JP2013224070A - Battery run out prevention device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery run out prevention device of a vehicle that can prevent an auxiliary battery from running out of the battery regardless of a state of the main battery.SOLUTION: An electronic control unit 70 starts charging of an auxiliary battery 40 by a voltage conversion device 50 (DC/DC converter), when voltage of the auxiliary battery 40 decreases to a predetermined first threshold voltage, and the voltage of a high voltage battery 30 is higher than a predetermined second threshold voltage. The electronic control unit 70 starts charging of the auxiliary battery 40 by an electric generator 60 by starting an engine 20 when the voltage of the auxiliary battery 40 decreases to the first threshold voltage and the voltage of the high voltage battery 30 is lower than the second threshold voltage.

Description

  The present invention relates to a battery rising prevention device for a vehicle.

  In vehicles equipped with an engine and a battery such as a range extender EV and a hybrid vehicle, there is a system for charging an auxiliary battery from a generator or a main battery during vehicle operation. However, the auxiliary battery cannot be charged when the vehicle is not operating, and the voltage of the auxiliary battery decreases.

  In Patent Document 1, an electric power supply path is formed after a certain time has elapsed since the ignition switch of the vehicle is turned off, and power is transmitted from the main battery to the auxiliary battery via the DC / DC converter. A technique for charging is disclosed.

JP 2006-174619 A

However, if the voltage of the main battery drops, the auxiliary battery cannot be charged and the battery runs out.
SUMMARY OF THE INVENTION An object of the present invention is to provide a battery run-off prevention device for a vehicle that can prevent battery run-up of an auxiliary battery regardless of the state of a main battery.

  According to the first aspect of the present invention, there is provided an auxiliary machine that is supplied with electric power from an auxiliary battery, a generator that is driven by an engine to charge the auxiliary battery, and the auxiliary battery is charged with electric power of a main battery. And a voltage conversion means capable, and when the voltage of the main battery is higher than a predetermined second threshold voltage when the voltage of the auxiliary battery drops to a predetermined first threshold voltage, the voltage First control means for starting charging of the auxiliary battery by means of conversion means; and when the voltage of the auxiliary battery drops to the first threshold voltage, the voltage of the main battery is greater than the second threshold voltage. Is lower, the second control means for starting the engine and charging the auxiliary battery by the generator is provided.

  According to the first aspect of the present invention, when the voltage of the auxiliary battery is lowered to the predetermined first threshold voltage by the first control means, the voltage of the main battery is set to the predetermined second voltage. If it is higher than the threshold voltage, charging of the auxiliary battery is started by the voltage conversion means. Further, when the voltage of the main battery is lower than the second threshold voltage when the voltage of the auxiliary battery drops to the first threshold voltage by the second control means, the engine is started and the auxiliary machine is operated by the generator. The battery is charged.

Therefore, the auxiliary battery can be prevented from running out regardless of the state of the main battery.
According to a second aspect of the present invention, in the vehicle battery prevention device according to the first aspect, the first control means sets the auxiliary battery voltage to a threshold voltage higher than the first threshold voltage. When it reaches, the charging of the auxiliary battery by the voltage conversion means may be terminated.

  According to a third aspect of the present invention, in the vehicle battery rising prevention device according to the first or second aspect, the second control unit is configured such that the voltage of the auxiliary battery is higher than the first threshold voltage. When the voltage is reached, the engine may be stopped.

According to a fourth aspect of the present invention, an auxiliary machine that is supplied with electric power from an auxiliary battery, a generator that is driven by an engine to charge the main battery, and the auxiliary battery can be charged with electric power of the main battery. A voltage conversion means, a first control means for starting charging of the auxiliary battery by the voltage conversion means when the voltage of the auxiliary battery drops to a predetermined first threshold voltage, and the auxiliary battery When the voltage of the main battery is lower than a predetermined second threshold voltage when the voltage of the machine battery drops to the first threshold voltage, or when the auxiliary battery is charged by the voltage conversion means Second control means for starting the engine and charging the main battery by the generator when the voltage of the main battery drops to the second threshold voltage;
The main point is that

  According to the fourth aspect of the present invention, the charging of the auxiliary battery is started by the voltage converting means when the voltage of the auxiliary battery is lowered to the first threshold voltage set in advance by the first control means. The Further, when the voltage of the auxiliary battery is lowered to the first threshold voltage by the second control means, the voltage of the main battery is lower than the predetermined second threshold voltage, or the voltage is corrected by the voltage conversion means. When the main battery voltage drops to the second threshold voltage due to the charging of the machine battery, the engine is started and the main battery is charged by the generator.

Therefore, the auxiliary battery can be prevented from running out regardless of the state of the main battery.
According to a fifth aspect of the present invention, in the vehicle battery prevention device according to the fourth aspect, the first control unit is configured such that the voltage of the auxiliary battery is charged by the voltage conversion unit. When the threshold voltage higher than the threshold voltage to be started is reached, charging of the auxiliary battery by the voltage conversion means may be terminated.

  6. The vehicle battery prevention apparatus according to claim 4, wherein the second control means is configured such that the voltage of the main battery starts the engine and causes the generator to When the threshold voltage higher than the threshold voltage for charging the main battery is reached, the driving of the engine may be stopped.

  According to the present invention, it is possible to prevent the auxiliary battery from running up regardless of the state of the main battery.

The block diagram which shows the electric constitution of the battery rising prevention apparatus of the vehicle in 1st Embodiment. The flowchart for demonstrating the effect | action of the battery rising prevention apparatus of a vehicle. The time chart for demonstrating the effect | action of the battery rising prevention apparatus of a vehicle. The time chart for demonstrating the effect | action of the battery rising prevention apparatus of a vehicle. The block diagram which shows the electric constitution of the battery rising prevention apparatus of the vehicle in 2nd Embodiment. The flowchart for demonstrating the effect | action of the battery rising prevention apparatus of a vehicle. The time chart for demonstrating the effect | action of the battery rising prevention apparatus of a vehicle. The time chart for demonstrating the effect | action of the battery rising prevention apparatus of a vehicle. The time chart for demonstrating the effect | action of the battery rising prevention apparatus of a vehicle.

(First embodiment)
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
The vehicle of this embodiment is a vehicle equipped with an engine and a battery, such as a range extender EV or a hybrid vehicle. Specifically, as shown in FIG. 1, the vehicle includes an engine 20, a high-voltage battery 30 as a main battery, an auxiliary battery 40, a voltage converter (DC / DC converter) 50, a generator 60, An electronic control unit (ECU) 70 is mounted.

  The high voltage battery (main battery) 30 is a high voltage battery of about 400 volts. A traveling motor is connected to the high voltage battery (main battery) 30 via an inverter so that the traveling motor can be driven by the electric power of the high voltage battery 30.

  The auxiliary battery 40 is a low voltage battery of about 13.5 volts. An auxiliary machine such as a radio 41 and a car navigation system 42 and an electronic control unit (ECU) 70 are connected to the auxiliary battery 40. The auxiliary equipment such as the radio 41, the car navigation system 42, and the electronic control unit (ECU) 70 are operated by supplying power from the auxiliary equipment battery 40. That is, the radio 41 and the car navigation system 42 are supplied with power from the auxiliary battery 40.

  A generator 60 is mechanically connected to the engine 20 via a clutch or the like. An auxiliary battery 40 is electrically connected to the generator 60. The generator 60 is driven by driving the engine 20. As the generator 60 is driven, DC power is generated, and the auxiliary battery 40 is charged.

  The high voltage battery 30 and the auxiliary battery 40 are connected via a voltage converter (DC / DC converter) 50. The voltage converter (DC / DC converter) 50 can charge the auxiliary battery 40 by stepping down the high voltage (400 volts or the like) of the high voltage battery 30 to a low voltage (13.5 volts). Yes. That is, the auxiliary battery 40 can be charged with the electric power of the high voltage battery 30 by the voltage converter (DC / DC converter) 50.

  The microcomputer 71 of the electronic control unit (ECU) 70 outputs a control signal to the voltage converter (DC / DC converter) 50 to control the voltage converter (DC / DC converter) 50. Further, the microcomputer 71 of the electronic control unit (ECU) 70 can drive and control the engine 20. Specifically, the microcomputer 71 of the electronic control unit (ECU) 70 controls the starter motor and performs fuel injection control and ignition control, and can start and stop the engine.

  An ignition switch (engine switch) 80 is connected to the radio 41, the car navigation system 42, the electronic control unit (ECU) 70, and the like. Then, an operation signal of the ignition switch 80 is sent to the radio 41, the car navigation system 42, the electronic control unit (ECU) 70, and the like.

  The electronic control unit (ECU) 70 has a voltage sensor 72, and the microcomputer 71 of the electronic control unit 70 monitors (detects) the voltage of the high voltage battery 30 based on a signal from the voltage sensor 72. Further, the electronic control unit (ECU) 70 has a voltage sensor 73, and the microcomputer 71 of the electronic control unit 70 monitors (detects) the voltage of the auxiliary battery 40 by a signal from the voltage sensor 73. ).

Next, the operation of the thus configured vehicle battery rising prevention device 10 will be described.
In the description of the action, it is assumed that the vehicle is not operated for a long time, and the ignition key is removed (the engine switch is in a non-operating state). In the present embodiment, the engine 20 is driven by the ignition switch 80 even when the ignition switch 80 is not operated (in this case, the radio 41 and the car navigation system 42 are not driven).

The microcomputer 71 of the electronic control unit (ECU) 70 executes the process shown in FIG. In explaining the processing content, the time charts of FIGS. 3 and 4 are used.
3 and 4, the voltage Va of the auxiliary battery 40, the voltage Vb of the high voltage battery (main battery) 30, the driving status of the voltage converter (DC / DC converter) 50, and the driving status of the engine 20 are shown from above.

  3 and 4, the minimum voltage at which the electronic control unit (ECU) 70 can operate normally is V1. This voltage V1 is a threshold voltage for the voltage Va of the auxiliary battery 40. Further, as shown in FIGS. 3 and 4, a threshold voltage (= V1 + α) that is higher than the threshold voltage (first threshold voltage) V1 by a predetermined voltage value α is set for the voltage Va of the auxiliary battery 40. Further, a threshold voltage (second threshold voltage) V2 is set for the voltage Vb of the high-voltage battery 30 as shown in FIGS.

  In FIG. 3, the voltage Va of the auxiliary battery 40 is higher than the threshold voltage V1 before the timing t1. Similarly, in FIG. 4, the voltage Va of the auxiliary battery 40 is higher than the threshold voltage V1 before the timing t11. 3 and 4, the voltage Va of the auxiliary battery 40 gradually decreases.

  The microcomputer 71 of the electronic control unit 70 determines whether or not the voltage Va of the auxiliary battery 40 has reached the threshold voltage V1 in step 100 of FIG. When the microcomputer 71 of the electronic control unit 70 detects that the voltage Va of the auxiliary battery 40 has reached the threshold voltage V1 (timing t1 and t11 in FIGS. 3 and 4), in step 101, the high voltage battery (main battery). It is determined whether the voltage Vb of 30 is less than the threshold voltage V2.

  Here, in FIG. 3, the voltage Vb of the high voltage battery (main battery) 30 is equal to or higher than the threshold voltage V2. In FIG. 4, the voltage Vb of the high voltage battery (main battery) 30 is less than the threshold voltage V2.

  If the voltage Vb of the high voltage battery 30 is equal to or higher than the threshold voltage V2 (timing t1 in FIG. 3), the microcomputer 71 of the electronic control unit 70 proceeds to step 102 and activates the voltage converter (DC / DC converter) 50. Then, the auxiliary battery 40 is charged from the high voltage battery 30 (charging is started). As the voltage converter (DC / DC converter) 50 is started (driven), the voltage Va of the auxiliary battery 40 increases as shown in FIG. The voltage Vb of the high voltage battery (main battery) 30 decreases as the voltage converter (DC / DC converter) 50 is driven.

  After executing the process of step 102, the microcomputer 71 of the electronic control unit 70 proceeds to step 104, where the voltage Va of the auxiliary battery 40 is a specified value (= V1 + α) obtained by adding a predetermined voltage value α to the threshold voltage V1. ) Is determined. At the timing t2 in FIG. 3, when the voltage Va of the auxiliary battery 40 reaches the specified value (= V1 + α), the microcomputer 71 of the electronic control unit 70 proceeds to step 105 and stops driving the voltage conversion device 50. (The charging of the auxiliary battery 40 is terminated). The electronic control unit (ECU) 70 is also in a standby state.

When the auxiliary battery 40 is charged by driving the voltage converter (DC / DC converter) 50 from t1 to t2 in FIG. 3, devices such as the radio 41 and the car navigation system 42 are not operating.
On the other hand, in step 101 of FIG. 2, since the voltage Vb of the high voltage battery (main battery) 30 is less than the threshold voltage V2 at the timing of t11 in FIG. 4, the microcomputer 71 of the electronic control unit 70 is If the voltage Vb of the high-voltage battery 30 is less than the threshold voltage V2 (timing t11 in FIG. 4), the routine proceeds to step 103 and the engine 20 is started. The generator 60 is driven by starting (driving) the engine 20. As the generator 60 is driven, the auxiliary battery 40 is charged and the voltage Va of the auxiliary battery 40 increases as shown in FIG.

  After executing the processing of step 103, the microcomputer 71 of the electronic control unit 70 proceeds to step 104, where the voltage Va of the auxiliary battery 40 is a specified value (= V1 + α) obtained by adding a predetermined voltage value α to the threshold voltage V1. ) Is determined. Then, at the timing t12 in FIG. 4, when the voltage Va of the auxiliary battery 40 reaches the specified value (= V1 + α), the microcomputer 71 of the electronic control unit 70 proceeds to step 105 and the engine 20 (generator 60). Stop driving. The electronic control unit (ECU) 70 is also in a standby state.

When the auxiliary battery 40 is charged by driving the engine 20 at t11 to t12 in FIG. 4, devices such as the radio 41 and the car navigation system 42 are not operating.
As described above, in a vehicle equipped with an engine and a battery, such as a range extender EV or a hybrid vehicle, in order to prevent a voltage drop (battery increase) of the auxiliary battery 40 when the vehicle is not operated for a long period of time, The voltage Va is monitored. Then, when the voltage Va of the auxiliary battery 40 decreases to the threshold voltage V1, the remaining capacity of the high voltage battery 30 is confirmed with the voltage Vb, and when there is a sufficient remaining capacity in the high voltage battery 30 (when the voltage Vb is high). Charges the auxiliary battery 40 from the high voltage battery 30. On the other hand, when the high voltage battery 30 does not have a sufficient remaining capacity (when the voltage Vb drops to the threshold voltage V2), the engine 20 is started to operate the generator 60, and the auxiliary battery 40 is charged with the generated electricity. To do. At this time, when the engine 20 is started and the generator 60 is operated, only the electronic control unit 70, which is the minimum necessary device, is operated, so that power consumption can be suppressed and power generation efficiency can be increased.

As described above, according to the present embodiment, the following effects can be obtained.
(1) The configuration of the vehicle battery rising prevention device includes a radio 41 and a car navigation system 42 as auxiliary devices, a generator 60, a voltage conversion device (DC / DC converter) 50 as voltage conversion means, and an electronic control unit 70. It has. The electronic control unit 70 as the first control means is configured such that the voltage Vb of the high-voltage battery 30 is predetermined when the voltage Va of the auxiliary battery 40 is reduced to a predetermined first threshold voltage V1. When the voltage is higher than the threshold voltage V2, charging of the auxiliary battery 40 is started by the voltage converter (DC / DC converter) 50. When the voltage Va of the auxiliary battery 40 drops to the first threshold voltage V1 and the voltage Vb of the high voltage battery 30 is lower than the second threshold voltage V2, the electronic control unit 70 as the second control means The engine 20 is started and the auxiliary battery 40 is charged by the generator 60. Therefore, regardless of the state of the high voltage battery 30 (even if the voltage of the high voltage battery 30 is lowered, the engine 20 is started and the auxiliary battery 40 is charged by the generator 60). Can be prevented.

  That is, as long as the fuel of the engine 20 continues, the high-voltage battery 30 can be charged to prevent a voltage drop (battery rise) of the auxiliary battery 40 over a long period of time. In addition, since the engine is not linked to the operation state of the ignition switch 80 when the engine is driven, only the electronic control unit 70, which is the minimum necessary device, is operating. Thereby, it can charge, suppressing power consumption.

  (2) When the voltage Va of the auxiliary battery 40 reaches a threshold voltage (= V1 + α) higher than the first threshold voltage V1, the electronic control unit 70 as the first control means converts the voltage as the voltage conversion means. Since the charging of the auxiliary battery 40 by the device (DC / DC converter) 50 is terminated, it is practically preferable.

  (3) The electronic control unit 70 as the second control means stops the driving of the engine 20 when the voltage Va of the auxiliary battery 40 reaches a threshold voltage (= V1 + α) higher than the first threshold voltage V1. Therefore, it is preferable practically.

(4) The electronic control unit 70 as the first control means and the second control means operates by receiving power supply from the auxiliary battery 40, and the electronic control unit 70 is normal at the first threshold voltage V1. The lowest voltage that can be operated. Therefore, since the first threshold voltage V1 is the lowest voltage at which the electronic control unit 70 can operate normally, the electronic control unit 70 can be operated normally.
(Second Embodiment)
Next, the second embodiment will be described focusing on the differences from the first embodiment.

  In this embodiment, the configuration shown in FIG. 5 is used instead of FIG. As shown in FIG. 5, a generator 61 is mechanically connected to the engine 20 via a clutch or the like. A high voltage battery (main battery) 30 is electrically connected to the generator 61. The generator 61 is driven by starting (driving) the engine 20. As the generator 61 is driven, DC power is generated and the high voltage battery 30 is charged. Since other configurations are the same as those in FIG. 1, the same reference numerals are given and description thereof is omitted.

Next, the operation of the thus configured vehicle battery rising prevention device 10 will be described.
The microcomputer 71 of the electronic control unit (ECU) 70 executes the process shown in FIG. In explaining the processing content, the time charts of FIGS.

  7, 8, and 9, the voltage Va of the auxiliary battery 40, the voltage Vb of the high voltage battery (main battery) 30, the driving status of the voltage converter (DC / DC converter) 50, and the driving status of the engine 20 are shown from above. Show.

  In FIGS. 7, 8, and 9, the minimum voltage at which the electronic control unit (ECU) 70 can operate normally is V1. This voltage V1 becomes the threshold voltage (first threshold voltage) for the voltage Va of the auxiliary battery 40. Further, a threshold voltage (= V1 + α) higher than the threshold voltage V1 by a predetermined voltage value α is set for the voltage Va of the auxiliary battery 40. Further, a threshold voltage (second threshold voltage) V2 is set for the voltage Vb of the high-voltage battery 30 as shown in FIGS. Further, a threshold voltage (= V2 + β) that is higher than the predetermined threshold voltage V2 by a predetermined voltage value β is set for the voltage Vb of the high-voltage battery 30.

  In FIG. 7, the voltage Va of the auxiliary battery 40 is higher than the threshold voltage V1 before the timing t21. Similarly, in FIG. 8, the voltage Va of the auxiliary battery 40 is higher than the threshold voltage V1 before the timing t31. In FIG. 9, the voltage Va of the auxiliary battery 40 is higher than the threshold voltage V1 before the timing t41. 7, 8 and 9, the voltage Va of the auxiliary battery 40 gradually decreases.

  The microcomputer 71 of the electronic control unit 70 determines (monitors) whether or not the voltage Va of the auxiliary battery 40 has decreased to the threshold voltage V1 in step 200 of FIG. This is the premise of the process of FIG. When the microcomputer 71 of the electronic control unit 70 detects that the voltage Va of the auxiliary battery 40 has reached the threshold voltage V1 (timing t21, t31, t41 in FIGS. 7, 8, and 9), voltage conversion is performed in step 201. The apparatus (DC / DC converter) 50 is started. As the voltage converter (DC / DC converter) 50 is started (driven), the voltage converter 50 charges the high voltage battery 30 to the auxiliary battery 40 (charging is started), as shown in FIGS. In addition, the voltage Va of the auxiliary battery 40 increases. On the other hand, the voltage Vb of the high-voltage battery (main battery) 30 decreases as the voltage converter (DC / DC converter) 50 is driven as shown in FIGS.

  The microcomputer 71 of the electronic control unit 70 determines whether or not the voltage Vb of the high voltage battery (main battery) 30 is equal to the threshold voltage V2 or whether the voltage Vb of the high voltage battery 30 is lower than the threshold voltage V2 in step 202 of FIG. judge.

  7 and 8, the voltage Vb of the high-voltage battery (main battery) 30 is higher than the threshold voltage V2 at timings t21 and t31 when Va = V1. In FIG. 7, the voltage Vb of the high voltage battery (main battery) 30 does not become the threshold voltage V2 even if the voltage Vb decreases as the voltage converter (DC / DC converter) 50 is driven. The voltage Vb of the battery (main battery) 30 decreases as the voltage converter (DC / DC converter) 50 is driven and becomes the threshold voltage V2. On the other hand, in FIG. 9, the voltage Vb of the high voltage battery (main battery) 30 is lower than the threshold voltage V2 at the timing t41 when Va = V1.

  The microcomputer 71 of the electronic control unit 70 determines that the voltage Vb of the high voltage battery 30 is equal to the threshold voltage V2 or the voltage Vb of the high voltage battery 30 is lower than the threshold voltage V2 (timing at t32 in FIG. 8 and t41 in FIG. 9). ), The process proceeds to step 203 and the engine 20 is started. The generator 61 is driven by starting (driving) the engine 20. The high voltage battery 30 is charged with the electric power generated as the generator 61 is driven, and the voltage Vb of the high voltage battery 30 increases as shown in FIGS.

  In step 204, the microcomputer 71 of the electronic control unit 70 determines whether or not the voltage Va of the auxiliary battery 40 has become a specified value (= V1 + α) obtained by adding the predetermined voltage value α to the threshold voltage V1. Then, at the timings t22, t33, and t42 in FIGS. 7, 8, and 9, the microcomputer 71 of the electronic control unit 70 proceeds to step 205 when the voltage Va of the auxiliary battery 40 reaches the specified value (= V1 + α). The drive of voltage converter (DC / DC converter) 50 is stopped (charging of auxiliary battery 40 by voltage converter 50 is terminated).

  In step 206, the microcomputer 71 of the electronic control unit 70 determines whether or not the voltage Vb of the high voltage battery 30 has become a specified value (= V2 + β) obtained by adding the predetermined voltage value β to the threshold voltage V2. 8 and 9, when the voltage Vb of the high-voltage battery 30 reaches the specified value (= V2 + β), the microcomputer 71 of the electronic control unit 70 proceeds to Step 207 and moves to the engine 20 (generator 60) is stopped. The electronic control unit (ECU) 70 is also in a standby state.

When charging the auxiliary battery 40 at t21 to t22, t31 to t34, and t41 to t43 in FIGS. 7, 8, and 9, devices such as the radio 41 and the car navigation system 42 are not operating.
In this way, it is possible to prevent a voltage drop (battery running out) of the auxiliary battery 40 only by adding the voltage sensors 72 and 73 and correcting the software of the ECU.

As described above, according to the present embodiment, the following effects can be obtained.
(5) As a configuration of the vehicle battery rising prevention device, the radio 41 and the car navigation system 42 as an auxiliary machine, a generator 61, a voltage conversion device (DC / DC converter) 50 as a voltage conversion means, and an electronic control unit 70 It has. Then, the electronic control unit 70 as the first control means compensates by the voltage conversion device (DC / DC converter) 50 when the voltage Va of the auxiliary battery 40 is lowered to a predetermined first threshold voltage V1. The charging of the battery 40 is started. Further, the electronic control unit 70 as the second control means is configured such that the voltage Vb of the high voltage battery 30 is predetermined when the voltage Va of the auxiliary battery 40 decreases to the first threshold voltage V1. When the voltage Vb of the high voltage battery 30 is lowered to the second threshold voltage V2 by charging the auxiliary battery 40 by the voltage conversion device 50 or when the voltage Vb is lower than V2, the engine 20 is started and the high voltage battery 30 is generated by the generator 61. To charge. Therefore, regardless of the state of the high voltage battery 30 (even if the voltage of the high voltage battery 30 decreases, the engine 20 is started, the high voltage battery 30 is charged by the generator 61, and the auxiliary battery 40 is charged by the voltage converter 50. Therefore, the auxiliary battery 40 can be prevented from running out.

  In other words, if the vehicle is equipped with a system for charging the high voltage battery 30 by driving the engine 20, it is possible to prevent the auxiliary battery 40 from running out for a long time only by adding the voltage sensors 72 and 73 and changing the software. Is possible.

  (6) When the voltage Va of the auxiliary battery 40 reaches the threshold voltage (= V1 + α) higher than the first threshold voltage V1, the electronic control unit 70 as the first control means (/ DC converter) 50 ends charging of auxiliary battery 40, which is practically preferable.

  (7) Since the electronic control unit 70 as the second control means stops driving the engine 20 when the voltage Vb of the high voltage battery 30 reaches a threshold voltage (= V2 + β) higher than the second threshold voltage V2. I liked it practically.

  (8) The electronic control unit 70 as the first control means and the second control means operates by receiving power supply from the auxiliary battery 40, and the electronic control unit 70 is normal at the first threshold voltage V1. The lowest voltage that can be operated. Therefore, since the first threshold voltage V1 is the lowest voltage at which the electronic control unit 70 can operate normally, the electronic control unit 70 can be operated normally.

The embodiment is not limited to the above, and may be embodied as follows, for example.
-The kind of engine is not limited, For example, a gasoline engine or a diesel engine may be sufficient.

-The type of auxiliary equipment is not limited, and anything other than radio or car navigation is acceptable.
The electronic control unit 70 is operated by receiving power from the auxiliary battery 40, but is not limited to this, and may be operated by receiving power from a power source different from the auxiliary battery 40. Good.

Next, a technical idea that can be grasped from the above embodiment will be added.
(A) The first control means and the second control means operate by receiving power from the auxiliary battery, and the first threshold voltage is determined by the first control means and the second control voltage. The vehicle battery prevention apparatus according to any one of claims 1 to 6, wherein the means is a minimum voltage at which normal operation is possible.

  DESCRIPTION OF SYMBOLS 20 ... Engine, 30 ... High voltage battery, 40 ... Auxiliary battery, 41 ... Radio, 42 ... Car navigation, 50 ... Voltage converter, 60 ... Generator, 61 ... Generator, 70 ... Electronic control unit (ECU).

Claims (6)

An auxiliary machine that receives power from the auxiliary battery, and
A generator that is driven by an engine to charge the auxiliary battery;
Voltage conversion means capable of charging the auxiliary battery with the power of the main battery;
If the voltage of the main battery is higher than a predetermined second threshold voltage when the voltage of the auxiliary battery drops to a predetermined first threshold voltage, the auxiliary battery is converted by the voltage conversion means. First control means for starting charging,
If the voltage of the main battery is lower than the second threshold voltage when the voltage of the auxiliary battery is reduced to the first threshold voltage, the engine is started and the auxiliary battery is turned off by the generator. A second control means for charging;
An apparatus for preventing a battery from rising in a vehicle.   The first control means terminates charging of the auxiliary battery by the voltage converting means when the voltage of the auxiliary battery reaches a threshold voltage higher than the first threshold voltage. Item 2. The battery rising prevention device according to Item 1.   The said 2nd control means stops the drive of the said engine, when the voltage of the said auxiliary battery reaches the threshold voltage higher than the said 1st threshold voltage, The drive of the said engine is characterized by the above-mentioned. Vehicle battery rise prevention device. An auxiliary machine that receives power from the auxiliary battery, and
A generator that is driven by an engine to charge the main battery;
Voltage conversion means capable of charging the auxiliary battery with the power of the main battery;
First control means for starting charging of the auxiliary battery by the voltage conversion means when the voltage of the auxiliary battery drops to a predetermined first threshold voltage;
When the voltage of the auxiliary battery is lowered to the first threshold voltage, the voltage of the main battery is lower than a predetermined second threshold voltage, or the auxiliary battery is charged by the voltage conversion means A second control means for starting the engine when the voltage of the main battery drops to the second threshold voltage and charging the main battery by the generator;
An apparatus for preventing a battery from rising in a vehicle.   The first control means terminates charging of the auxiliary battery by the voltage converting means when the voltage of the auxiliary battery reaches a threshold voltage higher than the first threshold voltage. Item 5. The vehicle battery rise prevention device according to Item 4.   6. The vehicle according to claim 4, wherein the second control unit stops driving the engine when the voltage of the main battery reaches a threshold voltage higher than the second threshold voltage. 7. Battery rise prevention device.