JPS60204231A - Charge controller for vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vehicle having an alarm control circuit that controls the power generation of a vehicle charging generator to maintain a proper charging state of a battery and warns of abnormalities in the charging system. The present invention relates to a charging control device for use in a vehicle.

[Conventional problems]

Conventional control devices detect power generation by turning off the lamp using the generator output, but when the battery load is small and a large generator output is not required, the generator output decreases and the lamp turns on incorrectly. There were times when I did.

Further, Japanese Utility Model Application Publication No. 57-111034 is an improvement plan for the above-mentioned problem, but if the circuit added to improve the above-mentioned problem breaks down, the function of the voltage control section may also be damaged.

[Object of the present invention]

For this reason, the present invention adds a circuit to prevent false alarms from being issued by alarm means, such as a charge indicator lamp, which informs whether power generation is normal or not, and even if this added circuit fails, The purpose of the present invention is to provide a vehicle charging control device that does not lose the original function of voltage regulation, which is to maintain the output voltage of a generator at an appropriate level.

[Summary of the invention]

The present invention has a switching means for turning on and off the current in the field winding according to the magnitude of the battery voltage, and also has a voltage control circuit for controlling this switching means.

It also has an alarm means, for example, a lamp, which is activated when it detects that the power generation state is abnormal.

Furthermore, it includes a capacitor that is charged by the output voltage of the generator, that is, integrates the output voltage signal, and a charge notification control that detects the voltage of the capacitor and drives the alarm means according to the voltage of the capacitor. Has a circuit.

However, the battery is still fully charged,
In addition, when the on-vehicle load is cut off, the alarm means may issue a false alarm.

In other words, in such a fully charged state, there is no need for the generator to charge the battery, and if the power consumption of the onboard load is low, there is no need to generate electricity, so the voltage regulation circuit cuts off the power to the field winding. If this occurs, the output of the generator will decrease for a relatively long time, causing the alarm means to issue a false alarm.

In the present invention, a false alarm prevention circuit is added that prevents this false alarm and does not impair the voltage regulation function of the voltage regulation circuit even if the circuit itself breaks down. has a function completely separate from the voltage regulation function.

By the way, in conventional systems, when such a false alarm occurs, the voltage adjustment function is directly affected, but with this, a failure in the false alarm prevention circuit can easily cause a failure in the voltage adjustment circuit. .

In the present invention, when a false alarm occurs, that is, when the battery voltage is higher than a set value, the discharge time constant of the capacitor is increased to reduce the degree to which the capacitor voltage decreases, and the transient This prevents the alarm means from issuing a false alarm due to a non-power generation state.

The drawings showing one embodiment of the present invention will be described above.

In the drawing, 1 is a battery, 2 is a key switch, and 3 is a three-phase AC generator driven by the vehicle engine, including a field winding 31 connected to the battery 1 at one end, and a Y-connected stator winding 32. , the three AC outputs of this stator winding 32 are rectified, one end is grounded, and the other end is connected to the battery 1.
It consists of a diode 33 connected to the positive terminal of.

Reference numeral 4 denotes an alarm control circuit, which includes an excitation current control transistor 41a serving as a switching means whose collector is connected to one end of the field winding 31, the field winding 31, and the transistor 41.
It has an excitation current control circuit consisting of a diode 41b whose anode side is connected to the connection point P with the battery l and whose cathode side is connected to the positive terminal of the battery l.

Further, a voltage adjustment circuit 4 comprising resistors j2a, 42b, 42c, a Zener diode 42d, and a transistor 42e.
2, and a known constant voltage circuit 43a, a comparator 43b,
43C143d, OR circuit 43e1 inverter 43f
1 diode 43g 1 transistor 43h, 43i, capacitor 43j1 resistor 43, 437! , 43m, 43
n, 43o, 43p, 43q, 43r, 43t, 43u
, 43xs43y, 432.

44 is a load driving transistor for alarm, and 5 is an alarm lamp serving as an alarm means. And mainly output point P2
-Resistance 43r-Diode 43g=Capacitor 43j-
A path from the comparator 43d to the OR circuit 43e to the driving transistor 44 constitutes a charge notification control circuit.

Next, the operation of the above configuration will be explained.

When the key switch 2 is turned on and the engine has not started yet, the output point P2 of the generator 3 is 0 (V), so
Smoothing capacitor 43j to which voltage is applied from output point P2 via resistor 43r and diode 43g
voltage becomes 0 [V], the output of the power generation detection comparator 43d becomes 1 level, the transistor 44 is made conductive via the OR circuit 43e and the resistor 43z, the lamp 5 is lit, and the generator 3 starts generating electricity. Inform the driver that you have not done so.

Also, since the generator 3 is not generating power, depending on the voltage of the battery l, the Zener diode 42 may be connected via the resistor 42a.
Since no breakdown current can be passed through d, the transistor 42c is turned off and the transistor 41a is turned on, causing an excitation current to flow through the field winding 31.

Next, the engine rotates, so that the AC power generator ta3 that is linked to the engine also rotates, and the excitation current flowing through the field winding 31 generates a generated voltage in the stator winding 32.

The output point P2 of the stator winding 32, the resistor 43r,
When the voltage of the smoothing capacitor 43j connected via the diode 43g becomes higher than the reference voltage of the power generation detection comparator 43d (the voltage determined by the resistors 43X and 43y), the power generation detection comparator 43d If the output becomes 0 level, and at this time, the other battery over-voltage alarm comparator 43b and battery low-voltage alarm comparator 43c do not detect any foreign products and their outputs indicate 0 level. , the transistor 44 is turned off, the lamp 5 is turned off, and the driver is informed that the generator 3 is generating power normally.

Note that when the battery 1 is charged by the output of the generator 3 and the battery voltage exceeds the set value, that is, when the Zener diode 42d breaks down, the transistor 42e is turned on, the transistor 41a is turned off, and the field winding 31 is turned on. The excitation current flowing through the generator 3 decreases, and the output of the generator 3 also decreases.

Next, when the battery 1 falls below the set value, that is, when the Zener diode 42d no longer breaks down, the transistor 41a turns on and increases the excitation current of the field winding 31, thereby increasing the output of the generator 3 again. By repeating the above operations, the voltage of battery l is maintained at the set value.

Next, the operation of the alarm circuit 43 will be explained.

As mentioned above, when the key switch 2 is turned on and the engine is not started yet, the output of the generator 3 is 0 [V].
Therefore, according to the operation described above, transistor 41a
is turned on, and in order to bring the connection point P+ to ground potential, the transistor 43h is turned on by the inverter 43f connected to this point P, so the voltage of the capacitor 43j is 0 (V). Therefore, the output of the comparator 43d turns on, turning on the transistor 44 and lighting the lamp 5 (indicating that power is not being generated).

The engine starts and the output voltage of generator 3 rises, output point P
2. When a current flows through the resistor 43r and the diode 43g and the voltage of the capacitor 43j exceeds a set value, the output of the comparator 43d becomes 0 level.

At this time, if the outputs of the battery overvoltage warning comparator 43b and the battery low voltage warning comparator 43C are at 0 level, the transistor 44 is turned off and the lamp 5 is turned off (notifying that power is being generated).

When the output of the generator 3 is small, which is the first problem with the conventional example, for example, when the battery 1 is fully charged and the on-vehicle load L (e.g. motor, headlamp, etc.) no longer consumes power. Even if the transistor 41a is turned off as the voltage of the battery 1 increases, the excitation current flowing through the field winding 3 gradually decreases via the flywheel diode 41b, so the output voltage of the generator 3 temporarily decreases. becomes high,
The voltage of the battery 1 also temporarily rises above the set value.

Moreover, since the load current has become small, it takes several seconds to return to the normal battery voltage, and during this time the transistor 4
1a is turned off and the field vA winding 31 is disconnected from the power source, the output of the generator 3 finally drops below a predetermined amount, and the lamp 5 is erroneously lit according to the above operation, indicating that the power generation state is normal. Despite this, a problem arises in that a notification indicating that power is not being generated is issued.

To solve this problem, we focused on the fact that when the voltage of the battery 10 is higher than the set value, the Zener diode 42d breaks down and the transistor 42e is turned on, so the transistor 41a is turned off. When the collector voltage (potential at point P1) is high, the signal of this high collector voltage is inverted by the inverter 43f, and this inverted signal turns off the transistor 43h to increase the discharge time constant of the capacitor 43j.

This reduces the degree to which the voltage of the capacitor 43j decreases, keeps the output of the comparator 43d at O level, and maintains the transistor 44 in the off state, so that the battery voltage is equal to or higher than the set value and the output of the power generator ta3 decreases. This prevents the lamp 5 from being erroneously lit when the lamp 5 is turned on. That is,
Inverter 43f, resistor 43u and transistor 43h
constitutes the entertainment W4i[a prevention circuit.

Furthermore, the above configuration does not adopt a method of forcibly increasing the excitation current to prevent a drop in generator voltage when the output of the generator decreases, as in Japanese Utility Model Application No. 5'111034.
Even if the lamp erroneous lighting prevention circuits 43f and 43h of the above embodiments fail, the voltage control functions such as stopping the power generation of the generator 3 and uncontrolled power generation will not be impaired.

Furthermore, the voltage control circuit 42 fails and the transistor 41a turns off, causing the lamp erroneous lighting prevention circuits 43f, 4
3h increases the discharge time constant of the capacitor 43j (even if this happens, the Zener diode 42d in the power generation detection section still detects the output voltage of the generator 3, so the capacitor 43j is at 0 [V] when the key switch is turned on. Since the output of the comparator 43d becomes a level and turns on the transistor 44, a power generation failure can be warned by lighting a lamp.

Further, if a failure suddenly occurs in the voltage control circuit 42 during power generation, a lamp is turned on in response to a battery low voltage alarm.

Therefore, the voltage of battery l is detected by resistor 430.43p, and resistors 43h, 43Il, 43m, 43n,
A reference voltage is formed by the transistor 43i, and when the transistor 41a is on, the low level potential at the point PI is inverted by the inverter 43f to turn on the transistor 43i.
As a result, the reference voltage is lowered, while transistor 41
When a is off, the reference voltage is raised.

That is, when the transistor 418 is on, the reference voltage is lowered, and when it is off, the reference voltage is raised.

On the other hand, under normal conditions, when the transistor 412 is on, the voltage of battery 1 should be higher than the set value (for example, 14.5V), and at this point, even if the reference voltage for battery low voltage alarm is high (for example, 13V), a false alarm will occur. There's nothing to do.

Further, the transistor 41a is turned off due to a failure in the voltage control circuit 42 as described above, and as a result, when power generation is stopped, the reference voltage is increased and a low voltage alarm can be issued at an early stage.

Also, when the power consumption of the on-vehicle load is large, the transistor 41a
Even if TFF is in the ON state, the load current may become larger than the output capacity of the power generation TFF13 and the voltage of the battery 1 may drop. Set the battery low voltage alarm value low (e.g. 8v) to prevent false alarms.

Regarding the battery overvoltage alarm, as mentioned above, when a large current load is cut off, the battery voltage temporarily increases, so when this battery voltage increases, the transistor 4
By using the fact that 1a is off, the reference voltage is set high when the transistor 412 is on and low when the transistor 412 is on, thereby preventing false alarms and providing early warning in the event of an abnormality (for example, when the battery is overcharged due to a short-circuit failure of the transistor 41a). It is possible to issue a warning.

[Effects of the present invention]

As described above, in the present invention, in order to determine the state in which the power consumption of the on-vehicle load is low and the battery is fully charged from the time that the switching means (41a) is turned off, the switch notching means is used. Since the electric charge in the capacitor of the integrating circuit is not discharged when the power is turned off, the voltage of the capacitor is prevented from dropping and reporting a power generation failure, and therefore the W4 notification of the alarm means can be prevented. or,
At this time, since the operation of the voltage control circuit that directly controls the current of the field winding is not changed in order to prevent a false alarm of a power generation failure, the alarm means is driven and the false alarm of the alarm means is prevented. Even if a failure occurs in the alarm control circuit, the failure does not spread to the voltage control circuit, so there is an advantage that the battery will not be damaged.

[Brief explanation of the drawing]

The drawing is an electrical wiring diagram of a vehicle charging control device showing one embodiment of the present invention. 4... Alarm control circuit, 5... Alarm means, l... Battery, 31... Field winding, 41a... Switching means. 43 J...Capacitor, P2, 43r, 43g,
43j, 43d, 43e, 44--charging notification control circuit. L... Vehicle load, 43... Voltage adjustment circuit, 43f,
43u, 43h...false alarm prevention circuit, 3...generator, 4...alarm control circuit. Representative Patent Attorney Takashi Okabe

Claims (1)

[Scope of Claims] Switching means (41a) that maintains the output voltage of the alternator at a set voltage by intermittent current in a field winding of an alternator that charges a vehicle battery and supplies power to an on-vehicle load; A voltage regulating circuit (42) that controls the switching means (41a) according to the battery voltage; a capacitor (43j) that takes the output voltage of the alternator as an input signal and integrates the input signal; A charge notification control circuit that determines the quality of power generation based on the magnitude of the integrated voltage generated.
an alarm means (5) which is driven according to the size of the integration circuit in the charge notification control circuit and notifies abnormal power generation of the alternator; and when the switching means is on, the electric charge of the capacitor is the warning means (when the battery is fully charged and the power consumption of the on-vehicle load is low);
5) A charging control device for a vehicle, comprising a false alarm prevention circuit that prevents false alarms.