JPH0822131B2 - Charging generator control device, charging generator control device adjusting method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for a charging generator, and more particularly to a control device suitable for a charging generator driven by an engine of an automobile or the like.

[Conventional technology]

The control device of the charging generator for automobiles inputs the output voltage of the charging generator and the voltage of the battery, controls the power generation operation by the charging generator so as not to cause overcharging or insufficient charging of the battery, and at the same time, charging generator It also has a function to warn when the output terminal of is disconnected. A conventional example of such a control device is disclosed in Japanese Patent Laid-Open No. 63-92233, in which a battery voltage VS is divided by a first voltage dividing circuit to a voltage V1 = k1.VS, and a charging generator is used. The output voltage VB of is divided by the second voltage dividing circuit to obtain the voltage V2 = k2 · VB. Then, when there is no wire disconnection and is normal, V1> V2, that is, VS> α · VB, α = k2 / k1 (<1) (1), and the input terminal from the battery to the control device (hereinafter also referred to as the S terminal) ) When V1 decreases due to disconnection, and when V1 decreases due to disconnection of the output terminal (hereinafter also referred to as B terminal) to the battery of the charging generator, V1 ≦ V2, that is, VS ≦ α · VB …… (2 ), The voltage division ratios k1 and k2 of the first and second voltage dividing circuits are set, and an alarm is issued when V1 ≦ V2, that is, when the wiring of the battery or the charging generator is disconnected. Output.
Also, the charging voltage of the battery is normally controlled to be 14.5V, which is the same as the above-mentioned voltage V1 set voltage V0.
In comparison with V1> V0, the charging generator is turned off, and when V1 <V0, it is turned on. However, if the battery or charging generator is disconnected,
The battery voltage VS is a constant value that is smaller than VS = 14.5V under normal conditions regardless of the output voltage VB of the charging generator (S
0V when the terminal is disconnected, about 12V when the B terminal is disconnected). Therefore, the first voltage divider circuit output V1 is always V1 <V0. If any of the above terminals is disconnected and the charging generator control is continued, the output voltage will be abnormal because it is uncontrolled. Will rise. Therefore, at the same time when any one of the above terminals is disconnected and an alarm is output, the charging generator is controlled by comparing the voltage V2 obtained by dividing the output VB with the set value V0. At this time, the charging generator output voltage VB is controlled so that V2 = V0, that is, VB = 14.5 / α [V] (3).

[Problems to be Solved by the Invention]

At the time when the above prior art was asked, the output of the automobile generator was 14V, 80A maximum,
Today, high-power generators of 100A or more are used. Also,
Electric wiring in the engine room is longer than before,
The voltage drop between the output terminal and the battery is increasing. On the other hand, generally, the relationship between the voltage VB at the output terminal of the generator and the voltage VS of the battery is VB = VS + RB · IB, where RB is the wiring resistance (Ω) and IB is the output current (A) of the charging generator. Therefore, as in today, wiring resistance RB = 2
-15mΩ, output current IB = 100-150A, and battery voltage VS is a constant value (1
4.5V), the maximum output voltage VB of the charging generator is 14.5 + 0.015 x 150 = 16.75V. Therefore, in order to prevent the abnormal alarm from being issued during normal operation, it is necessary to set each voltage division ratio so that V2 <V1 when VB = 16.75V and VS = 14.5V. To do this,
From equation (1), it is necessary that α <14.5 / 16.75 (4). On the other hand, when the voltage detection terminal (S terminal) of the battery of the control device is disconnected, the charging generator output VB is controlled to be 14.5 / α in order to prevent the uncontrolled state as described above. Then, at this time, from equation (4), VB = 14.5 / α> 16.75V (5). However, in this case, the output terminal (B terminal) of the charging generator is not disconnected from the battery and charging can be continued. However, considering that the load other than the battery is not connected, the charging is small. The voltage may rise and the battery may become overcharged. To prevent this
It is necessary to adjust VB to 16V or less, which is inconsistent with equation (5) as described above. That is, under the conditions of the charging generator and wiring used today, the voltage dividing ratio of the voltage dividing circuit of the formula (1) is set so that the alarm is not normally issued and the overcharge is prevented when the battery terminal is disconnected. There is a problem that the ratio α cannot be selected.

In recent generators, the neutral point rectifier (12 in Fig. 1)
There are many configurations that perform high-frequency rectification according to b), and the ripple voltage at the output terminal is extremely large. Figure 2 (a),
(B) is the maximum rotation speed of the 14V x 150A output generator = 17,
Output terminal voltage VB at 000r / min, wiring resistance RB = 5mΩ,
It is an example of a waveform of the battery voltage VS. Now, VB ≧ 17V
If the alarm is issued at that time, the alarm means may be driven during the shaded area in FIG. 2, and the charging indicator lamp may be dimly illuminated.

An object of the present invention is to prevent the false alarm even when a generator capable of supplying a large output is used, and to overcharge the battery even when the input terminal (S terminal) from the battery to the control device is disconnected. It is to provide a control device for a charging generator that does not cause

[Means for solving the problem]

In order to achieve the above object, in the present invention, the voltage dividing ratio k2 of the second voltage dividing circuit that monitors the connection state of the S terminal and divides the charging generator output voltage VB when the S terminal is disconnected.
A voltage division ratio switching circuit for increasing

[Work]

Voltage division ratio of the second voltage divider circuit when the S terminal is not disconnected
If k2 is k20, α in equation (1) is α0, and the respective values when the S terminal is off are k21 and α1, then α0 = k20 / k1, α1 = k21 / k1 (6) and k21 Since> k20, α0 <α1 (7). In order to prevent a false alarm at VB ≤ 16.75V when the S terminal is not disconnected, the condition of equation (4) above, α0
<14.5 / 16.75 is required, but in order to eliminate the false alarm due to the ripple voltage mentioned above, a value of α0 = 14.5 / 25 (8) is required. This is a condition that an alarm is issued when VB ≧ 25V when the S terminal is not disconnected. On the other hand, when the S terminal is disconnected, the value of α is switched to α1 in equation (6), so the output voltage VB of the charging generator is VB = 14.5 / α1 = (α0 / α1). It is controlled so that (14.5 / α0) = (α0 / α1) · 25 (9). Therefore, α1 that satisfies equation (7)
If is set sufficiently larger than α0, VB can be suppressed to about 16V when the S terminal is disconnected, and overcharging can be reliably prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a circuit diagram of a charging power generation system of an automobile. Generator 1
Is armature winding 11, three-phase full-wave rectifier 12a, neutral point rectifier 12
b, a field winding 13, and a voltage regulator 10. The battery 2 is connected to the output terminal (B terminal) of the generator 1 via the cable 5,
It is connected to the IG terminal via the key switch 3 and to the L terminal via the charging indicator lamp 4 provided on the instrument panel, and the electric machine load 6 is connected in parallel. The voltage regulator 10 is composed of a mixed thick film integrated circuit, and controls a field current such as a power transistor 20, a flywheel diode 21, and a resistor.
22,23,24,25,32, a power transistor 26 for driving the charge indicator lamp 4, capacitors 27,28,29, resistors 30a, 30b forming a first voltage dividing circuit, and a second voltage dividing circuit. Forming resistor 3
1a, 31b, 31c, and a monolithic IC 100 that drives the power transistors 20, 26.

The monolithic IC 100 includes a Zener diode 101, a comparator 102, an OR gate 103, an oscillation circuit 104, a reference voltage V0 generation circuit 105, an AND gate 106, NPN transistors 107, 108, 109, and
110,120, PNP transistors 111,112,113, diode 11
It consists of 4,115,116,117 and a resistor 118. Here, provided by the present invention is a transistor 120, resistors 31c, 32,
By adding this portion, the division ratio of the second division circuit is switched.

The operation of the above configuration will be described below. First, when the key switch 3 is turned on, a current is supplied from the battery 2 to the Zener diode 101 via the resistor 23, and the power supply voltage Vcc for driving the monolithic IC 100 rises. When the rotor (not shown) of the generator is stationary, no voltage is generated in the armature winding 11 and the diode 117 is cut off, so that no charge is stored in the capacitor 29. Then AND
The input d of the gate 106 becomes "0" level, and the transistor 1
09 is turned off, the power transistor 26 is turned on, and the charging indicator lamp 4 is turned on. On the other hand, since no power is being generated,
Since the voltage VS of the battery 2 is low and the first voltage divider circuit output V1 is also low and V1 <V0, the output c of the comparator 102 is at “0” level, and the oscillation signal of the oscillation circuit 104 passes through the transistors 107 and 108. Is transmitted to the parallel transistor 20. Then, the parallel transistor 20 conducts at a constant conduction rate, a constant field current flows in the field winding 13, and "initial excitation" is performed.

Next, when the rotor of the generator starts rotating, an AC voltage is generated in the armature winding 11, and the peak value of the AC voltage is charged in the capacitor 29 via the diode 117. When this value exceeds a certain value, a signal is given to the input terminal a of the oscillation circuit 104, the oscillation is stopped, the output terminal b becomes "0" level, and the signal of the input terminal c of the OR gate 103 is sent to the power transistor 20. It is transmitted and the initial excitation is completed. On the other hand, since the input terminal d of the AND gate 106 is at "1" level and the e terminal is at "1" level (the reason will be described later), the output terminal f
Becomes "1" level, the transistor 109 is turned on, the transistor 26 is turned off, and the charging indicator lamp 4 is turned off.

Here, if the S terminal is not disconnected, the transistor 12
Since 0 is on and the resistor 31c is short-circuited, the voltage dividing ratio k20 of the voltage dividing resistors 31a and 31b that divides the B terminal voltage is divided by the voltage dividing resistors 30a and 30b that divides the S terminal voltage VS. If it is set smaller than k1, (α0 = k20 / k1 <1),
The voltage at the voltage dividing point of the voltage dividing resistors 30a, 30b, that is, the first voltage dividing circuit output V1 becomes higher than the voltage at the voltage dividing point of the voltage dividing resistors 31a, 31b, that is, the second voltage dividing circuit output V2. , PNP transistor 111
Are conducted, and a minute current is caused to flow from the voltage dividing point of the first voltage dividing circuits 30a and 30b to the non-inverting input terminal of the comparator 102. This time,
The second voltage divider circuit output voltage V2 is the first voltage divider circuit output voltage V1.
Since it is lower, PNP transistor 112 shuts off. Then, due to the operation of the current mirror circuit by the PNP transistors 111 and 113, a current substantially the same as the current flowing in the transistor 111 flows in the transistor 113, the current is amplified in the transistor 110, and the voltage at the e terminal is raised to the "1" level. .

Next, when the rotation speed of the generator further increases, the voltage VS of the battery 2 increases, the first voltage divider circuit output voltage V1 increases, and the voltage of the non-inverting input terminal of the comparator 102 changes to the reference voltage V0.
When it becomes higher, the output c of the comparator 102 becomes “1” level, the output of the OR gate 103 becomes “1”, the transistors 107 and 108 are turned on, the power transistor 20 is cut off, and the field current flows to the flywheel diode 21 to decrease. To do. Then, the output voltage VB of the charging generator drops and the voltage VS of the battery 2 also drops. When the voltage VS of the battery 2 decreases, the first voltage divider circuit output voltage V1 also decreases, the output of the comparator 102 returns to "0" level, the output of the OR gate 103 is "0", and the transistors 107,1
08 is turned off, the power transistor 20 is turned on, the field current is energized, and the output voltage VB of the charging generator increases.

The above-described normal operation without disconnection of the S terminal has been described. At this time, the transistor 120 is on and the output voltage V2 of the second voltage dividing circuit is expressed as follows; V2 = k20.VB, k20 = Rb / (Ra + Rb) (10) Here, Ra is the resistance value of the resistor 31a, Rb is the resistance value of the resistor 31b, and k20 is the voltage division ratio of the second voltage dividing circuit (There is no S terminal disconnection). When).

Next, consider a case where the B terminal of the charging / distributor 1 is disconnected.
At this time, the battery 2 is not charged and the S terminal voltage VS drops. Then, the power transistor 20 continues to be conductive, and the output voltage VB of the charging generator rises. When this value reaches VB = VS / α0 (11) α0 = k20 / k1 (12) k1 = Rd / (Rd + Re) (13), the transistor 112 becomes conductive and the B terminal voltage VB becomes Adjusted to a constant value. Here, Rd and Re are resistance values of the resistors 30a and 30b of the first voltage dividing circuit, and k1 is a voltage dividing ratio of the circuit.
From the equations (10) and (11), the above adjustment value is given by V2-VBE = V0, that is, VB = (V0 + VBE) / k20 (14). Where VBE is the base of transistor 112
It is the voltage between the emitters. When VB becomes the value of the equation (11), the transistors 111, 113, 110 are turned off, the input e of the AND gate 106 is “0”, the output f is “0”, the transistor 109 is off, and the transistor 26 is on. The charging indicator lamp 4 lights up to give an alarm to the driver.

Next, the case where the S terminal of the charging generator 1 is disconnected will be described. At this time, the output voltage V1 of the first voltage dividing circuit becomes 0,
Transistors 111, 113, 110 are turned off and AND gate 106
The input e of the transistor is "0" and the output f is "0".
9 is off, transistor 26 is on, charging indicator light 4
Lights up. Further, since the transistor 120 is turned off and the resistor 31c is inserted in series with the resistor 31b of the second voltage dividing circuit, the second voltage dividing circuit output voltage V2 is V2 = k21 · VB, k21 = ( Rb + Rc) / (Ra + Rb + Rc) (15) where Rc is the resistance value of the resistor 31c. Therefore, the adjustment voltage VB at this time is given by VB = (V0 + VBE) / k21 (16) as in equation (14).

Looking at the above operation in terms of numerical values, first, an alarm should not be issued when the S terminal and B terminal are both connected and normal.
For this reason, as explained in the conventional example, it is necessary to give an alarm at the maximum voltage VBm that can be taken by VB under normal conditions. This is expressed by the formula (11) as VS / α0> VBm, that is, α0 < It means VS / VBm = 14.5 / VBm. Since the maximum voltage VBm should be considered to be about 25V as described in the conventional example (see FIG. 2), α0 = k20 / k1 <14.5 / 25 = 0.58 (17) should be set. . On the other hand, the regulated voltage when the S terminal is disconnected is given by equation (16), which must be about 16V to avoid overcharging the battery, so k21 = (V0 + VBE) / 16 (18) Here, when normal, V1 = V0 + VBE, that is, k1VS = 14.5k1 = V
Since voltage control is performed so that 0 + VBE, using this relational expression, equation (18) becomes 16 · k21 = 14.5 · k1, α1 = k21 / k1 = 14.5 / 16 ≈0.91 (19) Is required. In the conventional technology, k20 = k21, so it was not possible to simultaneously satisfy the equations (17) and (19).
In this example, k20 <k as can be seen from the equations (10) and (15).
It is 21, and both formulas can be satisfied at the same time. For example, if Ra / Rb = 3 and Rc / Rb = 1, then k20 = 1/4, k21 = 2/5, α0 / α1 = k20 / k21 = 5/8 = 0.625
Next, the condition α0 / α necessary to satisfy equations (17) and (19)
It can satisfy 1 <0.64. In this way, in this embodiment, a false alarm is prevented when the S terminal is not disconnected, and at the same time, the battery is not overcharged when the S terminal is disconnected.

Next, an embodiment of a resistance value adjusting method at the time of manufacturing the resistors 31a to 31c constituting the second voltage dividing circuit in the circuit of the embodiment shown in FIG. 1 will be described with reference to FIG. In FIG. 3, a transistor 20 is provided at each terminal of the voltage regulator prime 10.
Lamp 303 and fixed voltage generator 30 to check the status of
1. The variable voltage generator 302 is connected. Resistor 31a,
31b and 31c are thick film resistors printed on a ceramic substrate. In this state, the output of the variable voltage generator 302 is set to a value of the generated voltage that does not cause battery overcharge when the S terminal is disconnected, for example, 15.5V. If the adjustment voltage given by equation (16) exceeds 15.5V, the voltage actually applied to the B terminal of 15.5V is less than the adjustment voltage, and the S terminal is in the same state as when it is disconnected. Power transistor 20
Turns on, and the lamp 303 lights up. At this time, thick film resistor 31c
With a laser and gradually increase the resistance value Rc,
When the regulated voltage of the equation (16) decreases and reaches 15.5V, the power transistor 20 is cut off and the lamp 303 is turned off. If the laser processing is stopped at this point, the adjustment voltage when the S terminal is disconnected can be set to 15.5V. Note that S
Resistor 31c when the terminals are properly connected to the battery
Since the voltage is short-circuited, the adjustment voltage VB at this time becomes independent of the resistance value Rc as shown in equation (14), and the ratio of the resistance values Ra and Rb,
Also, it is determined by the values of V0 and VBE. Since these values vary, VB varies greatly, but when the B terminal in FIG. 1 is disconnected, the voltage supplied to the battery 2 and the load 6 is low, so
Even if there is some variation, there is no problem such as overvoltage being applied to the outside of the generator. According to the present embodiment, since the laser adjustment points of the hybrid thick film integrated circuit are small, it is possible to prevent an increase in processing time due to the addition of a circuit and reduce the manufacturing cost.

In the embodiment shown in FIG. 1 described above, the voltage regulator
Although all 10 are configured by hardware,
This can be replaced by a microcomputer program. FIG. 4 shows a flow chart at that time. A voltage regulator is composed of this processing unit, the lamp driving transistor 26 and the generator exciting transistor 20 of FIG. 1, and this program is periodically started. To be done. In FIG. 4, first, the battery voltage VS and the charge generator output voltage VB are taken in (step 400), and then it is checked whether or not the voltage VS is smaller than a sufficiently small positive voltage VS0 (step 4).
01), if it is small, set the division ratio k2 to k21 (step 4
02), if not small, set to k20 (step 403).
Here, k20 and k21 are the voltage division ratios of the second voltage dividing circuit described above. Next, compare k2 / VB and k1 / VS (step 404),
When the former is larger, V = k2 · VB (step 40
5) The transistor 26 is turned on to turn on the lamp (step 406). When k2 · VB is smaller, V = k
1 ・ VS (step 407). If the above V is larger than the reference voltage V0, the transistor 20 is turned off (generator non-excitation), and if it is smaller, the transistor 20 is turned on for a certain time (generator excitation) (steps 408 to 410). The processing in each of these steps is realized by software as performed by the circuit of FIG. It is clear that the same effect can be obtained. Further, the adjustment of the voltage division ratio k21 explained in FIG. 3 is to adjust the constant in the program in this embodiment, but this is the same as in FIG. 3 by providing a setting circuit such as a variable resistor. Can be done in any way.

〔The invention's effect〕

According to the present invention, by adding a simple circuit or by adding a simple process, there is an effect that it is possible to prevent false alarm of the charging generator and prevent battery overcharge when the battery voltage detection terminal is disconnected, Further, there is an effect that the added circuit can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a waveform diagram showing ripple waveforms of an output terminal and a battery terminal of a charging generator, and FIG. 3 is a diagram showing the voltage regulator 10 of FIG. FIG. 4 is an explanatory view of an embodiment of the method of adjusting the resistor of FIG. 4, and FIG. 1 ... Generator, 2 ... Battery, 4 ... Charging indicator, 10
...... Voltage regulator, 13 …… Field winding, 20 …… Power transistor, 26 …… Power transistor, 31a, 31b, 31c ……
Voltage dividing resistor, 100 …… monolithic IC, 120 …… transistor.

Front page continuation (72) Inventor Naotaka Takahashi 2477, Kashima Yatsu, Katsuta City, Ibaraki Prefecture 3 Hitachi Hitachi Automotive Engineering Co., Ltd. (72) Inventor Tetsuo Ueno 2520, Takata, Katsuta City, Ibaraki Prefecture Co., Ltd. Hitachi Sawa Factory

Claims (5)

[Claims] 1. A first voltage dividing means for taking in an output voltage of a battery and dividing it into a first predetermined ratio, and a second voltage dividing means for taking in an output voltage of a generator for charging the battery and dividing it into a second predetermined ratio. A terminal connection of the battery is monitored by an output voltage of the battery, and when the output voltage becomes smaller than a predetermined value, the second predetermined ratio of the second voltage dividing means is larger than the second predetermined ratio. The output voltage of the first voltage dividing means and the output voltage of the second voltage dividing means are compared with each other, and an alarm is output when the output voltage of the second voltage dividing means becomes high. And a voltage adjusting means for adjusting an output voltage of the generator by comparing an output voltage of the second voltage dividing means with a reference voltage. 2. The voltage adjusting means according to claim 1, wherein the voltage adjusting means compares the output voltage of the first voltage dividing means with the output voltage of the second voltage dividing means and uses the larger output voltage as a reference voltage. And a exciting current control means for turning off the exciting current of the generator when the reference voltage is larger than the reference voltage and turning on the exciting current when the reference voltage is smaller than the reference voltage. 3. The second partial pressure means according to claim 2,
A first resistor having an output voltage of the generator applied to its one terminal, and the one terminal connected to the other terminal of the first resistor, the connection point being the output of the second voltage dividing means. It is composed of a second resistor at an end and a third resistor connected between the other terminal of the second resistor and the ground, and the voltage dividing ratio switching means is a battery. Is a transistor connected in parallel to the third resistor, which is conductive when the input voltage is higher than the predetermined value and is non-conductive when the input voltage is lower than the predetermined value. 4. A method for adjusting a control device for a charging generator according to claim 3, wherein the input voltage from the battery is fixed to a value smaller than the predetermined value, and the input voltage from the generator is the battery at that voltage. Is fixed to a constant voltage that does not cause overcharge when charged, and the resistance value of the third resistor is adjusted so that the exciting current from the voltage adjusting means is turned off. Method of adjusting generator control device. 5. When the battery voltage value multiplied by the first partial pressure ratio is smaller than the generator output voltage value multiplied by the second partial pressure ratio, an alarm is output and the exciting current of the generator is controlled to generate electricity. In a control device of a charging generator for adjusting a machine output voltage, a first value is set as a value of the second voltage division ratio when the battery voltage is higher than a predetermined value, and the second voltage division ratio is set when the battery voltage is lower than the predetermined value. A first processing means for setting a second value larger than the first value as a value of, and a value obtained by multiplying the battery voltage value by the first voltage division ratio as a first product value, and the generator output voltage value as the second value. A value obtained by multiplying the voltage division ratio is set as a second product value, and when the second product value> the first product value, the second product value is set as a reference voltage value and an alarm is output.
Second processing means for setting the first product value as a reference voltage value without outputting an alarm when the second product value ≦ the first product value; comparing the reference voltage value with a reference voltage value; > When the reference voltage value is reached, the exciting current is turned off, and the reference voltage value ≤
And a third processing means for turning on the exciting current at a reference voltage value.