JP6533739B2 - Abnormality detection device for air cleaner - Google Patents

Description

  The present invention relates to an air cleaner abnormality detection device that detects clogging of an air cleaner.

  Conventionally, in an automobile, an abnormality detection device that detects clogging of the air cleaner using the fact that suction negative pressure, which is the pressure of air filtered by the air cleaner, changes in accordance with the degree of clogging of the air cleaner is It is equipped. As such an abnormality detection device, for example, Patent Document 1 discloses an abnormality detection device having a movable contact moving according to suction negative pressure, and a first contact and a second contact to which the movable contact can contact. In this abnormality detection device, when suction negative pressure corresponding to the first contact is generated, the movable contact moves to a position where it contacts the first contact to set the first contact in the ON state, and suction negative corresponding to the second contact When pressure is generated, the movable contact moves to a position where it contacts the second contact, and the second contact is set in the on state. Then, clogging of the air cleaner is detected based on on / off of the first contact and the second contact.

Unexamined-Japanese-Patent No. 8-319899

  However, in the abnormality detection device of Patent Document 1, for example, when the wire connected to the first contact is broken, the first contact is in the on state even if the movable contact is in contact with the first contact. It does not. Therefore, an abnormality detection device that detects clogging of the air cleaner based on the suction negative pressure is required to have a function of detecting disconnection of the wiring and clogging of the air cleaner.

  An object of the present invention is to provide an air cleaner abnormality detection device capable of detecting wire breakage and air cleaner clogging.

  The abnormality detection device of the air cleaner which solves the above-mentioned subject, when suction negative pressure which is the pressure of the air filtered by air cleaner exceeds setting pressure, the switch with which electricity supply is interrupted, and the amount of suctioned air which acquires suctioned air quantity It is detected that the wiring of the switch is broken on the condition that the acquisition unit and the switch are in the cut-off state and the amount of intake air is smaller than the determination value, and the switch is in the cut-off state And a processing unit configured to detect that the air cleaner is clogged on the condition that the amount of intake air is equal to or greater than a determination value.

  The switch is cut off if the switch wiring is broken due to a break in electrical wiring, connector connection failure, etc. or if the suction negative pressure exceeds the set pressure due to clogging of the air cleaner. is there. Further, the suction negative pressure when the air cleaner is clogged becomes larger as the amount of suctioned air is larger. Therefore, as in the above configuration, when the switch is in the shutoff state and the amount of intake air is smaller than the determination value, it can be determined that the switch is disconnected. Conversely, if the switch is in the shutoff state and the amount of intake air is equal to or greater than the determination value, it can be determined that the air cleaner is clogged. As described above, according to the above configuration, it is possible to detect the disconnection of the switch and the clogging of the air cleaner.

In the abnormality detection device for an air cleaner, it is preferable that the intake air amount acquisition unit is an air flow sensor.
According to the above configuration, the configuration of the intake air amount acquisition unit can be simplified.

In the abnormality detection device for an air cleaner, the processing unit may repeatedly determine whether or not the switch is restored to the energized state when it is detected that the wire of the switch is broken.
A break in the wiring of the switch may occur, for example, due to a contact failure of the connector. Such a disconnection may be caused by vibration during operation, but may be restored by vibration during operation. As described above, it is possible to detect that the switch has returned to the conductive state by repeatedly determining whether or not the switch returns to the conductive state after detecting the disconnection.

In the abnormality detection device for an air cleaner, it is preferable that the processing unit ends the processing when detecting that the air cleaner is clogged.
It is preferable that maintenance of the air cleaner be performed early if clogging of the air cleaner is detected. According to the above configuration, when clogging of the air cleaner is detected, a series of processing ends. Therefore, the means for notifying the user of the clogging of the air cleaner, for example, the warning light is maintained in the lighting state. As a result, it is possible to prompt the user for early maintenance.

  In the abnormality detection device for an air cleaner, the switch is supplied with power from a battery, and the processing unit acquires the state of the switch after the output voltage of the battery is stabilized after the engine is started. Is preferred.

  At the start of the engine and immediately after the start, the output voltage of the battery is unstable. Therefore, as in the above configuration, by acquiring the state of the switch after the output voltage of the battery is stabilized, the reliability of the detection result can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows schematic structure of the abnormality detection apparatus of the air cleaner of one Embodiment. The flowchart which shows the procedure of detection processing.

An embodiment of an air cleaner abnormality detection device will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the air taken in from the intake port 11 is taken into the engine 15 through the air cleaner 13 disposed in the intake passage 12. The air cleaner 13 is provided with an air filter that removes foreign matter contained in the intake air by filtering the intake air. The clogging of the air cleaner 13 is the clogging of the air filter described above, and is detected by the abnormality detection device 20 of the air cleaner.

The abnormality detection device 20 includes a switch 21 and an air flow sensor 22 between the air cleaner 13 and the engine 15 in the intake passage 12.
The switch 21 is connected to the battery 16, and the energized state is maintained when the suction negative pressure which is the pressure of the air filtered by the air cleaner 13 is equal to or less than the set pressure, and the suction negative pressure exceeds the set pressure. This is a normally closed switch that is in the shutoff state. The switch 21 is grounded via the ECU 25 and outputs a signal indicating the energized state to the ECU 25 when in the energized state, and stops the output of the signal to the ECU 25 when in the disconnected state. In addition, "negative pressure" here is the pressure on the negative side on the basis of atmospheric pressure, and the larger the pressure, the closer to vacuum, and the smaller, the closer to atmospheric pressure.

  The air flow sensor 22 functions as an intake air amount acquisition unit, detects an intake air amount Ga which is a mass flow rate of intake air flowing through the intake passage 12, and outputs a signal indicating the detected intake air amount Ga to the ECU 25.

  The ECU 25 mainly includes a microcomputer having a CPU, a ROM storing various control programs and various data such as determination values Gaj described later, and a RAM temporarily storing calculation results and various data in various calculations. Configured The ROM and the RAM are configured by the memory 27. The ECU 25 executes various processes based on various information acquired based on signals from various sensors etc. and various control programs and various data stored in the ROM.

  The ECU 25 functions as a processing unit, and detects an abnormality such as disconnection of the wiring of the switch 21 or clogging of the air cleaner 13 based on the signal from the switch 21 and the intake air amount Ga detected by the air flow sensor 22. Run. Here, “disconnection of the wiring of the switch 21” is, for example, a switch 21 due to a physical factor such as disconnection of an electrical wiring connecting the switch 21 and the battery 16 or connection failure of a connector connecting the electrical wirings. Is in the non-conductive state.

  In the detection process, the ECU 25 detects an abnormality when the output voltage of the battery 16 is unstable, when the reliability with respect to the output voltage of the battery 16 is low, and when the reliability with respect to the detection value of the air flow sensor 22 is low. Not detected That is, the ECU 25 is configured to be able to detect an abnormality in a state in which the following conditions are satisfied.

The starter for starting the engine 15 is not in operation. A predetermined time has elapsed since the start of the engine 15. The output voltage of the battery 16 is normally judged in the abnormality judgment processing of the battery 16. Airflow In the abnormality determination process of the sensor 22, it is determined that the detection value of the air flow sensor 22 is normal.

  In the detection process, when the ECU 25 detects that the wire of the switch 21 is disconnected, the ECU 25 writes a code indicating the disconnection of the switch 21 in a predetermined area of the memory 27 together with the detection time. Further, the ECU 25 lights the warning light 31 installed in the meter panel 30 to notify the user that the wiring of the switch 21 is broken.

  In the detection process, when detecting that the air cleaner 13 is clogged, the ECU 25 writes a code indicating the clogging of the air cleaner 13 in a predetermined area of the memory 27 together with its detection timing. Further, the ECU 25 calculates the degree of clogging of the air cleaner 13 based on, for example, the operating state of the engine 15 when the switch 21 is in the shutoff state, and sets the replacement time of the air cleaner 13 based on the calculation result. Do. Then, the ECU 25 turns on the warning lamp 31 installed on the meter panel 30 and displays a message indicating the set replacement time on the display unit 32 to prevent the air cleaner 13 from being clogged. Notify

  The procedure of the detection process performed by the ECU 25 will be described with reference to FIG. The ECU 25 immediately stops the detection process when the abnormality determination is made in a process different from the detection process such as the abnormality determination process of the air flow sensor 22 or the abnormality determination process of the battery 16. In addition, ECU25 may perform these abnormality determination processings, and another ECU may perform.

  As shown in FIG. 2, the ECU 25 first determines whether or not a predetermined time has elapsed from the start of the engine 15 (step S10), and when the predetermined time has elapsed (step S10: YES), the process of the next step S11 Migrate to In the next step S11, the ECU 25 obtains the state of the switch 21 and determines whether the switch 21 is in an energized state. When the switch 21 is in the energized state (step S11: YES), the ECU 25 determines that the wiring of the switch 21 is not broken and the air cleaner 13 is not clogged normally (step S12). ), Return to the process of step S11.

On the other hand, when the switch 21 is in the cutoff state (step S11: NO), the ECU 25 determines whether the intake air amount Ga is smaller than the determination value Gaj (step S13).
Here, when the air cleaner 13 is clogged, the suction negative pressure decreases as the suction air amount Ga decreases, and conversely, the suction negative pressure increases as the suction air amount Ga increases. That is, when the switch 21 changes to the shutoff state when the intake air amount Ga is small, there is a high possibility that the wiring of the switch 21 is broken rather than the clogging of the air cleaner 13. The determination value Gaj is a value for determining whether the interruption of the energization state of the switch 21 is due to the disconnection of the wiring of the switch 21 or the clogging of the air cleaner 13. The determination value Gaj is set based on, for example, the results of experiments and simulations which were previously performed on the non-clogged air cleaner 13 and the clogged air cleaner 13 as targets.

  When the intake air amount Ga is smaller than the determination value Gaj (step S13: YES), the ECU 25 detects that the wire of the switch 21 is broken (step S14). When the ECU 25 detects a break in the wiring of the switch 21, the ECU 25 writes a code indicating the break in the memory 27 together with the detection time (step S15). Then, the ECU 25 notifies the user that the wiring of the switch 21 is broken by lighting the warning light 31 (step S16). At this time, the ECU 25 may display on the display unit 32 a message indicating that the wire of the switch 21 is broken.

  In the next step S17, the ECU 25 repeatedly determines whether the switch 21 has returned to the energized state. Then, when the switch 21 returns to the energized state (step S17: YES), the ECU 25 controls the warning light 31 to the off state (step S18), and returns to the process of step S11. At this time, the ECU 25 may write that the switch 21 has returned to the conductive state in a predetermined area of the memory 27.

  On the other hand, when the intake air amount Ga is equal to or greater than the determination value Gaj (step S13: NO), the ECU 25 detects that the air cleaner 13 is clogged (step S19). The ECU 25 writes a code indicating clogging of the air cleaner 13 in the memory 27 together with its detection time (step S20). Then, the ECU 25 turns on the warning lamp 31 (step S21), calculates the replacement time of the air cleaner 13, and displays the calculated replacement time on the display unit 32 (step S22). Thereby, the ECU 25 notifies the user of the clogging of the air cleaner 13 and ends the detection process. When the detection processing is completed through step S22, the warning light 31 is maintained in the lit state during the operation of the engine 15, unless the release operation by the mechanic is performed.

The operation of the air cleaner abnormality detection device having the above-described configuration will be described.
In the above-described abnormality detection device 20, a normally closed switch 21 is used. Then, when the switch 21 is in the shutoff state, it is judged based on the intake air amount Ga at that time whether it is the shutoff due to the disconnection of the wiring of the switch 21 or the shutoff due to the clogging of the air cleaner 13. Do. Accordingly, the abnormality detection device 20 can detect the disconnection of the wiring of the switch 21 and the clogging of the air cleaner 13 separately.

According to the abnormality detection device for an air cleaner of the above embodiment, the following effects can be obtained.
(1) Using a normally closed switch as the switch 21 and based on the intake air amount Ga when the switch 21 is deenergized, disconnection of the wiring of the switch 21 and clogging of the air cleaner 13 It can be detected separately.

  (2) The ECU 25 acquires the intake air amount Ga based on the signal from the air flow sensor 22. Thus, the intake air amount Ga can be obtained without using the air flow sensor 22. For example, compared with the configuration in which the intake air amount Ga is calculated based on the pressure difference at the orifice installed in the intake passage 12, The quantity Ga can be obtained with a simple configuration.

  (3) The disconnection of the wiring of the switch 21 may occur due to the connection failure of the connector connected to the switch 21. The connection failure of the connector may be recovered due to the vibration during operation of the engine 15. Therefore, if the warning light 31 is maintained in the lighting state even if the disconnection of the wiring of the switch 21 is detected once, and the user is requested to perform maintenance, the user is forced to perform excessive maintenance. In this point, in the abnormality detection device 20, when the disconnection of the wiring of the switch 21 is detected, the ECU 25 repeatedly determines whether the switch 21 returns to the energized state. Then, when the switch 21 is returned to the energized state, the ECU 25 turns off the warning light 31 as being in the normal state. According to such a configuration, the frequency of maintenance caused by the disconnection of the wiring of the switch 21 can be reduced.

  (4) When the ECU 25 detects clogging of the air cleaner 13, the detection process is ended. Therefore, the warning light 31 is maintained in the lit state during operation of the engine 15, unless the maintenance operation of the air cleaner 13 is performed to release the warning light 31. Therefore, it is possible to prompt the user for the early maintenance of the air cleaner 13.

(5) The ECU 25 acquires the state of the switch 21 after the output voltage of the battery 16 is stabilized. This can increase the reliability of the result of the detection process.
(6) When the air flow sensor 22 or the battery 16 is determined to have an abnormality, the ECU 25 stops the execution of the detection process. That is, the ECU 25 does not execute the detection process when the reliability with respect to the output voltage of the battery 16 or the detection value of the airflow sensor 22 is low. This increases the confidence in the result of the detection process.

  (7) The warning light 31 is turned on when the disconnection of the wiring of the switch 21 is detected, and the warning light 31 is turned on when the clogging of the air cleaner 13 is detected, and the replacement time is displayed on the display unit 32. Ru. That is, the method of notifying the user is different between the disconnection of the switch 21 and the clogging of the air cleaner 13. Thereby, the user can determine the abnormality due to the lighting of the warning light 31.

In addition, the said embodiment can also be changed suitably as follows and can also be implemented.
The determination as to whether or not the output voltage of the battery 16 is stable is not limited to the time from the start of the engine 15, but may be determined based on, for example, a measured value of the output voltage.

  When the starter is operated to start the engine 15, it is rare that the power supply from the battery 16 to the switch 21 is interrupted due to factors other than the disconnection of the wiring of the switch 21. Therefore, in the detection process, the process in which the process of step S10 is omitted may be started immediately after the start of the engine 15.

  After detecting clogging of the air cleaner 13, the ECU 25 may determine whether the switch 21 is maintained in the shutoff state. According to such a configuration, the longer the lighting time of the warning light 31 is, the more accurate the clogging with the air cleaner 13 is.

  The ECU 25 may terminate the detection process when it detects a wire breakage of the switch 21 or a clogging of the air cleaner 13. According to such a configuration, when the ECU 25 detects an abnormality, the warning lamp 31 continues to be lit, which can prompt the user to perform early maintenance.

The intake air amount acquisition unit may be configured to acquire the amount of air taken by the engine 15, and is not limited to the air flow sensor 22.
For example, in the engine 15 that does not have an EGR device that recirculates a portion of exhaust gas to the intake passage 12, the intake air amount acquisition unit acquires the air amount calculated from the engine speed as the intake air amount Ga Good. Further, in the engine 15 that does not include the EGR device and has the throttle valve in the intake passage 12, the intake air amount acquisition unit calculates the amount of air calculated from the engine speed and the accelerator opening as the intake air amount Ga. It may be acquired as

  Also, for example, in the engine 15 provided with the EGR device, the intake air amount acquisition unit acquires a value obtained by subtracting the amount of EGR gas recirculated to the intake passage 12 from the amount of working gas intake by the engine 15 as the intake air amount Ga It is also good. In this configuration, the intake air amount acquisition unit can calculate the working gas amount from the equation of state based on the pressure and temperature of the working gas that the engine 15 sucks. Further, the intake air amount acquisition unit can calculate the amount of EGR gas from the flow amount calculation formula of the compressible fluid based on the opening degree of the EGR valve, the pressure difference in the EGR valve, the temperature of the working gas, and the like.

  Also, for example, in an engine provided with an EGR device in which an EGR passage is connected upstream of the DPF that captures particulate matter contained in exhaust gas, the intake air amount acquisition unit is calculated based on the pressure difference in the DPF The value may be acquired as the intake air amount Ga.

  The abnormality detection device 20 may be applied to, for example, the engine 15 including a turbocharger configured of a turbine disposed in the exhaust passage and a compressor disposed in the intake passage 12. In such a case, the switch 21 and the air flow sensor 22 are located between the air cleaner 13 and the compressor.

  The method of notifying the user that an abnormality has been detected is such that the user can distinguish between the disconnection of the wiring of the switch 21 and the clogging of the air cleaner 13 according to the lighting state of the warning light 31, for example, blinking and continuous lighting. It may be of any configuration.

  The method of notifying the user that an abnormality has been detected is not limited to the method of appealing to the user's sight such as the warning light 31. For example, the method of appealing to the user's hearing such as alarm sound or voice may be used. Alternatively, these visual and auditory methods may be combined.

  In the above embodiment, when the condition that the switch 21 is in the cutoff state and the intake air amount Ga is smaller than the determination value Gaj (step S11: NO, step S13: YES) is the condition 1, the ECU 25 satisfies the condition The wire breakage of the switch 21 was detected when 1 was satisfied. Further, when the condition that the switch 21 is in the cutoff state and the intake air amount Ga is equal to or larger than the determination value Gaj (step S11: NO, step S13: NO) is condition 2, the ECU 25 satisfies condition 2 Clogged air cleaner 13 was detected.

  Not limited to this, the ECU 25 may detect the disconnection of the wiring of the switch 21 when the condition 2 is satisfied after the satisfaction of the condition 1 or when the condition 1 is satisfied after the satisfaction of the condition 2 . That is, the ECU 25 may detect the disconnection of the wiring of the switch 21 by keeping the switch 21 in the shutoff state regardless of the intake air amount Ga.

  When the condition that the switch 21 returns to the energized state is condition 3 when the intake air amount Ga becomes smaller than the determination value Gaj, the ECU 25 continues the condition 3 after the condition 2 is satisfied. The clogging of the air cleaner 13 may be detected. That is, the ECU 25 causes the switch 21 to be in the cutoff state when the intake air amount Ga is equal to or greater than the determination value Gaj, and causes the switch 21 to be in the conduction state when the intake air amount Ga is smaller than the determination value Gaj. The clogging of the cleaner 13 may be detected.

  DESCRIPTION OF SYMBOLS 11 ... Air intake, 12 ... Air intake passage, 13 ... Air cleaner, 15 ... Engine, 16 ... Battery, 20 ... Abnormality detection apparatus, 21 ... Switch, 22 ... Air flow sensor, 25 ... ECU, 27 ... Memory, 30 ... Meter panel , 31 ... warning light, 32 ... display part.

Claims (5)

A switch that is deenergized when a suction negative pressure, which is a pressure of air filtered by the air cleaner, exceeds a set pressure;
An intake air amount acquisition unit for acquiring an intake air amount;
It is detected that the wire of the switch is broken on the condition that the switch is in the shutoff state and the intake air amount is smaller than the determination value, and the switch is in the shutoff state, and And a processing unit that detects that the air cleaner is clogged on the condition that the intake air amount is equal to or greater than a determination value. The air cleaner abnormality detection device according to claim 1, wherein the intake air amount acquisition unit is an air flow sensor. The air cleaner abnormality detection device according to claim 1, wherein the processing unit repeatedly determines whether or not the switch returns to the energized state when it detects that the wiring of the switch is broken. The air cleaner abnormality detection device according to any one of claims 1 to 3, wherein the processing unit terminates the process when detecting that the air cleaner is clogged. The switch is powered by the battery,
The air cleaner abnormality detection device according to any one of claims 1 to 4, wherein the processing unit acquires the state of the switch after the output voltage of the battery is stabilized after the engine is started.