JP2010047117A - Failure determination device for telltale light source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure determination device for a telltale light source, easily determining failure of a light source at an appropriate timing. <P>SOLUTION: A computer 11 of an engine ECU 10 outputs a turn-on request signal and a turn-off request signal for a glow telltale 100 to a computer 21 of a meter ECU 20. The computer 21 of the meter ECU 20 detects a turn on and off state of an LED 120 based on consumption voltage of the LED 120 of the glow telltale 100 and outputs the detection result to the computer 11 of the engine ECU 10. The computer 11 of the engine ECU 10 determines a failure of the LED 120, based on the turn-on and turn-off state indicated by the turn-on and turn-off request signal and the turn-on and turn-off state indicated by the detection result. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a failure determination device that is provided in a combination meter of a vehicle and that determines the failure of a telltale light source used for telltale that displays predetermined information.

  A tell tale provided in a vehicle combination meter or the like displays predetermined information by turning on a tell tale light source (see, for example, Patent Document 1). Therefore, when the light source is out of order, it is not possible to appropriately display information by telltale.

Therefore, in order to determine the failure of the light source, a lighting instruction is forcibly output to the telltale light source, and the light source is turned on / off at that time by visually or visually confirming the light source. I was judging.
JP-A-6-52707

  However, the conventional method of judging a failure of a light source visually or with a visual recognition device requires a human work for judging the failure, which is troublesome and may not be able to judge the failure at an appropriate time. It was. For example, at the time of departure from the vehicle (when the ignition is turned on), it is preferable to determine the failure of the telltale light source. It was difficult to judge.

  The present invention has been made based on this situation, and an object of the present invention is to provide a telltale light source failure determination device that can easily determine a failure of a light source at an appropriate time. is there.

  In order to achieve the object, the invention according to claim 1 is directed to a failure determination device for a telltale light source that determines a failure of a telltale light source that is switched on / off based on a turn-on / off request signal output from a turn-on / decision determination device. A power consumption detection circuit for detecting a power consumption voltage of the telltale light source, a light-off state of the telltale light source indicated by the power consumption voltage, and a light-off state of the telltale light source indicated by the light-off request signal. And failure determination means for determining whether or not the telltale light source has failed.

  In this way, if it is determined whether or not the tellurite light source has failed based on the comparison between the on / off state indicated by the consumption voltage of the telltale light source and the on / off state indicated by the on / off request signal, Therefore, it is possible to automatically determine the failure without the need for the above operation. Therefore, for example, as shown below, it is possible to determine the failure of the light source at an appropriate time, such as determining the failure of the light source when the ignition is turned on.

  Claim 2 is a light source used for a tell tale that needs to display information on whether the tell tale light source is abnormal or normal when the ignition is turned on, and the failure determination means is configured to detect the failure when the ignition is turned on. It is characterized by determining whether or not the telltale light source has failed.

  In the case of a light source used for a tell terre that needs to indicate whether the tell tale light source is abnormal or normal when the ignition is turned on, the failure determination of the tell tale light source is also performed when the ignition is turned on. It is preferable to do so.

  According to a third aspect of the present invention, when a failure is determined by the failure determination means, a telltale that is set in advance as being related to the telltale light source determined to be the failure is turned on.

  In this way, even if the telltale light source that is the subject of failure determination fails, another telltale relating to the light source is turned on. When this other telltale is turned on, the user can be made aware that there is a possibility that the telltale light source that is the target of the failure is broken.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a lighting control device 1 having a function as a failure determination device of the present invention. The lighting control device 1 controls the lighting of the tell terres such as the Grotel tail 100 and the check engine tell tail 200, and determines a failure of the LED 120 (see FIG. 2) that is a light source for the Grotel tail.

  The lighting control device 1 includes an engine ECU 10 and a meter ECU 20. These ECUs 10 and 20 are provided with computers 11 and 21, respectively, and when the computers 11 and 21 execute programs stored in a ROM (not shown), the engine ECU 10 performs predetermined engine control, The function as the lighting / extinguishing determination device in the claims is executed. On the other hand, the meter ECU 20 performs predetermined meter control and also tells the tail tail to be turned on and off.

  A fuel temperature signal detected by the fuel temperature sensor 30 is input to the computer 11 of the engine ECU 10. This fuel temperature sensor 30 detects directly or indirectly the temperature of the fuel when it is injected into the combustion chamber of the engine.

  The computer 11 of the engine ECU 10 outputs a turn-on / off request signal for the Grotel tail 100 and the check engine tell tail 200 to the computer 21 of the meter ECU 20 based on the fuel temperature signal. The computer 21 of the meter ECU 20 performs a process of turning on / off the telltales 100 and 200 based on the turn-on / off request signal, detects the on / off state of the LED 120 that is the light source of the glow teller tail 100, and outputs the detection result to the engine. Output to the computer 11 of the ECU 10. The processing contents of the computers 11 and 21 will be described in detail later.

  The tell terres such as the Grotel tail 100 and the check engine tell tale 200 are provided with a drive circuit for driving a light source provided in the tell tale. FIG. 2 is a diagram illustrating a drive circuit 110 provided in the Grotel tail 100. The drive circuit 110 of the Grotel tail 100 includes a consumption voltage detection circuit 130 that detects a consumption voltage of the LED 120.

  The drive circuit 110 includes a first transistor Tr1. The collector terminal of the first transistor Tr1 is connected to one terminal of the LED 120 via the first resistor R1, and the emitter terminal is connected to the cathode terminal of the diode D. The base terminal is connected to one end of the fourth resistor R4 and the fifth resistor R5.

  The anode terminal of the diode D is connected to the ignition power supply IG +. The side of the LED 120 opposite to the side to which the first resistor R1 is connected is grounded, and a first capacitor C1 is connected to the LED 120 in parallel.

  As described above, one end of the fourth resistor R4 is connected to the base terminal of the first transistor Tr1, and the other end is connected to the emitter terminal of the first transistor Tr1 and the cathode terminal of the diode D. As described above, one end of the fifth resistor R5 is connected to the base terminal of the first transistor Tr1, and the other end is connected to the collector terminal of the second transistor Tr2.

  The second transistor Tr2 has an emitter terminal grounded and a base terminal connected to the computer 21 of the meter ECU 20 via a sixth resistor R6. One end of the seventh resistor R7 is also connected to the computer 21 of the meter ECU 20, and the other end of the seventh resistor R7 is grounded.

  The above-described consumption voltage detection circuit 130 includes a second resistor R2, a third resistor R3, and a Zener diode ZD. The second resistor R2 and the third resistor R3 are connected in series with each other, and one end of the second resistor R2 is connected to the anode terminal of the LED 120. One end of the Zener diode ZD is also connected to the anode terminal of the LED 120, and one end of the third resistor R3 and one end of the Zener diode ZD are grounded.

  The voltage divided by the second resistor R2 and the third resistor R3 is input to the computer 21 of the meter ECU 20. Therefore, this voltage input to the computer 21 changes corresponding to the consumption voltage Vk of the LED 120. Further, the consumption voltage Vk of the LED 120 is several volts when turned on and 0 V when turned off. Therefore, the computer 21 can determine whether the LED 120 is turned on or off based on the input voltage from the consumption voltage detection circuit 130. A second capacitor C2 is connected in parallel to the third resistor R3. The second capacitor C <b> 2 prevents erroneous determination of the on / off state of the LED 120 when a temporary noise component is input to the computer 21.

  Next, the operation of the drive circuit 110 configured as described above will be described. When trying to turn on the LED 120, the computer 21 of the meter ECU 20 outputs a signal (Hi signal) for turning on the second transistor Tr2 as a lighting signal. When the second transistor Tr2 is turned on, the voltage at the base terminal of the first transistor Tr1 becomes a voltage determined by the voltage dividing ratio between the fourth resistor R4 and the fifth resistor R5, thereby turning on the first transistor Tr1.

  Therefore, since the current from the ignition power supply IG + flows to the LED 120, the LED 120 is turned on. At this time, as described above, a voltage having a potential indicating that the LED 120 is lit is input to the computer 21. The first capacitor C1 is provided to prevent a current from flowing to the LED 120 due to a leakage current of the first transistor Tr1 or the like even though the computer 21 of the meter ECU 20 does not output a lighting signal. .

  When the LED 120 is turned off, the computer 21 of the meter ECU 20 outputs a signal (Lo signal) for turning off the second transistor Tr2 as a turn-off signal. As a result, the first transistor Tr1 is also turned off, and the LED 120 is turned off.

  Next, the on / off control process performed by the computers 11 and 21 of the engine EUCU 10 and the meter ECU 20 will be described based on the flowchart shown in FIG.

  In step S1, it is determined whether the ignition is on. This determination is made by the engine ECU 10 and the meter ECU 20 respectively. Note that one ECU 10, 20 may make a determination, and the other ECU 10, 20 may obtain a determination result.

  When the ignition is on, the computer 11 of the engine ECU 10 executes step S2 and subsequent steps, and the computer 21 of the meter ECU 20 executes step S10 and subsequent steps.

  First, steps S2 to S9 that are processes performed by the computer 11 of the engine ECU 10 will be described. In step S2, it is determined whether the fuel temperature is sufficient. Specifically, this determination is to determine whether or not the fuel temperature determined based on the signal from the fuel temperature sensor 30 is equal to or higher than a preset reference temperature.

  If the fuel temperature is lower than the reference temperature, the determination in step S2 is negative and the process proceeds to step S3. In step S3, fuel is preheated using a glow plug. In step S <b> 4, a lighting request signal for requesting lighting of the Grotel tail 100 is output to the computer 21 of the meter ECU 20. On the other hand, when the fuel temperature is equal to or higher than the reference temperature, step S2 is affirmative and the process proceeds to step S5. In step S5, a turn-off request signal for requesting turn-off of the Grotel tail 100 is output to the computer 21 of the meter ECU 20. When these steps S4 or S5 are executed, step S6 is executed next.

  When step S4 or S5 is executed and a lighting request signal or a light extinction request signal for the Grotel tail 100 is output to the computer 21 of the meter ECU 20, the computer 21 of the meter ECU 20 turns on the LED 120 of the Grotel tail 100 as described later. A signal indicating the detection result of the extinguished state is transmitted to the computer 11 of the engine ECU 10.

  In step S6, the detection result of the on / off state of the LED 120 indicated by the signal transmitted from the meter ECU 20 indicates that the signal transmitted to the meter ECU 20 in step S4 or S5, that is, the on / off state indicated by the lighting request signal or the extinguishing request signal. To determine whether or not.

  If the on / off state indicated by the request signal does not match the detection result of the on / off state, the process proceeds to step S7. In step S7, it is determined that a failure of the LED 120 has been detected. In step S8, a lighting request signal for requesting lighting of the check engine telltale 200 is output to the computer 21 of the meter ECU 20.

  When the failure of the LED 120 of the Grotel tail 100 is detected, the check engine tell tail 200 is turned on in this manner by turning on another tell tail related to the Grotel tail 100. This is to show that

  On the other hand, if the turn-off state indicated by the request signal matches the detection result of the turn-off state, the process proceeds to step S9, and a turn-off request signal for requesting turn-off of the check engine telltale 200 is sent to the computer 21 of the meter ECU 20. Output. After executing step S8 or S9, the process returns to step S1.

  Next, steps S10 to S16, which are processes performed by the computer 21 of the meter ECU 20, will be described. In step S10, it is determined whether the request signal for the Grotel tail 100 transmitted from the engine ECU 10 is a turn-on request signal or a turn-off request signal.

  When engine ECU10 performs step S4, ie, when the lighting request signal is transmitted, it progresses to step S12 and makes LED120 light. On the other hand, when the engine ECU 10 executes step S5, that is, when a turn-off request signal is transmitted, the process proceeds to step S11 and the LED 120 is turned off. These steps S11 or S12 output a signal for turning on or off the transistor Tr2, as described above.

  After executing step S11 or S12, step S13 is executed. In step S13, the on / off state of the LED 120 is detected. And a detection result is transmitted to engine ECU10. The on / off state of the LED 120 is detected based on the input voltage from the consumption voltage detection circuit 130 as described above.

  In step S14, it is determined whether the request signal for the check engine telltale 200 transmitted from the engine ECU 10 is a turn-on request signal or a turn-off request signal. When the engine ECU 10 executes step S8, that is, when a lighting request signal for the check engine telltale 200 is transmitted, the process proceeds to step S16, and a light source (not shown) of the check engine telltale 200 is turned on. On the other hand, when the engine ECU 10 executes step S9, that is, when a turn-off request signal is transmitted to the check engine tell tale 200, the process proceeds to step S15 and the light source of the check engine tell tale 200 is turned off. And after performing these steps S15 or S16, it returns to step S1.

  As described above, according to the present embodiment described above, the lighting state of the LED 120 is detected by detecting the consumption voltage Vk of the LED 120, and the lighting state of the LED 120 detected from the consumption voltage Vk and the request signal indicate. The failure determination of the LED 120 is performed based on the comparison with the lighting-off state. Therefore, it is possible to automatically make a failure determination without requiring human work.

  Although the Grotel tail 100 needs to display information when the ignition is turned on, in this embodiment, the failure determination of the LED 120 which is the light source of the Grotel tail 100 is performed from the time when the ignition is turned on. Therefore, it can be determined from the time when the ignition is turned on whether or not the on / off state of the Grotel tail 100 is due to the failure of the LED 120.

  Further, in this embodiment, when the LED 120 of the Grotel tail 100 is determined to be out of order, the check engine tell tail 200 that is set in advance as related to the Grotel tail 100 is turned on. As a result, the user can recognize that the LED 120 of the Grotel Tail 100 may be broken.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

It is a block diagram which shows the structure of the lighting control apparatus 1 provided with the function as a failure determination apparatus of this invention. FIG. 3 is a diagram showing a drive circuit 110 provided in the Grotel tail 100. It is a flowchart which shows the lighting-off control process which each computer 11 and 21 of engine EUCU10 and meter ECU20 performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Lighting control apparatus, 10: Engine ECU (ON / OFF determination apparatus), 11: Computer, 20: Meter ECU, 21: Computer, 30: Fuel temperature sensor, 100: Grotel tail, 110: Drive circuit, 120: LED ( Grotel tail light source), 130: consumption voltage detection circuit, 200: check engine tell tail

Claims (3)

A telltale light source failure determination device that determines a failure of a telltale light source that is switched on and off based on a turn-on / off request signal output from a turn-on / off determination device,
A consumption voltage detection circuit for detecting a consumption voltage of the telltale light source;
It is determined whether or not the telltale light source has failed based on a comparison between a light-off state of the telltale light source indicated by the voltage consumption and a light-off state of the telltale light source indicated by the turn-off request signal. A failure determination device for telltale light source, comprising: In claim 1,
The light source for telltale is a light source used for telltale that needs to display abnormal or normal information when the ignition is turned on,
The failure determination unit of the tell tale light source determines whether or not the tell tale light source has failed when the ignition is turned on. In claim 1 or 2,
When a failure is determined by the failure determination unit, a telltale light source failure determination device that lights a telltale that is set in advance as being related to the telltale light source that is determined to be a failure.

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