JP4238820B2 - Vehicle power generation control device - Google Patents

Description

  The present invention relates to a vehicle power generation control device that adjusts an output voltage of a vehicle generator mounted on a passenger car, a truck, or the like.

Conventionally, a power generation control device that has an overheat protection function that reduces the excitation current of a vehicular generator when the temperature becomes higher than a normal value, or that gives a predetermined warning to the driver during the overheat protection operation Is known (for example, see Patent Document 1). In this power generation control device, when the temperature of the measurement target part becomes high, the excitation current can be reduced and the output of the vehicle generator can be lowered. Therefore, heat generation by the vehicle generator is suppressed, and the vehicle generator In addition, it is possible to prevent thermal damage to each part of the power generation control device.
Japanese Patent No. 3439964 (page 4-8, FIG. 1-8)

  By the way, in the power generation control device disclosed in Patent Document 1, a warning is output to the driver when the overheat protection function is activated, but the overheat protection function may be activated to return to a normal temperature. There was a problem that an originally unnecessary warning action may be performed. In particular, when the warning is performed in a simple manner (for example, when all abnormalities in the power generation system are notified by turning on the charge lamp), the driver only knows that some abnormality has occurred in the power generation system. Therefore, even if the temperature falls to the normal range after that and the warning output is stopped, is it a temporary temperature rise and then returned to normal, or is it a sign that a serious abnormality will occur in the power generation system in the future? I don't know and I'm very anxious.

  The present invention was created in view of the above points, and an object of the present invention is to provide a vehicle power generation control device capable of preventing the occurrence of unnecessary warnings.

To solve the problems described above, the power generation controller of the invention, Ru reduces the excitation current of the vehicle generator when the temperature of the measurement position is detected to be equal to or higher than the upper limit temperature of the proper range Overheat protection means that performs overheat protection operation, power generation suppression determination means that determines whether or not the power generation amount of the vehicle generator is suppressed during the overheat protection operation by detecting the actually flowing excitation current, and the detected excitation current When the power generation suppression determination means determines that the power generation amount of the vehicular generator is not suppressed due to the increase in the power generation, the alarm means performs an alarm operation. Since the alarm operation is not performed in a normal state in which the overheat protection function works effectively and the power generation amount of the vehicle generator is suppressed, it is possible to prevent an unnecessary warning from being generated when the temperature is high. As a result, it is possible to avoid a situation in which the driver is more uneasy than necessary.

  Further, the time when the power generation suppression determination means determines that the power generation amount of the vehicle generator is not suppressed is measured, and an alarm output signal is output when the measurement time exceeds the reference time. It is desirable to further include a timer means, and the alarm means preferably performs an alarm operation when an alarm output signal is output from the timer means. As a result, it is possible to confirm the effect of the overheat protection operation being performed, and that there is a possibility that thermal damage may occur when the temperature rises beyond the normal range. It is possible to reliably warn the driver or the like.

  Hereinafter, a vehicle power generation control device according to an embodiment to which the present invention is applied will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a vehicle power generation control device according to an embodiment to which the present invention is applied. In addition, a connection state between the vehicle power generation control device and a vehicle power generator, a battery, or the like is shown. Yes.

  In FIG. 1, the vehicle power generation control device 1 of the present embodiment controls the excitation current of the vehicle generator 2 so that the terminal voltage of the battery 3 becomes a predetermined adjustment voltage setting value (for example, 14 V), and the vehicle The lighting state of the charge lamp 5 is controlled according to whether there is an abnormality in the power generation state of the generator 2 for vehicles or the power generation control device 1 for the vehicle itself.

  The vehicle generator 2 includes a three-phase stator winding 200 included in the stator, a rectifier circuit 202 provided for full-wave rectification of the three-phase output of the stator winding 200, and a rotor. And an excitation winding 204 provided. The control of the output voltage of the vehicular generator 2 is performed by appropriately intermittently controlling the energization of the excitation winding 204 by the vehicular power generation control device 1. The output terminal (B terminal) of the vehicle generator 1 is connected to the battery 3 and the electric load 4, and charging power is supplied from the output terminal to the battery 3 and operating power is supplied to the electric load 4. The

  Next, a detailed configuration and operation of the vehicle power generation control device 1 will be described. As shown in FIG. 1, the vehicle power generation control device 1 includes an excitation drive transistor 10, a freewheeling diode 12, a sense resistor 14, a voltage control circuit 20, a temperature sensor 22, an overheat protection circuit 24, an AND circuit 26, and an excitation current determination circuit. 30, a temperature determination circuit 32, a battery voltage determination circuit 34, an abnormality determination circuit 36, an alarm counter 38, a reset counter 40, and an alarm output circuit 42.

  The excitation drive transistor 10 is a switching element connected in series with the excitation winding 204, and interrupts the excitation current flowing through the excitation winding 204. The freewheeling diode 12 is connected in parallel to the exciting winding 204 and recirculates the exciting current when the exciting drive transistor 10 is in the off state. The sense resistor 14 is inserted between the source of the excitation drive transistor 10 and the ground (E terminal), and is used to detect the excitation current flowing in the excitation winding 204 through the source and drain of the excitation drive transistor 10. It is done.

  The voltage control circuit 20 compares the terminal voltage (battery voltage) of the battery 3 taken in through the terminal S with a predetermined adjustment voltage, and outputs a control signal corresponding to the comparison result. For example, when the battery voltage becomes lower than the adjustment voltage, a high level control signal is output. Conversely, when the battery voltage becomes higher than the adjustment voltage, a low level control signal is output.

  The temperature sensor 22 detects a temperature at a predetermined measurement position of the vehicle power generation control device 1 (for example, a temperature of a heat radiation fin (not shown) that promotes heat radiation of the excitation drive transistor 10). The overheat protection circuit 24 reduces the excitation current and suppresses the power generation amount of the vehicle generator 2 when the temperature detected by the temperature sensor 22 is equal to or higher than the upper limit temperature T corresponding to the upper limit value of the normal range. Perform the action. For example, the overheat protection circuit 24 generates and outputs an excitation current limiting PWM signal that reduces the continuity (duty) when the excitation drive transistor 10 is intermittent. The AND circuit 26 outputs an excitation drive signal as a logical sum signal of the control signal output from the voltage control circuit 20 and the excitation current limiting PWM signal output from the overheat protection circuit 24. This excitation drive signal is input to the gate of the excitation drive transistor 10. Note that a method other than lowering the conduction rate of the excitation drive transistor 10 may be used for the protective operation for reducing the excitation current. For example, the excitation current may be reduced by changing the adjustment voltage used in the voltage control circuit 20 to a low value or changing the voltage applied to the excitation winding 204 to a low value.

  The excitation current determination circuit 30 detects the excitation current based on the voltage across the sense resistor 14 and outputs an abnormality detection signal when the detected excitation current is rising during the overheat protection operation. The temperature determination circuit 32 outputs an abnormality detection signal when the temperature detected by the temperature sensor 22 is rising during the overheat protection operation. The battery voltage determination circuit 34 outputs an abnormality detection signal when the battery voltage taken in through the S terminal is rising during the overheat protection operation. The abnormality determination circuit 36 performs an operation for determining whether or not the power generation amount of the vehicle generator 2 is suppressed during the overheat protection operation. At least one of the excitation current determination circuit 30, the temperature determination circuit 32, and the battery voltage determination circuit 34 is performed. When the state in which the abnormality detection signal is output from one continues, it is determined that the amount of power generation is not suppressed, and the abnormality continuation pulse is output at predetermined time intervals.

  The alarm counter 38 performs a counting operation according to the abnormal continuation pulse output from the abnormality determination circuit 36, and outputs an alarm signal when the count value reaches a predetermined value. The reset counter 40 performs a counting operation in synchronization with a predetermined clock signal, and resets the count of the alarm counter 38 when the count value reaches a predetermined value. The reset counter 40 is reset by the abnormal continuation pulse output from the abnormality determination circuit 36. Accordingly, when the state in which no abnormality continuation pulse is output from the abnormality determination circuit 36 continues for a certain time (T1), the alarm counter 38 is reset, while the state in which the abnormality continuation pulse is output from the abnormality determination circuit 36 is a certain time (T2). When the operation continues, an alarm signal is output from the alarm counter 38.

  When an alarm signal is output from the alarm counter 38, the alarm output circuit 42 performs a predetermined alarm operation by turning on the charge lamp 5 connected between the L terminal and the positive terminal of the battery 3. The charge lamp 5 is turned on as an example of the warning operation. Instead of turning on the charge lamp 5, an alarm signal is transmitted from the alarm output circuit 42 to an external control device (not shown), and the external control device is turned on. May be used to perform some kind of alarm operation.

  The above-described overheat protection circuit 24 is the overheat protection means, the abnormality determination circuit 36 is the power generation suppression determination means, the alarm output circuit 42 is the alarm means, the temperature determination circuit 32 is the temperature determination means, and the battery voltage determination circuit 34 is the battery voltage. The exciting current determining circuit 30 corresponds to the exciting current determining means, the alarm counter 38 and the reset counter 40 correspond to the determining means, respectively.

  The vehicle power generation control device 1 of the present embodiment has such a configuration, and the operation thereof will be described next. FIG. 2 is a flowchart showing an operation procedure of alarm output performed during the overheat protection operation in the vehicle power generation control device 1.

  During the power generation operation, the overheat protection circuit 24 determines whether or not the temperature detected by the temperature sensor 22 is equal to or higher than the upper limit temperature T (step 100). If the detected temperature is lower than the upper limit temperature T, a negative determination is made and this determination is repeated. When the detected temperature is equal to or higher than the upper limit temperature T, an affirmative determination is made in the determination in step 100, and the overheat protection circuit 24 starts an overheat protection operation for reducing the excitation current (step 101).

  After the overheat protection operation starts, the overheat protection circuit 24 determines again whether or not the temperature detected by the temperature sensor 22 is equal to or higher than the upper limit temperature T (step 102). If the detected temperature is maintained at the upper limit temperature T or higher, an affirmative determination is made, and then the abnormality determination circuit 36 determines whether or not an abnormal state has been detected (step 103). Here, the abnormal state to be determined refers to a state in which an abnormality detection signal is output from at least one of the excitation current determination circuit 30, the temperature determination circuit 32, and the battery voltage determination circuit. When an abnormality detection signal is output from at least one of these three circuits, an affirmative determination is made. Next, the abnormality determination circuit 36 and the alarm counter 38 determine the duration of the abnormal state for a predetermined time (T2). It is determined whether or not the above has been reached (step 104). When an abnormal continuation pulse is output from the abnormality determination circuit 36 at a predetermined time interval, and the count value of the alarm counter 38 is updated in synchronization with the abnormal continuation pulse and reaches a count value corresponding to the predetermined time T2. An alarm signal is output from the alarm counter 38. Therefore, when an alarm signal is not output (negative determination in the determination in step 104), the process returns to step 102 and the detected temperature determination operation is repeated. When an alarm signal is output from the alarm counter 38 (affirmative determination in step 103), the alarm output circuit 42 performs an alarm output operation by turning on the charge lamp 5 (step 105). Thereafter, with the alarm output operation maintained, the process returns to step 102 and the detected temperature determination operation is repeated.

  Further, when the detected temperature becomes lower than the predetermined temperature T after the overheat protection operation starts, a negative determination is made in the determination of step 102. Next, the overheat protection circuit 24 stops the overheat protection operation for reducing the excitation current (step 106). When the overheat protection operation is stopped, the alarm counter 38 is reset by the reset counter 40 after a certain time T1 has elapsed, and the output of the alarm signal is also stopped. For this reason, the alarm output circuit 42 stops the alarm output operation (step 107). Then, it returns to step 100 and the temperature determination by the overheat protection circuit 24 is repeated.

  As described above, since the alarm operation is not performed in the normal state where the overheat protection function works effectively and the power generation amount of the vehicle generator 2 is suppressed, an unnecessary warning is prevented from being generated when the temperature is high. can do. As a result, it is possible to avoid a situation in which the driver is more uneasy than necessary.

  In addition, by using the temperature determination circuit 32, the battery voltage determination circuit 34, and the excitation current determination circuit 30, it is possible to reliably check whether the power generation amount is suppressed. In particular, by determining the temperature rise at the measurement position, it is possible to know whether there is a reduction in the amount of power generation indirectly, and to prevent various circuits existing around the measurement position from being thermally damaged by suppressing power generation. be able to. In addition, by determining whether the battery voltage has risen, it is possible to indirectly know whether or not the amount of power generation has been reduced, and to prevent the overvoltage from being applied to the battery 3 or the electric load 4 to cause damage or a reduction in lifespan. Can be prevented. In addition, by determining the increase in the excitation current, it is possible to directly know whether or not there is a reduction in the amount of power generation.

  In addition, by performing an alarm operation after a certain period of time has elapsed since the start of the overheat protection operation, the effect of the overheat protection operation being performed can be confirmed, and the temperature has risen beyond the normal range. It is possible to reliably warn the driver and the like that there is a possibility that thermal damage may occur when the operation is continued for longer than this.

  In addition, this invention is not limited to the said embodiment, A deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above embodiment, the three circuits of the excitation current determination circuit 30, the temperature determination circuit 32, and the battery voltage determination circuit 34 are provided. However, the abnormality determination circuit includes one or two of these three circuits. 36 may be used to determine whether power generation is suppressed.

It is a figure which shows the structure of the vehicle electric power generation control apparatus of one Embodiment. It is a flowchart which shows the operation | movement procedure of the alarm output performed during an overheat protection operation | movement in a vehicle electric power generation control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle power generation control apparatus 2 Vehicle generator 10 Excitation drive transistor 12 Freewheeling diode 14 Sense resistor 20 Voltage control circuit 22 Temperature sensor 24 Overheat protection circuit 26 AND circuit 30 Excitation current determination circuit 32 Temperature determination circuit 34 Battery voltage determination circuit 36 Abnormality judgment circuit 38 Alarm counter 40 Reset counter 42 Alarm output circuit 200 Stator winding 202 Rectifier circuit 204 Excitation winding

Claims (2)

Overheat protecting means for performing a reduced allowed Ru overheat protection operation the magnetizing current of the vehicle generator when the temperature of the measurement position is detected to be equal to or higher than the upper limit temperature of the proper range,
Power generation suppression determination means for determining presence or absence of power generation amount suppression of the vehicular generator during the overheat protection operation by detecting an actually flowing excitation current ;
Alarm means for performing an alarm operation when a determination that the power generation amount of the vehicular generator is not suppressed is performed by the power generation suppression determination means because the detected excitation current is increased ;
A vehicle power generation control device comprising: In claim 1,
Time measuring means for measuring the time when the determination that the power generation amount of the vehicle generator is not suppressed is performed by the power generation suppression determining means, and outputting an alarm output signal when the measured time exceeds a reference time Further comprising
The vehicle power generation control device, wherein the alarm means performs the alarm operation when the alarm output signal is output from the time measuring means.

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