JPH0741789B2 - Failure diagnosis device for vehicle air conditioning system - Google Patents

Description

The present invention relates to a failure diagnosis device for a vehicle air conditioning system.

[Description of Prior Art] As one of the prior arts related to the present invention, Japanese Utility Model Laid-Open No. 56-67.
There is an abnormality diagnosis device for an electronic control unit for an automobile described in Japanese Patent No. 405. This detects the diagnosed part where an abnormality has occurred,
The detected location to be diagnosed is stored in a non-volatile memory, and when the key switch of the car is turned on, the contents of the above memory are read to display the location to be diagnosed where an abnormality has occurred. It is intended to diagnose abnormalities that are non-steady and lack reproducibility due to the above.

However, in such a conventional technique, when applied to failure diagnosis of a sensor or the like of a vehicle air conditioning system, it is not possible to distinguish attachment / detachment of the sensor or the like at the time of inspection or the like and an original abnormality caused by poor contact or the like. Therefore, there is a possibility that the attachment / detachment during inspection or maintenance may be diagnosed as a failure.

[Object of the Invention] The present invention has been made based on the above viewpoint, and an object thereof is to prevent mis-diagnosis of attachment / detachment at the time of inspection etc. as a failure, and to fail only an original abnormality caused by a contact failure or the like. It is an object of the present invention to provide a failure diagnosis device for a vehicle air conditioning system that is effective in diagnosing the above.

[Means for Achieving the Object] In the present invention, as shown in FIG. 1, an abnormality detecting means for detecting an abnormality in a diagnosis portion of a vehicle air conditioning system and a diagnosis portion in which the abnormality has occurred, , Based on the detection of the abnormality detecting means, stores the number of times of abnormality occurrence in the diagnosed location and stores the number of times of abnormality occurrence in the diagnosed location where the abnormality is detected in the rewritable nonvolatile memory The arithmetic storage means and, when a failure diagnosis is requested, determine a portion to be diagnosed in which the number of times of occurrence of abnormality is a predetermined value or more based on the stored contents of the arithmetic storage means, and detect the failure based on detection by the abnormality detecting means. It has a failure determination means that determines failure in the diagnosed part where an abnormality occurs at the time of requesting diagnosis and gives failure information, and attaches and detaches the diagnosed part at the time of inspection etc. as the number of occurrences of abnormality within a predetermined value. With a vehicle air conditioning system failure diagnosis device that absorbs
To achieve the above objectives.

[Embodiment of the Invention] FIG. 2 is a block diagram showing an embodiment of the present invention.

In the figure, reference numeral 1 is a duct of an air conditioning system for a vehicle, in which a blower 2, an evaporator 3 and a heater core 4 are arranged. The blower 2 has its air volume controlled by the control unit 5. The evaporator 3 and the heater core 4 are arranged downstream of the blower 2, and an air mix door 6 for adjusting the mixing ratio of cold air and warm air is provided between them. The opening degree of the air mix door 6 is controlled via an actuator 7 under the control of the control unit 5. An intake door 8 for selecting the introduction of inside and outside air is provided at the uppermost stream of the duct 1, and the introduction selection control is performed via an actuator 9 under the control of the control unit 5. There is. At the most downstream side of the duct 1, a differential door 10 that opens and closes the defroster outlet, a vent door 11 that opens and closes the vent outlet, and a floor door 12 that opens and closes the floor outlet.
Are provided, and the respective opening / closing control is performed via the actuators 13, 14, 15 under the control of the control unit 5. A swing louver 16 is provided at the vent outlet, and its drive control is performed via an actuator 17 under the control of the control unit 5. Reference numeral 18 is a compressor of the air conditioning system, and an electromagnetic clutch 19 controlled by the control unit 5 turns on / off the coupling with an engine (not shown).

The control unit 5 includes a blower drive circuit 20, an air mix door drive circuit 21, and an intake door drive circuit 22.
A differential door drive circuit 23, a vent door drive circuit 24,
Floor door drive circuit 25 and swing louver drive circuit 26
And a compressor drive circuit 27, and a control unit 28 that gives control signals to these drive circuits. The control unit 28
A CPU 280 that performs air conditioning control and failure diagnosis, a memory 281 that stores control programs and fixed data and temporarily stores necessary data, and an electrically rewritable and nonvolatile EEPROM 282 that stores failure diagnosis data. ,
An input / output circuit 283 is provided, and a control signal is given to each driver circuit through the input circuit 283. 29 is a room temperature sensor that detects the temperature inside the vehicle, 30 is an outside air temperature sensor that detects the outside air temperature, and 31 is the evaporator 3 and the emiax door 6.
And a duct sensor for detecting the temperature of the air blown from the evaporator 3, 32 is a solar sensor provided on the upper surface of the dashboard for detecting the amount of solar radiation, and 33 is provided on the heater core 4 and the water temperature of the heater core 4 is predetermined. A water temperature switch which is turned on / off depending on whether the value is equal to or more than a value, 34 is a potentiometer which detects the opening degree of the air mix door 6, and these detection information is provided to the control unit 28 through the input / output circuit 283. There is. Reference numeral 35 is an operation panel, and operation information thereof is given to the control unit 28 through the input / output circuit 283. FIG. 3 is a view showing an example of the operation pulse 35, 350 is a temperature setting air which is composed of a slide volume with variable resistance, 351 is a blower air flow controller which is also composed of a slide volume with variable resistance, 352a Is an auto switch for requesting air conditioning control in auto mode, 352 is an LED for automatic display, 353a is a swing bar switch for turning on / off the swing louver 16, 353b is an LED for swing louver on / off display, and 354a is Inside / outside air selector switch, 35
4b is an outside air introduction mode display LED, 354c is an inside air introduction mode display LED, 355a is a vent mode switch, 355b is a vent mode display LED, 356a is a by / level mode switch, 356b is a by / level mode display LED, 357a is foot mode switch, 357b is LED for foot mode display, 3
58a is a foot / diff mode switch, 358b is a foot / diff mode display LED, 359a is a diff mode switch, 359b
Is a differential mode display LED, and 360a is an A / C mode that controls the compressor 18 at an on / off temperature of 0 ° C./3° C. regardless of the heat load and the compressor 18 by changing the on / off temperature according to the heat load. ECO mode to control and compressor 1
A compressor switch with a three-stage switching configuration that puts 8 in the off state and an off mode, 360a is an LED for A / C mode display, 360c is
ECO mode display LED. The control unit 28 has an operation panel 35.
Blower 2, air mix door 6, intake door based on the operation information given by
8, room temperature sensor 29, outside air temperature sensor 30, duct sensor 31, solar radiation sensor 32, water temperature switch 33, aerial door along with the function of controlling the mode doors 10 to 12 and the compressor 18 to perform conventionally well-known vehicle interior air conditioning control It has a function of performing failure diagnosis of the potentiometer 34, the temperature setting device 350, and the blower air flow controller 351.

FIG. 4, FIG. 5 and FIG. 6 are examples of the control flow chart of the above configuration, and the operation of the configuration of FIG.

When the ignition switch is turned on, the program starts, and after initialization, it enters the determination of the failure diagnosis request in step 40. Operation panel 35
Of the two different switches, for example, the auto switch 352a and the differential mode switch 359a are both pressed, and if they are both pressed, the failure diagnosis is started. Get into control. Since the determination of the failure diagnosis request is performed only once after the ignition switch is turned on and after initialization, when the failure diagnosis is requested, the auto switch 352a and the differential mode switch 35 are used.
It is necessary to turn on the ignition switch while pressing 9a and 9a together, which prevents accidental switching to the failure diagnosis mode.

When it is determined in step 40 that there is no failure diagnosis request, step 41 is entered, and the operation information of the operation panel 35 and the detection means.
Conventionally known vehicle interior air conditioning control is performed based on the detection information from 29 to 34, and following this vehicle interior air conditioning control, the room temperature sensor 2
9. Abnormality detection of the outside air temperature sensor 30, the duct sensor 31, and the air mix door potentiometer 34 is performed, and the closed loop processing for returning to the vehicle interior air conditioning control in step 41 is performed. Well-known means for detecting disconnection, contact failure, short circuit, or the like can be applied to the abnormality detection, and is performed based on, for example, determining whether or not the detection signal satisfies a predetermined normal value range. The abnormality detection of the room temperature sensor 29 is performed in step 42 subsequent to the vehicle interior air conditioning control, and if it is determined to be normal, the abnormality detection of the outside air temperature sensor 30 is performed in step 43, and if the abnormality is detected, the procedure proceeds to step 44. In step 44, it is determined whether or not the room temperature sensor 29 was abnormal when the program passed the previous time. If it was normal when the program passed the previous time, step 45 is entered, and it was abnormal when the program passed the previous time. If so, step 43 is entered. Step
At 45, the number of times the abnormality has occurred in the room temperature sensor 29 is incremented by 1, and the abnormal portion representing the room temperature sensor 29 and the number of times the abnormality has occurred are stored in the EEPROM 282, and then step 43 is entered.
In step 43, abnormality detection of the outside air temperature sensor 30 is performed, and if it is determined to be normal, the duct sensor 31 abnormality detection is performed in step 46. If abnormality is detected, step 47 is entered.
In step 47, it is judged whether or not the outside air temperature sensor 30 was abnormal when the program passed last time, and if it was normal when the program passed last time, step 48 is entered, and it is abnormal when the program passed last time. If so, step 46 is entered. At step 48, the number of times the abnormality has occurred in the outside air temperature sensor 30 is incremented by +1 to store the abnormal portion representing the outside air temperature sensor 30 and its abnormality generation circuit in the EEPROM 282, and then step 46 is entered. In step 46, abnormality detection of the duct sensor 31 is performed, and if it is determined to be normal, the abnormality detection of the air mix door potentiometer 34 of step 49 is performed, and if abnormality is detected, step 50 is entered. In step 50, the duct sensor was
It is judged whether or not 31 is abnormal, and if it is manufacturing at the time of the previous program passage, step 51 is entered,
If the previous program was also abnormal when it passed, step 49 is entered. In step 51, the number of occurrences of abnormality in the duct sensor 31 is incremented by +1 to store the abnormal portion representing the duct sensor 31 and the number of occurrences of abnormality in the EEPROM 282, and then step 49 is entered. In step 49, the abnormality of the air mix door potentiometer 34 is detected, and if it is determined to be normal, the process returns to the vehicle interior air conditioning control of step 41, and if the abnormality is detected, the routine proceeds to step 52. In step 52,
When the air mix potentiometer 34 was abnormal at the time of the previous program passage, it is judged whether it is normal at the time of the previous program passage, and step 53 is entered, and when it is also abnormal at the time of the previous program passage. Then, the process returns to the vehicle interior air conditioning control in step 41. In step 53, the abnormality count of the air mix door potentiometer 34 is set to +1.
Increment and air mix door potentiometer
EEPROM282
Then, the process returns to the vehicle interior air conditioning control in step 41. By such an operation, abnormality detection of the room temperature sensor 29, the outside air temperature sensor 30, the duct sensor 31, and the air mix door potentiometer 34 during the vehicle interior air conditioning control is performed, and the number of occurrences of these abnormalities is stored in a nonvolatile manner. .

If it is determined in step 40 that there is a failure diagnosis request, step 54 is entered, and the compressor switch 36 on the operation panel 35
Switch 0a to the failure diagnosis mode and perform the next step
At 55, the display LED on the operation panel 35 is switched to the failure diagnosis mode. When the compressor switch 360a is switched to the failure diagnosis mode, the compressor switch 360a is controlled to be a two-stage selection switch which selectively selects a current failure diagnosis and a past failure diagnosis, which will be described later. By switching to the failure diagnosis mode, the display LED indicates whether the current / past failure diagnosis is normal / failed, the failure location in the case of failure, and whether the current failure diagnosis or past failure diagnosis is selected. Switching control is performed so as to perform selection display to be displayed. In this example, the failure is indicated by blinking the automatic display LED 352b and the mode display LEDs 355b, 356b, 357b, 35
8b, 359b, inside air / outside air introduction mode display LEDs 354b, 354c and swing louver on / off display LED 353b are used to indicate a failure location, and vent-mod display LED 355b, outside air introduction mode display LED 354 and auto display LED are turned on. By displaying the normal condition, the A / C mode display LED 360b lights up to display the past failure diagnosis selected, and the ECO mode display LED 360c
Lights up to display the current fault diagnosis selection. After switching to such a failure diagnosis mode, in step 56, the flag F
Is set to "1", and the next step 57 is to determine whether to cancel the diagnosis. Whether the diagnosis is released or not is determined by two switches on the operation panel 35 such as an auto switch 352a and an inside / outside air changeover switch.
This is performed based on whether or not both 354a and 354a are in the pressed state. If both are pressed, the failure diagnosis is canceled and the vehicle interior air conditioning control is entered, and in other states, step 58 is entered. In step 58, the flag F is judged. If the program has passed for the first time after the failure diagnosis is requested, the flag F is "1".
After initially setting 0a to the current failure diagnosis selection state, the flag F is set to "0" in step 60 and the ECO mode display LED 360c is turned on in step 61 to enter the current failure diagnosis in step 62, and then to step 57. Return. Since the flag F is set to "0" in the second and subsequent program passages, step 58 to step 63 are entered. Step 63
Then, the selection operation of the compressor switch 360a is judged, and if the failure diagnosis is currently selected, step 61
Enter the above-mentioned ECO mode display LED 360c and perform the current failure diagnosis in step 62. If past failure is selected, enter step 64 and enter the ECO mode display LED.
After the A / C mode display LED 360b is turned on instead of the 360c, the past failure diagnosis of step 65 is performed. For the current fault diagnosis in step 62 or the past fault diagnosis in step 65, see step 57.
Then, the above operation is repeated. When it is determined in step 57 that the failure diagnosis has been canceled, the process proceeds to step 66, and in step 66 and the next step 67, the compressor switch 360a
After returning the display LED to the original mode, the vehicle interior air conditioning control of step 41 is started.

FIG. 5 is an example of a control flowchart for the present failure diagnosis in step 62 of FIG. After canceling the past failure diagnosis display at the start of the current failure diagnosis, step 70 is entered to detect an abnormality such as disconnection of the room temperature sensor 29, and upon detection of that abnormality, the vent mode display LED 355b of step 71 is turned on and step 72 After flashing the LED 352b for auto display, the current failure diagnosis is exited. If the room temperature sensor 29 is normal, the process proceeds from step 70 to step 73 to detect an abnormality such as disconnection of the outside air temperature sensor 30. Upon detection of the abnormality, the by / level mode display LED 356b in step 74 is turned on and step 72 is detected.
After the LED 352b for automatic display of blinks, the current failure diagnosis is exited. If the outside air temperature sensor 30 is normal, the process proceeds from step 73 to step 75 to detect an abnormality such as disconnection of the duct sensor 31. Upon detecting the abnormality, the LED 357b for displaying the foot mode in step 76 is turned on and the automatic display in step 72 is displayed. After flashing the LED 352b for use, the current failure diagnosis is exited. If the duct sensor 31 is normal, step 75 to step 77
Then, the abnormality detection such as the disconnection of the air mix door potentiometer 34 is performed, and the detection is performed to turn on the differential mode display LED 359b in step 78 and blink the automatic display LED 352b in step 72, and then exit the fault diagnosis. If the air mix door potentiometer 34 is normal, proceed from step 77 to step 79 to detect an abnormality such as disconnection of the slide volume of the temperature setter 350, and when the abnormality is detected, the outside air introduction mode display LED 354b in step 80 lights up. Then, through the blinking of the automatic display LED 352b in step 72, the current failure diagnosis is exited. If the temperature setting device 350 is normal, the process proceeds from step 79 to step 81 to detect an abnormality such as a disconnection of the slide volume of the blower air flow controller 351. Upon detection of the abnormality, the inside air introduction mode display LED 354c is turned on in step 82. And LED for step 72 auto display
After the blinking of 352b, the current failure diagnosis is exited. If the blower air flow controller 351 is normal, step 81 to step 83
To detect abnormalities in the on / off operation of the water temperature switch 33, and normally detect that the swing louver on / off display LED 35b in step 84 lights up and the auto display LED 352b in step 72 blinks. Get out of the diagnosis. An abnormality in the on / off operation of the water temperature switch 33 can be easily determined based on, for example, the engine water temperature display signal. If the water temperature switch 33 is normal, the process proceeds from step 83 to step 85 to detect an abnormality such as a disconnection of the solar radiation sensor 32, and when the abnormality is detected, the foot / def mode display LED 358b is lit in step 86 and the automatic display in step 72 is performed. After flashing the LED 352b for use, the current failure diagnosis is exited. If the solar radiation sensor 32 is normal, the process proceeds from step 85 to step 87, and the vent mode display LED 3
55b lighting, LED for outside air introduction mode display at the next step 88
After illuminating 354b and then illuminating the automatic display LED 352b in step 89, the current failure diagnosis is exited. If an abnormality occurs at the time of diagnosis by such a current failure diagnosis, it is possible to recognize the failure and the failure point by blinking the automatic display LED 352b and lighting the display LED corresponding to the abnormal point, and it is normal. In some cases, the vent mode display LED 355b, the outside air introduction mode display LED 354b, and the automatic display LED 352b can be turned on to recognize that all the diagnosis points are normal.

FIG. 6 is an example of a control flowchart for past failure diagnosis in step 65 of FIG. After clearing the current fault diagnosis display at the start of past fault diagnosis, go to step 90 and
The number of occurrences of abnormality of the room temperature sensor 29 is read from 2 and it is determined whether the number of occurrences of abnormality is equal to or greater than a predetermined value n. After the LED 355b is turned on and the auto mode display LED 352b in step 92 is blinked, the past failure diagnosis is exited. The number of times the room temperature sensor 29 has failed is a predetermined value
If it is below, proceed from Step 90 to Step 93 to check the EFPROM
The number of times the abnormality has occurred in the outside air temperature sensor 30 is read from 282. If the number of times the abnormality has occurred is greater than or equal to a predetermined value n, it is determined that there is a failure, and the bi / level mode display LED 356b in step 94 is turned on and the automatic mode display in step 92 is displayed. The LED 352b flashes and exits past failure diagnosis. If the normal number of occurrences of the outside air temperature sensor 30 is less than or equal to the predetermined value n, the process proceeds from step 93 to step 95, the number of abnormal occurrences of the duct sensor 31 is read from the EEPROM 282, and whether or not the number of abnormal occurrences is greater than or equal to the predetermined value n. If it is equal to or more than the predetermined value n, it is determined that a failure occurs, and the foot mode display LED 357b is turned on in step 96 and the auto mode display LED 352b is blinked in step 92, and the past failure diagnosis is exited. Duct sensor 31
If the number of occurrences of abnormality is less than the predetermined value n, the process proceeds from step 95 to step 97, the number of occurrences of abnormality of the air mix door potentiometer 34 is read from the EEPROM 282, and it is determined whether the number of occurrences of abnormality is not less than the predetermined value r. The
If the value is equal to or more than the predetermined value n, it is determined that a failure has occurred, and the differential mode display LED 359b is turned on in step 98 and the auto mode display LED 352b is blinked in step 92, and the past failure diagnosis is exited. If the number of occurrences of abnormality of the air mix door potentiometer 34 is less than or equal to the predetermined value n, step 97 to step
Proceed to 99, and the vent mode display LED 355 in step 99 concerned
Illumination of b, LED 3 for the outside air introduction mode display in the next step 100
After turning on 54b and further turning on the LED 352b for automatic display in the next step 101, the past failure diagnosis is exited. The predetermined value n is selected, for example, about 10 times in consideration of the number of times of attachment / detachment of the diagnosed portion due to repair, inspection and the like. Also, the predetermined value n
Is based on the empirical rule of the number of times each is detached due to repairs,
The value may be different depending on each diagnosed location. According to such a past failure diagnosis, it is possible to absorb an abnormality caused by the attachment / detachment of a diagnosed portion at the time of repair, inspection, etc., as the number of times of occurrence of abnormality within a predetermined value n, and a contact failure occurred before the diagnosis. It is possible to efficiently diagnose abnormalities that lack reproducibility such as. Then, by blinking the automatic display LED 352b and lighting the display LED corresponding to the failure point, it is possible to recognize that a failure occurred before the diagnosis and the failure point, and also the vent mode display LED 355b, the outside air introduction. By lighting the mode display LED 354b and the automatic display LED 352b, it can be recognized that all the diagnosed points were normal before the diagnosis.

In the above-mentioned embodiment, the present failure diagnosis and the past failure diagnosis are selectively selected by the compressor switch. However, both of them are displayed in an overlapping manner without being selected so that the configuration is simplified. May be. Further, it is possible to add a conventionally known reset means for resetting the number of occurrences of abnormality when the number of occurrences of abnormality exceeds a predetermined value.

[Effects of the Invention] As described above, according to the present invention, a portion to be diagnosed where an abnormality has occurred prior to failure diagnosis and the number of times of occurrence of the failure are stored in a rewritable nonvolatile memory, and an abnormality occurs during failure diagnosis. Since the number of times that exceeds the specified value is determined as a failure, it is possible to absorb the abnormalities caused by the attachment / detachment of the diagnosed part at the time of repair, inspection, etc. It is possible to efficiently diagnose a non-reproducible abnormality such as poor contact that occurred before, prevent misdiagnosis of detachment at the time of inspection etc. as a failure, and only the original abnormality caused by poor contact etc. It is possible to provide a failure diagnosis device for a vehicle air conditioning system that is effective in diagnosing.

[Brief description of drawings]

1 is a block diagram of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is a diagram showing an example of the operation panel of FIG. 2, and FIG. 4 is a configuration of FIG. Control flowchart of the fifth
FIG. 6 is a control flowchart of the present failure diagnosis of FIG.
The figure is a control flowchart of the past failure diagnosis of FIG. 1 ... Duct, 2 ... Blower, 3 ... Evaporator, 4
...... Heater core, 5 ...... Control unit, 6 ......
Air mix door, 8 …… intake door, 10 …… differential door, 11 …… vent door, 12 …… floor door, 18 …… compressor, 28 …… control unit, 282 …… EEPROM, 29 …… room temperature sensor, 30 …… Outside temperature sensor, 31 ... Duct sensor,
32 …… solar radiation sensor, 33 …… water temperature switch, 34 …… air mix door potentiometer, 35 …… operation panel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hirofumi Nagaoka, No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. In the Konan factory (72) Inventor Yoshihiko Sakurai, 39, Toyo, Chiyo-ji, Konan-cho, Osato-gun, Saitama Prefecture Diesel Equipment Co., Ltd. In the Konan factory (56) Reference JP-A-61-41515 (JP, A)

Claims (1)

[Claims] 1. A failure diagnosis device for detecting a failure at a location to be diagnosed in an air conditioning system for a vehicle, detects whether the location to be diagnosed is normal or abnormal, and provides detection information indicating normality / abnormality at the location to be diagnosed. Abnormality detection means, in response to the detection information of the abnormality detection means, the occurrence of an abnormal state is counted as the number of occurrences of abnormality every time the diagnosed location repeats a normal state and an abnormal state, and the diagnosed location where the abnormality is detected And an abnormality occurrence frequency thereof, which is stored in a rewritable non-volatile memory, and which increments the corresponding occurrence frequency of the diagnosed location by +1 each time the diagnosed location changes from a normal state to an abnormal state. In response to a failure diagnosis request given from the outside, the abnormality storage means to be incremented, and there is a portion to be diagnosed in which the number of occurrences of abnormality is a predetermined value or more based on the stored contents of the abnormality storage means. Whether or not the abnormality occurs, the past failure determination means for determining the failure at the location to be diagnosed for which the number of occurrences of the abnormality is equal to or more than the predetermined value, and providing the failure information in the past, and the failure diagnosis request given from the outside. A fault diagnosis of a vehicle air-conditioning system, characterized in that it has a current failure determination means for determining a failure point at a diagnosed portion where an abnormality currently occurs based on the detection information from the detection means, and providing current failure information. apparatus.