JPH07170672A - Output current controller of generator for vehicle - Google Patents

Abstract

PURPOSE:To improve engine starting by suppressing generation after starting an engine and at the same time provide the output current controller of a generator for vehicle which can properly suppress generation according to temperature with a simple circuit configuration. CONSTITUTION:When an engine temperature is at a first level or less when starting an engine, the continuity rate of a switch 10 is limited and then the continuity rate limitation of the switch 10 is canceled when the temperature reaches a second level which is higher than the first level, thus reducing engine load when starting the engine at a low temperature where the engine starting property deteriorates and at the same time canceling the limitation in output current of a generator 2 and charging a battery after the engine is started and the engine us warmed up and the generated torque increases.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output current control device for a vehicle generator.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 3-173325 discloses a control device for an AC generator for a vehicle, which suppresses power generation for a predetermined time after starting the engine to improve the starting performance of the engine.

[0003]

However, the apparatus disclosed in the above publication requires the addition of electronic circuits such as a fixed-cycle oscillator and a multi-stage frequency divider in order to configure a timer of several tens of seconds or more, and the circuit scale and power consumption are increased. There was a problem that the consumption would increase. In addition, since the delay time of this timer has to be uniform regardless of the engine temperature at the time of start, at low temperatures, the suppression of power generation is released before the engine torque is sufficiently established (the engine rotation is sufficiently raised). . On the contrary, at room temperature, even after the engine torque has been sufficiently established (the engine rotation has risen sufficiently), power generation is suppressed while sacrificing the necessary charging of the battery.

The present invention has been made in view of the above problems, and realizes an improvement in engine starting performance by suppressing power generation after the engine is started with a simple circuit configuration, and also suppresses power generation appropriately in accordance with temperature. It is an object of the present invention to provide a possible output current control device for a vehicle generator.

[0005]

SUMMARY OF THE INVENTION An output current control device for a vehicle generator according to the present invention is a switch for connecting and disconnecting an exciting current of a vehicle generator which is driven by an engine to charge a battery, and a terminal voltage of the battery. Generated voltage adjusting means for opening and closing the switch based on the state quantity related to the engine, temperature detecting means for detecting the state quantity interlocked with the temperature of the engine, and the temperature based on the signal input from the temperature detecting means. A first judging means for judging whether or not the level is below a level, a conductivity rate limiting means for limiting a conductivity rate of the switch when the temperature is below the first level at the time of starting, and a signal from the temperature detecting means. Second determining means for determining whether or not the temperature has reached a second level or higher, which is higher than the first level, based on the input; and the case where the temperature has reached a second level or higher. It is characterized in that it comprises a conduction rate limit canceling means for canceling the conduction rate limit of the switch.

[0006]

The generated voltage adjusting means opens / closes the switch based on the state quantity related to the terminal voltage of the battery to interrupt the exciting current of the engine-driven vehicle generator. The charging current to the battery is interrupted according to the interruption of. When the state quantity (hereinafter, also referred to as temperature) corresponding to the temperature of the engine is equal to or lower than the first level at the time of starting, the conduction ratio of the switch is limited, and then the temperature reaches the second level or higher higher than the first level. For example, release the switch conductivity limitation.

With this configuration, the engine load at the time of low temperature starting, in which the engine startability is deteriorated, can be reduced and the startability can be improved, and at the same time, the engine is started and the engine is warmed up, and the generated torque is generated. After increasing, the limit of the output current of the generator is released and the battery is charged. Further, when the engine is cold, it becomes slower for the temperature to reach the second level, so the engine load is reduced until the engine is warmed up and the torque increases, and the rotation speed is improved and the actual output torque is increased. Can be increased.

On the contrary, when the engine is warm, the temperature reaches the second level sooner, so that if the engine is warmed up quickly, the battery charging current is immediately increased to avoid the consumption of the battery. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an output current control device for a vehicle generator according to the present invention will be described below with reference to the drawings. (Structure) FIG. 1 shows a block diagram of this apparatus.

Reference numeral 1 is a voltage for controlling the exciting current flowing through the exciting coil 8 of the generator 2 so that the output voltage of the vehicular generator 2 which supplies current to the battery 3 and the electric load 7 does not exceed a predetermined regulated voltage. It is a regulator. The voltage regulator 1 constitutes the power generation voltage adjusting means, the temperature detecting means, the first determining means, the conduction rate limiting means, the second determining means, and the conduction rate limiting releasing means in the present invention. .

Reference numeral 4 denotes an ignition switch for applying a power supply voltage to the voltage regulator 1, which connects the high end of the battery 3 and the power supply terminal of the voltage controller 1. Other,
The high end of the battery 3 is fed to the starter 5 via the ignition switch 4 and to the vehicle electric load 7 via the load switch 6. Hereinafter, the voltage regulator 1 will be further described.

Reference numeral 10 is a switch composed of a transistor with a grounded emitter, which connects and disconnects the exciting current supplied to the exciting coil 8. The resistors 31 and 32 are connected in series to form a voltage dividing circuit that divides the output voltage of the generator 2, and the divided voltage Vk of the generated voltage is output from the connection node of the resistors 31 and 32.

The resistors 33 and 34 and the diode (temperature detecting means) 16 are connected in series to constitute a first voltage dividing circuit for dividing the reference voltage V _CC supplied from the reference voltage line Lc. Adjusting voltage Vr from the connection node of 34
And the anode voltage Vd is output from the connection node between the resistor 34 and the diode 16. The resistors 35, 36 and 37 constitute a second voltage divider circuit which is connected in series and divides the reference voltage V _CC supplied from the reference voltage line Lc, and the reference voltage Vb is supplied from the connection node of the resistors 35 and 36. Then, the reference voltage Va is output from the connection node of the resistors 36 and 37.

Reference numeral 11 denotes a divided voltage Vk of the generated voltage and an adjustment voltage Vk.
It is a comparator that compares r. Reference numeral 12 compares a reference voltage waveform 13 input from a not shown periodic oscillation circuit with the anode voltage Vd of the diode 16, and when the anode voltage Vd is large (when the temperature is low), the switch 1
This is a comparator that cuts off 0.

Reference numeral 20 denotes an anode voltage V of the diode 16.
When d is equal to or higher than the reference voltage Vb (for example, the voltage at the diode 16 at 0 ° C.), the output is set to Lo by the output voltage of the comparator 19, and the voltage of the diode 16 is equal to the reference voltage Va (for example, This is a hold circuit that is reset by the output of the comparator 18 when the diode 16 has a voltage of 50 ° C. or less) and the output becomes Hi.
It consists of flip-flops.

Reference numeral 14 is a NOR circuit which outputs the NOR logic output of the outputs of the comparators 11 and 12, and the switch 10 is controlled by the output of the NOR circuit 14. Comparator 12
The output signal line 12a from the NOR circuit to the NOR circuit 14 is clamped by a clamp transistor 15 having a grounded emitter, and the clamp transistor 15 is controlled by the hold circuit 20.

Reference numeral 38 is a resistor that limits the output current of the comparator 12. Reference numeral 17 is a transistor that is controlled by an inverter circuit including a resistor 25 fed from the reference voltage line Lc in the voltage regulator 1 and a transistor 22 having a grounded emitter, and clamps the anode of the diode 16. 23 is a constant voltage diode connected in series with the resistor 26. The constant voltage diode 23 level-shifts the reference voltage Vcc of the reference voltage line Lc and applies it to the base of the transistor 22. The reference voltage line Lc is fed from the battery 3 through the resistor 27 and the ignition switch 4.

By doing this, the ignition
After turning on the switch 4, the reference voltage V _CCIs a constant voltage diode
Threshold voltage of transistor 23 + emitter of transistor 22
Base ON voltage V_BEWhile rising to the voltage determined by
Voltage V_CC(While it is unstable), place both ends of diode 16
Reset, the hold circuit 20 is reset, and the reference voltage V
_CCIs stabilized at a predetermined voltage, the transistor 22 becomes conductive.
Then, the transistor 17 is cut off and the comparator 12,
Anode 16 of diode 16 is connected to each input terminal of 18 and 20.
The pressure Vd will be applied.

The operation of the voltage regulator 1 will be described below. When the ignition switch 4 is turned on at a low temperature start (for example, when the temperature is 0 ° C. or less), the power supply voltage V of the voltage regulator 1 is increased.
_{When CC} stabilizes at the specified voltage, transistor 22 turns on.
Then, the transistor 17 is turned off, and the anode voltage Vd is applied to the + input terminal of the comparator 19.

Anode voltage V of diode 16 at 0 ° C.
d becomes larger than the reference voltage Vb, the output of the comparator 19 becomes Hi, the hold circuit 20 is set, the transistor 15 is turned off, and the signal voltage of the duty ratio output from the comparator 12 is switched through the NOR circuit 14. 10 is applied to the switch 10, and the switch 10 interrupts the exciting current at this duty ratio.

That is, at 0 ° C. or lower, the duty ratio of the exciting current is determined by the duty ratio of the signal voltage output from the comparator 12. Even if the engine is started and the generator 2 is driven by the engine, the exciting current of the exciting coil 8 is limited, so the torque of the generator is also reduced, and the startability of the engine and the stability of the idle rotation state are improved. To do.

In this exciting current limiting operation, the temperature of the voltage regulator 1 rises, the anode voltage Vd of the diode 16 becomes equal to or lower than the reference voltage Va (voltage corresponding to 50 ° C.), and the hold circuit 20 is reset. To continue. That is, when the diode 16 becomes 50 ° C. and the anode voltage Vd becomes equal to or lower than the reference voltage Va, the comparator 18 becomes Hi, the hold circuit 20 is reset, and the hold circuit 2 is reset.
The clamp transistor 15 is turned on by the Hi signal output from 0, and the switch 10 is controlled only by the output voltage of the comparator 11 through the NOR circuit 14.

The temperature rise of the voltage regulator 1 within the above range generally needs several minutes to several tens of minutes in an idle state or a low-speed running state, and this time is for warming up the engine and increasing the engine output torque. It's enough time. When the ignition switch 4 is turned on at a normal temperature start (for example, at 25 ° C.), the transistor 22 is turned on.
N, when the transistor 17 is turned off, the diode 16
Is less than Vb, the output of the comparator 19 becomes Lo, the hold circuit 20 remains reset, and the exciting current of the generator 2 is not limited.

The operation of the transistor 17 will be described in more detail below. After the ignition switch 4 is turned on, the transistor 22 is turned off and the transistor 17 is turned on for a short period until the reference voltage V _CC of the reference voltage line Lc is stabilized. Therefore, during this period, the anode voltage Vd becomes 0 V, the diode 16 is set to a pseudo high temperature state, the comparator 19 is Lo, and the comparator 18 is
Becomes Hi, and the hold circuit 20 is reliably reset regardless of voltage instability. During this period, the clamp transistor 15 is turned on and the comparator 12 releases the conduction rate limitation. Of course, conversely to the above, the hold circuit 20 is operated with the anode voltage Vd set to Hi only for the short period.
May be forcibly set.

FIG. 2A shows the relationship between the forward voltage drop of the diode 16 functioning as the temperature detecting means and the temperature, and FIG. 2B shows the relationship between the voltage waveform 13 and the reference voltages Vb and Va. . In this embodiment, the conductivity limiting comparator 12 compares the anode voltage Vd (temperature signal) of the diode 16 with the voltage waveform 13. Therefore, as can be seen from FIGS. 2A and 2B, the ON duty ratio of the comparator 12 decreases as the temperature rises and the anode voltage Vd of the diode 16 decreases.
The inversion by the NOR circuit 14 is designed to increase the ON duty ratio of the switch 10, that is, the conduction rate of the exciting current. As a result, the comparator 12 functions to reduce the exciting current at low temperature and increase the exciting current at high temperature. Further, as shown in FIG. 2B, the anode voltage Vd = Va at 50 ° C. is the minimum of the voltage waveform 13. It is set a little smaller than the value. With this, when the temperature rises from a low temperature to about 50 ° C., the anode voltage V
d = Va becomes smaller than the minimum value Vmin of the voltage waveform 13, and as a result, the conduction rate limitation by the comparator 12 is released in the vicinity of 50 ° C.

Once the temperature of the diode 16 (anode voltage Vd) exceeds 50 ° C. (reference voltage Va) once, the conduction rate limitation by the comparator 12 is not activated unless it falls below 0 ° C. (reference voltage Va) again. . That is, since the temperature of the diode 16 (anode voltage Vd) does not fall below 0 ° C. (reference voltage Vb) after the engine is started, it is possible to limit the conduction rate only when the engine temperature is low immediately after the engine is started and the torque is small. it can.

FIG. 3 is a circuit diagram showing an example of the hold circuit 20. (Embodiment 2) Another embodiment is shown in FIG. This example
In the circuit of the first embodiment, the resistors 51 to 60, the capacitor 53,
The AND circuit 56, the transistors 54, 21, and 27 and the capacitor 26 are added, and the clamp transistor 15 and the resistor 38 are omitted.

The new features of this circuit will be described below.
First, during the period from the turning on of the ignition switch 4 to the start of power generation by the generator 2 (while the power generation is stopped), the conduction rate (ON duty ratio) of the switch 10 is made as small as possible to generate heat from the voltage regulator 1. To prevent the power generation suppression time after the engine is started from decreasing. This is because the engine is not started even though the voltage regulator 1 is energized by the ignition switch 4 being turned on and the diode 16 is heated, and as a result, the electrical conductivity is limited after the generator 2 starts to generate power. This is to prevent the (power generation suppression) time from being shortened.

Specifically, the one-phase generated voltage of the generator 2 is converted into a direct current by a low-pass filter composed of resistors 51 and 52 and a capacitor 53 and applied to the base of a transistor 54 whose emitter is grounded. Since the reference voltage Vcc is applied to the transistor 54 from the reference voltage line Lc through the resistor 57, the transistor 54 is turned off when the one-phase generated voltage is small, and the collector of the transistor 54 is Hi at one input terminal of the AND circuit. Is output.

Therefore, during the power generation stop period, the rectangular wave pulse 55 is sent to the switch 10 through the AND circuit 56 and the NOR circuit 14, and the switch 10 outputs a smaller ON duty ratio to the rectangular wave pulse 55 and the output signal from the comparator 12. Excitation current is passed at (conductivity). If the engine speed increases and the generated voltage increases,
The output of the AND circuit is cut off, and the switch 10 is limited in conduction ratio mainly by the constant duty ratio of the signal output from the comparator 12. The comparator 12 is turned off due to the temperature rise of the diode 16, and the switch 10 is intermittently controlled by the variable duty ratio of the signal output from the comparator 11.

In the first embodiment, the temperature rises (50
When the temperature of the voltage regulator 1 becomes 0 ° C. or lower after the hold circuit 20 is reset, the power generation suppressing operation is performed again. In this embodiment, however, the hold circuit 20 does not reach 0 ° C.
It becomes Hi when starting below ℃, and Lo when it exceeds 50 ℃
become. When the hold circuit 20 becomes Lo even once even if the temperature rises, the transistor 27 is turned off, thereby turning on the transistor 17 and the voltage of the diode 16 until the ignition switch 4 is opened and closed again. Hold circuit 2
The reset state of 0 is continued. In this way, the conductivity rate is not limited until the next engine start.

The capacitor 26 has the reference voltage line L after the transistor 17 is turned on and the hold circuit 20 is reset by turning on the ignition switch 4.
When the reference voltage Vcc of c increases and the transistor 22 turns on, the transistor 17 is temporarily turned off. At this time, if the anode voltage Vd of the diode 16 is high, it is for setting the hold circuit 20. is there.

Further, in the conduction rate limited state (power generation restrained state), that is, in the state where the hold circuit 20 is Hi, the battery 3
Since the charge amount of is decreased, the transistor 21 is turned on by the Hi output of the hold circuit 20 in this conduction rate limited state.
Then, the adjustment voltage Vk is lowered. With this configuration, the ON duty ratio of the signal output from the comparator 11 is reduced in the power generation suppression state, and when the engine speed is increased (that is, when the required load current can be supplied even in the power generation suppression state). ), The ON duty ratio of the switch 10 increases, and the amount of charge to the battery 4 becomes U.
P, the insufficient charge is reduced even in the power generation suppression state.

Further, in the above-described embodiments, when the ignition switch 4 is turned on, the transistor 22 is turned on and the transistor 17 is turned off so that the temperature detecting element (diode) is activated.
Although the control of the hold circuit 20 by 16 is started,
This timing may be the start of power generation of the generator 2.
Further, in the above embodiment, the diode is used as the temperature detecting means, but other temperature detecting means such as a thermistor may be used and the engine temperature may be directly detected.

The comparator 11 constitutes the power generation voltage adjusting means in the present invention, the diode 16 constitutes the temperature detecting means in the present invention, and the comparator 19 constitutes the first judging means in the present invention. Reference numeral 12 constitutes the conductivity limiting means in the present invention, comparator 18 constitutes the second determining means in the present invention, and the clamp transistor 15 or the transistor of the second or larger embodiment is the conductivity limiting releasing means in the present invention. Are configured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an apparatus according to a first embodiment.

FIG. 2 is a diagram showing characteristics of a diode 16 of FIG.

FIG. 3 is a circuit diagram showing a hold circuit 20 of FIG.

FIG. 4 is a circuit diagram showing a second embodiment.

[Explanation of symbols]

1 is a voltage regulator, 2 is a vehicle generator, 3 is a battery, 4
Is an ignition switch, 10 is a switch, 11 is a comparator (power generation voltage adjusting means), 12 is a comparator (conductivity limiting means), 16 is a diode (temperature detecting means), 18 is a comparator (second determining means), 19 is a comparator. (First determination means), 15 is a clamp transistor (conduction rate restriction releasing means).

Claims (1)

[Claims] 1. A switch for connecting and disconnecting an exciting current of a vehicle generator driven by an engine to charge a battery, and a generated voltage adjusting means for opening and closing the switch based on a state quantity related to a terminal voltage of the battery, Temperature detection means for detecting a state quantity linked to the temperature of the engine; first determination means for determining whether or not the temperature has dropped below a first level based on a signal input from the temperature detection means; Conductivity limiting means for limiting the conductivity of the switch when the temperature is lower than or equal to a first level, and the temperature is equal to or higher than a second level higher than the first level based on a signal input from the temperature detecting means. Second determination means for determining whether or not there is a conduction rate restriction release means for releasing the conduction rate restriction of the switch when the temperature becomes equal to or higher than a second level. , The output current control device of the vehicle generator, characterized in that it comprises a.