JP2002235599A - Trouble diagnosing device for cab-over type truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent data from being recorded as a trouble history in a trouble history recorder 3 since, even if a trouble diagnosing part 7 incorporated in an engine electronic controller 6 executes trouble diagnosis in the inspections and operating checks of a cab-over type truck in the state of raising a cab and judges to be faulty, the trouble is not a real trouble. SOLUTION: When a cab switch 1 detects that the cab is not lowered, a data recording prohibition flag 5 is set to prohibit the recording of the trouble history. Accordingly, even if a trouble code occurs by the inspections and operating check, it can be prevented that it is recorded as a trouble record. Also, a trouble code occurred during the inspection with the cab raised is stored a trouble code temporary storage part 4 and, when even one same trouble code occurs after the cab is lowered, the recording of the trouble history is also prohibited. As a result, the same trouble as the trouble code occurred during the inspection is not recorded as the trouble history.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnosis device for a cab-over type truck.

[0002]

2. Description of the Related Art In addition to cab-over type trucks,
Recent trucks are equipped with an engine electronic control unit, but this device has a built-in failure diagnosis unit, and performs failure diagnosis automatically. Failure diagnosis is performed when the track is in a normal state, and when a failure is diagnosed, data relating to the failure diagnosis is recorded. In addition,
The data relating to the failure diagnosis includes a failure code representing the content of the failure, input / output data to and from the engine electronic control unit before and after the failure diagnosis is performed, control data, and the like.

In a cab-over type truck, various sensors, switches, connectors, actuators and the like are installed under the cab. Therefore, when checking them, check with the cab raised.
After the inspection, the cab is lowered. In such a cab-over type truck, if the fault is diagnosed by the fault diagnosis performed when the cab is raised and in an abnormal state of being inspected, the fault is a real fault. Or whether a signal indicating a failure has just been output due to an inspection operation (for example, if a connector is disconnected for inspection, the electrical signal passing therethrough exhibits the same state as a failure in which the signal is turned off) ), Not obvious.

[0004] Therefore, when performing an inspection by raising the cab,
Even if the failure diagnosis is executed and the failure is diagnosed, there are several techniques for not recording data relating to the failure diagnosis. A first such technique is to not record when the engine is stopped. The system automatically detects when the engine has stopped and does not record it while the engine is stopped.

[0005] As a second type, there is a method in which a manual switch called a data recording inhibition switch is attached to the failure diagnosis device so that recording is not performed while the switch is on. In this case, when raising the cab and performing an inspection, the operator turns on the data recording inhibition switch,
Turn off after inspection. As a conventional document relating to a cab-over type truck failure diagnosis device, there is, for example, JP-A-8-202441.

[0006]

The above-mentioned prior art has the following problems. The first technique has a problem in that data relating to a failure diagnosis that has occurred during inspection may be recorded as a failure history when the engine starts operating. This is because, depending on the engine electronic control unit with the built-in failure diagnosis device, if the failure diagnosis is executed and the data related to the failure diagnosis is generated, the data is maintained while the operating state is continued. There is something. If the engine electronic control unit is of this type, the data held at the moment when the engine is started to operate and the recording is permitted is recorded in a predetermined storage unit for storing the failure history. Will be done.

In the second technique, after the cab is lifted and the inspection is completed, the operator sometimes inadvertently forgets to turn off the data recording prohibition switch. Is executed, the data related to the failure diagnosis remains unrecorded. Further, the data relating to the failure diagnosis generated during the inspection is temporarily stored in the engine electronic control device incorporating the failure diagnosis device, but the data is deleted by resetting the engine electronic control device. Previously, when the worker turned off the data recording prohibition switch,
There is also a problem that the data is recorded in a predetermined storage unit that stores the failure history. An object of the present invention is to solve the above problems.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an engine electronic control unit having a built-in failure diagnosis unit and a failure diagnosis data including a failure code generated by the failure diagnosis unit. In a failure diagnosis device for a cab-over type truck including a failure history recording device for recording as a history, a cab switch for detecting whether or not a cab is lowered, and provided in the failure history recording device and set. A data recording prohibition flag that prohibits the recording of the failure history if it is reset, and releases the prohibition if reset, and a failure code that is provided in the failure history recording device and that is generated while the data recording prohibition flag is set. Is temporarily stored, and the memory is deleted when the engine electronic control unit is reset. When the cab has not been lowered, the data recording prohibition flag is set to prohibit the recording of the failure history, and even after the cab has been lowered and the data recording prohibition flag has been reset, the failure code is set. When the same failure code as one of the failure codes stored in the temporary storage unit is generated, the data recording prohibition flag is set to prohibit the recording of the failure history.

(Operation) While the cab is raised, a data recording prohibition flag is set to prohibit the recording of the failure history, so that a failure code is generated due to inspection and operation check. However, the failure code, input / output data before and after the occurrence of the failure code, control data, and the like are not recorded as a failure history.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a failure diagnosis device for a cab-over type truck according to the present invention. In FIG. 1, 1 is a cab switch, 2 is an alarm device, 3 is a failure history recording device, 4 is a failure code temporary storage unit, 5 is a data recording prohibition flag, 6 is an engine electronic control unit, 7 is a failure diagnosis unit, 8 Is a key switch, 9 is an input system, 10 is an output system, and 11 is a communication network.

The cab switch 1 is a switch for detecting whether or not the cab is down. The warning device 2 is a device that issues a warning when the truck is in a dangerous state in relation to the up / down state of the cab. For example, if the side brake is released when the cab is raised, the truck is in a dangerous state, and an alarm is issued in such a case. A signal is sent from the key switch 8 to the failure history recording device 3 and the engine electronic control device 6, which is a signal for notifying the on / off state of the key switch 8. The operation power supply of the failure history recording device 3 and the engine electronic control device 6 is performed by a power supply (not shown), but after the key switch 8 is turned off, the engine stops.
After a predetermined failure diagnosis operation (diagnosis of a failure when the key switch is turned off and an operation of writing the diagnosis result) is completed, the supply of the operation power is automatically cut off. As a result of the interruption, the engine electronic control unit 6 is reset.

The engine electronic control unit 6 is a control unit for controlling an engine (not shown), and has a built-in failure diagnosis unit 7. The input system 9 is a device that inputs a certain signal to the engine electronic control unit 6, such as various sensors and switches. The output system 10 indicates a device (eg, actuators) from which some signal such as a control signal is output from the engine electronic control device 6. The failure diagnosis unit 7 performs a failure diagnosis and generates a failure code representing the content of the found failure.

The failure history recording device 3 is a device for recording data relating to the failure diagnosis executed by the failure diagnosis unit 7.
A data recording prohibition flag 5 is provided. When the data recording prohibition flag 5 is set, the recording of the data in the failure history recording device 3 is prohibited, and when reset, the recording is enabled. The provision of the failure code temporary storage unit 4 and the data recording prohibition flag 5 is one of the features of the present invention. Alarm device 2, Failure history recording device 3,
The exchange of information between the engine electronic control units 6 is performed through the communication network 11. For example, information indicating that the cab is up or down is sent from the cab switch 1 via the alarm device 2 to the communication network 11.
Be sent to When a failure is diagnosed, a failure code indicating the type of the failure, input / output data before and after the diagnosis, and control data are sent from the engine electronic control unit 6 to the communication network 11.

Next, an operation relating to recording of data such as a failure code will be described. FIG. 2 is a flowchart illustrating a processing operation of the failure history recording device 3. Step 1: Check whether the cab is down based on the switch signal from the cab switch 1. Step 2: If the cab has not been lowered, the data recording prohibition flag 5 is set. As a result, even if the failure diagnosis is performed by the failure diagnosis unit 7 and a failure code is generated, recording of the failure code or the like as a failure history in the failure history recording device 3 is prohibited. Step 3: Even if the data recording prohibition flag 5 is being set, only the generated fault code is stored in the fault code temporary storage unit 4. This is to make it possible to know later what kind of failure has occurred during the inspection.

Step 4: If the cab is lowered in Step 1, the data recording prohibition flag 5 is reset.
When reset, if the fault diagnosis is executed and a fault code is generated, the fault code, input / output data,
The control data and the like are recorded in the failure history recording device 3 as a failure history. Step 5: A failure diagnosis is performed by the failure diagnosis unit 7,
When a fault code is generated, it is checked whether the same fault code exists in the fault codes stored in the fault code temporary storage unit 4. What is stored in the fault code temporary storage unit 4 is a code of a fault that occurred during the inspection with the cab raised or a fault that occurred before that. If the same fault code is generated this time as one of them, it does not indicate that a new fault has occurred. If the same fault code is not found in the fault code temporary storage unit 4, the process proceeds to step S7. Step 6... If the same code is found in the fault code temporary storage unit 4, it is only necessary to indicate the fault that has already occurred, as described above, and there is no need to record it. .

Step 7: It is checked whether or not the engine electronic control unit 6 has been reset. If not, go to the end. This check is
The determination is made based on whether data is no longer sent from the engine electronic control device 6 to the failure history recording device 3 for a predetermined time or more. If it is not sent, it is determined that it has been reset. The reason for checking by this method is as follows. The engine electronic control unit 6 is configured to continue sending data to the failure history recording device 3 unless reset. However, some engine electronic control units 6 are not reset immediately even when the key switch 8 is turned off. Therefore, it is more reliable to check whether data is no longer sent from the engine electronic control unit 6 than to check by turning off the key switch 8. For example, some engine electronic control devices 6 are designed to keep operating for a few seconds after the key switch is turned off, but if such a device is used and the key switch is turned off, a malfunction occurs. During that time, the history recording device 3 needs to keep monitoring whether data is sent.

Step 8: If the engine electronic control unit 6 is reset, the data recording prohibition flag 5 is reset. This is so that the failure history can be recorded when the engine electronic control unit 6 is set next time. Step 9: The fault code stored in the fault code temporary storage unit 4 is deleted. Since the engine electronic control unit 6 is reset and no failure code is generated, there is no need to make a comparison determination as in step 5. Therefore, these failure codes used as a reference for comparison are deleted.

[0018]

As described above, the cab-over type truck fault diagnosis apparatus of the present invention has the following effects. As long as the cab is not lowered, the data recording prohibition flag is set and the recording of the failure history is prohibited.
Even if a fault code is generated due to the inspection or operation check, the fault code is not recorded as a fault history. There is no manual data recording prohibition switch to prohibit the recording of the failure history when inspecting with the cab raised, so there will be no recording errors due to the operator forgetting to operate the switch. . The fault code generated during the inspection with the cab raised is stored in the fault code temporary storage unit 4, and if the same fault code occurs after the cab is lowered,
Since the recording of the failure history is prohibited because it does not represent a new failure, the same failure code that occurred during the inspection is prevented from being recorded as the failure history.

[Brief description of the drawings]

FIG. 1 is a diagram showing a failure diagnosis device for a cab-over type truck according to the present invention.

FIG. 2 is a flowchart illustrating a processing operation in the failure history recording device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cab switch, 2 ... Alarm device, 3 ... Failure history recording device, 4 ... Failure code temporary storage unit, 5 ... Data recording prohibition flag, 6 ... Engine electronic control unit, 7 ... Failure diagnosis unit,
8 key switch, 9 input system, 10 output system, 1
1. Communication network

Claims (1)

[Claims] 1. A cab-over type including an engine electronic control unit having a built-in failure diagnosis unit and a failure history recording device for recording data relating to a failure diagnosis including a failure code generated by the failure diagnosis unit as a failure history. In the truck failure diagnosis device, a cab switch for detecting whether or not the cab is lowered is provided in the failure history recording device, and when set, prohibits recording of a failure history, and when reset, A data recording prohibition flag for releasing the prohibition, provided in the failure history recording device,
A failure code temporary storage unit that temporarily stores a failure code generated while the data recording prohibition flag is set, and the storage is erased when the engine electronic control unit is reset. If the cab has not been lowered, the data recording prohibition flag is set to prohibit the recording of the failure history, and even after the cab has been lowered and the data recording prohibition flag has been reset, the data is stored in the fault code temporary storage unit. One of the stored fault codes
When the same failure code is generated, the data recording prohibition flag is set to prohibit the recording of the failure history, so that a failure diagnosis apparatus for a cab-over type truck is provided.