JP2946592B2 - Power supply for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a vehicle that generates a plurality of types of DC voltages based on an output from a generator rotated by an engine.

[Prior Art] A vehicle power supply device is usually mounted on a vehicle by rectifying a current flowing through an armature winding of a generator rotated by an engine to generate a DC voltage, and using the generated DC voltage. Power is supplied to the electrical load. Also, the generator is not rotated when the engine is stopped, and the generated power from the generator cannot be obtained. Therefore, the battery is charged with the DC voltage generated during the rotation of the generator, and when the rotation of the generator is stopped, the battery is charged. Power is supplied to the load.

In recent years, various electric loads having different operating voltages have been mounted on vehicles, and it has been demanded that a power supply device can be supplied with electric power at various DC voltages corresponding to these electric loads. .

Conventionally, in order to meet such demands, a DC voltage obtained by full-wave rectification of the current flowing through the armature winding is applied to a series circuit composed of two batteries, and the connection point of the batteries is changed to the armature winding. DC voltage obtained by full-wave rectification of each battery voltage by connecting to the neutral point of
The power is supplied by the voltage across two batteries connected in series to an electric load that operates at a high voltage, and the power is supplied by the voltage of one battery to an electric load that operates at a low voltage. Use a generator with a plurality of armature windings for each voltage, and provide a rectifier circuit and a battery for each winding to provide an electrical load corresponding to each voltage. It is considered to supply power respectively.

[Problems to be Solved by the Invention] In the above-described measures, power can be supplied to electric loads having different operating voltages, but power can be supplied at a different voltage even when the rotation of the generator is stopped. Since a battery is provided for each voltage in order to
A plurality of batteries must be mounted on the vehicle, and there is a problem that the power supply device becomes large and the weight of the vehicle increases.

On the other hand, in order to obtain a plurality of types of DC voltages from one battery, for example, the technology described in Japanese Patent Application Laid-Open No. 62-163599 discloses a battery for a conventional vehicle power supply device that generates a specific DC voltage. Connect a DC-DC converter and
It is easily conceivable to generate a DC voltage different from the battery voltage using a DC converter. In other words, the above publication discloses that in a power supply device that rectifies an output from a generator and converts the rectified DC voltage into an AC voltage by an inverter, a battery used for energizing a field winding of the generator is charged. Therefore, it is described that the DC voltage obtained by rectifying the generator output is stepped down by a DC-DC converter, and from this description it is easy to use a DC-DC converter to obtain a plurality of DC voltages. Can be considered.

However, when using a DC-DC converter like this,
Although only one battery is required, a DC-DC converter must be provided for each voltage in order to generate a DC voltage different from the battery voltage. Sometimes, the DC-DC converter must always be operated, which causes various problems such as an increase in the size of the power supply device, an increase in the weight of the vehicle, and an increase in cost, and is not suitable for general public vehicles.

Therefore, the present invention can generate a plurality of types of DC voltages with one battery, not only when the generator is rotating but also when the generator is stopped, without using a DC-DC converter for generating a different voltage. It has been made to provide a vehicle power supply device.

Means for Solving the Problems In order to achieve the above object, an invention according to claim 1 is a generator including a field rotor rotated by an engine of a vehicle and an armature stator. And a rectifier for rectifying the current flowing through the armature winding of the generator and feeding the rectified current to the plurality of output terminals (9, 15). A battery (13) connected to one output terminal (9) and charged by receiving a predetermined DC voltage rectified by the rectification means; and a second output terminal ( 15) a switching means (TR1) for forming an energization path to the armature winding for supplying power to the power supply, and a switching means (TR1) intermittently controlled by a control signal (21); and a rotation stop detecting means (40) for detecting rotation stop of the generator. The rotation of the generator is detected by the rotation stop detecting means. When the stop is detected, a control signal for causing the switching means to be turned on and off at a predetermined cycle is applied, and when the rotation of the generator is stopped, the battery is output from the battery via the switching means, the armature winding and the rectifying means. The gist of the present invention is a vehicle power supply device including: a control unit (20 (excluding 40)) for supplying power to a second output terminal (15) of the plurality of output terminals.

Next, the invention described in claim 2 is characterized in that the armature winding is made of a Y-connected three-phase, and the switching means (TR1) is connected to a neutral point (3a). The gist of the present invention is a vehicle power supply device.

[Operation] In the vehicle power supply device according to the present invention configured as described above, when the generator is rotating, the rectifying unit includes:
The current flowing through the armature winding is rectified by the rotation of the generator to generate a plurality of DC voltages, and the battery is charged with a specific DC voltage among the generated DC voltages.

On the other hand, when the engine stops and the generator stops rotating,
Although the generated power of the generator is lost and the DC voltage is not generated by the generated power, in the present invention, the fact is detected by the rotation stop detecting means, and the rotation stop of the generator is stopped by the rotation stop detecting means. Is detected, the switch means provided on the power supply path from the battery to the armature winding supplying power to the second output terminal is turned on and off according to the control signal output from the control means, and the switching means, The power is supplied to the second output terminal via the armature winding and the rectifier. For this reason, even if the rotation of the generator is stopped, it is possible to flow a current through the armature winding of the generator in the same manner as when the generator is rotating, and it is possible to generate a plurality of types of DC voltages in the rectifier. Become like That is, in the present invention, when the rotation of the generator is stopped, the switching means causes the armature winding and the rectifier to function as a DC-DC converter so that a DC voltage can be generated in the same manner as when the generator is rotating.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 is a schematic configuration diagram showing the configuration of the entire vehicle power supply device of the embodiment.

The power supply device for a vehicle according to the present embodiment includes two types of armature windings 1, 3 for a high voltage and a low voltage on an armature stator as generators.
And a rectifier circuit 5, 7 rectifies the current flowing through each armature winding 1, 3 to generate two types of high and low DC voltages.

Each of the armature windings 1 and 3 is composed of a three-phase armature winding connected in a Y-connection, and the armature winding 1 for high voltage has a total of 2 for each of the phases x, y and z.
The windings are wound four times, and the armature winding 2 for low voltage is wound six times in total for each phase u, v, w. The rectifier circuits 5, 7 for rectifying the current flowing through the armature windings 1, 3 are respectively connected to the armature windings.
The armature winding 1 is configured as a well-known diode bridge that is connected to the terminals of the respective phases 1 and 3 to perform three-phase full-wave rectification.
The rectifier circuit 5 on the side generates a high voltage of 48 VDC, and the rectifier circuit 7 on the armature winding 3 side generates a low voltage of 12 VDC. The output terminal (high-voltage output terminal) 9 of the rectifier circuit 5 is connected to a high-voltage load 11 operating at 48 V DC and a battery 13 for storing 48 V, and the output terminal (low-voltage output terminal) 15 of the rectifier circuit 7 is , Low voltage load 17 operating on DC 12V
It is connected to the.

Next, the low-voltage armature winding 3 Y-connected as described above.
The neutral point 3a is grounded via a diode D1 whose forward direction is toward the neutral point 3a, and is connected to the low voltage rectifier circuit 7 via a diode D2 whose reverse direction is toward the neutral point 3a. Connected to the positive pole. The neutral point 3a is also connected to the positive pole of the rectifier circuit 5 for high voltage via the transistor TR1. The transistor TR1 is used to supply current to the low-voltage armature winding 3 from the battery 13 when the rotation of the generator is stopped.
Is turned on / off by a control signal input to the base terminal 21 from the terminal.

The field winding 23 wound on the field rotor of the generator includes:
A well-known voltage regulator 25 that controls the field current so that the output voltage from the high-voltage rectifier circuit 5 becomes constant (48 V) is connected.

Next, the low-voltage control circuit 20 is configured as shown in FIG.

As shown in the figure, in the low-voltage control circuit 20, the terminal voltage of the low-voltage output terminal 15 is applied to the differential amplifier via the smoothing circuit 30.
Input to 32 non-inverting input terminals (+). Differential amplifier 32
The reference voltage Vref from the reference voltage generating circuit 34 is input to the inverting input terminal (−) of the reference voltage generator. The differential amplifier 32 outputs the low voltage according to the deviation between the low voltage output terminal 15 and the reference voltage Vref. A lower voltage is output as the terminal voltage of the output terminal 15 is lower. In this embodiment, the output voltage is designed to fluctuate in the range of 0 to 2.5 V with respect to the fluctuation of the terminal voltage of the low voltage output terminal 15 caused by the fluctuation of the low voltage load 17.

Next, the output terminal of the differential amplifier 32 is connected to the non-inverting input terminal (+) of the comparator 36. The sawtooth wave generated by the triangular wave generation circuit 38 and changing from 0 to 5 V at a constant period T is input to the inverting input terminal (-) of the comparator 36.
The comparator 36 outputs a signal that goes high when the output voltage of the differential amplifier 32 is equal to or higher than the voltage level of the sawtooth wave. Therefore, the comparator 36 outputs a control signal in which the ratio of the high level, that is, the duty ratio (t / T shown in the drawing) changes within a range of 0 to 50% in accordance with the output voltage from the differential amplifier 32. Is generated.

The control signal generated by the comparator 36 is a rotation detector
The signal is input to the AND circuit 42 together with the detection signal from 40. The rotation detector 40 is equivalent to the above-described rotation stop detection means for detecting the rotation state of the generator, and outputs a detection signal that is low when the generator is rotating and high when the rotation of the generator is stopped. . Therefore, the output terminal of the AND circuit 42 is at the Low level when the generator is rotating, and switches between the High-Low level according to the control signal from the comparator 36 when the generator is stopped rotating.

Next, the output terminal of the AND circuit 42 is connected to the light emitting diode 46 in the photocoupler 44 via the resistor R1.
The circuit 42 causes the light emitting diode 46 to emit light when its output terminal goes to the high level. On the other hand, the phototransistor 48 in the photocoupler 44 has a battery voltage (48
V), the emitter side is the base terminal of transistor TR1
21 and grounded via a resistor R2. Therefore, when the light emitting diode 46 emits light, the phototransistor 48 conducts, a current flows through the resistor R2, the transistor TR1 is turned on by the voltage across the resistor R2, and the battery is connected to the neutral point of the low-voltage armature winding 3. A voltage of 48 V will be applied.

Next, the operation of the vehicle power supply device of the present embodiment configured as described above will be described.

First, when the generator is rotating, a low level signal is output from the rotation detector 40.
The emitter terminal of R1 is always at the Low level, and the transistor TR1 is turned off. On the other hand, in this state, since the generator is rotating, a current flows through each of the armature windings 1 and 3 according to the rotation speed of the generator and the field current flowing through the field winding 23, and In circuits 5 and 7, a DC voltage is generated.
As described above, the field current of the field winding 23 is determined by the voltage regulator.
25, the output voltage of the high-voltage rectifier circuit 5 is controlled to be 48 V, so that the output voltage of the high-voltage rectifier circuit is always controlled to 48 V, and power is supplied to the high-voltage load 11 by this output voltage. And the battery 13 is charged. Also, at this time, since the turn ratio of the armature windings 1 and 3 is 24: 6, the output voltage of the low-voltage rectifier 7 is 12 V (= 48 V
× 6/24).

In this state, the diodes D1 and D2 function as so-called power generation auxiliary diodes (exciter diodes), and output the third harmonic component to the low voltage load 17 side, thereby contributing to the improvement of the generated power.

Next, when the generator stops rotating, the rotation detector
The transistor TR1 is detected by the transistor TR1 according to a control signal which is detected by the voltage control circuit 20 and subjected to duty control so that the terminal voltage of the low voltage output terminal 15 becomes a predetermined level.
Are turned on and off. Then, a high voltage of 48 V of the battery 13 is applied to the neutral point 3a of the low-voltage armature winding 3 at a predetermined cycle, and each phase winding of the low-voltage armature winding 3 and the low-voltage rectifier circuit 7, A pulsating voltage is applied to the loop passing through the low voltage load. In this loop, since the parallel circuit of each phase winding of the low voltage armature winding 3 is connected in series, the high voltage of the battery 13 is determined by the on-off frequency and the duty ratio of the transistor TR1 with respect to this inductance. Is converted to low voltage suitable for low voltage load with low loss. That is, the switching of the transistor TR1 causes the low-voltage armature winding 3 and the low-voltage rectifier circuit 7 to operate as a DC-DC converter.

At this time, the diode D1 functions as a flywheel diode for suppressing a flyback voltage generated when the transistor TR1 is turned off, and the electromagnetic energy stored in each phase winding of the low-voltage armature winding 3 when the transistor TR1 is turned on. Consumption without loss.

As described above, in the vehicle power supply device of the present embodiment, when the generator rotates, the current flowing through the armature windings 1 and 3 by the rotation is rectified by the rectifier circuits 5 and 7 so that Generates DC voltage of each kind (48V and 12V)
1 and 17, respectively, and when the rotation of the generator is stopped, power is supplied to the high-voltage load 11 by the output voltage from the battery 13 that has been charged during the rotation of the generator. In this case, the battery 13 and the low-voltage armature winding 3 are turned on and off at a predetermined cycle, so that a current flows through the low-voltage armature winding 3 in the same manner as when the generator is rotating. The rectification circuit 7 generates a low voltage by rectification to supply the voltage. Therefore, not only when the generator is rotating but also when the generator is stopped, two types of DC voltage can be generated by one battery without using a DC-DC converter for generating different types of DC voltage. Can be generated.

Here, in the above-described embodiment, the vehicle power supply device using the generator having the armature windings for generating the respective voltages in order to generate two types of DC voltages has been described. Even in a power supply device in which one line is used and a rectifier circuit for rectifying a current flowing through the armature winding is connected to a neutral point of the armature winding to generate two types of DC voltages. When the rotation of the generator is stopped, the armature winding is energized by the battery voltage.
By generating various types of DC voltages, power can be supplied to various loads.

Further, in the above-described embodiment, the vehicle power supply device that generates two types of DC voltages has been described. However, when generating more types of DC voltages and supplying power to loads corresponding to the respective voltages, For example, a plurality of types of armature windings corresponding to each voltage are wound around a stator of a generator, and when the generator is rotating, currents flowing through the armature windings are individually rectified to generate respective voltages. At the same time, the battery is charged with a specific voltage, and when the rotation of the generator is stopped, the plurality of armature windings except for the armature winding for generating the battery voltage are respectively energized by the battery voltage. Good.

[Effects of the Invention] As described above, in the vehicle power supply device of the present invention, when the generator rotates, the current flowing through the armature winding is rectified by the rotation to generate a plurality of DC voltages. The battery is charged with a specific DC voltage of the generated DC voltage, and when the generator stops rotating, the armature winding is energized by the battery power, and the armature winding and the rectifier are connected to the DC-DC. By functioning as a converter, a plurality of DC voltages are generated in the same manner as when the generator is rotating.Therefore, without using a DC-DC converter for converting the battery voltage to a different type of DC voltage, one DC-DC converter is used. A plurality of types of DC voltages can be generated by the battery. Therefore, according to the present invention, the power supply device can be increased in size,
A plurality of types of DC voltages can be generated and power can be supplied to a load corresponding to each voltage without increasing the weight of the device, and the power supply device is optimal for general public vehicles.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing the configuration of the entire vehicle power supply device of the embodiment, and FIG. 2 is an electric circuit diagram showing the configuration of the low-voltage control circuit. DESCRIPTION OF SYMBOLS 1 ... High voltage armature winding, 5 ... High voltage rectifier circuit 3 ... Low voltage armature winding, 7 ... Low voltage rectifier circuit 11 ... High voltage load, 13 ... Battery 17 …… Low voltage load, 25 …… Voltage regulator 20 …… Low voltage voltage control circuit 30 …… Smoothing circuit, 32 …… Differential amplifier 34 …… Reference voltage generation circuit, 36 …… Comparator 38 …… Triangle wave Generation circuit, 40 Rotation detector 42 AND circuit, 44 Photocoupler

Claims (2)

(57) [Claims] A generator provided with a field rotor rotated by an engine of the vehicle and an armature stator; and a current flowing through an armature winding of the generator being rectified to form a plurality of output terminals. And a rectifying means for supplying power to the first and second output terminals, wherein the rectifying means is connected to a first output terminal (9) of the plurality of output terminals and rectifies a predetermined DC voltage by the rectifying means. A battery (13) to be received and charged, and an energization path from the battery to an armature winding for supplying power to the second output terminal (15) of the plurality of output terminals are formed, and the control signal (21) Intermittent switching means (TR1) and rotation stop detecting means (4
0), when the rotation stop detection means detects the rotation stop of the generator, outputs a control signal for causing the switching means to be turned on and off at a predetermined cycle, and outputs the switching signal from the battery when the generator stops rotating. Means, control means (20 (excluding 40)) for supplying power to the second output terminal (15) of the plurality of output terminals via the armature winding and the rectifying means. Power supply for vehicles. 2. The armature winding comprises three phases connected in a Y-connection, and the switching means (TR) is connected to a neutral point (3a) thereof.
The vehicle power supply device according to claim 1, wherein 1) is connected.