JP2015094262A - Starter control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the lowering of a battery voltage while suppressing the deterioration of engine startability, in a starter control device.SOLUTION: This starter control device controls drive of a starter which intervenes between a load and a battery, and has a first relay for on/off-operating supply of a current. The starter control device comprises: a resistor which is connected to the first relay in series thereto; a second relay which is connected to the resistor in parallel therewith, and controls a short circuit of the resistor; and control means which controls opening/closing of a contact point of the second relay. The control means starts to carry electricity to a load by making the first relay close its contact point and simultaneously starts to carry electricity to the resistor by making the second relay separated its contact point, and short-circuits the resistor by closing the contact point of the second relay accompanying a change of a potential difference between both ends of the resistor to a value lower than a first threshold voltage from a value not lower than the first threshold voltage which is set at a prescribed voltage.

Description

  The present invention relates to a starter control device for starting an engine by energizing a load.

  Conventionally, when an engine is started by a starter, that is, when supply of current (hereinafter referred to as starter current) from a battery to a motor is started, a large current called an inrush current flows to the motor. For this reason, the terminal voltage of a battery may fall remarkably temporarily, and electric devices, such as meters and audio, may stop operation momentarily. This is called instantaneous interruption.

  In Patent Document 1, an electromagnetic switch that opens and closes a main contact provided in a motor circuit, a current suppression resistor connected in series with the main contact, a short-circuit relay provided so that the current suppression resistor can be short-circuited, and a short circuit There has been proposed a starter including a timer circuit for delaying the operation relay. The timer circuit sets a resistor energization time, which is a time until energization of the short-circuit relay after energization of the electromagnetic switch is started. Since the motor and the battery are connected via the current suppression resistor within the resistor energization time, the starter current supplied from the battery to the motor is suppressed. That is, inrush current can be suppressed. Then, after the resistor energization time has elapsed, the current suppression resistor is short-circuited and the motor and the battery are directly connected, so that a normal starter operation is performed. Thereby, it can suppress that an inrush current flows into a motor, and can suppress the voltage drop of a battery. As a result, instantaneous interruption can be prevented.

JP 2009-287459 A

  However, in Patent Document 1, the resistor energization time is set in advance in the timer circuit. Depending on the set resistor energization time, the inrush current cannot be suppressed or the starter current is excessively suppressed. Therefore, there is a possibility that a problem may occur in the startability, for example, the engine starts getting worse. Further, since the resistor energization time is constant, there is a problem that the resistor energization time cannot be optimized due to changes in the characteristics of the battery and the motor over time, and the engine startability deteriorates.

  The present invention has been made in view of the above problems, and an object of the present invention is to suppress a battery voltage drop while suppressing deterioration of engine startability in a starter control device.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate a corresponding relationship with specific means described in the embodiments described later as one aspect, and limit the technical scope of the invention. Not what you want.

  In order to achieve the above object, according to the present invention, there is provided a load that operates when current is supplied from a battery, and is interposed between the load and the battery to turn on and off the supply of current to the load of the battery by opening and closing contacts. A starter control device for controlling driving of a starter having a first relay, a resistor connected in series with the first relay, and connected in parallel with the resistor, and short-circuiting the resistor by opening and closing the contact A second relay for controlling, and a control means for controlling the opening and closing of the contact of the second relay. The control means energizes the load by closing the contact of the first relay, and at the same time, the second relay The contact is opened with respect to the relay to start energization of the resistor, and the potential difference between both ends of the resistor is changed from a value greater than or equal to the first threshold voltage set to a predetermined voltage to a value less than the first threshold voltage. Due to the change, the second It is characterized by short-circuiting the resistor by closing contacts over.

  According to this, the first relay is closed and the supply of the starter current from the battery to the load is started, and at the same time, the second relay is opened. For this reason, the inrush current flowing through the load flows from the battery to the load via the resistor. This resistor suppresses the peak value of the inrush current, that is, the maximum value of the starter current.

  By the way, since a starter current having a peak flows in the resistor, a potential difference having a peak occurs at both ends of the resistor. In the present invention, the period in which the starter current flows through the resistor is from the time when the load is energized to the time when the potential difference of the resistor changes from a value greater than or equal to the first threshold voltage to a value less than the first threshold voltage. . In other words, when the current value of the starter current is equal to or greater than a predetermined value, the current is supplied to the load via the resistor. For this reason, unlike the prior art, the time during which the starter current flows through the resistor, in other words, the time during which the second relay is opened is not too long or too short. Therefore, the inrush current can be suppressed while ensuring the startability of the engine. In addition, since the time during which the starter current flows through the resistor depends on the potential difference between both ends of the resistor, it is possible to cope with changes in the battery and load characteristics over time and environmental changes. For example, in the present invention, when the voltage of the battery is lower than normal at low temperatures, the period during which the potential difference of the resistor is equal to or higher than the first threshold voltage is shortened, so that the starter current passes through the resistor. The flow time can be shortened.

1 is a circuit diagram showing a schematic configuration of a starter control device according to a first embodiment. It is a flowchart which shows the operation | movement flow of a starter control apparatus. It is a timing chart which shows the operation timing of a starter control device. 10 is a timing chart showing the operation timing of the starter control device according to Modification 1. It is a circuit diagram which shows schematic structure of the starter control apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the operation | movement flow of a starter control apparatus. It is a timing chart which shows the operation timing of a starter control device. It is a flowchart which shows the operation | movement flow of the starter control apparatus which concerns on 3rd Embodiment. It is a timing chart which shows a time-dependent change of battery voltage.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals are given to the same or equivalent parts.

(First embodiment)
First, a schematic configuration of the starter control device according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the starter control device 10 is a device that is interposed between the battery 100 and the starter 200 and controls driving of the starter 200.

  The starter 200 includes, for example, a motor 210 for starting an automobile engine as a load, and a first relay 220 that controls supply of current from the battery 100 to the motor 210. The first relay 220 is a normally open electromagnetic relay. When the coil 221 is energized, the contact 222 is closed and energized. Energization of the coil 221 is controlled by a starter relay 300 interposed between the coil 221 and the battery 100. The starter relay 300 is also a normally open electromagnetic relay, and its opening and closing is controlled by, for example, the ECU 400 for engine control.

  The operation will be briefly described. When the contact of the starter relay 300 is closed by a control signal from the ECU 400, the coil 221 is energized and the contact 222 of the first relay 220 is closed. As a result, a starter current is supplied from the battery 100 to the motor 210 via the starter control device 10.

  The starter control device 10 will be described in detail. The starter control device 10 includes a second relay 20, a resistor 30, and a control unit 40. Furthermore, the starter control device 10 includes a subtraction circuit 50 and a comparator 60. The control unit 40 corresponds to control means in the claims.

  The second relay 20 is connected in series between the battery 100 and the first relay 220. The second relay 20 is a normally closed electromagnetic relay, and the contact 22 is opened when the coil 21 is energized. Conversely, when the coil 21 is not energized, the contact 22 is in a closed state. That is, the second relay connects the battery 100 and the first relay 220 in a state where the resistance can be almost ignored except for the contact resistance and the wiring resistance of the contact 22. The coil 21 is connected to the battery 100 in parallel with the coil 221 of the first relay 220. The coil 21 is energized when both the starter relay 300 and the switching element 23 that is on / off controlled by the control unit 40 are turned on.

  The resistor 30 is connected to the battery 100 in parallel with the second relay 20. Therefore, the starter current flows through the second relay 20 when the contact 22 of the second relay 20 is closed, and flows through the resistor 30 when the contact 22 is open.

  Control unit 40 is connected to ECU 400 and controls starter control device 10 based on an instruction from ECU 400. As described above, the control unit 40 is connected to the switching element 23 and outputs a signal for controlling on / off to the switching element 23. Thereby, the control part 40 controls the electricity supply to the coil 21, when the starter relay 300 is a closed state. That is, the opening / closing of the contact 22 of the second relay 20 is controlled. The control unit 40 is connected to a comparator 60 described later, and a signal is input from the comparator 60. Detailed operations performed by the control unit 40 will be described in detail later.

  The subtraction circuit 50 is a circuit that outputs a potential difference between both ends of the resistor 30. As shown in FIG. 1, the subtraction circuit 50 in the present embodiment has a generally well-known circuit configuration including resistors 50 a to 50 d and a comparator 51. That is, the potentials at both ends of the resistor 30 are respectively input to the input terminal of the comparator 51 and the difference is output to the comparator 60 described later.

  In the comparator 60, the subtraction circuit 50 and the reference potential source 61 are connected to two input terminals, respectively. Then, the potential difference between both ends of the resistor 30 output by the subtraction circuit 50 is compared with the first threshold voltage defined by the reference potential source 61. Then, a signal based on the comparison result is output to the control unit 40.

  Next, with reference to FIG. 2 and FIG. 3, the operation | movement and effect of the starter control apparatus 10 which concern on this embodiment are demonstrated.

  First, as shown in FIG. 2, step S1 is executed. Step S1 is a step in which supply of starter current is started in order to start driving of the motor 210 of the starter 200. This step S1 is executed at time t0 in FIG. Step S1 is executed when the driver turns on an ignition switch (not shown). When step S1 is executed, the starter relay 300 is closed and the coil 221 is energized. As a result, the contact 222 of the first relay 220 is closed and the starter current starts to flow.

  Step S2 is executed simultaneously with step S1. That is, this step S2 is executed at time t0 in FIG. Step S <b> 2 is a step in which the control unit 40 turns on the switching element 23. ECU 400 issues an instruction to control unit 40 to turn on switching element 23 at the same time as step S1 is executed. Since the starter relay 300 is in the closed state in step S1, the coil 21 of the second relay 20 is energized and the contact 22 is released by executing step S2.

  The starter current that starts to flow from time t0 flows through the resistor 30 without passing through the second relay 20 in the separated state. The resistance value of the resistor 30 is larger than that of the second relay 20. For this reason, the absolute value of the starter current can be suppressed, and the inrush current can be suppressed.

  Next, step S3 is executed. Step S <b> 3 is a step in which the comparator 60 compares the potential difference between both ends of the resistor 30 output by the subtraction circuit 50 with the first threshold voltage. In step S3, it is determined whether or not the potential difference between both ends of the resistor 30 is equal to or higher than the first threshold voltage. If the potential difference is equal to or higher than the first threshold voltage (YES determination in FIG. 2), the process proceeds to step S4. Step S3 is continuously executed until a YES determination is made. That is, if the determination is NO, step S3 is continued.

  Step S4 is a step in which the comparator 60 outputs a predetermined voltage. In step S3, since the potential difference between both ends of the resistor 30 is equal to or higher than the first threshold voltage, the comparator 60 outputs, for example, a positive supply voltage supplied to the comparator 60. Thereby, as shown in FIG. 3, the signal output from the comparator 60 to the control unit 40 rises. A time t1 in FIG. 3 indicates a time when a signal output from the comparator 60 to the control unit 40 rises.

  Next, step S5 is executed. In step S5, as in step S3, the comparator 60 compares the potential difference between both ends of the resistor 30 output by the subtraction circuit 50 with the first threshold voltage. In step S5, it is determined whether or not the potential difference across the resistor 30 has fallen below the first threshold voltage. If the potential difference is lower than the first threshold voltage (YES in FIG. 2), the process proceeds to step S6. Step S5 is continuously executed until a YES determination is made. That is, if the determination is NO, step S5 is continued.

  Step S6 is a step in which the comparator 60 outputs a predetermined voltage. In step S5, since the potential difference between both ends of the resistor 30 is lower than the first threshold voltage, the comparator 60 outputs a negative supply voltage supplied to the comparator 60, for example. As a result, the signal output from the comparator 60 to the control unit 40 falls as shown in FIG. A time t2 in FIG. 3 indicates a time when the signal output from the comparator 60 to the control unit 40 falls.

  Step S <b> 7 is executed by using the signal output from the comparator 60 to the control unit 40 as a trigger. Step S <b> 7 is a step in which the control unit 40 turns off the switching element 23. By executing step S7, the energization to the coil 21 of the second relay 20 is interrupted, and the contact 22 is closed. That is, the resistor 30 is short-circuited. For this reason, the starter current is supplied to the motor 210 without passing through the resistor 30.

  According to this, the time during which the starter current flows through the resistor 30 is a value in which the potential difference between both ends of the resistor 30 is greater than or equal to the first threshold voltage and less than the first threshold voltage from time t0 when the motor 210 is energized. It is assumed that the time is changed to time t2. In other words, when the current value of the starter current is equal to or greater than a predetermined value, the current is supplied to the motor 210 via the resistor 30. For this reason, unlike the prior art, the time during which the starter current flows through the resistor 30 is not too long or too short. Therefore, the inrush current can be suppressed while ensuring the startability of the engine. In addition, since the time during which the starter current flows through the resistor 30 depends on the potential difference between both ends of the resistor 30, it is possible to cope with changes in the characteristics of the battery 100 and the motor 210 over time and environmental changes.

(Modification 1)
In step S7 of the first embodiment, turning off the switching element 23 may cause ringing R1 in the starter current as shown in FIG. Along with this, ringing R2 may also occur in the potential difference between both ends of the resistor 30.

  In order to prevent the voltage of the battery 100 from decreasing due to such ringing, as shown in FIG. 4, after step S7 (time t2), the output of the subtraction circuit 50, that is, the voltage across the resistor 30 is reduced. When it becomes more than a 1st threshold voltage, it can also be set as the structure which the control part 40 turns ON the switching element 23. FIG.

(Second Embodiment)
In the first embodiment, an example in which the inrush current is detected from the potential difference between both ends of the resistor 30 has been described. On the other hand, in this embodiment, the voltage drop of the battery 100 is detected and the example which opens / closes the 2nd relay 20 is shown.

  As shown in FIG. 1, the signal input to the comparator 60 in the first embodiment is a signal output from the subtraction circuit 50. In the present embodiment, as shown in FIG. 5, a voltage obtained by dividing the voltage of the battery 100 by resistors 60 a and 60 b is input to the comparator 60. A reference potential source 62 that defines the second threshold voltage is connected to the other input terminal of the comparator 60. Note that the portions other than the input to the comparator 60 are the same as those in the first embodiment, and thus the description thereof is omitted.

  With reference to FIG. 6 and FIG. 7, operation | movement and the effect of the starter control apparatus 10 which concern on this embodiment are demonstrated.

  First, as shown in FIG. 6, step S1 is executed. Step S1 is a step in which supply of starter current is started in order to start driving of the motor 210 of the starter 200. This step S1 is executed at time t0 in FIG. Step S1 is executed when the driver turns on an ignition switch (not shown). When step S1 is executed, the starter relay 300 is closed and the coil 221 is energized. As a result, the contact 222 of the first relay 220 is closed and the starter current starts to flow.

  Step S2 is executed simultaneously with step S1. That is, this step S2 is executed at time t0 in FIG. Step S <b> 2 is a step in which the control unit 40 turns on the switching element 23. ECU 400 issues an instruction to control unit 40 to turn on switching element 23 at the same time as step S1 is executed. Since the starter relay 300 is in the closed state in step S1, the coil 21 of the second relay 20 is energized and the contact 22 is released by executing step S2.

  The starter current that starts to flow from time t0 flows through the resistor 30 without passing through the second relay 20 in the separated state. The resistance value of the resistor 30 is larger than that of the second relay 20. For this reason, the absolute value of the starter current can be suppressed, and the inrush current can be suppressed.

  Next, step S3 is executed. In step S3, the comparator 60 compares the voltage of the battery 100 divided by resistance (hereinafter simply referred to as the voltage of the battery 100) with the second threshold voltage. In step S3, it is determined whether or not the voltage of the battery 100 has become equal to or lower than the second threshold voltage. When the voltage of the battery 100 is equal to or higher than the second threshold voltage (YES determination in FIG. 6), the process proceeds to step S4. Step S3 is continuously executed until a YES determination is made. That is, if the determination is NO, step S3 is continued.

  Step S4 is a step in which the comparator 60 outputs a predetermined voltage. In step S3, since the voltage of the battery 100 is equal to or lower than the second threshold voltage, the comparator 60 outputs, for example, a positive supply voltage supplied to the comparator 60. Thereby, as shown in FIG. 7, the signal output from the comparator 60 to the control unit 40 rises. A time t1 in FIG. 7 indicates a time when a signal output from the comparator 60 to the control unit 40 rises.

  Next, step S5 is executed. In step S5, as in step S3, the comparator 60 compares the voltage of the battery 100 with the second threshold voltage. In step S5, it is determined whether or not the voltage of the battery 100 exceeds the second threshold voltage. When the voltage of the battery 100 exceeds the second threshold voltage (YES determination in FIG. 6), the process proceeds to step S6. Step S5 is continuously executed until a YES determination is made. That is, if the determination is NO, step S5 is continued.

  Step S6 is a step in which the comparator 60 outputs a predetermined voltage. In step S5, since the voltage of the battery 100 exceeds the second threshold voltage, the comparator 60 outputs a negative supply voltage supplied to the comparator 60, for example. As a result, as shown in FIG. 7, the signal output from the comparator 60 to the control unit 40 falls. A time t2 in FIG. 7 indicates a time when a signal output from the comparator 60 to the control unit 40 falls.

  Step S <b> 7 is executed by using the signal output from the comparator 60 to the control unit 40 as a trigger. Step S <b> 7 is a step in which the control unit 40 turns off the switching element 23. By executing step S7, the energization to the coil 21 of the second relay 20 is interrupted, and the contact 22 is closed. That is, the resistor 30 is short-circuited. For this reason, the starter current is supplied to the motor 210 without passing through the resistor 30.

  According to this, the time during which the starter current flows through the resistor 30 is that the voltage of the battery 100 has changed from a value below the second threshold voltage to a value greater than the second threshold voltage from time t0 when the motor 210 is energized. The time is up to time t2. In other words, when the current value of the starter current is equal to or greater than a predetermined value, the current is supplied to the motor 210 via the resistor 30. For this reason, unlike the prior art, the time during which the starter current flows through the resistor 30 is not too long or too short. Therefore, the inrush current can be suppressed while ensuring the startability of the engine. Further, as in the case of the first embodiment, since the time during which the starter current flows through the resistor 30 depends on the voltage of the battery 100, it can cope with changes in the characteristics of the battery 100 and the motor 210 over time and environmental changes. can do.

(Modification 2)
In step S7 of the second embodiment, the switching element 23 may be turned off to cause ringing in the starter current. Along with this, ringing can also occur in the voltage of the battery 100.

  Ringing of the voltage of the battery 100 may cause a momentary interruption of electric devices such as meters and audio. In order to suppress this, the control unit 40 may be configured to turn on the switching element 23 when the voltage of the battery 100 becomes equal to or lower than the second threshold voltage after step S7 (time t2) shown in FIG. it can.

(Third embodiment)
In the present embodiment, in addition to the configuration of the second embodiment, for example, the ECU 400 can be notified of a failure due to the fixed second relay.

  With reference to FIG. 8 and FIG. 9, operation | movement and the effect of the starter control apparatus 10 which concern on this embodiment are demonstrated. Note that the operation up to step S4 is the same as the operation in the second embodiment, and a description thereof will be omitted.

  Step S5 is executed after step S4. If YES is determined in step S5, the switching element 23 is turned off through steps S6 and S7 by the same operation as in the second embodiment. On the other hand, when it becomes NO determination in step S5, as shown in FIG. 8, it progresses to step S8.

  Step S8 is a step of determining whether or not the voltage of the battery 100 is lower than a third threshold voltage set lower than the second threshold voltage. If NO is determined in step S8, the process returns to step S5 again. On the other hand, as shown in FIG. 9, when the voltage of the battery 100 falls below the third threshold voltage at time t3, a YES determination is made in step S8. In this case, the process proceeds to step S9.

  Step S9 is a step of determining whether or not the duration of the state where the voltage of the battery 100 is lower than the third threshold voltage has reached a predetermined time. The predetermined time is, for example, a time when the operation of the peripheral device to which power is supplied from the battery 100 cannot be maintained if the state in which the voltage of the battery 100 is lower than the third threshold voltage continues for this time. As shown in FIG. 9, the voltage of the battery 100 in the present embodiment is lower than the third threshold voltage between time t3 and time t4. If t4-t3 has not reached the predetermined time, step S9 is NO and the process returns to step S5.

  On the other hand, if the predetermined time has been reached, a YES determination is made and processing proceeds to step S10. In this case, although the switching element 23 is on, that is, the second relay 20 is disconnected and the starter current is flowing through the resistor 30, the peripheral device may be disconnected instantaneously. It means to go. As a cause of this, it is considered that an abnormality that the contact 22 of the second relay 20 is fixed occurs and is always closed. Therefore, in step S10, the control unit 40 notifies the ECU 400 that an abnormality has occurred in the second relay 20, for example. Then, ECU 400 instructs to display such information on an instrument panel or the like in the automobile compartment. The driver can know the abnormality of the starter control device 10 by this display.

  As described above, in the configuration of the present embodiment, it is possible to detect an abnormality due to the fixation of the second relay 20 from the voltage of the battery 100.

(Other embodiments)
The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In each of the above-described embodiments and modifications, analog signals are input to the control unit 40 from the subtraction circuit 50 and the battery 100, respectively, and the switching element 23 is controlled based on the signals. However, the signal input to the control unit 40 is not limited to an analog signal. For example, in the first embodiment, an AD conversion circuit may be inserted between the subtraction circuit 50 and the control unit 40 to convert a signal input to the control unit 40 into a digital signal. Similarly, in the second embodiment, an AD conversion circuit may be inserted between the battery 100 and the control unit 40 to convert a signal input to the control unit 40 into a digital signal.

DESCRIPTION OF SYMBOLS 10 ... Starter control device 20 ... 2nd relay 23 ... Switching element 30 ... Resistor 40 ... Control part 50 ... Subtraction circuit 61 ... Reference potential source 100 ... Battery 200 ... starter, 210 ... motor, 220 ... first relay 300 ... starter relay

Claims (5)

A load (210) that is operated by being supplied with current from the battery (100), and a first current that is interposed between the load and the battery and that turns on / off the supply of current to the load by opening / closing contacts. A starter control device for controlling driving of a starter (200) having a relay (220),
A resistor (30) connected in series with the first relay;
A second relay (20) connected in parallel with the resistor and controlling a short circuit of the resistor by opening and closing a contact;
Control means (40) for controlling the opening and closing of the contacts of the second relay,
The control means includes
Energizing the load by closing the contact of the first relay, simultaneously opening the contact with the second relay to start energizing the resistor,
The contact of the second relay is closed when the potential difference across the resistor changes from a value greater than or equal to the first threshold voltage set to a predetermined voltage to a value less than the first threshold voltage. Then, the starter control device is characterized in that the resistor is short-circuited.   After the contact of the second relay is closed and the resistor is short-circuited, when the potential difference between both ends of the resistor is equal to or higher than the first threshold voltage, the contact of the second relay is opened to release the resistor The starter control device according to claim 1, wherein the body is energized. A load (210) that is operated by being supplied with current from the battery (100), and a first current that is interposed between the load and the battery and that turns on / off the supply of current to the load by opening / closing contacts. A starter control device for controlling driving of a starter (200) having a relay (220),
A resistor (30) connected in series with the first relay;
A second relay (20) connected in parallel with the resistor and controlling a short circuit of the resistor by opening and closing a contact;
Control means (40) for controlling the opening and closing of the contacts of the second relay,
The control means includes
Energizing the load by closing the contact of the first relay, simultaneously opening the contact with the second relay to start energizing the resistor,
When the voltage of the battery has changed from a value below the second threshold voltage set to a predetermined voltage to a value above the second threshold voltage, the contact of the second relay is closed to A starter control device characterized by short-circuiting a resistor.   The control means outputs a notification signal for notifying the fixation of the second relay when the voltage of the battery falls below a third threshold voltage set lower than the second threshold voltage. The starter control device according to claim 3.   After the contact of the second relay is closed and the resistor is short-circuited, when the potential difference at both ends of the resistor is equal to or lower than the second threshold voltage, the contact of the second relay is opened to release the resistor The starter control device according to claim 3 or 4, wherein the body is energized.

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