JP2005348484A - Vehicle power control device - Google Patents

Abstract

An external electronic control unit controls a charging voltage based on temperature information without providing a dedicated temperature sensor in addition to a temperature sensor in an alternator.
An electronic control unit estimates the temperature in an engine room based on an output voltage (charging voltage) from an alternator and performs charge control of a battery based on the estimated temperature. It is not necessary to provide another temperature sensor dedicated to the electronic control unit 21 in addition to the temperature sensor 23c in 23. Therefore, the increase in the number of parts can be prevented and the overall cost increase can be reduced.
[Selection] Figure 1

Description

  The present invention relates to a vehicle power supply control apparatus that controls charging of a battery in an automobile by adjusting an output voltage of an alternator.

  In the engine room of the automobile, the charging control for the battery 1 is performed by an alternator 3 as shown in FIG. The alternator 3 includes a generator 7 that converts the rotational force of the engine 5 into electric energy, and a regulator 9 that controls an output voltage from the generator 7 (for example, Patent Document 1).

  The conventional alternator 3 includes a temperature sensor 11 therein. The temperature sensor 11 detects the temperature of the case of the regulator 9, for example, and the battery 1 is detected based on the detected temperature information. The charging voltage to be supplied to is autonomously controlled inside the alternator 3. Specifically, when the temperature of the regulator 9 decreases, the chemical reaction inside the battery 1 slows down and the acceptability of the charging voltage deteriorates. The control is performed to increase the charging voltage supplied to the battery 1 (the output voltage of the alternator 3), and conversely, the charging voltage (the output voltage of the alternator 3) is reduced to prevent overcharging of the battery 1 at high temperatures. Control was performed.

  Here, the temperature sensor 11 inside the regulator 9 is mounted on a printed wiring board constituting the regulator 9, and an output terminal to the outside is not formed.

JP 07-135741 A

  By the way, in addition to the autonomous adjustment control of the charging voltage by the temperature sensor 11 in the alternator 3, there is a request that some kind of temperature control, for example, the charging / discharging timing and the charging voltage for the battery 1 are adjusted and controlled by the temperature of the engine room. There is.

  For example, the types of the battery 1 and the engine 5 vary greatly depending on the vehicle case and the vehicle type. In addition, even in the case of an automobile having the same vehicle type and vehicle type, the manner of charging / discharging the battery 1 varies greatly depending on the operation status such as the running frequency of the automobile.

  Therefore, as in the prior art, only uniform output voltage adjustment based on the temperature inside the alternator 3 may cause a deviation from proper power supply control in the actual vehicle. For example, as shown in FIG. 4, it has been desired to perform control according to temperature using an external electronic control unit (ECU) 13.

  In this case, the detection result of the temperature sensor 11 in the regulator 9 may be used as it is in the external electronic control unit 13, but the temperature sensor 11 is a circuit component of a system closed on the printed wiring board in the regulator 9. And provided as an internal element of the alternator 3 as a unit. For this reason, unless a dedicated output terminal for outputting the detection result of the temperature sensor 11 from the alternator 3 to the outside is formed, it is difficult to output to the outside. If the configuration of the alternator 3 is such that the detection result of the temperature sensor 11 therein can be output to the outside, an output terminal for external output must be additionally formed, and the circuit configuration therefor is also provided. Due to the complexity, the price of the alternator 3 itself as a unit is not only significantly increased, but it also takes time and labor to connect it when mounted on a car.

  Therefore, conventionally, in addition to the autonomous control (basic adjustment) in the regulator 9, some control based on the temperature by the external electronic control unit 13 (for example, according to the operation status such as the vehicle case, the vehicle type, and the driving frequency of the vehicle) ( When performing the correction adjustment, in addition to the temperature sensor 11 in the regulator 9, it is necessary to provide another temperature sensor 15 such as a thermistor in the engine room, and an increase in cost due to an increase in the number of parts is inevitable. .

  On the other hand, if the temperature is estimated based on the output voltage of the alternator 3, it is not necessary to provide another temperature sensor 15 in addition to the temperature sensor 11 in the regulator 9, and the increase in the number of parts is prevented. As a result, the cost increase can be reduced.

  Therefore, an object of the present invention is to provide a vehicle having a simple configuration that can control a charging voltage based on temperature information by an external electronic control unit without providing a dedicated temperature sensor in addition to the temperature sensor in the alternator. It is to provide a power supply control device.

  In order to solve the above-described problems, the present invention is a vehicle power supply control device that controls charging of a battery in an automobile by adjusting an output voltage of an alternator, and generates power according to the rotational force of an engine and supplies the battery to the battery. And an electronic control unit that estimates the temperature in the engine room based on the charging voltage from the alternator and controls the alternator based on the estimated temperature. Is.

  In the vehicle power supply control device according to the first aspect of the present invention, the electronic control unit estimates the temperature in the engine room based on the output voltage (charging voltage) from the alternator, and based on the estimated temperature, the battery Since the charging control is performed, it is not necessary to provide a dedicated temperature sensor for detecting the temperature in the engine room outside the alternator, thereby preventing an increase in the number of parts and reducing the overall cost increase.

<Configuration>
FIG. 1 is a block diagram showing a vehicle power supply control apparatus according to an embodiment of the present invention. As shown in FIG. 1, this vehicle power supply control device is provided with a temperature sensor 23 c inside the alternator 23, and the alternator 23 autonomously adjusts the output voltage (charging voltage) based on the temperature detection result of the temperature sensor 23 c. When the control (basic adjustment) is performed and the electronic control unit (ECU) 21 also performs charge control (correction adjustment) by temperature, the electronic control unit 21 is dedicated to the electronic control unit 21 separately from the temperature sensor 23c in the alternator 23. Instead of providing a temperature sensor, the temperature in the engine room is estimated based on the output voltage (charge voltage) from the alternator 23.

  Here, as shown in FIG. 1, the alternator 23 includes a generator 23a that converts the rotational force of the engine 24 into electric energy, and a regulator 23b that controls the output voltage from the generator 23a. The temperature sensor 23c is installed inside the regulator 23b. The temperature sensor 23c detects, for example, the temperature of the case of the regulator 23b, and the charge supplied to the battery 25 based on the detected temperature information. The voltage is autonomously controlled (basic adjustment) inside the regulator 23b. Specifically, for example, as shown in FIG. 3, as the temperature of the regulator 23 b decreases, the internal chemical reaction of the battery 25 slows down and the acceptability of the charging voltage deteriorates. To increase the charging voltage (the output voltage of the regulator 23b) to be supplied to. Conversely, control is performed to reduce the charging voltage (the output voltage of the regulator 23b) so as to prevent overcharging of the battery 25 at high temperatures.

  In addition to the temperature self-regulation in the regulator 23b in the alternator 23, the electronic control unit 21 controls charging (correction) of the battery 25 based on the temperature, for example, according to the operation status such as the vehicle case, the vehicle type, and the driving frequency of the vehicle. And a function of estimating the temperature in the engine room based on the output voltage (charge voltage) from the regulator 23b of the alternator 23 in the engine room.

  Specifically, the electronic control unit 21 includes an analog processing unit 31 to which an output voltage of the regulator 23b is input, an arithmetic processing unit 33 that performs predetermined arithmetic processing in accordance with a signal given from the analog processing unit 31, A conversion unit 35 that converts the calculation processing result in the calculation processing unit 33 into an analog signal and controls the regulator 23b of the alternator 23 is provided.

  When the output voltage of the alternator 23 (charge voltage applied to the battery 25) is input, the analog processing unit 31 quantizes the output level of the output voltage and converts it into a digital signal, and this digital signal is sent to the arithmetic processing unit 33. Output.

  The arithmetic processing unit 33 is a functional component that operates according to a predetermined software program in a CPU (microphone processor) of a general computer to which a nonvolatile storage device such as a flash ROM and a RAM are connected. In the non-volatile storage device of the arithmetic processing unit 33, for example, as shown in FIG. 3, data indicating the correlation between the appropriate charging voltage of the battery 25 and the temperature in the engine room is stored in a data table or a function expression. Pre-stored in format. Such correlation is determined in advance by a prior experiment or simulation. Then, the CPU of the arithmetic processing unit 33 estimates the temperature in the engine room based on the digital signal given from the analog processing unit 31, and uses the regulator 23b to control charging of the battery 25 based on this temperature. Data for control is calculated, and the calculation result is output to the conversion unit 35.

  The conversion unit 35 converts the calculation result in the calculation processing unit 33 into a voltage, outputs the voltage to the regulator 23b in the alternator 23, and gives a PWM signal to the regulator 23b. The control is performed to realize the voltage.

<Operation>
The operation of the vehicle power supply control apparatus having the above configuration will be described. First, when the engine 24 of the automobile is operated, the rotational force of the engine 24 is transmitted to the generator 23a of the alternator 23, and the generated voltage is output to the regulator 23b by the electromotive force of the generator 23a. Then, a charge voltage is output to the battery 25 by voltage control in the regulator 23b.

  At this time, the temperature sensor 23c installed inside the regulator 23b detects the temperature of the case, for example. The regulator 23b autonomously controls (basic adjustment) the charging voltage supplied to the battery 25 based on the temperature information detected by the temperature sensor 23c.

  Specifically, when the temperature of the regulator 23b decreases, the chemical reaction inside the battery 25 slows down and the charge voltage acceptability deteriorates, and the case where the temperature is relatively low as shown in FIG. Is controlled to increase the charging voltage supplied to the battery 25 (the output voltage of the alternator 23), while decreasing the charging voltage (the output voltage of the alternator 23) to prevent overcharging of the battery 25 at high temperatures.

  In parallel with this, the electronic control unit 21 estimates the temperature in the engine room based on the charging voltage supplied from the alternator 23 to the battery 25, for example, the operation status such as the vehicle grade, the vehicle type, and the driving frequency of the vehicle. Accordingly, the regulator 23b is controlled (corrected and adjusted).

  Specifically, first, when a charging voltage is input to the analog processing unit 31 of the electronic control unit 21, the output level of the output voltage is quantized and converted into a digital signal and output to the arithmetic processing unit 33.

  The arithmetic processing unit 33 estimates the temperature in the engine room based on the digital signal given from the analog processing unit 31, and controls the regulator 23b to control the charging of the battery 25 based on this temperature. Calculate the data. The calculation result is output to the conversion unit 35.

  The conversion unit 35 converts the calculation result in the calculation processing unit 33 into a voltage, outputs the voltage to the regulator 23b in the alternator 23, and gives a PWM signal to the regulator 23b. Realize voltage.

  As described above, the electronic control unit 21 estimates the temperature in the engine room based on the output voltage (charging voltage) from the alternator 23, and controls the charging of the battery 25 based on the estimated temperature. In addition to the temperature sensor 23c in 23b, there is no need to provide another dedicated temperature sensor for detecting the temperature in the engine room, so that an increase in the number of parts can be prevented and the overall cost increase can be reduced.

  Note that when the temperature in the engine room is estimated based on the output voltage from the alternator 23, the voltage adjustment based on the temperature sensor 23c inside the alternator 23 actually varies, and therefore the estimation is based on the output voltage. In many cases, an error occurs in the temperature value. However, since it is possible to roughly estimate the temperature in the engine room, it is possible to roughly detect whether the temperature in the engine room is low or high, and based on the rough detection result. This is effective when charge / discharge control (correction adjustment) of the battery 25 is permitted.

  In the above embodiment, the temperature sensor 23c in the regulator 23b autonomously adjusts the charging voltage, and the electronic control unit 21 further controls the temperature in the engine room based on the output voltage (charging voltage) from the alternator 23. The case where the estimation is performed and the charging control of the battery 25 is performed based on the estimated temperature has been described. However, the regulator 23b does not have the temperature sensor 23c, and the regulator 23b autonomously adjusts the charging voltage. If not, the electronic control unit 21 estimates the temperature in the engine room based on the output voltage (charging voltage) from the alternator 23, and performs charging control of the battery 25 based on the estimated temperature. There is no problem.

It is a block diagram which shows simply the structure of the motor vehicle carrying the electronic control unit as a vehicle power supply control apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows one conventional vehicle power supply control apparatus. FIG. 4 is a diagram illustrating autonomous control of output voltage according to temperature in an alternator 23. It is a block diagram which shows the other conventional vehicle power supply control apparatus.

Explanation of symbols

21 Electronic control unit 22 Non-volatile storage device 23 Alternator 23a Generator 23b Regulator 23c Temperature sensor 24 Engine 25 Battery

Claims (1)

A vehicle power supply control device that adjusts an output voltage of an alternator to control charging of a battery in an automobile,
The alternator that generates power according to the rotational force of the engine and adjusts and outputs the charging voltage to the battery;
A vehicle power supply control device comprising: an electronic control unit that estimates a temperature in an engine room based on the charging voltage from the alternator and controls the alternator based on the estimated temperature.

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