JP3374543B2 - Control device for vehicle alternator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vehicle alternator, and in particular, it is possible to detect an abnormality in all phases of a rectifier by monitoring an output voltage of one phase or a neutral point of an armature. It was done like this.

[0002]

2. Description of the Related Art Published patent publication (Showa 57-500672)
No.) discloses a technique for detecting an abnormality in a rectifying diode of a vehicle multi-phase AC generator. This is because the output of each phase is connected via a resistor and the symmetry of the AC component at the common connection point is monitored, as described in the same Japanese Patent Publication Nos. 42-44 and FIG. By doing so, the abnormality of the rectifying diode is detected.

[0003]

However, the above-mentioned prior art has a problem that it is necessary to take out the outputs of all phases of the AC generator, which requires a large number of terminals and complicates the circuit configuration. The present invention has been made to solve the above problems, and an object of the present invention is to provide a control device for a vehicle alternator capable of detecting an abnormality in a rectifier without increasing the number of terminals.

[0004]

In order to achieve the above object, a controller for a vehicle alternator according to the present invention according to claim 1 is a one-phase or neutral point output voltage of an armature and a full-wave rectifier.
The output voltage of the generated generator divided by a predetermined division ratio.
A comparator for comparing and outputting a rectangular wave, a duty detection circuit for detecting the duty of the output waveform of the comparator , an abnormality warning means of the rectifier, and the detected duty not within a predetermined range. And a warning unit driving circuit for driving the abnormality warning unit according to the judgment signal of the duty judging circuit.

In order to achieve the above-mentioned object, the invention according to claim 2 is the control device for a vehicle AC generator according to claim 1, wherein the on-duty of the exciting circuit for exciting the field coil is not more than a predetermined value. A determination cancellation circuit for canceling the determination of the duty determination circuit is provided.

In order to achieve the above object, the invention according to claim 3 is the control device for a vehicle alternator according to claim 1 or claim 2, wherein a one-phase or neutral-point output voltage of the armature, It is characterized in that a comparator for comparing the divided voltage value of the output voltage of the rectifier is provided, and the comparison signal of the comparator is inputted to the duty detection circuit.

In order to achieve the above-mentioned object, the invention according to claim 4 is the control device for a vehicle alternator according to claim 1 or 2, wherein a one-phase or neutral-point output voltage of the armature, It is characterized by comprising a comparator for comparing with a set predetermined voltage level, and inputting a comparison signal of the comparator to the duty detection circuit.

In order to achieve the above object, the invention according to claim 5 is the control device for an automotive alternator according to any one of claims 1 to 4, wherein the output of the generator is
For one rectifying diode that constitutes the rectifier from the voltage
A first threshold value or voltage equal to or higher than the voltage including the voltage drop .
The voltage drop of one rectifier diode from the land voltage
Set the voltage below a second threshold value obtained by subtracting, have a voltage comparison circuit for comparing the one phase output of the detected the armature,
When the one-phase output voltage is equal to or higher than the first threshold value or equal to or lower than the second threshold value, the alarm means drive circuit drives the abnormality alarm means of the rectifier.

[0009]

According to the control device for the vehicle alternator of the present invention as defined in claim 1, one phase of the armature or
Neutral output voltage and full-wave rectified generator output voltage
The value divided by a predetermined voltage division ratio is compared by a comparator, and the
A rectangular wave is output from the comparator. Of the output waveform of this comparator
The duty is detected by the duty detection circuit, and it is determined whether the duty detected by the duty determination circuit is within a predetermined range. The abnormality warning means of the rectifier is driven by the determination signal that the duty is not within the predetermined range. Therefore, by monitoring the duty of the one-phase or neutral-point output voltage waveform of the armature, it is possible to detect and warn the abnormality of the rectifying diodes connected to all the phases. There is an effect that the circuit configuration can be simplified without having to take out the phase output.

According to another aspect of the present invention, there is provided the control device for the vehicle AC generator of the present invention, wherein when the on-duty of the exciting circuit for exciting the field coil is equal to or less than the predetermined value, the decision canceling circuit causes the duty judging circuit to operate. The judgment is canceled. After the vehicle load is eliminated, the output of the armature will decrease until the power supply voltage drops below the adjustment voltage,
In this case, the alarm that the rectifier is abnormal will not be erroneously output.

According to the control apparatus for a vehicle AC generator of the present invention as defined in claim 3, a comparator for comparing the one-phase or neutral point output voltage of the armature with the divided voltage value of the output voltage of the rectifier. Is input to the duty detection circuit. Since it is determined whether the duty of the one-phase or neutral-point output voltage of the armature at the voltage division value level is within a predetermined range, there is an effect that the abnormality of the rectifier can be accurately detected. .

According to another aspect of the present invention, there is provided a control device for a vehicle AC generator of a comparator, which compares a one-phase or neutral point output voltage of an armature with a set predetermined voltage level. The comparison signal is input to the duty detection circuit. By comparing with the predetermined voltage level, there is an effect that the abnormality of the rectifier can be detected without the need of the voltage dividing circuit.

According to the control device for an automotive alternator of the present invention as defined in claim 5, at least one threshold value of high or low is set, and the one-phase output voltage of the armature sets this threshold value. When it deviates, the abnormality alarm means of the rectifier is driven. Therefore, even if the rectifiers on the (+) side and (-) side of the detected phase are in the open abnormality at the same time, there is an effect of detecting the abnormality.

[0014]

【Example】

(First Embodiment) A first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a circuit diagram of a control device 1 for a vehicle AC generator according to this embodiment. Reference numeral 2 denotes a vehicle AC generator (hereinafter referred to as a generator), which includes an armature 3 in which armature windings are Y-connected, a field winding 4, and a rectifier 5 for full-wave rectifying a three-phase AC output. The rectifier 5 is formed by connecting six rectifier diodes 5a. The three-phase AC output generated by the generator 2 is rectified into a DC output by the rectifier 5 and supplied to the battery 6 and the vehicle electric load 7. 8 is a key switch, 9
Is a charge lamp.

In the control device 1, 11 is the control device 1.
The power supply circuit 12 supplies power to each circuit described later, and 12 is a voltage adjustment circuit that adjusts the voltage of the battery 6 to a predetermined voltage value. Reference numeral 13 is a power transistor for driving a field current, which is turned on / off by the output of the voltage adjusting circuit 12 to adjust the field current. 14 is a power transistor 13
It is a flywheel diode that circulates the field current when is turned off. 15 and 16 are full-wave rectified generator 2
1 is a voltage dividing resistor for dividing the output voltage of No. 1, and 17 is a comparator for comparing the one-phase output voltage of the armature with the divided voltage.

Reference numeral 18 is a duty detection circuit for detecting the duty of the output waveform of the comparator 17, and 19 is a duty signal detected by the duty detection circuit 18, which is input to determine whether the duty value is within a predetermined range. It is a duty determination circuit for determining whether or not. 20 is a charge lamp 9
When it is determined that the detected duty value is not within the predetermined range, the base transistor receives the “H” signal output from the duty determination circuit 19 and conducts to turn on the charge lamp 9. . Reference numeral 21 denotes a judgment cancel circuit, which detects the conduction ratio of the power transistor 13 for driving the field current and outputs a judgment cancellation signal to the duty judgment circuit 19 when the conduction ratio is equal to or less than a predetermined value. . A specific electric circuit diagram of the control device 1 is shown in FIG.

The operation of the control device 1 having the above structure will be described below. First, when the key switch 8 is turned on, the power supply circuit 1
The voltage of the battery 6 is applied to the power source 1, and power is supplied to each of the circuits in the control device 1. The voltage adjustment circuit 12 detects the voltage of the battery 6 and turns on / off the power transistor 13 to adjust it to a predetermined voltage value, adjusts the field current flowing through the field winding 4, and outputs the output of the generator 2. To control.
The comparator 1 compares the one-phase output voltage waveform of the armature 3 with a value obtained by dividing the full-wave rectified output voltage of the generator 2 with a predetermined division ratio.
7, the output waveform shows a regular rectangular wave having a duty when the one-phase output voltage waveform is cut at the voltage division value level. The duty of the output waveform is detected by the duty detection circuit 18, and the duty determination circuit 19 further determines whether the duty value is within a predetermined range.

When the generator 2 is generating power in a normal state, the one-phase output voltage waveform of the armature 3 has a duty of 50%.
Shows a substantially rectangular wave. However, if any one of the rectifier diodes 5a of the rectifier 5 is opened or short-circuited, the duty varies and deviates from 50%. The duty value in this case changes depending on the rotation speed of the generator 2 and the output current.

FIGS. 3 (a) and 3 (b) are characteristic diagrams showing the relationship between the output current and the duty at another rotation speed with a normal phase when one rectifying diode 5a is opened or short-circuited. is there. Generally, (+) of the rectifier 5
If the rectifying diode 5a on the negative side fails, the duty becomes higher than 50%, and the rectifying diode 5a on the (−) side
If it fails, it will be lower than 50%. The duty of the opened or shorted phase is 50% or less when the (+) side rectifying diode 5a is opened, and 50% or more when the (−) side rectifying diode 5a is opened. Further, at the time of short circuit, the duty is 0% regardless of whether the rectifying diode 5a is on the (+) side or the (−) side. The duty varies even when two rectifying diodes 5a of different phases fail.

Utilizing the above phenomenon, the determination reference of the duty determination circuit 19 is set in a predetermined range with a duty of 50% as the center value, and the one-phase output voltage waveform of the armature 3 is monitored to detect the rectifier 5. One rectifying diode 5a of all phases or two rectifying diodes 5 of different phases
It is possible to detect the abnormality of a. When the duty judging circuit 19 judges that the duty is out of the predetermined range with the central value of 50%, the "H" signal output from the duty judging circuit 19 is received at the base terminal to charge the lamp. The drive transistor 20 is turned on, the charge lamp 9 is turned on, and an alarm is issued.
It is preferable that the determination standard of the duty determination circuit 19 is set to be slightly wide in a predetermined range with a center value of 50% so as to prevent erroneous determination due to noise or the like. In this case, in the duty detection circuit 18 and the duty determination circuit 19,
By providing the delay function, it is possible to prevent the alarm from being issued based on a temporary duty fluctuation due to noise.

When the amount of power generated by the generator 2 is reduced, the one-phase output voltage waveform of the armature 3 is gradually distorted and the rectangular wave is no longer shown (see FIG. 4). Therefore, 1
Depending on the voltage level at which the duty of the phase output voltage waveform is detected, accurate determination becomes impossible, and even if the actual duty is 50%, it is erroneously determined that an abnormality has occurred in the rectifier 5, and the charge lamp 9 is turned on. It may cause an alarm. Therefore, the resistance ratio of the voltage dividing resistors 15 and 16 that divides the full-wave rectified output voltage of the generator 2 is set to 1: 1 and the duty of the one-phase output voltage waveform is set to 1 / the output voltage of the generator 2. By detecting at the level of 2, the rectifier diode 5a of the rectifier 5 can be used even when the power generation amount is small to some extent.
It is possible to accurately determine the abnormality.

Further, when a relatively large load of the vehicle load is eliminated, the generator 2 is temporarily in a power generation stop state until the battery voltage that has become equal to or higher than the predetermined adjustment voltage falls below the adjustment voltage again. Become. Therefore, the duty is 0
Even though the generator 2 is normal, the charge lamp 9 is turned on and an alarm is issued. Therefore, when the conduction rate of the power transistor 13 that drives the field current is equal to or less than a predetermined value, the cancellation signal from the determination cancellation circuit 21 cancels the determination of the duty determination circuit 19 so that the alarm is not issued. There is. The threshold value for the conductivity of the power transistor 13 is determined by the armature 3
1-phase output voltage waveform is gradually distorted and the duty is 5
The cancellation signal is preferably set to be output before it shows 0%.

In the above-described first embodiment, the abnormality of the rectifier 5 for all the phases can be detected only by monitoring the one-phase output voltage waveform of the armature 3, so that the number of terminals and the signal lines connected to the terminals are increased. There is no need and cost will not increase.

(Second Embodiment) In the first embodiment, the one-phase output voltage waveform of the armature 3 is monitored in order to detect the abnormality of the rectifier 5. The abnormality of the rectifier 5 can also be detected by monitoring the voltage waveform.
In this case, the neutral point output voltage waveform of the armature 3 does not become a rectangular wave as shown in FIG. 4, so that the voltage dividing resistors 15 and 16 are dissimilarly to the case where the rectangular wave of the first embodiment is distorted. It is necessary to make the resistance ratio of 1: 1. However, this is the case where only the output side of the generator 2 is divided and the threshold value is set, as shown in FIG. Normally, the voltages input to the non-inverting input terminal and the inverting input terminal of the comparator 17 are both divided voltage values. Therefore, in the end, the ratio of dividing the one-phase output and the generator output is 1: 2 (for example, if the one-phase output is divided into ½, the generator output is divided into ¼). It should be The same applies to the partial pressure ratio of the first embodiment.

In the first and second embodiments described above, the threshold value set by the comparator 17 is compared with the output voltage waveform to generate a rectangular wave, and the duty detection circuit 1
Although the duty is detected by inputting it to the comparator 8, the comparator 17 is not always necessary if the duty can be calculated directly from the shape of the output voltage waveform in the detection circuit. For example, an integration circuit may be used as the duty detection circuit, and any circuit capable of detecting whether the output of the integration circuit is higher or lower than the normal value may be used.

(Third Embodiment) In the third embodiment, when the duty is detected based on the one-phase output voltage waveform of the armature 3, the one-phase output voltage is obtained as in the first embodiment. Is equal to or higher than a voltage obtained by adding a voltage drop corresponding to one rectifying diode 5a from the output voltage of the generator 2 (for example, 16V output or more) or equal to or lower than a voltage obtained by subtracting a voltage drop corresponding to one rectifying diode 5a from a ground voltage (eg below -2V). ) Is provided with a high voltage detection circuit or a low voltage detection circuit. FIG. 5 shows an example of the high voltage detection circuit. By including the high-voltage detection circuit and the low-voltage detection circuit, an abnormality can be detected even when the (+) side and (-) side rectifying diodes 5a of the phase being detected are open at the same time (in this case, the duty cycle). Indicates 50%).

[Brief description of drawings]

FIG. 1 is a circuit diagram of a control device for a vehicle AC generator.

FIG. 2 is a specific electric circuit diagram of a control device for a vehicle AC generator.

FIG. 3 is a characteristic diagram showing the relationship between the output current and the duty of another normal one-phase and neutral point output at a certain rotation speed when the rectifying diode fails.

FIG. 4 is a one-phase and neutral point output voltage waveform diagram in a normal state.

FIG. 5 is a circuit diagram showing an example of a high voltage detection circuit.

[Explanation of symbols]

1 control device 2 generator 3 armature 5 rectifier 9 Charge lamp 13 Power transistor 15, 16 division resistance 17 Comparator 18 Duty detection circuit 19 Duty judgment circuit 20 Driving transistor 21 Judgment cancellation circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-60-87635 (JP, A) JP-A-6-276799 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02J 7/14-7/24 H02P 9/30

Claims (5)

(57) [Claims] 1. A and 1-phase or neutral point output voltage of the armature
Divide the full-wave rectified output voltage of the generator with a predetermined division ratio
And a comparator that outputs a rectangular wave by comparing the
A duty detection circuit for detecting the duty of the output waveform of the comparator, a duty determination circuit for determining whether or not the detected duty is within a predetermined range, a rectifier abnormality warning means, and the detected duty. A control device for a vehicle alternator, comprising: a warning means drive circuit that drives the abnormality warning means in response to a determination signal of the duty determination circuit that determines that the duty ratio is not within a predetermined range. 2. An excitation circuit for exciting a field coil is turned on.
The control device for the vehicle alternator according to claim 1, further comprising a determination cancel circuit that cancels the determination of the duty determination circuit when the duty is equal to or less than a predetermined value. 3. A comparator for comparing a one-phase or neutral point output voltage of the armature with a divided voltage value of the output voltage of the rectifier, and inputting a comparison signal of the comparator to the duty detection circuit. The control device for the vehicle alternator according to claim 1 or 2, characterized in that. 4. A comparator for comparing a one-phase or neutral point output voltage of the armature with a set predetermined voltage level, and inputting a comparison signal of the comparator to the duty detection circuit. The control device for the vehicle alternator according to claim 1 or 2. 5. The rectifier based on the output voltage of the generator
A voltage drop for one rectifying diode
Above the first threshold value above ground pressure or ground voltage
Set the rectified one diode second threshold voltage drop of the voltage below minus of, have a voltage comparison circuit for comparing the one phase output of the detected the armature, the one-phase output voltage The abnormality warning means of the rectifier is driven by the warning means drive circuit when the first threshold value or more or the second threshold value or less . The control device for the vehicle alternator according to one .