JPH06351173A - Voltage controller of vehicle power generator - Google Patents

Abstract

PURPOSE:To provide a power controller of vehicle power generator which can dissolve, even with simple and economical structure, sudden change of generated power while changing over an adjusting voltage. CONSTITUTION:A capacitor 14 having a large capacity is provided, as a means for gradually changing an excitation current of a rotor coil 2, in a regulator 3 for changing the excitation current current of the rotor coil 2. Moreover, an adjusting voltage VR as a first preset voltage is changed with an accelerated/ decelerated running detector 7 and a switching transistor 11 is switched on and cut off through an AND circuit 20 in view of eliminating sudden change of the generated voltage of the generator 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage control device for a vehicular generator, which controls a generator voltage by intermittently supplying an exciting current flowing through a rotor coil of the vehicular generator.

[0002]

2. Description of the Related Art Conventionally, there is provided a battery charger which comprises a generator for charging a battery under the control of a regulator and which increases the charge level for a period of time following the net discharge of the battery. 49-7
It is disclosed in Japanese Patent No. 2636. In this battery charger, as shown in FIG.
Because of the positive feedback circuit through the voltage regulator, the voltage regulator has one state in which transistors 31 and 29 are on and transistor 26 is off, and transistors 31 and 2
It oscillates with the other state in which 9 is in the off state and transistor 26 is in the on state. When the transistors 31 and 29 are turned off, the energy stored in the field winding 33 is lost through the diode 34, and the field winding 3
The circuit is maintained so that the average current flowing through 3 holds the voltage of the storage battery 16 at the desired level. As long as the synchronous generator 11 is producing sufficient power to satisfy the conditions of the ignition control load 22 and any other load of the storage battery 16, the voltage of the storage battery 16 is at a level at which the Zener diode 25 conducts. The adjustment voltage is determined by the current flowing through the Zener diode 25. Typically, when a powered device powered by a 12 volt battery operates at 12 volts, the voltage regulator is set to charge the battery 16 to 14.2 volts. However, at any point in time, if the current supplied by the synchronous generator 11 is less than the required current, the net charge on the storage battery 16 will be discharged and the potential between the positive supply lines 18 and 15 will be reduced by the zener diode 25. It drops to a value where it no longer conducts, and transistors 29 and 31 are fully on. In such a state, it can be said that the field winding 33 is fully energized and the voltage regulator is operating at an infinite mark-space ratio. The purpose of the transistors 42 and 45 and their associated components is to detect the net discharge of the battery 16 and to change the regulated voltage for a predetermined period after the battery 16 has been net discharged. When the storage battery is not discharged, the transistor 3
1 becomes alternately conductive and non-conductive. When this transistor 31 becomes conductive, the positive power supply line 18
To capacitor 38, resistor 39 and transistor 31
A current flows through and discharges the capacitor 38. However, when transistor 31 is turned off, capacitor 38 rapidly discharges through diode 37. As long as the Zener diode 25 is conducting and the voltage regulator is in oscillation, the capacitor 38 turns on the transistor 42.
Design the circuit so that it is never charged enough to turn it on. In such a state, transistors 42 and 45
Does not affect the operation of the circuit. However, the storage battery 16
Causes a net discharge, the Zener diode 25 becomes non-conductive as described above, and the transistor 31 remains on for a considerable time. In such a state, the capacitor 38 is sufficiently charged and current flows from the base of the transistor 42 to the diode 41 and the resistor 39. This current consists of two components, the emitter-base current of transistor 42 and the discharge current of capacitor 46. The circuit determines that the collector voltage of the transistor 42 increases linearly until the transistor 42 saturates and that at the saturation point of the transistor 42 the transistor 45 also saturates. When the transistor 45 becomes conductive, the resistor 23
The resistance value between the interconnection points 24 and 24 and the negative feed line 15 changes due to the resistance 40, increasing the voltage at which the storage battery 16 is charged under the control of the voltage regulator. This voltage typically increases from 14.2 volts to 14.8 volts.
Even if the transistor 45 is turned on, it does not affect the operation of the storage battery charging device as long as the storage battery 16 is still discharged, but when the synchronous generator 11 starts charging the storage battery 16 again, the Zener diode 25 becomes 14. It will not conduct at 2 volts, but will conduct at 14.8 volts due to the conduction of transistor 45. This causes transistor 31 to remain conductive and fully excite synchronous generator 11 until the potential reaches 14.8 volts. Transistor 31 turns off and the voltage regulator oscillates normally. As soon as transistor 31 turns off, diode 37
And 41 and capacitor 38 separate resistor 39 from transistor 42, at which point capacitor 4
The charging current of 6 supplies the base current to the transistor 42. The values of resistors 39, 43 and 44 are chosen appropriately so that capacitor 46 discharges quickly and charges relatively slowly. Therefore, transistors 42 and 45 are held on by capacitor 46 for a predetermined period. Since the transistor 45 saturates at the beginning of this period, the battery 16 is regulated to 14.8 volts,
During the remainder of this period, transistor 45 begins to decrease from its saturation, causing battery 16 voltage to gradually decrease from 14.8 volts to the normal 14.2 volts. However, in order to prevent the driver from feeling uncomfortable due to changes in the brightness of the headlights and changes in the fan sound of the air conditioner, it is necessary to increase the capacity of the capacitor 46 in order to reduce the voltage changes, which results in a high cost. was there.

Further, in Japanese Patent Application Laid-Open No. 59-213239, the adjustment voltage of a voltage regulator is increased by increasing the adjustment voltage of the voltage regulator during deceleration of the vehicle to perform regenerative braking, and lowering the adjustment voltage of the voltage regulator during vehicle acceleration and idling. When suppressing the output and reducing the engine load, in order not to give an uncomfortable feeling due to an increase or decrease in the adjustment voltage, FIG.
There is disclosed a control device for an on-vehicle generator that includes an adjustment voltage generation circuit 12 in which the adjustment voltage is gradually switched by the charging / discharging action of the large-capacity capacitor 128 as shown in FIG. 4, but a capacitor 128 having a time constant of several seconds is required. The cost was high.

[0004]

Further, in such a vehicle-mounted generator controller, a smoothing function by a smoothing circuit with a built-in capacitor, a triangular wave generating circuit and a comparing circuit as disclosed in Japanese Utility Model Laid-Open No. 34900/1988 is used. However, adding 2 requires two capacitors having a time constant of several seconds, which results in a significant cost increase. The present invention has been made to solve the above problems, and has a gradual excitation function and eliminates a sudden change in the charging current to the battery when the adjustment voltage changes, without requiring two expensive capacitors. It is an object of the present invention to provide a voltage control device for a vehicle generator that is capable of performing.

[0005]

As a concrete means for solving the above-mentioned problems, the present invention provides a vehicle generator for controlling the voltage of the vehicle generator by interrupting an exciting current flowing through a rotor coil. In the voltage control device, the second set voltage higher than the first set voltage is compared with the battery voltage,
When the battery voltage is equal to or higher than the second set voltage, a shut-off means for shutting off the conduction of the exciting current control transistor, and when the battery voltage is equal to or lower than the second set voltage, the battery voltage is compared with the first set voltage. When the battery voltage is equal to or lower than the second set voltage, the gradual excitation means that outputs a constant period pulse having a duty value according to the long-term integrated value of the comparison output, and according to the duty value of the constant period pulse of the gradual excitation means. And a switching means for switching the adjustment voltage as the first set voltage, the voltage control device for a vehicle generator being provided. It

[0006]

According to the voltage control device for a vehicle generator having the above-mentioned structure, when the battery voltage is equal to or higher than the second set voltage, the exciting current control transistor is cut off by the cutoff means. The voltage drops quickly and the battery is not overcharged. When the battery voltage is equal to or lower than the second set voltage, the battery voltage is compared with the first set voltage, and a constant period pulse having a duty value corresponding to the long-term integrated value of the comparison output is output from the gradual excitation means. Then, since the exciting current controlling transistor is made conductive or cut off by the conduction cutoff device according to the duty value of the constant period pulse of the gradual excitation device, the battery voltage is suppressed to the first set voltage. Since the switching means switches the first setting means, the adjustment voltage is gradually switched by the action of the gradual excitation means.

[0007]

[First Embodiment] A first embodiment of a voltage control device for a vehicle generator according to the present invention.
Embodiments will be described with reference to the accompanying drawings. FIG. 1 is a circuit diagram showing a first embodiment of a voltage control device for a vehicle generator.
V _A is the detection voltage of the battery 4. V _C is the output voltage (high, low, and open) of the acceleration / deceleration running detection device 7. V _H is an overvoltage level as the second set voltage of the detection voltage V _A of the battery 4. V _R represents a regulated voltage (normally 12.8 V to 15 V) as the first set voltage, V _RL is a low voltage side regulated voltage (about 12.8 V), and V _RM is a medium voltage side regulated voltage (about 14.5 V). ), And V _RH represents a high voltage side adjustment voltage (about 15 V). The adjustment voltages V _RL and V
_RM and V _RH are not limited to the above, and may be set to required voltages.

The vehicle generator 1 is composed of a rotor coil 2, a rectifier 9, a stator coil 8 and the like. The rectifier 9 rectifies a three-phase AC voltage generated by the rotation of the rotor coil 2 as an excitation winding. And generate a DC voltage. The regulator 3 is the rotor coil 2
A By intermittently switching transistor 11 connected in series, to control as the output voltage of the exciting current (hereinafter referred to as field current) by controlling the generator 1 rotor coil 2 becomes the first set voltage V _R . The battery 4 is charged by the output current of the generator 1. The electric load 5 is a load that consumes electric power, such as various lamps such as a headlight, a hazard lamp, and a flasher, and various devices such as a starter, an air conditioner, a wiper, and a radio. Reference numeral 6 is an ignition switch. The acceleration / deceleration running detection device 7 detects a running state (acceleration, deceleration, etc.) of the vehicle, sets the first set voltage V _R in the regulator 3 to the low voltage side adjustment voltage V _RL during acceleration, and the first set voltage V _RL during deceleration. Three kinds of output voltages, high, low and open, are input to the regulator 3 in order to set the set voltage V _R to the high voltage side adjustment voltage V _RH and to set the medium voltage side adjustment voltage V _RM during other steady running and idling. To do.

The flywheel diode 10 is a diode for processing an electromotive force induced by the rotor coil 2.
When the switching transistor 11 is turned on, it supplies a field current to the rotor coil 2, and when it is turned off, the field current of the rotor coil 2 is cut off. The overvoltage protection comparator 12 cuts off the switching transistor 11 by applying a low signal to the AND circuit 20 when the detection voltage V _A of the battery 4 exceeds the overvoltage level V _H (for example, 15 V). Voltage detection comparator 1
If the detection voltage V _A of the battery 4 is higher than the first set voltage V _R when the conduction of the switching transistor 11 is controlled by the duty value according to the voltage of the capacitor 14, the capacitor 3 is decreased in voltage. The conduction ratio of the switching transistor 11 is reduced, and the battery 4
If the detection voltage V _A is lower than the first set voltage V _R , the capacitor voltage is increased to increase the conduction ratio of the switching transistor 11.

The comparator 15 is a large-capacity capacitor 14
Is compared with the triangular wave voltage generated by the triangular wave generator 16 having a predetermined cycle, and a pulse voltage having a duty value corresponding to the voltage of the capacitor 14 is output. 17a-1
7i is a resistor. Zener diodes 18 and 19 operate as constant voltage sources. AND circuit 20 is battery 4
When the detection voltage V _A of the above is less than the overvoltage V _H , the conduction of the switching transistor 11 is controlled according to the pulse voltage output from the comparator 15.

Next, the operation of the above-described voltage control device for a vehicle generator will be described. When the vehicle decelerates, the output voltage V _{C of the} acceleration / deceleration running detection device 7 becomes high, and as a result,
The adjustment voltage V _{R changes} from the medium voltage side adjustment voltage V _RM to the high voltage side adjustment voltage V _RH . The duty of the switching transistor 11 was controlled so that the detection voltage V _A of the battery 4 was the intermediate voltage side adjustment voltage V _RM until then, but the adjustment voltage V _R
When the adjustment voltage V _RM changes from the medium voltage adjustment voltage V _RM to the high voltage adjustment voltage V _RH , the output of the comparator 13 becomes high and the large capacity capacitor 14 is charged. As a result, the on-duty of the switching transistor 11 increases and the output current of the generator 1 increases, so that the generated power at the time of deceleration is regenerated by the battery 4 and becomes regenerative braking by becoming a load of the engine. At this time, the output current is increased in accordance with the voltage change of the large-capacity capacitor 14, so that the output voltage of the generator 1 gradually increases without a sudden increase.

When deceleration of the vehicle is completed, the output voltage V _{C of the} acceleration / deceleration running detection device 7 is switched to the open state, and the adjustment voltage V _R changes from the high voltage side adjustment voltage V _RH to the medium voltage side adjustment voltage V _RM . Therefore, the output of the comparator 13 becomes low, and the large capacity capacitor 14 is gradually discharged. As a result, the on-duty value of the switching transistor 11 gradually decreases, the output current of the generator 1 gradually decreases, and the generated voltage also gradually decreases. When the detected voltage V _C of the battery 4 drops to the medium voltage side adjustment voltage V _RM , the discharging of the capacitor 14 is stopped, and the switching transistor 11 is controlled with an on-duty value according to the voltage of the capacitor 14 at that time. .

During acceleration of the vehicle, the acceleration / deceleration running detection device 7
Output voltage V _C becomes low, and the adjustment voltage V _R changes from the intermediate voltage side adjustment voltage V _RM to the low voltage side adjustment voltage V _RL . Therefore, the output of the comparator 13 becomes low similarly to the end of deceleration of the vehicle, and the large-capacity capacitor 14 is gradually discharged. Then, as the on-duty value of the switching transistor 11 decreases, the output voltage of the generator 1 decreases, and the detected voltage of the battery 4 becomes the low-side adjustment voltage V.
_{When the} voltage decreases to _RL, the discharge of the capacitor 14 stops, and the switching transistor 11 is controlled with an on-duty value according to the long-term integrated voltage of the capacitor 14 at that time.

Next, when the acceleration of the vehicle is completed, the output voltage V _{C of the} acceleration / deceleration running detection device 7 is switched to the open state, and the adjustment voltage V _R is changed from the low voltage side adjustment voltage V _RL to the medium voltage side adjustment voltage V _R.
Become _RM . Therefore, the output of the comparator 13 becomes high, and the large capacity capacitor 14 is gradually charged. As a result, the on-duty of the switching transistor 11 gradually increases, so the output current of the generator 1 gradually increases, and the generated voltage also gradually increases. Then, when the detected voltage V _C of the battery 4 rises to the medium voltage side adjustment voltage V _RM , the charging of the capacitor 14 is stopped, and the switching transistor 11 is controlled with the on-duty value according to the long-term integrated voltage voltage of the capacitor 14 at that time. Is done.

As described above, according to the present embodiment, since the adjustment voltage V _R can be changed gently depending on the running state of the vehicle, it is possible to prevent a sudden change in the generated voltage. Furthermore, since the on-duty of the switching transistor 11 can be gradually changed when the electric load 5 is turned on and off, it is possible to prevent a sudden change in the driving torque of the generator 1. Therefore, it is possible to prevent the engine speed from transiently dropping or rising due to turning on or off of the electrical load 5. In addition, when the large electric load 5 is cut off, the generator 1
Since the output current of the generator 1 is gradually reduced, the output voltage of the generator 1 transiently rises. In this case, when the detection voltage V _A of the battery 4 exceeds the overvoltage V _H so that the regulator 3 and the acceleration / deceleration running detection device 7 are not adversely affected by the abnormal increase in the output voltage of the generator 1. In addition, by forcibly turning off the switching transistor 11,
It is possible to prevent an abnormal increase in the output voltage of the generator 1.

Next, a second embodiment of the present invention will be described. FIG. 2 is a circuit diagram showing the overall configuration of the voltage control device for a vehicle generator according to the second embodiment. The second embodiment is the same as the first.
Instead of the large-capacity capacitor 14 in the embodiment, U /
The circuit using the D counter 53 is used for long-term integration. Reference numerals 50a to 50l are resistors, 51 is a power generation state detection device, and 52 is a transistor which constitutes an adjustment voltage switching means. Reference numeral 54 is an inverter, 55 is a PWM circuit (pulse width modulation circuit), and V _O is an output detection voltage of the generator 1. U
When the input terminal D of the / D counter 53 is high, it counts up at the timing of a clock signal (not shown), and when the input terminal D is low, it also counts down. Then, a voltage pulse having a duty corresponding to the count value of the U / D counter 53 is output from the PWM (pulse width modulation) circuit 55.

As the negative input voltage of the overvoltage protection comparator 12, the divided voltage value of the output detection voltage V _O of the generator 1 is directly input instead of the detection voltage V _A of the battery 4. Further, the divided value of the detection voltage V _A of the battery 4 is input to the negative side of the comparator 13. The adjustment voltage V _R is switched by switching the divided voltage value of the detection voltage V _A of the battery 4 by the transistor 52 which is the adjustment voltage switching means. The output of the F1 terminal of the U / D counter 53 becomes high when the on-duty value of the switching transistor 11 becomes 100%, and when the count value becomes larger than less than 100% (for example, 60%), the output of the F0 terminal becomes high. Output goes high.

When the discharged state of the battery 4 continues, the detected voltage V _A of the battery 4 falls below the first set voltage V _R U / D.
The counter 53 counts up until the on-duty value of the switching transistor 11 reaches 100%. As a result, the high signal at the F1 terminal of the U / D counter 53 causes the output of the Q terminal of the power generation state detection device 51 to go high, turning on the transistor 52 and increasing the voltage division ratio of the detection voltage V _A of the battery 4. Become. Therefore, the battery 4
Since the terminal voltage of is controlled by a regulated voltage higher than the regulated voltage up to that point, the charging current of the battery 4 can be increased and the capacity recovery of the battery 4 can be accelerated.

When the battery 4 is charged with the above-mentioned high voltage side adjustment voltage and approaches the full charge state, the charging current decreases, so that the on-duty value of the switching transistor 11 becomes less than 100% (for example, 60%) or less, U / D
A low signal is output from the F0 terminal of the counter 53. This signal is inverted by the inverter 54 and becomes a high signal, which is input to the R terminal of the power generation state detection device 51. as a result,
The output of the Q terminal of the power generation state detecting device 51 is reset to low, turning off the transistor 52. Therefore, the voltage division ratio of the detection voltage V _A of the battery 4 becomes small. Therefore, the terminal voltage of the battery 4 changes from the high voltage side adjustment voltage to the low voltage side adjustment voltage, and the count value of the U / D counter 53 gradually decreases. Therefore, as the field current flowing through the rotor coil 2 gradually decreases, the output voltage of the generator 1 gradually decreases from the high voltage side adjustment voltage to the low voltage side adjustment voltage.

As described above, in the second embodiment, the adjustment voltage can be changed gently without using an expensive capacitor that requires a large space. Moreover, since it is possible to switch gradually even when switched to a first set voltage is regulated voltage V _R in accordance with the running state of the vehicle as in the first embodiment, it prevents an abrupt change of the power generation voltage be able to. Furthermore, since the on-duty value of the switching transistor 11 can be gradually changed when the electric load 5 is turned on and off, it is possible to prevent a sudden change in the driving torque of the generator 1. Therefore, it is possible to prevent the engine speed from transiently dropping or rising due to turning on or off of the electrical load 5. In addition, in the idle state of the vehicle in which the maximum output current of the generator 1 is reduced, by turning on the electric fan,
Although the output voltage of the generator 1 often becomes equal to or lower than the regulated voltage, in the present embodiment, by appropriately selecting the high-voltage side regulated voltage V _RH , the average value of the output voltage becomes the regulated voltage without excess or deficiency of charging. can do. Furthermore, when the engine continues to rotate at high speed such as during high-speed traveling, the battery 4 approaches a fully charged state, so that the output voltage of the generator 1 becomes the low-voltage side adjustment voltage V _{RL and} the drainage of the battery 4 due to overcharging can be prevented. .

[0021]

The voltage control device for a vehicular generator according to the present invention has the above-described structure, switches the adjustment voltage as the first set voltage lower than the second set voltage, and changes the fixed period pulse of the gradual excitation means. Since the exciting current control transistor is turned on and off according to the duty value, a simple and inexpensive configuration prevents abrupt changes in the adjustment voltage, and prevents changes in the brightness of the headlights from giving the driver a feeling of strangeness. It has an excellent effect that it can be done.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an overall configuration of a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing an overall configuration of a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing an overall configuration of a conventional example.

FIG. 4 is a circuit diagram showing an overall configuration of a conventional example.

[Explanation of symbols]

(Corresponding to FIG. 1 and FIG. 2 only) 1 ... Vehicle generator, 2 ... Rotor coil, 3 ... Regulator, 4 ... Battery, 5 ... electrical load,
7 ... Acceleration / deceleration running detection device, 11 ... Switching transistor, 14 ... Large capacity capacitor, 20 ...
AND circuit, 51 ... Power generation state detecting device, 52 ... Transistor forming adjustment voltage switching means, 53 ... Counter circuit (U / D counter), 55 ... PWM circuit (pulse width modulation circuit) V _A ... Battery detection voltage, V _C ... Acceleration / deceleration running detection device output voltage, V _H ... Overvoltage as a second set voltage, V _O ... output voltage of the generator, V _R ... adjusting voltage as a first set voltage, V _RL ... Low voltage side adjustment voltage,
V _RM ... Medium voltage side adjustment voltage, V _RH ... High voltage side adjustment voltage

Claims (1)

[Claims] 1. A voltage control device for a vehicle generator that controls the voltage of a vehicle generator by interrupting an exciting current flowing through a rotor coil, wherein a second set voltage and a battery voltage higher than a first set voltage are set. In comparison, when the battery voltage is equal to or higher than the second set voltage, a shut-off means for shutting off the conduction of the exciting current control transistor, and when the battery voltage is equal to or lower than the second set voltage, the battery voltage is set to the first set voltage. When the battery voltage is equal to or lower than the second set voltage, the duty cycle of the constant-cycle pulse of the slow-cycle means is compared with that of the constant-cycle pulse having a duty value corresponding to the long-term integrated value of the comparison output. And a switching means for switching the adjustment voltage as the first set voltage, the conduction cutoff means turning on and off the exciting current control transistor according to a value. Voltage control apparatus for a vehicle generator that.