JP5796445B2 - Vehicle power supply device - Google Patents

Description

  The present invention relates to a vehicle power supply device.

  In a vehicle, in a vehicle power supply device that supplies power to a motor drive circuit or the like, a relay is used to connect the battery and the drive circuit. A power supply device used in a vehicle is described in, for example, Japanese Patent Laid-Open No. 2000-134707 (Patent Document 1). The power supply device supplies power to the drive circuit mainly in conjunction with the ignition being turned on.

  Generally, the relay has a connection conductor that connects / disconnects one terminal portion and the other terminal portion. The connection conductor is connected to both terminal portions in a connected state (on state) and is isolated from both terminal portions in a non-connected state (off state).

JP 2000-134707 A

  However, when the relay shifts from the on state to the off state, an arc may occur between the contact points of the terminal portion and the connection conductor, and welding may occur between the two. When the connection conductor and the terminal portion are welded, the relay cannot be shifted from the on state to the off state. That is, although the ignition is off, an on failure occurs in which the connection conductor is not separated from the terminal and the on state is maintained.

  When such an on-failure occurs, the power is kept supplied to the drive circuit, and the battery continues to supply power even when the ignition is off. That is, the battery power is wasted. It is required to detect the occurrence of this ON failure without using a new detection device (detection dedicated device) from the viewpoint of manufacturing cost.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle power supply device that can detect an on-failure of a relay without using a new detection device.

An invention of a vehicle power supply device according to claim 1 for solving the above-mentioned problems is provided with a battery, a motor drive circuit for driving a motor, and the battery and the motor drive circuit, which are electrically connected to each other to turn on / off an ignition A relay for electrically connecting / disconnecting the battery and the motor drive circuit in conjunction with the control circuit, and a controller for detecting on / off of the ignition and controlling the motor drive circuit. The drive circuit includes a signal transmission unit that transmits a status signal that can identify the state of the motor drive circuit to the control device, and the signal transmission unit outputs the status signal when the motor drive circuit is powered. and transmitted to the control device to stop the transmission of the status signal and the power supply is stopped to the motor drive circuit, wherein the control device, the ignition is o A detector for detecting the ON failure of the relay based on the status signal state, characterized in that it comprises a storage unit for storing the detection of the ON failure in the detection unit.

  According to a second aspect of the present invention, in the first aspect of the present invention, the control device includes a notification unit for notifying the user that a failure has occurred, and the control device operates the notification unit when an on-failure is stored in the storage unit. It is characterized by making it.

  According to a third aspect of the present invention, in the first aspect of the present invention, the control device includes notification means for notifying the user that a failure has occurred. And the notification means is activated when the number of times of detection is equal to or greater than a predetermined value set in advance.

  According to a fourth aspect of the present invention, in the first aspect, the control device determines whether or not the detection unit has detected an ON failure of the relay when the ignition is turned off. When an ON failure of the relay is detected, the ON failure is stored in the storage unit.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the status signal is a PWM signal.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the battery and the relay are electrically connected to each other, and the battery and the relay are electrically connected in conjunction with on / off of the ignition. Switch means for connecting / disconnecting electrically, wherein the relay is electrically connected to the battery, a second terminal portion electrically connected to the motor drive circuit, and the switch A third terminal portion electrically connected to the means, and a connecting conductor portion for electrically connecting / disconnecting the first terminal portion and the second terminal portion based on power feeding from the third terminal portion, It is characterized by providing.

  According to the first aspect of the present invention, the control device recognizes that the ignition is off, and compares the ignition state with the state of the motor drive device based on the status signal to detect whether the relay is on or not. be able to. That is, when the ignition is off and the status signal indicating the “driving state” is received, it can be understood that the relay remains on. That is, according to the present invention, it is possible to detect an ON failure of the relay. Further, since communication between the control device and the motor drive device is used, there is no need to newly use a detection device.

  According to the second aspect of the present invention, the notification device is activated when an on-failure is detected. Thereby, a user such as an occupant can easily know that an on-failure has occurred.

  According to the invention of claim 3, when the ignition is turned on, the notification device is activated if the number of times of on-failure detection up to the previous time is equal to or greater than a predetermined value. The predetermined value can be set arbitrarily, and the reliability of failure detection is improved by setting the predetermined value a plurality of times.

  According to the invention of claim 4, when the ignition is turned off, the number of on-failure detections in the storage unit is increased and stored with the detection of the on-failure. The user can know, for example, whether or not an on-failure has been detected when the ignition is turned on or off by using a notification device or the like.

  According to the fifth aspect of the present invention, even when an abnormality such as a short circuit of wiring occurs in communication between the control device and the motor drive device, it is possible to determine whether or not there is an on-failure from the state of the rectangular wave. That is, an on-failure can be detected with higher accuracy.

  According to the invention of claim 6, the relay can be directly controlled by the switch means, and the present invention can be realized with a simpler configuration. That is, an increase in manufacturing cost can be suppressed.

It is a circuit block diagram which shows the vehicle power supply device 1 of this embodiment. 4 is a flowchart showing an operation of the vehicle power supply device 1.

  Next, the present invention will be described in more detail with reference to FIG. 1 and FIG. The vehicle power supply device 1 according to the present embodiment includes a battery 2, an ignition switch 3, a relay 4, a motor drive circuit 5, a control device 6, and a notification device 7. The battery 2 is of 12V standard, the positive electrode is electrically connected to the ignition relay unit 3 (third terminal unit 323) and the relay 4 (first terminal unit 41), and the negative electrode is electrically connected to the vehicle ground (ground). It is connected.

  The ignition switch 3 has one terminal electrically connected to the positive electrode of the battery 2 and the other terminal electrically connected to the relay 4 and the control device 6. The ignition switch 3 connects (on) / disconnects (off) one terminal and the other terminal in conjunction with the on / off of an ignition (not shown). That is, the ignition switch 3 electrically connects / disconnects the battery 2, the control device 6, and the relay 4 (third terminal portion 43) via the control device 6 in conjunction with ignition on / off. The ignition switch 3 may be composed of a switch element. Further, the ignition switch 3 may be a relay.

  The relay 4 includes a first terminal portion 41, a second terminal portion 42, a third terminal portion 43, a fourth terminal portion 44, a coil 45, and a connection conductor 46. The first terminal portion 41 is electrically connected to the positive electrode of the battery 2. The second terminal portion 42 is electrically connected to the motor drive circuit 5. The third terminal portion 43 is electrically connected to the other terminal of the ignition switch 3. The fourth terminal portion 44 is electrically connected to the vehicle ground.

  The coil 45 has one end electrically connected to the third terminal portion 43 and the other end electrically connected to the fourth terminal portion 44. The connection conductor 46 is a substantially T-shaped conductor, and is attracted to the coil 45 by a magnetic force generated when the coil 45 is supplied with power to electrically connect the first terminal portion 41 and the second terminal portion 42. . When the power supply to the coil 45 is stopped, the connection conductor 46 is isolated from the first terminal portion 41 and the second terminal portion 42, and both are made in a non-connected state.

  When the ignition is turned on, the relay 4 is supplied with the coil 45 via the ignition switch 3 to electrically connect the first terminal portion 41 and the second terminal portion 42. When the ignition is turned off, the relay 4 stops the power supply from the battery 2 to the coil 45 by the ignition switch 3 and brings the first terminal portion 41 and the second terminal portion 42 into a disconnected state. In other words, the relay 4 electrically connects / disconnects the battery 2 and the motor drive circuit 5 in conjunction with ignition on / off.

  The motor drive circuit 5 is electrically connected to the relay 4, the control device 6, the motor M, and the vehicle ground. The motor drive circuit 5 is a circuit that is supplied with power from the battery 2 and receives a control signal from the control device 6 to drive the motor M. The motor drive circuit 5 includes a drive unit 51 and a signal transmission unit 52.

  The drive unit 51 is electrically connected to the second terminal unit 42 of the relay 4, the control device 6, and the motor M. The drive unit 51 is supplied with power from the battery 2 via the relay 4, receives a control signal from the control device 6, and drives the motor M accordingly.

  The signal transmission unit 52 is electrically connected to the drive unit 51 and the control device 6. The signal transmission unit 52 includes a transistor 52a, and switches the transistor 52a to generate a PWM (Pulse Width Modulation) signal. The PWM signal is a status signal that represents the state of the motor drive circuit 5 based on the duty ratio.

  The signal transmission unit 52 transmits a PWM signal to the control device 6 when the motor drive circuit 5 is supplied with power, and stops transmission when the power supply is stopped. The PWM signal represents a drive waiting state, a drive state, or the like depending on the duty ratio.

  The control device 6 is an ECU (electronic control unit) that controls the motor drive circuit 5, and is electrically connected to the battery 2, the ignition switch 3, the motor drive circuit 5, and the notification device 7. The control device 6 includes an IG detection circuit unit 61, a power supply circuit unit 62, a microcomputer 63, a memory 64, and a switching element 65.

  The IG detection circuit unit 61 is electrically connected to the other terminal of the ignition switch 3, the power supply circuit unit 62, and the microcomputer 63. The IG detection circuit unit 61 detects that the ignition is turned on when the ignition switch 3 is turned on to supply power, and detects that the ignition is turned off when power supply is stopped. The IG detection circuit unit 61 transmits a detection result (IG on signal or IG off signal) to the power supply circuit unit 62 and the microcomputer 63. The IG detection circuit unit 61 is mainly composed of a transistor 61a and the like. The base terminal of the transistor 61a is electrically connected to the ignition switch 3, the collector terminal is connected to the microcomputer 63, and the emitter terminal is electrically connected to the vehicle ground.

  The power supply circuit unit 62 is electrically connected to the positive electrode of the battery 2, the IG detection circuit unit 61, and the microcomputer 63 via a self-holding power supply 63a described later. When the power supply circuit unit 62 receives the IG ON signal from the IG detection circuit unit 61, the power supply circuit unit 62 steps down the power supply of the battery 2 to the operating voltage and supplies it to the microcomputer 63.

  The microcomputer 63 (corresponding to the “detection unit”) is a microcomputer having a CPU, and is electrically connected to the IG detection circuit unit 61, the power supply circuit unit 62, the memory 64, the motor drive circuit 5, and the notification device 7. ing. The microcomputer 63 is activated by being supplied with power from the power supply circuit unit 62.

  The microcomputer 63 receives the IG ON signal from the IG detection circuit unit 61 and recognizes that the ignition is ON. The microcomputer 63 turns on / off a switching element 65 to be described later in response to turning on / off of the ignition switch 3. The microcomputer 63 receives the PWM signal from the signal transmission unit 52 of the motor drive circuit 5 and recognizes the state of the motor drive circuit 5. The microcomputer 63 issues a command to the motor drive circuit 5 to control the motor drive circuit 5.

  The microcomputer 63 has a self-holding power source 63a and operates for a certain period of time after the ignition is turned off. The microcomputer 63 confirms the PWM signal of the motor drive circuit 5 when receiving the IG off signal from the IG detection circuit unit 61. When the microcomputer 63 receives the PWM signal while receiving the IG off signal, the microcomputer 63 determines that the relay 4 is on and writes the number of detections in the memory 64. The self-holding power source is held when the ignition is turned on. The self-holding power supply may be provided in the power supply circuit unit 62.

  A memory 64 (corresponding to a “storage unit”) is a nonvolatile memory and is electrically connected to the microcomputer 63. The memory 64 stores the number of times that the microcomputer 63 has determined that an on failure has occurred.

  The switching element 65 is a field effect transistor having a gate terminal electrically connected to the microcomputer 63, a source terminal electrically connected to the positive electrode of the battery 2, and a drain terminal electrically connected to the third terminal portion 43 of the relay 4.

  The switching element 65 receives a command from the microcomputer 63 and supplies power to the third terminal portion 43 of the relay 4. That is, power is supplied from the battery 2 to the relay 4 by the microcomputer 63 applying a voltage to the gate terminal. The microcomputer 63 turns on / off the switching element 65 in conjunction with ignition on / off.

  The notification device 7 is means for notifying the user that a failure has occurred. In the present embodiment, the notification device 7 is a lamp and is incorporated in a place where the user can visually recognize, for example, an instrument panel. The notification device 7 operates according to a command from the control device 6 and turns on the lamp.

  Here, the failure detection operation of the microcomputer 63 will be described with reference to FIG. First, when activated, the microcomputer 63 reads the number of on-failure detections from the memory 64 (S1). Subsequently, the microcomputer 63 enters an on-failure determination process (S2, S21), and determines whether or not the number of detections is equal to or greater than a predetermined value (in this embodiment, 2) (S22).

  Here, when the number of times of detection is equal to or greater than a predetermined value (S22: Yes), the microcomputer 63 determines that the relay 4 is in an on failure (S23). In this case, the microcomputer 63 instructs the notification device 7 to turn on the lamp. On the other hand, if the number of times of detection is less than the predetermined value (S22: No), the process proceeds to the main process (S3). The main process means a normal process for controlling the motor drive circuit 5. The microcomputer 63 executes main processing and the like while the ignition is on (S4: No) (S3).

  Subsequently, when the ignition is turned off (S4: Yes), the microcomputer 63 executes an on-failure determination process (S5, S51). First, the microcomputer 63 reads the state of the motor drive circuit 5 (S52). If the microcomputer 63 does not receive the PWM signal, the motor driving circuit 5 is in a stopped state, and if the microcomputer 63 receives the PWM signal, the motor driving circuit 5 is operating. The microcomputer 63 confirms the presence or absence of the PWM signal and determines whether or not the motor drive circuit 5 is operating (S53).

  When the PWM signal is received (S53: Yes), since the motor drive circuit 5 is operating with the ignition turned off, the microcomputer 63 temporarily determines that the relay 4 has an on failure. Then, the microcomputer 63 increases the number of detections of the memory 64 by 1 (increment) (S54), assuming that an on-failure is detected.

  On the other hand, when the PWM signal is not received (S53: No), since the motor drive circuit 5 is stopped, it can be determined that the relay 4 operates normally, and the microcomputer 63 detects the detection stored in the memory 64. The number of times is reset to 0 (S55).

  The microcomputer 63 increases the number of detections by 1 when the on-failure is detected and stores it in the memory 64. If the microcomputer 63 does not detect the on-failure, the microcomputer 63 stores the number of detections as 0 in the memory 64 (S6). Thereafter, the microcomputer 63 turns off and stops the self-holding power supply (S7).

  According to the present embodiment, the on failure of the relay 4 can be detected by checking the PWM signal when the ignition is turned off. That is, this embodiment can detect an on-failure using the status signal of the motor drive circuit 5 without using a new detection device.

  Here, the predetermined value can be set to 1. However, by setting the predetermined value a plurality of times (two or more) as in the present embodiment, failure detection with higher reliability is possible. The on-failure is a failure that is maintained while the motor drive circuit 5 is supplied with power, and even if an on-failure actually occurs in the first failure detection, there is no adverse effect. Therefore, setting the predetermined value a plurality of times is effective in improving the reliability.

  Note that a constant value signal (high, low) may be used as the status signal of the motor drive circuit 5. That is, the signal transmission unit 52 may transmit a high signal (or low signal) while the motor drive circuit 5 is operating, and may transmit a low signal (or high signal) when the motor drive circuit 5 is stopped. This can also detect an on-failure.

  In the present embodiment, a PWM signal is used as the status signal of the motor drive circuit 5. For this reason, even if there is an abnormality such as a wiring short circuit, the on-failure can be detected with high accuracy in the present embodiment. This is because it is possible to identify whether or not the PWM signal is transmitted although the rectangular wave is distorted even if there is a wiring abnormality when the on-failure occurs. Moreover, the existing status signal can be used, and the design becomes easy.

  Further, the notification device 7 is not limited to a lamp, and may be a notification by sound (for example, a buzzer). Even when the notification device 7 is not provided, the user can know the on failure or the number of on failure detections by checking the memory 64 at the time of repair or the like.

  Further, the control device 6 may be set to operate the notification device 7 without waiting for the next ignition on after the on failure is detected. That is, after detecting the on-failure, the control device 6 stores the detection result in the memory 64 (S54, S6) and activates the notification device 7. In this case, the notification device 7 is operated by, for example, a self-holding power source of the control device 6 or has a power source that can be supplied even when the ignition is off.

  Even in this case, the notification device may be operated after the number of detections stored in the memory 64 exceeds a predetermined value. That is, steps S22 and S23 are inserted after S6 in FIG. 2, and the microcomputer 63 operates the notification device 7 in the ignition-off state when the failure is confirmed. As a result, the reliability can be improved and the user can know the on failure when the ignition is turned off. In this way, when the ignition is turned off, the control device 6 reads the number of times of on-failure detection from the memory 64 when the on-failure is stored in the memory 64, and the number of times of detection is equal to or greater than a predetermined value set in advance. In some cases, the notification means 7 may be activated.

  The power supply route to the relay 4 is not limited to the above. For example, the third terminal portion 43 of the relay 4 may be connected to the other terminal of the ignition switch 3 instead of the switching element 65. Thereby, it is possible to design without using the switching element 65. As described above, the power supply from the battery 2 to the third terminal portion 43 of the relay 4 may be performed directly from the ignition switch 3 without using the control device 6.

1: vehicle power supply device, 2: battery,
3: Ignition switch (switch means),
4: Relay,
41: 1st terminal part, 42: 2nd terminal part, 43: 3rd terminal part, 44: 4th terminal part,
45: Coil, 46: Connection conductor,
5: Motor drive circuit, 51: Drive unit, 52: Signal transmission unit,
6: Control device 61: IG detection circuit unit 62: Power supply unit
63: Microcomputer (detection unit), 64: Memory (storage unit), 65: Switching element,
7: Notification device

Claims (6)

Battery,
A motor drive circuit for driving the motor;
A relay that is electrically connected to the battery and the motor drive circuit and electrically connects / disconnects the battery and the motor drive circuit in conjunction with ignition on / off;
A controller for detecting on / off of the ignition and controlling the motor driving circuit;
With
The motor drive circuit has a signal transmission unit that transmits a status signal capable of identifying the state of the motor drive circuit to the control device ,
The signal transmission unit transmits the status signal to the control device when the motor driving circuit is fed, and stops sending the status signal when feeding to the motor driving circuit is stopped.
The control device includes a detection unit that detects an ON failure of the relay based on the status signal when the ignition is OFF, and a storage unit that stores that an ON failure is detected by the detection unit. A power supply device for a vehicle. In claim 1,
Provide a notification means to inform the user that it is a malfunction,
The control device activates the notifying means when an on-failure is stored in the storage unit. In claim 1,
Provide a notification means to inform the user that it is a malfunction,
When the ignition is turned on, the control device reads the number of on-failure detections from the storage unit, and activates the notification unit when the number of times of detection is equal to or greater than a predetermined value. A vehicle power supply device. In claim 1,
The control device determines whether the detection unit has detected an ON failure of the relay when the ignition is turned off, and when the detection unit detects an ON failure of the relay, An on-failure is stored in a storage unit. In any one of Claims 1-4,
The vehicle power supply apparatus according to claim 1, wherein the status signal is a PWM signal. In any one of Claims 1-5,
Switch means electrically connected to the battery and the relay, and electrically connecting / disconnecting the battery and the relay in conjunction with on / off of the ignition;
The relay includes a first terminal portion electrically connected to the battery, a second terminal portion electrically connected to the motor drive circuit, and a third terminal portion electrically connected to the switch means. And a connection conductor portion for electrically connecting / disconnecting the first terminal portion and the second terminal portion based on power feeding from the third terminal portion. .

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