JP2013068195A - Abnormality detection apparatus of fuel filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly detect clogging of a fuel filter without referring to a running distance or driving time.SOLUTION: A pressure sensor 14 is provided on one of an inlet side and an outlet side of the fuel filter 4 where the pressure drastically changes when fuel cannot pass through the fuel filter 4 with normal passing resistance. A temperature sensor 15 for detecting the temperature of fuel is provided in a proper position of a fuel path from a fuel tank 1 to the fuel filter 4. A control device 16 is further provided, which determines the clogging of the fuel filter 4 if the temperature detected by the temperature sensor 15 is the set temperature or higher when the pressure detected by the pressure sensor 14 shows a significant change exceeding a set pressure, and which determines that the fuel becomes like wax, if the detected temperature is lower than the set temperature.

Description

  The present invention relates to a fuel filter abnormality detection device.

  In general, a fuel filter in a vehicle engine is provided with a fuel filter that filters out foreign matter in the fuel, and the foreign matter is sent to the engine by removing the foreign matter in the fuel with the fuel filter. Therefore, stable engine performance is maintained in advance.

  Since the fuel filter accumulates foreign matters due to use over a long period of time and eventually becomes clogged, it is necessary to replace the fuel filter before reaching such clogging. The fuel filter elements are exchanged based on the travel distance and operation time of the vehicle. More specifically, when the travel distance reaches a predetermined km number or the operation time reaches a predetermined number of years. In such a case, the element is exchanged.

  Incidentally, as prior art document information related to clogging of this type of fuel filter, there is Patent Document 1 below.

JP 2006-283724 A

  However, there are various types of usage of vehicles. Especially in the case of transport vehicles such as trucks, there are vehicles with usage types that always run only on paved roads, and only on unpaved gravel roads. In addition, there are cases where the fuel filter is clogged quickly due to the use of poor fuel, so it is only necessary to decide the replacement time based on the distance traveled and the operating time. In some cases, the fuel filter may be clogged earlier, and the vehicle may be damaged by continuing to operate without recognizing that the fuel filter is clogged.

  The present invention has been made in view of the above circumstances, and an object thereof is to enable direct detection of clogging of a fuel filter without using a travel distance or an operation time as a guide.

  The present invention is provided with a pressure sensor on the side where the pressure largely fluctuates between the inlet side and the outlet side of the fuel filter when the fuel cannot pass through the fuel filter with a normal passage resistance, and from the fuel tank to the fuel filter. A temperature sensor for detecting the temperature of the fuel at an appropriate position in the fuel system to reach, if the detected temperature of the pressure sensor shows a large fluctuation exceeding the set pressure, and the detected temperature of the temperature sensor is equal to or higher than the set temperature The present invention relates to an abnormality detection device for a fuel filter, comprising a control device for determining clogging of the fuel filter and determining whether the fuel is waxed if the temperature is below the set temperature.

  Thus, in this way, when the fuel cannot pass through the fuel filter with a normal passage resistance, an excessive pressure fluctuation that occurs on either the inlet side or the outlet side of the fuel filter is captured by the pressure sensor. Abnormality can be determined, and the temperature of the fuel when the excessive pressure fluctuation is detected is detected by a temperature sensor. When the fuel temperature falls below the set temperature, the wax of the fuel When it is determined that there is a temporary increase in passage resistance due to liquefaction, and an excessive increase in pressure is detected under conditions where the fuel temperature is higher than the set temperature and fuel is not expected to be waxed Therefore, it is possible to determine that a continuous increase in passage resistance occurs due to clogging caused by foreign matter accumulated on the fuel filter.

  Further, in the present invention, the control device is configured to instruct the engine output limitation when it is determined that the fuel filter is clogged, or it is instructed to temporarily limit the engine output when it is determined that the fuel is waxed. In this case, when the fuel filter is clogged or the fuel is waxed, it is possible to avoid vehicle failure by limiting the engine output. It becomes possible.

  Further, in the present invention, it is preferable that the control device is configured to notify the driver of the determination result by the notification means, and in this way, the driver is notified of the abnormality and the unreasonable driving is restrained. In addition, it is possible to promote measures such as replacement of fuel filter elements.

  When the fuel filter is a positive pressure type, a pressure sensor is preferably provided on the inlet side of the fuel filter. When the fuel filter is a negative pressure type, a pressure sensor is provided on the outlet side of the fuel filter. A sensor is preferably provided.

  According to the fuel filter abnormality detection device of the present invention described above, various excellent effects as described below can be obtained.

  (I) According to the invention described in claim 1 of the present invention, based on the detected pressure of the pressure sensor and the detected temperature of the temperature sensor, the fuel filter is directly clogged without using the travel distance and the operation time as a guide. It is possible to detect automatically, and it is also possible to distinguish and detect temporary pressure fluctuations due to fuel waxing without confusion with clogging, so it is necessary to grasp the appropriate replacement time of the fuel filter element Therefore, it is possible to prevent problems such as vehicle failure by continuing to operate without recognizing that the fuel filter is clogged.

  (II) According to the second and third aspects of the present invention, when the fuel filter is clogged or the fuel is waxed, the output of the engine is limited to make it more reliable. In addition, vehicle failure can be avoided.

  (III) According to the invention described in claim 4 of the present invention, it is possible to notify the driver of abnormality and to restrain the unreasonable driving, and to promote measures such as replacement of the elements of the fuel filter. Therefore, a vehicle failure can be avoided more reliably.

  (IV) According to the invention described in claims 5 and 6 of the present invention, when the fuel cannot pass through the fuel filter with a normal passage resistance depending on whether the fuel filter is a positive pressure type or a negative pressure type. An abnormal pressure fluctuation can be reliably captured by arranging a pressure sensor on the side where the pressure fluctuates greatly.

It is the schematic which shows an example of the form which implements this invention. It is a flowchart which shows the concrete method of control in the control apparatus of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an example of an embodiment for carrying out the present invention, which is illustrated in the case of a fuel filter applied to a common rail type fuel injection device. The fuel in the fuel tank 1 is fed by the cam shaft of the supply pump 2. It is sucked up by the feed pump 3 that is driven, and foreign matter and the like are filtered through the fuel filter 4 and then sent to the supply pump 2, and the fuel boosted to a predetermined pressure by the supply pump 2 is supplied to the common rail 5. The pressure is supplied and stored.

  The fuel filter 4 is provided with an overflow valve 6, and when the internal pressure in the fuel filter 4 becomes a predetermined value or more, the overflow valve 6 is opened and the fuel passes through the overflow pipe 7 and the through feed pipe 8. Via the fuel tank 1.

  The supply pump 2 is provided with a through feed valve 9 for maintaining the fuel pressure in the common rail 5 at a predetermined pressure. When the internal pressure in the supply pump 2 exceeds a predetermined value, the through feed valve 9 is provided. 9 is opened so that the fuel is returned to the fuel tank 1 through the through feed pipe 8.

  Further, the high-pressure fuel in the common rail 5 is supplied to a plurality of injectors 11 provided for each cylinder of the engine via the injection pipe 10 and injected into the cylinders from the nozzles of the injectors 11. Of the fuel supplied to each injector 11, the fuel that has not been spent for injection into each cylinder is collected from each injector 11 into the leakage pipe 12 as leaked fuel, and passes through the through feed pipe 8. It is returned to the fuel tank 1.

  Further, a pressure limiter 13 is attached to the common rail 5, and when the pressure in the common rail 5 exceeds a predetermined value, the pressure limiter 13 opens and the fuel is supplied to the fuel tank 1 via the overflow pipe 7 and the through feed pipe 8. The pressure of the common rail 5 is maintained at a predetermined pressure.

  In this embodiment, a pressure sensor 14 for detecting the fuel pressure is provided on the inlet side of the fuel filter 4, and a temperature sensor 15 for detecting the temperature of the fuel is provided on the inlet side of the feed pump 3. The detection signals 14 a and 15 a from the pressure sensor 14 and the temperature sensor 15 are input to the control device 16.

  Here, since the temperature of the fuel is monitored by the temperature sensor 15 at the inlet side of the feed pump 3, existing equipment can be used for the temperature sensor 15. For a common rail type fuel injection device, it is only necessary to provide a new pressure sensor 14 substantially on the inlet side of the fuel filter 4.

  Further, in the control device 16, the abnormality of the fuel filter 4 is determined based on the detection signals 14a and 15a from the pressure sensor 14 and the temperature sensor 15, and more specifically, the flowchart of FIG. In step S1, it is determined whether or not the pressure detected by the pressure sensor 14 is equal to or higher than a predetermined set pressure. As long as the pressure falls below the set pressure, the process proceeds to “NO” and the determination is made. Repeated.

  Here, the set pressure in step S1 is determined as an allowable upper limit pressure for assuring the reliability of the feed pump 3, and when the fuel cannot pass through the fuel filter 4 with a normal passage resistance, the fuel is set. Abnormality is determined by catching an excessive pressure rise occurring on the entry side of the filter 4.

  On the other hand, if the detected pressure is equal to or higher than the predetermined set pressure, the process proceeds to “YES”, and whether or not the temperature detected by the temperature sensor 15 is equal to or higher than the predetermined set temperature in the next step S2. If the temperature is lower than the set temperature, the process proceeds to “NO” to reach step S3, where it is determined that the fuel is waxed, and the process proceeds to next step S4 to blink the indicator lamp 17 (notification means). And temporary engine output restriction is instructed.

  That is, even if the fuel cannot pass through the fuel filter 4 with a normal passage resistance and an excessive pressure rise is detected on the inlet side of the fuel filter 4, it is not always clogged with foreign matter accumulated on the fuel filter 4. It cannot be determined that there is.

  This is because, when the vehicle travels under a condition where the outside air temperature is low, the fuel system path from the fuel tank 1 to the fuel filter 4 is cooled by the traveling air, so that the fuel becomes wax and becomes a high viscosity state, and the fluidity of the fuel is remarkably increased. It is because it may become difficult to pass through the fuel filter 4 normally.

  Therefore, when the detected pressure of the pressure sensor 14 is equal to or higher than the set pressure and the detected temperature of the temperature sensor 15 is lower than the set temperature, the control device 16 determines that the fuel is waxed, and the indicator lamp 17 on the instrument panel. Command signals 17a and 18a are output to a fuel injection control device 18 that controls fuel injection by the injector 11 (the control device 16 that detects an abnormality of the fuel filter 4 may also serve as an indicator lamp 17). Flashing and temporary engine output limitation are instructed, and an abnormality notification to the driver and avoidance of vehicle failure are achieved. Since the waxing of the fuel is eliminated as the fuel temperature rises, the engine output restriction in this case may be temporary.

  If the temperature detected by the temperature sensor 15 is equal to or higher than the predetermined set temperature in the previous step S2, the process proceeds to “YES”. In step S5, it is determined that the fuel filter 4 is clogged, and the next step. Proceeding to S6, the lighting of the indicator lamp 17 and the engine output limit are instructed.

  In this case, since the pressure detected by the pressure sensor 14 is equal to or higher than the set pressure and the temperature detected by the temperature sensor 15 is equal to or higher than the set temperature, the pressure is excessively increased under conditions where no waxing of the fuel is assumed. Then, it is determined that the clogging due to the foreign matter accumulated on the fuel filter 4 is the cause, and command signals 17a and 18a are output to the indicator lamp 17 and the fuel injection control device 18 to turn on the indicator lamp 17 and limit the engine output. Is instructed to notify the driver of abnormality and avoid vehicle failure.

  Thus, in this way, when the fuel cannot pass through the fuel filter 4 with a normal passage resistance, the pressure sensor 14 captures an excessive pressure fluctuation that occurs on the inlet side of the fuel filter 4 to determine an abnormality. In addition, the temperature of the fuel when the excessive pressure fluctuation is captured is detected by the temperature sensor 15, and when the temperature of the fuel falls below the set temperature, the fuel is waxed. Only when it is determined that a temporary increase in passage resistance has occurred, and an excessive increase in pressure is detected under conditions where the fuel temperature is higher than the set temperature and the fuel is not expected to be waxed, It is possible to determine that a continuous increase in passage resistance has occurred due to clogging caused by foreign matter accumulated on the fuel filter 4.

  Therefore, according to the above embodiment, the clogging of the fuel filter 4 is directly detected based on the detected pressure of the pressure sensor 14 and the detected temperature of the temperature sensor 15 without using the travel distance and the operation time as a guide. In addition, temporary pressure fluctuations due to fuel waxing can be detected separately without being confused with clogging, so that it is possible to grasp the appropriate replacement time of the elements of the fuel filter 4 and By continuing to drive without recognizing that the filter 4 is clogged, it is possible to prevent problems such as vehicle failure.

  Further, particularly in the present embodiment, since the control device 16 is configured to limit the engine output when it is determined that the fuel filter 4 is clogged or the fuel is waxed, the fuel filter 4 is clogged. If the engine is waxed or the fuel is waxed, it is possible to more reliably avoid a vehicle failure by limiting the engine output.

  Furthermore, when the control device 16 determines that the fuel filter 4 is clogged or the fuel is waxed, the driver can be notified of the abnormality by turning on or flashing the indicator lamp 17 to restrain the unreasonable driving. Since measures such as replacement of the elements of the fuel filter 4 can be promoted, a vehicle failure can be avoided more reliably.

  In the embodiment described above, the case of the positive pressure type in which the fuel is pushed from the upstream side of the fuel filter 4 by the feed pump 3 and filtered is described. However, the feed pump 3, the fuel tank 1, In the case of the negative pressure type in which the fuel filter 4 is interposed between the fuel filter 4 and the feed pump 3 sucks and filters the fuel from the downstream side of the fuel filter 4, the fuel passes through the fuel filter 4 with a normal passage resistance. An abnormality may be determined by capturing an excessive pressure drop (negative pressure) that occurs on the outlet side of the fuel filter 4 when the fuel filter 4 cannot be used.

  Further, the fuel filter abnormality detection device of the present invention is not limited to the above-described embodiment, and the notification means may be an alarm buzzer or the like, and other within the scope not departing from the gist of the present invention. Of course, various changes can be made.

DESCRIPTION OF SYMBOLS 1 Fuel tank 4 Fuel filter 14 Pressure sensor 14a Detection signal 15 Temperature sensor 15a Detection signal 16 Control apparatus 17 Indicator lamp (notification means)
17a Command signal 18 Fuel injection control device 18a Command signal

Claims (6)

  When the fuel cannot pass through the fuel filter with a normal passage resistance, the fuel system is provided with a pressure sensor on the side where the pressure largely fluctuates between the inlet side and the outlet side of the fuel filter and from the fuel tank to the fuel filter A temperature sensor for detecting the temperature of the fuel at an appropriate position on the road, and when the detected pressure of the pressure sensor shows a large fluctuation exceeding the set pressure, the fuel filter eyes are detected if the detected temperature of the temperature sensor is equal to or higher than the set temperature. An abnormality detection device for a fuel filter, comprising: a control device for determining clogging and determining whether the fuel is waxed if the temperature is below the set temperature.   2. The fuel filter abnormality detection device according to claim 1, wherein when the control device determines that the fuel filter is clogged, the control device instructs to limit the output of the engine.   3. The fuel filter abnormality detection device according to claim 1, wherein the control device is configured to instruct a temporary output limitation of the engine when it is determined that the fuel is waxed.   The fuel filter abnormality detection device according to claim 1, 2 or 3, wherein the control device is configured to notify the driver of the determination result by a notification means.   5. The fuel filter abnormality detection device according to claim 1, wherein when the fuel filter is of a positive pressure type, a pressure sensor is provided on the inlet side of the fuel filter.   5. The fuel filter abnormality detection device according to claim 1, wherein when the fuel filter is a negative pressure type, a pressure sensor is provided on the outlet side of the fuel filter.

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