so as to be a power source for supplying power to the ignition coil.
A required voltage predicting unit for predicting a voltage required by the spark plug;
A power source determination unit for determining whether or not the second battery serves as a power source for supplying power to the ignition coil;
The required voltage predicting unit predicts that the voltage required by the spark plug is equal to or higher than a preset threshold value for voltage determination, and the power supply determining unit supplies power to the ignition coil from the second battery. A switching control unit that switches a power source that supplies power to the ignition coil from the second battery to the first battery when it is determined that the power source works as a power source.
A power supply control device comprising: It further has an accelerator pedal opening detector for detecting the opening of the accelerator pedal,
The required voltage predicting unit detects whether the accelerator pedal opening detected by the accelerator pedal opening detecting unit is equal to or greater than a predetermined threshold value for determining an accelerator pedal opening, or detected by the accelerator pedal opening detecting unit. A voltage determination in which a voltage required by the spark plug is set in advance when the rate of change in a preset period of the opening of the accelerator pedal is equal to or greater than a threshold value for change rate determination set in advance The power supply control device according to claim 1, wherein the power supply control device predicts that the threshold value is greater than or equal to a threshold value. An intake pressure detection unit for detecting a pressure in an intake pipe for sending air to the internal combustion engine;
The required voltage predicting unit is a voltage in which a voltage required by the spark plug is set in advance when the pressure in the intake pipe detected by the intake pressure detecting unit is equal to or higher than a preset threshold value for pressure determination. The power supply control device according to claim 1, wherein the power supply control device predicts that the determination threshold value is exceeded. The vehicle has a supercharger that increases an intake air amount to the internal combustion engine,
An accelerator pedal opening detector that detects the opening of the accelerator pedal, and an intake pressure detector that detects the pressure in the intake pipe that feeds air into the internal combustion engine,
When the required voltage predicting unit determines that the region is a high supercharging region based on the detection result of at least one of the accelerator pedal opening detecting unit and the intake pressure detecting unit, the voltage required by the spark plug is preliminarily determined. The power supply control device according to claim 1, wherein the power supply control device is predicted to be equal to or higher than a set voltage determination threshold value.

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