JP3841088B2 - Vehicle power generation control device - Google Patents

Description

  The present invention relates to a vehicle power generation control device that detects a voltage supplied to an electric load and controls a power generation state of a vehicle generator.

  The vehicular generator performs auxiliary battery charging while the vehicle is running and covers the power for engine ignition, lighting, and other various electrical components. Even when the load condition changes, the output voltage A power generation control device is connected to keep the power supply constant. Recently, in particular, there is an increasing need to improve battery life by controlling the charging voltage of a battery with high precision.To meet this demand, an external voltage detection terminal with low current consumption is provided. The number of vehicle power generation devices that control the voltage of the detection terminal to a predetermined adjustment voltage set value is increasing.

  However, if an abnormality occurs in which the voltage detection line connected to the external voltage detection terminal is disconnected or disconnected, that is, if a voltage difference occurs between the battery terminal voltage and the external voltage detection terminal, the external voltage detection terminal is Since the control is performed so as to maintain the adjustment voltage set value, the battery voltage rises and the battery is likely to be overcharged.

As a technique for solving such an inconvenience, a “vehicle generator control device” disclosed in Japanese Patent Laid-Open No. 62-104440 is known. This control device has a voltage control circuit that determines that the voltage detection line is disconnected when the voltage at the external voltage detection terminal is extremely low, and limits the output voltage of the vehicular generator from becoming excessive. ing.
Japanese Patent Laid-Open No. 62-104440

  By the way, in the method disclosed in Japanese Patent Laid-Open No. 62-104440, the battery is prevented from being overcharged when the external voltage detection terminal is disconnected from the voltage detection line or when the voltage detection line is disconnected. However, if a small contact failure occurs at the connection between the external voltage detection terminal and the voltage detection line and the contact resistance increases, or the resistance value of the voltage detection line gradually increases for some reason. In such a case, the abnormality cannot be detected, and the output voltage of the vehicular generator becomes high, and an excessive voltage may be applied to the battery or other electric load.

  The present invention was created in view of the above points, and its purpose is to increase the output voltage of a vehicular generator even when contact failure occurs in an external voltage detection terminal or voltage detection line. It is an object of the present invention to provide a vehicular power generation control device that can limit the voltage and prevent the application of an excessive voltage to an electric load such as a battery.

In order to solve the above-described problem, the vehicle power generation control device according to the present invention is configured to detect the voltage applied to the electrical load connected to the output terminal of the vehicle generator via the voltage detection line. An external voltage detection terminal connected to a load; a voltage control circuit for controlling a power generation state of the vehicular generator so that a voltage of the external voltage detection terminal becomes a predetermined adjustment voltage setting value; and the external voltage detection terminal An impedance switching circuit that switches the input impedance to a low impedance side for a predetermined period after starting the voltage control circuit, the impedance switching circuit via the resistor and transistor provided outside the voltage control circuit Grounding the external voltage detection terminal, switching the input impedance of the external voltage detection terminal to the low impedance side, the impedance The resistance of the replacement circuit, the external voltage detection terminal is passing a relatively large current to the contact resistance generated at the contact portion of a voltage detection line, an enlarged intrinsic contact surface of the contact portion, the contact portion of the reliability It is possible to employ a vehicular power generation control device characterized by ensuring the above.

  With this configuration, it is possible to ensure reliability in the connection portion by flowing a large current through the connection portion where the contact failure occurs.

  Hereinafter, a vehicle power generation control device (hereinafter referred to as a “regulator”) according to an embodiment to which the present invention is applied will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram showing a configuration of a regulator according to a first embodiment to which the present invention is applied. In addition, a connection state between the regulator and a vehicle generator and a battery is shown.

  In FIG. 1, the regulator 1 performs control so that the voltage at an external voltage detection terminal (S terminal) provided for detecting the voltage applied to the battery 3 becomes a predetermined adjustment voltage setting value (for example, 14 V). Is for. A start instruction detection terminal (IG terminal) is connected to the battery 3 via the ignition switch 4. When the ignition switch 4 is turned on, the control operation by the regulator 1 is started.

  The vehicle generator 2 includes a three-phase stator coil 21 included in a stator as a stator, a rectifier circuit 23 provided for full-wave rectification of the three-phase output of the stator coil 21, and a rotor. A field coil 22 included in the rotor is included. The output voltage of the vehicular generator 2 is controlled by appropriately turning on / off the energization of the field coil 22 by the regulator 1. The output terminal (B terminal) of the vehicle generator 2 is connected to the battery 3, and a charging current is supplied from the B terminal to the battery 3.

  Next, the detailed configuration and operation of the regulator 1 will be described. As shown in FIG. 1, the regulator 1 has a transistor 11 as a switching element connected in series to a field coil 22, a free wheel diode 12 connected in parallel to the field coil 22, and an input impedance of the S terminal. An impedance switching circuit 13 that switches to the low impedance side for a predetermined period, and a voltage control that instructs conduction and cutoff of the transistor 11 so that the voltage at the S terminal linked to the output voltage of the vehicle generator 2 becomes a predetermined adjustment voltage setting value. The circuit 14 includes a power generation detection circuit 15 that detects a power generation state based on any phase voltage of the stator coil 21.

  The impedance switching circuit 13 includes a transistor 30 and resistors 31 and 32. When the ignition switch 4 is turned on and a start instruction is sent, the transistor 30 connected to the IG terminal via the resistor 32 becomes conductive, so that the S terminal is grounded via the resistor 31 and the transistor 30. , The input impedance of the S terminal is switched to the low impedance side. That is, the impedance switching circuit 13 grounds the external voltage detection terminal (S terminal) via the resistor 31 and the transistor 30 provided outside the voltage control circuit 14.

  The voltage control circuit 14 includes transistors 40 to 45, Zener elements 46 and 47, a capacitor 48, and resistors 49 to 58. The Zener element 46 is selected to have a characteristic that breaks when the voltage at the S terminal becomes equal to or higher than the adjustment voltage setting value. At this time, the transistor 40 is turned on and the collector potential is lowered. The collector of the transistor 40 is connected to the base of the transistor 11. When the collector potential of the transistor 40 is lowered, the transistor 11 is cut off, so that the current flowing through the field coil 22 is reduced. On the other hand, when the voltage at the S terminal is equal to or lower than the adjustment voltage set value, the transistor 40 is cut off, the transistor 11 is turned on, and the current flowing through the field coil 22 increases.

  The Zener element 47 is selected to have a characteristic that breaks when the voltage at the B terminal becomes equal to or higher than the adjustment voltage setting value (protection voltage value) when the transistor 45 is cut off. 41 becomes conductive and the collector potential is lowered. The collector of the transistor 41 is connected to the base of the transistor 11, and the transistor 11 is cut off when the collector potential of the transistor 40 decreases.

  When there is no voltage difference between the S terminal voltage and the IG terminal voltage, the transistor 44 is cut off, so that the two transistors 42 and 43 constituting the current mirror circuit are both cut off. Further, when the current from the IG terminal flows to the base of the transistor 45 through the resistor 56, the transistor 45 becomes conductive and draws the B terminal current through the resistors 51 and 57, so that the voltage drop in the resistor 51 increases. Thus, the adjustment voltage for the B terminal is increased by the voltage drop.

  On the other hand, when the S terminal voltage decreases and a voltage difference occurs between the S terminal voltage and the IG terminal voltage, the transistor 44 is turned on, so that both the transistors 42 and 43 are turned on and the transistor 45 is turned off. When the transistor 42 is turned on, the base current of the transistor 44 is drawn through the resistor 55, so that the conduction state of the transistor 44 is maintained until the IG terminal voltage disappears.

  The power generation detection circuit 15 includes a diode 60, a capacitor 61, resistors 62 to 64, and a transistor 65. The one-phase voltage of the stator coil 21 is applied to one end of the resistor 62, and the peak value is detected and held by the diode 60 and the capacitor 61. While the vehicle generator 2 is generating power, this peak value voltage is applied to the base of the transistor 65 via the resistor 64, and a base current flows, so that the transistor 65 is turned on. As a result, the transistor 30 in the impedance switching circuit 13 described above is cut off, and no current flows through the resistor 31.

  The regulator 1 of this embodiment has such a configuration, and the operation thereof will be described next.

  In a state where the connection between the S terminal and the voltage detection line 5 connected to the S terminal is securely established, when the ignition switch 4 is turned on, the base current flowing from the IG terminal through the resistor 32 causes the transistor 30 to be turned on. Although conducting and a current flows through the resistor 31, the contact resistance 6 is almost absent, so the IG terminal voltage and the S terminal voltage are almost equal. Therefore, the transistor 44 is cut off, the transistor 43 is also cut off, and the transistor 45 becomes conductive. At this time, the Zener element 47 does not break and the transistor 41 is cut off. Although the adjustment voltage at the B terminal becomes high, the battery voltage before the power generation by the vehicle generator 2 is less than the adjustment voltage setting value. Similarly, the transistor 40 is cut off without causing the Zener element 46 to break. Therefore, the base current of the transistor 11 is supplied through the resistor 58 and the transistor 11 becomes conductive. Thereby, the current of the field coil 22 increases, and the output voltage increases as the rotational speed of the vehicle generator 2 increases. When the output voltage of the vehicular generator 2 increases, the transistor 65 becomes conductive and the transistor 30 is cut off, so that the impedance of the S terminal increases again.

  Next, the operation when the ignition switch 4 is turned on while the contact resistance 6 is generated between the S terminal and the voltage detection line 5 or in the voltage detection line 5 will be described. The transistor 30 is turned on by the base current flowing from the IG terminal via the resistor 32. Therefore, the S terminal voltage is a value obtained by dividing the terminal voltage of the battery 3 by the resistor 31 and the contact resistor 6. As a result, a voltage difference is generated between the IG terminal voltage and the S terminal voltage, the transistor 44 is turned on, and the transistor 45 is cut off, so that the field coil current does not exceed the adjusted voltage value. Is controlled.

  Thus, in this embodiment, when the contact resistance 6 is generated in either the S terminal or the voltage detection line 5, the transistor 30 is turned on for a predetermined period until power generation is started, and the contact resistance 6 The voltage drop caused by the above can be increased and the contact failure can be detected reliably. At this time, the transistor 44 is also turned on by the conduction of the transistor 44 and draws the base current of the transistor 44. Therefore, the transistor 44 maintains the conduction state until the ignition switch 4 is turned off and an operation stop instruction is sent. . As a result, even if the contact resistance 6 is generated in either the S terminal or the voltage detection line 5, the output voltage of the vehicular generator 2 is suppressed from being excessive, and the battery 3 is overcharged. Can be prevented. In addition, since the transistor 30 is cut off during normal power generation or when the ignition switch 4 is off, the current consumption via the S terminal voltage can be made extremely small, and the battery 3 can be prevented from discharging. Further, even when a slight contact failure occurs, the reliability of the contact portion can be ensured by enlarging the true contact surface by temporarily flowing a relatively large current through the resistor 31. It is possible to return to a good contact state again.

[Second Embodiment]
FIG. 2 is a diagram showing a configuration of a regulator according to a second embodiment to which the present invention is applied. In addition, a connection state between the regulator and a vehicle generator, a battery, and the like is shown. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the regulator of the present embodiment, the voltage detection line 5 is connected to the electric load 7, and the supply voltage from the vehicle generator 2 to the electric load 7 is detected via the S terminal.

  The regulator 1A shown in FIG. 2 includes a transistor 11, a freewheeling diode 12, an impedance switching circuit 13A, and a voltage control circuit 14A.

  The impedance switching circuit 13A includes a transistor 70, resistors 71 and 74, a diode 72, and a capacitor 73. When the ignition switch 4 is turned on, a base current is supplied to the transistor 70 via the resistor 74 and the capacitor 73, and the transistor 70 is turned on for a certain period until the voltage across the capacitor 73 is saturated. To the low impedance side. The diode 72 is for forming a discharge path for the capacitor 73.

  The voltage control circuit 14A includes transistors 42 to 44, 90 and 91, comparators 92 and 93, a capacitor 48, and resistors 53 to 55 and 75 to 81. When the ignition switch 4 is turned on and the IG terminal voltage becomes high, a base current flows through the transistor 90 via the resistor 75, and the transistor 90 becomes conductive. As a result, a voltage obtained by dividing the S terminal voltage by the two resistors 76 and 77 is applied to the negative input terminal of the comparator 92. Further, a predetermined reference voltage V1 is applied to the + side input terminal of the comparator 92, and when the S terminal voltage becomes equal to or higher than the adjustment voltage setting value, the output of the comparator 92 is inverted from the high level to the low level.

  In a state where the contact resistance 6 is generated in either the S terminal or the voltage detection line 5, the transistor 43 is turned on, so that a base current flows through the transistor 91 through the resistor 78 and the transistor 91 is turned on. Therefore, a voltage obtained by dividing the output voltage (B terminal voltage) of the vehicle generator 2 by the two resistors 79 and 80 is applied to the negative input terminal of the comparator 93. In addition, a predetermined reference voltage V2 is applied to the + side input terminal of the comparator 93, and when the output voltage of the vehicle generator 2 becomes equal to or higher than the adjustment voltage setting value, the output of the comparator 93 is changed from a high level to a low level. Invert.

  The AND circuit 94 outputs a logical product of signals output from the two comparators 92 and 93. Therefore, when the output of any of the comparators 92 and 93 becomes low level, the transistor 11 is cut off, and the current of the field coil 22 is reduced.

  In the voltage control circuit 14A described above, when the ignition switch 4 is turned off, the transistors 90 and 91 are cut off, so that the discharge current of the battery 3 can be suppressed. A mechanism that shuts off the transistors 90 and 91 when the ignition switch 4 is turned off constitutes a second impedance switching circuit.

  Thus, in this embodiment, when the contact resistance 6 is generated in either the S terminal or the voltage detection line 5, the transistor 70 is turned on for a predetermined period until the voltage across the capacitor 73 is saturated. A voltage drop caused by the contact resistance 6 can be increased, and a contact failure can be reliably detected. At this time, the transistor 44 is also turned on by the conduction of the transistor 44 and draws the base current of the transistor 44. Therefore, the transistor 44 maintains the conduction state until the ignition switch 4 is turned off. As a result, even if the contact resistance 6 is generated in either the S terminal or the voltage detection line 5, the output voltage of the vehicular generator 2 is suppressed from being excessive, and the battery 3 is overcharged. Can be prevented. Further, since the transistor 90 is cut off when the ignition switch 4 is in the OFF state, the current consumption via the S terminal voltage can be made extremely small, and the discharge of the battery 3 can be prevented. Further, even when a slight contact failure occurs, the reliability of the contact portion can be ensured by temporarily flowing a relatively large current through the resistor 71, and good contact is achieved again. It can be returned to the state.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the voltage applied from the battery 3 to the IG terminal via the ignition switch 4 is used as a signal for instructing the operation start of the voltage control circuits 14 and 14A. The voltage control circuit 14 or 14A may be instructed to start the operation in response to the voltage or current signal from. The operation start instruction method may include a circuit that detects the rotation of the vehicular generator 2 and generates a start signal in the regulators 1 and 1A.

  Further, in the above-described embodiment, a contact failure of the S terminal or the voltage detection line 5 is detected using the voltage difference between the S terminal voltage and the IG terminal voltage, but the value of the S terminal voltage is less than the normal battery voltage. May be determined to be poor contact when the value falls below a value (for example, 10V in the case of a 12V battery).

It is a figure which shows the structure of the regulator of 1st Embodiment. It is a figure which shows the structure of the regulator of 2nd Embodiment.

Explanation of symbols

1 Regulator (Vehicle power generation control device)
DESCRIPTION OF SYMBOLS 2 Vehicle generator 3 Battery 4 Ignition switch 5 Voltage detection line 6 Contact resistance 11 Transistor 12 Freewheeling diode 13 Impedance switching circuit 14 Voltage control circuit 15 Power generation detection circuit 22 Field coil

Claims (1)

An external voltage detection terminal connected to the electric load via a voltage detection line in order to detect an applied voltage value to the electric load connected to the output terminal of the vehicle generator;
A voltage control circuit for controlling the power generation state of the vehicle generator so that the voltage of the external voltage detection terminal becomes a predetermined adjustment voltage setting value;
An impedance switching circuit for switching the input impedance of the external voltage detection terminal to the low impedance side for a predetermined period after the voltage control circuit is started,
The impedance switching circuit grounds the external voltage detection terminal via a resistor and a transistor provided outside the voltage control circuit, and switches the input impedance of the external voltage detection terminal to a low impedance side,
The resistor of the impedance switching circuit allows a relatively large current to flow through the contact resistance generated at the contact portion between the external voltage detection terminal and the voltage detection line, and enlarges the intrinsic contact surface of the contact portion. A power generation control device for a vehicle characterized by ensuring reliability .