JPS63151511A - Device for diagnosing trouble in air conditioning system for vehicle - Google Patents

Abstract

PURPOSE:To prevent an errorneous diagnosis and improve the reliability of diagnosing device by storing abnormality generating spots and the number of times of generating abnormalities on the spots to judge and indicate the presence of troubles in the spots in which said number times exceeds a predetermined value when troubles are required to be diagnosed. CONSTITUTION:Respective signals from a room temperature sensor 29, atmosphere temperature sensor 30 duct sensor 31, sun beam sensor 32, water temperature switch 33 and air mix door potentiometer 34 are sent to the input of a control unit 28. A CPU 280 controls air conditioning and diagnoses troubles to store abnormality generating spots and the number of times of generating abnormalities in the spots in a non-volatile EEPROM 282 capably of being rewritten. When a request for diagnosing troubles is input by a control panel 35, the control unit 28 indicates among data stored in the EEPROM 282 spots in which the number of times of troubles exceeds a predetermined value. By this constitution is indicated only original abnormalities such as defective contact as troubles to improve the reliability of the apparatus.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a failure diagnosis device for a vehicle air conditioning system.

[Description of prior art] As one of the prior art related to the present invention,
There is an abnormality diagnosis device for an electronic control device for an automobile described in Japanese Patent No. 67505. This detects the location to be diagnosed where an abnormality has occurred, stores the detected location to be diagnosed in a non-volatile memory, and reads the contents of the memory when the key switch of the car is turned on to identify the location to be diagnosed where an abnormality has occurred. It is intended to diagnose abnormalities that are irregular and lack reproducibility due to poor contact, half-wire breakage, etc.

However, when such conventional technology is applied to failure diagnosis of sensors, etc. of vehicle air conditioning systems, it is not possible to distinguish between the attachment and detachment of sensors, etc. during inspection, and actual abnormalities caused by poor contact, etc. Therefore, there is a risk that attachment and detachment during inspection, maintenance, etc. will be diagnosed as a failure.

[Object of the Invention] The present invention has been made based on the above-mentioned viewpoint, and its purpose is to prevent misdiagnosis of attachment/detachment as a failure during inspection, etc., and to identify only the original abnormality caused by poor contact etc. as a failure. It is an object of the present invention to provide a fault diagnosis device for a vehicle air conditioning system that is effective in diagnosing.

[Means for Achieving the Object] As shown in FIG. 1, the present invention includes an abnormality detecting means for detecting an abnormality in a part to be diagnosed of a vehicle air conditioning system and a part to be diagnosed where an abnormality has occurred. , based on the detection by the abnormality detecting means, counts the number of times an abnormality has occurred in the part to be diagnosed, and stores the part to be diagnosed where an abnormality has been detected and the number of times the abnormality has occurred in the part to be diagnosed in a rewritable non-volatile memory. an arithmetic storage means; upon request for fault diagnosis, determines as a failure a diagnosed location where the number of times an abnormality has occurred is greater than or equal to a predetermined value based on the stored contents of the arithmetic storage means; It has a failure determination means for determining a diagnosed part where an abnormality has occurred at the time of a diagnosis request as a failure, and a display means for displaying a diagnosed part determined as a failure by the failure determination means, and is used for inspection, etc. The above object is achieved by a fault diagnosis device for a vehicle air conditioning system that absorbs attachment/detachment of a diagnostic point as a number of abnormal occurrences within a predetermined value.

[Embodiments of the invention] FIG. 2 is a configuration diagram showing an embodiment of the present invention.

In the figure, l is a duct of a vehicle air conditioning system, and a blower 2, an evaporator 3, and a heater core 4 are disposed inside the duct. The air volume of the blower 2 is controlled by a control unit 5. The evaporator 3 and the heater core 4 are arranged downstream of the blower 2, and an air mix door 6 is provided between them to adjust the mixing ratio of cold air and warm air. The opening degree of the air mix door 6 is controlled via an actuator 7 placed under the control of the control unit 5. An intake door 8 is provided at the most upstream side of the duct 1 to select the intake of inside and outside air, and the intake selection is controlled via an actuator 9 placed under the control of the control unit 5. There is. At the most downstream side of the duct 1, there are provided a defroster door 10 for opening and closing the defroster outlet, a vent door 11 for opening and closing the vent outlet, and a floor door 12 for opening and closing the floor outlet. Opening/closing control is performed via actuators 13, 14, and 15 placed therein.

A swing looper 16 is provided at the vent outlet, and its drive is controlled via an actuator 17 placed under the control of the control unit 5. Reference numeral 18 denotes a compressor of the air conditioning system, which is connected to an engine (not shown) by an electromagnetic clutch 19 controlled by the control unit 5.
It is set to be turned off.

The control unit 5 includes a blower drive circuit Q n l
-〒7S-,/y I V 7WHilh riil
'ML 91 Sends control signals to the saw door drive circuit 22, differential door drive circuit 23, vent door drive circuit 24, floor door drive circuit 25, swing louver drive circuit 26, compressor drive circuit 27, and these drive circuits. The control unit 28 is provided with a control unit 28 to provide Control part 2
8 includes a CPU 280 that performs air conditioning control and fault diagnosis, a memory 281 that stores control programs and fixed data and temporarily stores necessary data, and an electrically rewritable and nonvolatile memory that stores fault diagnosis data. EEPROM 282 and an input/output circuit 283, and a control signal is given to each drive circuit via the input/output circuit 283. 29 is a room temperature sensor that detects the temperature inside the vehicle; 30 is an outside temperature sensor that detects the outside temperature; 31
3 is a duct sensor provided between the evaporator 3 and the air mix door 6 to detect the temperature of the air blown out from the evaporator 3; 32 is a solar radiation sensor provided on the upper surface of the dash board to detect the amount of solar radiation; and 33 is provided in the heater core 4. A water temperature switch 34 is turned on/off depending on whether the water temperature of the heater core 4 is above a predetermined value, and 34 is a potentiometer that detects the opening degree of the air mix door 6. These detection information is sent to the control unit 28 through the input/output circuit 283. It is designed to be given to Reference numeral 35 denotes an operation panel, the operation information of which is supplied to the control section 28 through an input/output circuit 283. FIG. 3 is a diagram showing an example of the operation panel 35, where 350 is a temperature setting device composed of a slide volume with a variable resistance value, 351 is a blower air volume regulator similarly composed of a slide volume with a variable resistance value, and 352
a is an auto switch for requesting air conditioning control in auto mode, 352b is an auto display LED, 353a is a swing louver switch for turning on/off the swing louver 16, 353b is an LED for swing louver on/off display% 354a 354b is an outside air introduction mode display LED, 354c is an inside air introduction mode display LED, 355a is a vent mode switch, 3
55b is a vent mode display LED, 356a is a bi/
Level mode switch, 356b is bi/level mode display LED, 357a is 7-/to mode switch, 3
57b is a foot mode display LED, 358a is a foot/differential mode switch, 358b is a foot/differential mode display LED, 359a is a differential mode switch, 359
b is a differential mode display LED; 360a is an A/C mode that controls the compressor 18 at an on/off temperature of, for example, 0° C. and 73° C., regardless of the heat load; A compressor switch 360a has a three-stage switching configuration of an ECO mode that controls the compressor 18 and an OFF mode that turns the compressor 18 off.
/C mode display LED, 360C is an ECO mode display LED. The control unit 2 controls the blower 2, the air mix door 6, the intake door 8, . In addition to the function of controlling the mode doors 10 to 12 and the compressor 1B to perform conventionally well-known vehicle interior air conditioning control, the room temperature sensor 29. Outside temperature sensor, 30. Duct sensor 31. Solar radiation sensor 32. Water temperature switch 33, air mic door potentiometer 34. It has a function of diagnosing the failure of the temperature setting device 350 and the blower air volume regulator 351.

FIGS. 4, 5, and 6 are examples of control flowcharts for the above configuration, and the operation of the configuration shown in FIG. 2 will be explained using these together below.

The program starts when the ignition switch is turned on, and after initialization, it enters step 40 to determine a failure diagnosis request. The presence or absence of a request for failure diagnosis is determined by two different switches on the operation panel 35, such as the auto switch 35.
2a and differential mode switch 359. This is performed based on whether or not both a and a are pressed. If both are pressed, failure diagnosis is entered, and in any other state, vehicle interior air conditioning control is entered. Determination of a failure diagnosis request is performed only once following initialization after turning on the ignition switch, so when requesting failure diagnosis, press the ignition switch while holding down both the auto switch 352a and the differential mode switch 359a. This prevents the failure diagnosis mode from being activated inadvertently.

If it is determined in step 40 that there is no failure diagnosis request, the process proceeds to step 41, where conventionally known vehicle interior air conditioning control is performed based on the operation information on the operation panel 35 and the detection information from the detection means 29 to 34. Following the control, the room temperature sensor 29. Outside temperature sensor 30. An abnormality is detected in the duct sensor 31 and the air mix door potentiometer 34, and a closed loop process is performed that returns to the vehicle interior air conditioning control in step 41. For the abnormality detection, well-known means for detecting disconnection, poor contact, short circuit, etc. are applied. For example, the determination is made based on whether or not the detection signal satisfies a predetermined normal value range. Detection of an abnormality in the room temperature sensor 29 is performed in step 42 following the vehicle interior air conditioning control, and if it is determined to be normal, the outside temperature sensor 3 is detected in step 43.
0 abnormality detection and step 4 by detecting the abnormality.
Enter 4. In step 44, it is determined whether or not the room temperature sensor 29 was abnormal when the program was passed last time, and if it was normal when the program was passed last time, the process goes to step 45, and it is determined that the room temperature sensor 29 was also abnormal when the program was passed last time. If so, step 43 is entered. In step 45, the number of abnormality occurrences of the room temperature sensor 29 is incremented by +1,
After storing the abnormal location representing the room temperature sensor 29 and the number of times the abnormality has occurred in the EEPROM 282, step 43 is entered. In step 43, an abnormality is detected in the outside air temperature sensor 30, and when it is determined to be normal, the process proceeds to step 46 to detect an abnormality in the duct sensor 31, and when an abnormality is detected, the process proceeds to step 47. In step 47, it is determined whether or not the outside temperature sensor 30 was abnormal when the program was passed last time, and if it was normal when the program was passed last time, the process goes to step 48, and if the sensor 30 was abnormal when the program was passed last time. If so, step 46 is entered. In step 48, the number of times the abnormality has occurred in the outside temperature sensor 30 is incremented by +1, and the abnormality location representing the outside temperature sensor 30 and the number of times the abnormality has occurred are stored in the EEPROM 282, and then step 46 is entered. In step 46, an abnormality of the duct sensor 31 is detected, and when it is determined to be normal, the process proceeds to step 49, which detects an abnormality in the air mix door potentiometer 34, and when an abnormality is detected, the process proceeds to step 50.

In step 50, it is determined whether or not the duct sensor 31 was abnormal when the program was passed last time, and if it was normal when the program was passed last time, step 51 is performed.
If there was an abnormality during the previous program passage, the program enters step 49. In step 51, the number of abnormal occurrences of the duct sensor 31 is incremented by +1, and the abnormal location representing the duct sensor 31 and the number of abnormal occurrences thereof are set to E.
After storing the data in the EPROM 282, the program enters the step 49. In step 49, an abnormality of the air mix door potentiometer 34 is detected, and if it is determined to be normal, the process returns to step 41 to control the vehicle interior air conditioning, and if an abnormality is detected, the process proceeds to step 52.

In step 52, it is determined whether or not the air mix door potentiometer 34 was abnormal when the program was passed the previous time.If the air mix door potentiometer 34 was normal when the program was passed the previous time, the process goes to step 53, and the air mix door potentiometer 34 is judged to be abnormal when the program was passed the previous time. If there is an abnormality, the process returns to step 41 to control the vehicle interior air conditioning. In step 53, the number of times an abnormality has occurred in the air mix door potentiometer 34 is incremented by +1, and the abnormality location representing the air mix door potentiometer 34 and the number of times the abnormality has occurred are stored in the EEPROM 282, and then the process returns to step 41, which is the vehicle interior air conditioning control. Due to this operation, the room temperature sensor 29. Abnormalities in the outside temperature sensor 30, duct sensor 31, and air mix door potentiometer 34 are detected, and the number of times these abnormalities occur is stored in a non-volatile memory.

If it is determined in step 40 that there is a failure diagnosis request, the process proceeds to step 54, in which the compressor switch 360a of the operation panel 35 is switched to failure diagnosis mode, and in the next step 55, the display LED of the operation panel 35 is changed to failure diagnosis mode. Switch. compressor switch 360
a is a 0 display LED that is controlled to be a two-stage selection switch that selectively selects a current fault diagnosis and a past fault diagnosis, which will be described later, when the mode is switched to the fault diagnosis mode.
By switching to the fault diagnosis mode, you can display the normal/failure display during current and past fault diagnosis, the fault location display in the case of a fault, and the selection to display whether current fault diagnosis or past fault diagnosis is selected. Switching is controlled so that the display is performed. In this example, the auto display LE
A failure is indicated by flashing D352b, and mode display LEDs 355b, 356b, 357b, 358b
, 359b and an LED 354b for displaying the inside/outside air introduction mode.
354c and LED 35 for swing louver on/off indication
3b to display the fault location, LED 355b for vent mode display, LED 354b for outside air introduction mode display
Normality is indicated by lighting the auto display LED, the past failure diagnosis selection is indicated by lighting the A/C mode display LED 360b, and the ECO mode display LED is lit.
The current fault diagnosis selection is displayed by lighting 0360c. After switching to such a fault diagnosis mode, step 5
In step 6, flag F is set to "1", and the next step 57 is to determine whether to cancel the diagnosis.
For example, auto switch 352a
This is performed based on whether or not both the and the inside/outside air changeover switch 354a are pressed. If both are pressed, the fault diagnosis is canceled and the vehicle interior air conditioning control is entered. Otherwise, the process proceeds to step 58. enter. In step 58, flag F is determined, and if this is the first time the program has passed after the failure diagnosis request, flag F is "1", so step 59
After initially setting the compressor switch 360a to the currently selected state of failure diagnosis, the flag F in step 60 is set.
After the "0" processing and the lighting of the ECO mode display LED 360c in step 61, the process enters the current fault diagnosis in step 62, and then returns to step 57. Since the flag F is set to "0" during the second and subsequent program passes, the program enters step 63 from step 58. In step 63, the selection operation of the compressor switch 360a' is determined, and if failure diagnosis is currently selected, step 61 is entered and the above-mentioned ECO mode display L is selected.
Turn on the ED360c and perform the current fault diagnosis in step 62, and if past fault diagnosis is selected,
Enter step 64 and LE0360c for ECO mode display
Instead, after lighting the A/C mode display LE0360b, the past failure diagnosis in step 65 is performed, step 62
After the current fault diagnosis or the past fault diagnosis in step 65, the process returns to step 57 and repeats the above-mentioned operation.If it is determined in step 57 that the fault diagnosis should be canceled, the process moves to step 66, and the process proceeds to step 66 and the next step 67. After returning the compressor switch 360a and the display LED to their original modes, the vehicle interior air conditioning control is started in step 41.

FIG. 5 is an example of a control flowchart of the current fault diagnosis in step 62 of FIG. After canceling the past failure diagnosis display at the start of the current failure diagnosis, the process enters step 70 and detects an abnormality such as a disconnection of the room temperature sensor 29. Upon detection of the abnormality, the vent mode display LED 355 goes to step 71.
b lighting and auto display LED 35 in step 72
2b blinks, the current failure diagnosis is performed. If the room temperature sensor 29 is normal, the process proceeds from step 70 to step 73, where an abnormality such as a disconnection of the outside temperature sensor 30 is detected.
When the abnormality is detected, the bi/level mode display LED 356b lights up in step 74 and the auto display LED 352b flashes in step 72, and the current failure diagnosis is performed.If the outside temperature sensor 30 is normal, step 73
The process then proceeds to step 75, in which an abnormality such as a disconnection of the duct sensor 31 is detected. Upon detection of the abnormality, the foot mode display LED 357b lights up in step 76, and the auto display LED 352b blinks in step 72, and the current fault diagnosis is performed. If the duct sensor 31 is normal, the process advances from step 75 to step 77, and abnormalities such as disconnection of the air mix door potentiometer 34 are detected.
At that detection, 1−+ −, −IF5 Q hgi M s−−
K Yuunta T-RrMt! After 'sQb lights up and the auto display LED 352b flashes in step 72, the current failure diagnosis is performed. If the air mix door potentiometer 34 is normal, steps 77 to 79
Step 80 then proceeds to step 80 to detect an abnormality such as disconnection of the slide volume of the temperature setting device 350.
After the outside air introduction mode display LED 354b lights up and the auto display LED 352b flashes in step 72, the current failure diagnosis is skipped.If the temperature setting device 350 is normal, the process advances from step 79 to step 81, and the blower air volume is adjusted. An abnormality such as a break in the slide volume of the device 351 is detected, and when the abnormality is detected, the LED 354c for displaying the inside air introduction mode is turned on in step 82 and the LED 354c is turned on in step 72.
After the automatic display LED 352b blinks, the current failure diagnosis is skipped.If the blower air volume regulator 351 is normal, the process proceeds from step 81 to step 83, where an abnormality in the on/off operation of the water temperature switch 33 is detected. When the abnormality is detected, the swing louver on/off display LED 353b lights up in step 84 and the auto display LED 352b flashes in step 72, and the current failure diagnosis is performed. For example, this can be easily determined based on the engine water temperature display signal. If the water temperature switch 33 is normal, step 8
Step 3 proceeds 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/default mode display LED 358b lights up in step 86 and the auto display LED 352b blinks in step 72, and the current malfunction is detected. If the solar radiation sensor 32 is normal, the process proceeds from step 85 to step 87, in which the vent mode display LED 355b is turned on in step 87, and the outside air introduction mode display LED 354b is turned on in the next step 88.
is lit, and the auto display LED 352b is lit in the next step 89, and the current fault diagnosis is skipped.If an abnormality has occurred during the first diagnosis by such current fault diagnosis, the auto display LED 352b is turned on. The failure and failure location can be recognized by blinking the LED 352b and lighting the display LED corresponding to the abnormal location, and if it is normal, the vent mode display LED 355b, the outside air introduction mode display LED 354b, and the auto display LED 35.
By lighting 2b, it can be recognized that all the diagnosed parts are normal.

FIG. 6 is an example of a control flowchart for past failure diagnosis in step 65 of FIG. After canceling the current fault diagnosis display at the start of past fault diagnosis, step 90 is entered, and EE
The number of abnormality occurrences of the room temperature sensor 29 is read from the PROM 282, and it is determined whether the number of abnormality occurrences is greater than or equal to a predetermined value n.If the number of abnormality occurrences is greater than or equal to the predetermined value n, it is determined that there is a failure and the vent mode display is performed in step 91. Lighting of LED 355b and LED 35 for displaying auto mode in step 92
After 2b blinks, the past failure diagnosis is skipped. If the number of abnormalities of the room temperature sensor 29 is less than a predetermined value n, the state is 2.
Proceeding from step 90 to step 93, the number of abnormal occurrences of the outside temperature sensor 30 is read from the EEPROM 282, and it is determined whether the number of abnormal occurrences is greater than or equal to a predetermined value n, and if it is greater than or equal to the predetermined value n, it is determined to be a failure. Then, in step 94, the bi/level mode display LED 356b is turned on, and in step 92, the auto mode display LED 352b is turned on.
If the number of abnormality occurrences of the outside temperature sensor 30 is equal to or less than the predetermined value n, the past failure diagnosis is skipped after flashing.Step 9
Step 3 proceeds to step 95, where the number of abnormal occurrences of the duct sensor 31 is read from the EEFROM 282, and it is determined whether the number of abnormal occurrences is greater than or equal to a predetermined value n. Lighting of the foot mode display LED 357b in step 96 and step 9
After the flashing of the auto mode display LED 352b in step 2,
If the number of abnormality occurrences of the duct sensor 31 is less than or equal to a predetermined value n, the past failure diagnosis is skipped.
Proceeding to step 97, the number of abnormal occurrences of the air mix door potentiometer 34 is read from the EEPROM 282, and it is determined whether the number of abnormal occurrences is greater than or equal to a predetermined value n. In addition to ¥4, the LED 359b for differential mode display in step 2-button 98 is lit and the LED 352b for auto mode display in step 92 is lit.
If the number of abnormalities in the air mix door potentiometer 34 is less than or equal to a predetermined value n, the process advances from step 97 to step 99, and in step 99, the vent mode display LED 355b is turned on. LED for displaying outside air introduction mode for next step 100
354b and, in the next step ioi, the automatic display LED 352b is turned on, and the past failure diagnosis is extracted. The predetermined value n is selected to be, for example, about 10 times, taking into account the number of times the part to be diagnosed is attached and detached during repairs and inspections. Further, the predetermined value n may be a different value depending on each location to be diagnosed based on the empirical rule of the number of times of attachment/detachment due to repairs, etc. According to such past failure diagnosis,
Abnormalities caused by attachment and detachment of the part to be diagnosed during inspection etc. can be absorbed as the number of abnormalities occurring within a predetermined value n, and abnormalities that lack reproducibility such as contact failures that occurred before the time of diagnosis can be efficiently diagnosed. By flashing the auto display LED 352b and lighting the display LED corresponding to the failure location, it is possible to recognize that a failure has occurred and the failure location before diagnosis. LED355b, LED for displaying outside air introduction mode
354b and the auto display LED 352b, it is possible to recognize that all the diagnosed points were normal before diagnosis.

In the embodiment described above, the current fault diagnosis and the past fault diagnosis are selectively selected by the compressor switch, but the configuration is simplified by displaying both of them overlapping each other without making a selection. Furthermore, a conventionally known reset means for resetting the number of abnormal occurrences when the number of abnormal occurrences exceeds a predetermined value can be added.

[Effects of the Invention] As explained above, according to the present invention, the location to be diagnosed where an abnormality has occurred before the fault diagnosis and the number of times the abnormality has occurred are stored in a rewritable non-volatile memory, and the abnormality is detected during the fault diagnosis. Since the number of occurrences exceeding a predetermined value is determined as a failure and displayed, abnormalities caused by attaching and detaching the part to be diagnosed during repair and inspection can be absorbed as the number of abnormality occurrences within the predetermined value. This makes it possible to efficiently diagnose abnormalities that lack reproducibility, such as poor contact, that occurred before the time of diagnosis. It is possible to provide a failure diagnosis device for a vehicle air conditioning system that is effective in diagnosing only abnormalities as failures.

[Brief explanation of the drawing]

Fig. 11 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 block diagram of the operation panel of Fig. 2. Control flowchart of the configuration of
Figure 5 is a control flowchart of the current fault diagnosis in Figure 4;
FIG. 6 is a control flow chart of the past failure diagnosis shown in FIG. 1... Duct 2... Blower 3... Evaporator 4... Heater core 5... Control unit 6... Air mix door 8... Intake door lO... Differential door 11... Vent door 12 ...Floor door 18...Compressor
28...Control unit 282...EEPROM 2
9... Room temperature sensor 30... Outside temperature sensor 31.
...Duct sensor 32...Solar radiation sensor 33...
Water temperature switch 34...Air mix door potency recognition meter 35...Operation panel

Claims (1)

[Claims] An anomaly detection means for detecting an abnormality in a part to be diagnosed in a vehicle air conditioning system and a part to be diagnosed where an abnormality has occurred, and based on the detection by the abnormality detection means, it is possible to count and rewrite the number of times an abnormality has occurred in the part to be diagnosed. an arithmetic storage means for storing in a non-volatile memory a diagnostic location where an abnormality has been detected and the number of times the abnormality has occurred at the diagnostic location; a failure determining means for determining a diagnosed point having a predetermined value or more as a failure, and determining a diagnosed point having an abnormality at the time of requesting the failure diagnosis as a failure based on the detection by the abnormality detecting means; 1. A failure diagnosis device for a vehicle air conditioning system, comprising display means for displaying a location to be diagnosed that is determined to be a failure by the means.