JP2005317282A - Failure diagnostic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure diagnostic system capable of conducting failure diagnosis even if working power is not supplied to a failure diagnostic means from a power supply circuit. <P>SOLUTION: The failure diagnostic system 10 is equipped with a first power supply circuit 1 supplying working power to the failure diagnostic means 3 and a second power supply circuit 2 supplying working power to the failure diagnostic means 3 when the working power from the first power supply circuit 1 is not supplied to the failure diagnostic means 3. Even when working power is not supplied from the first power supply circuit 1 to the failure diagnostic 3, since the working power is supplied from the second power supply circuit 2 to the failure diagnostic means 3, failure diagnosis can be conducted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a failure diagnosis apparatus for diagnosing a system failure, and more particularly to an improved technique for performing failure diagnosis even when the system is stopped.

In a fuel cell vehicle in which the fuel cell system is mounted on a vehicle as an on-board generator, means for detecting a gas leak such as hydrogen gas is provided. For example, Japanese Patent Application Laid-Open No. 2003-229148 discloses a configuration in which the entire fuel cell system is covered with a package, and a leak gas or the like remaining in the upper part of the package is detected by a gas sensor.
JP 2003-229148 A

  However, in the fuel cell system mounted on the vehicle, the sensor power for failure diagnosis is supplied through the EUC (control unit), so the power is not supplied to the sensor while the vehicle is stopped (battery operation stopped). Failure diagnosis cannot be performed. For this reason, even if a gas leak occurs in the vehicle, the gas leak cannot be detected unless a time of about several seconds elapses after the key switch of the vehicle is turned on. In addition, it is not preferable to supply power to the sensor even when the vehicle is stopped (always power supply) because the battery consumption increases. Furthermore, if the non-energized state of the sensor continues for a long time, there may be a problem that it takes time to purge dust or the like adhering to the surface of the sensor element at the next activation.

  Therefore, an object of the present invention is to solve the above-described problems and to propose a failure diagnosis apparatus that can perform failure diagnosis even when operating power is not supplied from the power supply circuit to the failure diagnosis means.

  In order to solve the above problems, the failure diagnosis apparatus of the present invention includes a first power supply circuit capable of supplying an operation power to the failure diagnosis means, and a case where the operation power from the first power supply circuit is not supplied to the failure diagnosis means And a second power supply circuit capable of supplying operating power to the failure diagnosis means. Even when the operating power is not supplied from the first power supply circuit to the failure diagnosing means, the operating power is supplied from the second power supply circuit to the failure diagnosing means, so that the failure diagnosis can be performed.

  As the second power supply circuit, for example, one that intermittently supplies operating power to the failure diagnosis means is preferable. With this configuration, the power consumption of the second power supply circuit can be reduced.

  The first power supply circuit and the second power supply circuit preferably have independent power supplies. By providing an independent power source for each of the first power supply circuit and the second power supply circuit, even if the power supply from one of the power supply circuits is stopped, the power is supplied from the other power supply circuit. be able to.

  As the failure diagnosis means, for example, a gas sensor that detects gas is suitable. Even if the operating power is not supplied from the first power supply circuit to the failure diagnosis means, if the gas sensor can be operated by the operating power supplied from the second power supply circuit, the gas sensor is not energized for a long time. It becomes possible not to be in a state, and deterioration of the gas sensor can be suppressed.

  The first power supply circuit is constituted by a fuel cell, the second power supply circuit is constituted by a battery, and when the fuel cell is in operation, the operating power is supplied from the fuel cell to the failure diagnosis means, and the fuel cell is stopped. In the case of the inside, the operation power may be supplied from the battery to the failure diagnosis means. With such a configuration, even when the operation of the fuel cell is stopped, the operation power can be supplied to the failure diagnosis means, and failure diagnosis can be performed.

  According to the present invention, even when the operating power is not supplied from the first power supply circuit to the failure diagnosing means, the operating power is supplied from the second power supply circuit to the failure diagnosing means, so that the failure diagnosis can be performed.

  Next, the configuration of the failure diagnosis apparatus of the present embodiment is shown with reference to each drawing. As shown in FIG. 1, the failure diagnosis apparatus 10 includes a first power supply circuit 1, a second power supply circuit 2, a failure diagnosis means 3, an energization open switch 4, an energization close switch 5, an intermittent switch mechanism 6, and A vehicle battery 7 is provided. Here, a configuration example for diagnosing a vehicle failure is illustrated, but the present invention is not limited to a specific application. The failure diagnosing means 3 includes, for example, a sensor circuit that detects a change in a specific physical quantity caused by a system failure or the like, or a determination circuit that determines a system failure state. As a specific example of the failure diagnosing means 3, a hydrogen sensor or the like that detects hydrogen gas leakage caused by a valve failure or piping damage of a hydrogen tank or a hydrogen piping system mounted on a fuel cell vehicle is suitable. The first power supply circuit 1 is a power supply device provided with an independent power supply different from the second power supply circuit 2. For example, a fuel cell is preferable. The first power supply circuit 1 supplies operating power to the failure diagnosis means 3 when a vehicle or an in-vehicle power system (for example, a fuel cell system) is activated or operated (for example, during battery operation). The second power supply circuit 2 is a power supply device provided with an independent power supply different from the first power supply circuit 1. For example, a chargeable / dischargeable secondary battery (battery) or the like is suitable. The second power supply circuit 2 temporarily stops the operation of the fuel cell when the vehicle or the on-vehicle power system (for example, the fuel cell system) is stopped (for example, the battery operation is stopped) or stopped (for example, idling or deceleration). (Including the case where the vehicle travels only by supplying power from the battery.) The operating power is supplied to the failure diagnosing means 3 during driving.

  The first power supply circuit 1 and the second power supply circuit 2 have the same polarity and are wired so that the operation power can be supplied to the failure diagnosis means 3 through the power supply lines 11, 12, 13, 14, 15. Yes. An opening switch 4 when energized that is switched on when energized is disposed at the connection point of the power lines 12 and 13, and further, a power line connected to the intermittent switch mechanism 6 so as to bypass the open switch 4 when energized. 16 and 17 are wired. The power line 16 is provided with an energization closing switch 5 that is switched off when energized. Here, the energized open switch 4 is an open / close switch that is switched on when energized and turned off when de-energized. The energization closing switch 5 is an open / close switch that is switched off when energized and switched on when de-energized. The intermittent switch mechanism 6 is a switch that operates upon receiving power supply from the vehicle battery 7, and intermittently opens or closes the power supply lines 16 and 17 so as to be intermittently connected or disconnected. The intermittent switch mechanism 6 further has a timer function, and can open and close the switch for a predetermined time set by the timer.

  FIG. 1 shows a state of power supply to each component when the vehicle is activated (for example, when an in-vehicle fuel cell system is in operation). Since power is supplied from the first power supply circuit 1 when the vehicle is started, the energization open switch 4 is switched on and the energization close switch 5 is switched off. As a result, operating power is supplied from the first power supply circuit 1 to the failure diagnosis means 3 through the power supply lines 11, 12, 13, 14, and 15, while the power supply lines 16 and 17 are turned off. FIG. 2 shows the state of power supply to each component when the vehicle is stopped (for example, the on-vehicle fuel cell system is stopped). Since no power is supplied from the first power supply circuit 1 when the vehicle is stopped, the energization open switch 4 is switched off and the energization close switch 5 is switched on. As a result, operating power is supplied from the second power supply circuit 2 to the failure diagnosis means 3 through the power supply lines 12, 16, 17, 13, and 14, while the power supply lines 11 and 15 are turned off. As described above, since the operating power is supplied from the second power supply circuit 2 to the failure diagnosis means 3 when the vehicle is stopped, the failure diagnosis of the system (for example, gas leak detection) is possible even when the vehicle is stopped. In addition, power consumption from the second power supply circuit 2 can be reduced by intermittently supplying power from the second power supply circuit 2 to the failure diagnosis means 3 by the intermittent switch mechanism 6 (intermittent power supply). If a secondary battery is used as the second power supply circuit 2, the life of the secondary battery can be extended. In addition, if a gas sensor (for example, a hydrogen sensor) that detects gas leakage is used as the failure diagnosis means 3, the gas sensor can be operated even before the vehicle is started. In the case of a hydrogen sensor that converts hydrogen into a voltage signal and detects hydrogen gas, deterioration (sensitivity reduction) of the hydrogen sensor can be suppressed by supplying an operating power to the hydrogen sensor and activating the platinum catalyst. Moreover, since the temperature of the hydrogen sensor can be increased in a short time, the time for removing (purging) miscellaneous gases can be shortened.

  The failure diagnosis means 3 may be a single sensor or a combination of a sensor and an ECU (control device) that performs failure determination control. The power supply circuit for supplying the operation power to the failure diagnosis means 3 can be selected from a fuel cell, a secondary battery, an in-vehicle battery (for example, 12V DC power supply), and two or more power supply circuits. (For example, a combination of fuel cell + battery A + battery B) may be used. Further, only one power supply circuit (for example, a secondary battery or a battery) may be provided and a plurality of supply circuits may be provided.

It is explanatory drawing of the failure diagnosis apparatus at the time of vehicle starting. It is explanatory drawing of the failure diagnosis apparatus at the time of a vehicle stop.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st power supply circuit 2 ... 2nd power supply circuit 3 ... Failure diagnosis means 4 ... Open switch at the time of energization 5 ... Close switch at the time of energization 6 ... Intermittent switch mechanism 7 ... Battery for vehicle 10 ... Failure diagnosis device 11-17 ... Power line

Claims (5)

  A first power supply circuit capable of supplying operating power to the failure diagnosing means; and a second power supply capable of supplying operating power to the failure diagnosing means when the operating power from the first power supply circuit is not supplied to the failure diagnosing means. A fault diagnosis device comprising a power supply circuit.   The failure diagnosis apparatus according to claim 1, wherein the second power supply circuit intermittently supplies operation power to the failure diagnosis unit.   3. The failure diagnosis device according to claim 1, wherein the first power supply circuit and the second power supply circuit each include an independent power source. 4.   The failure diagnosis apparatus according to any one of claims 1 to 3, wherein the failure diagnosis unit is a gas sensor that detects gas. 5. The failure diagnosis device according to claim 1, wherein the first power supply circuit is a fuel cell, the second power supply circuit is a battery, and the fuel cell is A failure diagnosis apparatus in which an operating power is supplied from the fuel cell to the failure diagnosis unit when in operation, and an operation power is supplied from the battery to the failure diagnosis unit when the fuel cell is not in operation .

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