JP7309532B2 - Anomaly detector - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detection device for detecting an abnormality in a feed pump that draws up fuel from a fuel tank.

2. Description of the Related Art In recent years, a vehicle such as a truck equipped with a diesel engine is known that uses part of fuel sucked up by a feed pump to lubricate a driving system (see, for example, Patent Document 1).

JP-A-2000-249027

By the way, in order to ensure the lubrication of the driving system, it is necessary to lubricate using a highly clean fuel. High-cleanliness fuel is obtained by filtering the fuel sucked up by the feed pump with a fuel filter. However, even if a fuel filter with high filtration efficiency is used, it is difficult to prevent contamination of the fuel during regular replacement of the fuel filter or replacement of related parts. In addition, since fuel enters the feed pump before it is filtered by the fuel filter, if foreign matter is mixed with the fuel, the foreign matter may enter the feed pump, causing seizure or abnormal wear due to the foreign matter being dragged by the fuel, possibly resulting in damage to the feed pump. . If the feed pump is damaged, it may lead to engine malfunction such as engine stall or inability to restart. On the other hand, it is difficult for drivers to foresee engine malfunctions, so in order to prevent damage to the feed pump, they are relying on improving the contamination resistance of the feed pump itself and educational activities on preventing foreign matter from entering during maintenance. is the current situation.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an abnormality detection device capable of detecting an abnormality in a feed pump at an early stage.

An abnormality detection device according to the present invention includes a fuel tank, a feed pump communicating with the fuel tank to suck up fuel from the fuel tank, a fuel filter communicating with the feed pump to filter the fuel sucked by the feed pump, and a fuel tank. A first temperature sensor that detects the temperature of the fuel supplied from the feed pump to the feed pump, a second temperature sensor that detects the temperature of the fuel supplied from the feed pump to the fuel filter, and a fuel temperature detected by the first temperature sensor and an abnormality determination unit that determines abnormality of the feed pump based on the temperature of the fuel detected by the second temperature sensor.

In this abnormality detection device, when foreign matter is mixed in the fuel, the foreign matter gets caught in the feed pump, causing the feed pump to generate heat. As a result, the temperature of the fuel discharged from the feed pump is higher than the temperature of the fuel supplied to the feed pump. And this tendency increases with the lapse of time. Therefore, by comparing the temperature of the fuel supplied from the fuel tank to the feed pump with the temperature of the fuel supplied from the feed pump to the fuel filter, it is possible to determine whether the feed pump is abnormal. That is, if the fuel temperature detected by the second temperature sensor is higher than the fuel temperature detected by the first temperature sensor by a predetermined threshold value or more, it can be determined that the feed pump is abnormal. As a result, an abnormality in the feed pump can be detected early.

A first temperature sensor detects the temperature of fuel in the vicinity of the feed pump in a first flow path of fuel from the fuel tank to the feed pump, and a second temperature sensor detects a second flow path of fuel from the feed pump to the fuel filter. , the temperature of the fuel may be detected in the vicinity of the feed pump. Upstream and downstream of the feed pump, the temperature of the fuel can vary with distance from the feed pump. Therefore, in this abnormality detection device, the first temperature sensor and the second temperature sensor detect the temperature of the fuel in the vicinity of the feed pump, so that the abnormality detection accuracy of the feed pump can be further improved.

The first temperature sensor and the second temperature sensor may be attached to the feed pump. In this abnormality detection device, the first temperature sensor and the second temperature sensor are attached to the feed pump so that the first temperature sensor and the second temperature sensor detect the temperature of the fuel at the inlet and outlet of the feed pump. can be done. Therefore, the feed pump abnormality detection accuracy can be further improved, and the device can be miniaturized.

The apparatus may further include an abnormality processing section that performs abnormality processing to reduce the rotation speed of the engine when the abnormality determination section determines that the feed pump is abnormal. In this abnormality detection device, when the abnormality determination section determines that the feed pump is abnormal, the abnormality detection section executes the abnormality processing section to reduce the rotation of the engine. can do.

A pressure-feeding pump that communicates with the feed pump and pressure-feeds the fuel filtered by the fuel filter, and a common rail that communicates with the pressure-feeding pump and supplies the fuel pressure-fed from the pressure-feeding pump to the plurality of fuel injection devices. good. In this abnormality detection device, by providing the pressure feed pump and the common rail, it is possible to supply fuel of uniform pressure to the plurality of fuel injection devices.

ADVANTAGE OF THE INVENTION According to this invention, abnormality of a feed pump can be detected early.

1 is a schematic configuration diagram of an abnormality detection device according to an embodiment; FIG. 1 is a block diagram showing the functional configuration of an abnormality detection device according to an embodiment; FIG. 4 is a graph showing an example of the relationship between normal fuel temperature and passage of time; FIG. 5 is a graph showing an example of the relationship between the temperature of fuel at the time of abnormality and the passage of time; FIG. It is a flow chart which shows operation of the abnormality detection device concerning an embodiment.

Preferred embodiments of the present invention will now be described in detail with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

As shown in FIGS. 1 and 2, the abnormality detection device 1 of the present embodiment includes a fuel tank 2, a feed pump 3, a pumping pump 4, a fuel filter 5, a common rail 6, and a plurality of fuel injection devices 7. , a first temperature sensor 8 , a second temperature sensor 9 , an abnormality determination section 10 , and an abnormality processing section 11 . The feed pump 3 and pressure feed pump 4 are unitized as a supply pump 12, for example. However, the feed pump 3 and pressure-feeding pump 4 may be configured separately without being unitized as the supply pump 12 .

The feed pump 3 is a low-pressure pump that communicates with the fuel tank 2 and sucks up fuel from the fuel tank 2 . A flow path 13 through which fuel flows is formed between the fuel tank 2 and the feed pump 3 , and the feed pump 3 sucks up fuel from the fuel tank 2 through the flow path 13 . The feed pump 3 also feeds the fuel to the pressure feed pump 4 through a flow path 14 formed in the supply pump 12 . Examples of the feed pump 3 include a tocoloid pump.

The pressure-feeding pump 4 is a high-pressure pump that is communicated with the feed pump 3 and pressure-feeds the fuel sucked up by the feed pump 3 to the common rail 6 . A flow path 15 through which fuel flows is formed between the pressure-feeding pump 4 and the common rail 6 , and the pressure-feeding pump 4 pressure-feeds the fuel to the common rail 6 through the flow path 15 . The pressure feed pump 4 pressurizes the fuel supplied from the feed pump 3 to 200 to 250 MPa, for example, and feeds it to the common rail 6 . For example, a plunger can be used as the pressure-feeding pump 4 .

The fuel filter 5 is a filtering device that is communicated with the feed pump 3 and filters the fuel sucked up by the feed pump 3 . Between the feed pump 3 and the fuel filter 5, a channel 16 and a channel 17 through which fuel flows are formed. The fuel sent out from the feed pump 3 is supplied to the fuel filter 5 through the flow path 16 and filtered by the fuel filter 5 . The fuel filtered by the fuel filter 5 is returned to the feed pump 3 through the flow path 17 and then sent out to the pressure pump 4 through the flow path 14 . That is, the feed pump 3 feeds the fuel sucked up from the fuel tank 2 to the fuel filter 5 to be filtered by the fuel filter 5 , and then feeds the fuel filtered by the fuel filter 5 to the pressure feed pump 4 .

Between the feed pump 3 and the fuel tank 2, a passage 18 passing through a drive system such as a crankshaft is formed. return to fuel tank 2 through . The fuel supplied to the flow path 18 serves to lubricate the drive system.

The common rail 6 temporarily stores the fuel pressure-fed from the pressure-feeding pump 4 and supplies high-pressure fuel to the plurality of fuel injection devices 7 . A flow path 19 through which fuel flows is formed between the common rail 6 and the fuel injection device 7 , and fuel is supplied from the common rail 6 to the fuel injection device 7 through the flow path 19 . Between the common rail 6 and the fuel tank 2, a flow passage 20 is formed through which fuel flows. 2.

A plurality of fuel injection devices 7 are provided corresponding to each cylinder of the engine. The fuel injection device 7 injects high-pressure fuel supplied from the common rail 6 into a cylinder of the engine or into an intake pipe following the cylinder. A flow passage 21 through which fuel flows is formed between the fuel injection device 7 and the fuel tank 2 , and the fuel returned from the fuel injection device 7 is returned to the fuel tank 2 through the flow passage 21 .

The first temperature sensor 8 is a temperature sensor that detects the temperature T1 of fuel supplied from the fuel tank 2 to the feed pump 3 . That is, the first temperature sensor 8 detects the temperature T1 of the fuel in the fuel flow path 13 flowing from the fuel tank 2 to the feed pump 3 . Here, in the flow path 13 positioned on the upstream side of the feed pump 3, the temperature T1 of the fuel may change as the distance from the feed pump 3 increases. Therefore, it is preferable to detect the fuel temperature T1 in the vicinity of the feed pump 3 . Therefore, the first temperature sensor 8 may be attached to, for example, the feed pump 3 or the supply pump 12 to detect the fuel temperature T1 at the inlet of the feed pump 3 in the flow path 13 . The first temperature sensor 8 transmits the detected fuel temperature T<b>1 to the abnormality determination unit 10 .

The second temperature sensor 9 is a temperature sensor that detects the temperature T2 of fuel supplied from the feed pump 3 to the fuel filter 5 . That is, the second temperature sensor 9 detects the temperature T2 of fuel in the flow path 16 of fuel flowing from the feed pump 3 to the fuel filter 5 . Here, in the flow path 16 located downstream of the feed pump 3, the temperature T2 of the fuel may change as the distance from the feed pump 3 increases. Therefore, it is preferable to detect the fuel temperature T2 in the vicinity of the feed pump 3 . Therefore, the second temperature sensor 9 may be attached to, for example, the feed pump 3 or the supply pump 12 to detect the fuel temperature T2 at the outlet of the feed pump 3 in the flow path 16 . The second temperature sensor 9 transmits the detected fuel temperature T<b>2 to the abnormality determination unit 10 .

The abnormality determination section 10 is electrically connected to the first temperature sensor 8 and the second temperature sensor 9 . The abnormality determination unit 10 determines abnormality of the feed pump 3 based on the fuel temperature T<b>1 detected by the first temperature sensor 8 and the fuel temperature T<b>2 detected by the second temperature sensor 9 . The abnormality determination unit 10 is configured by, for example, an ECU [Electronic Control Unit]. The ECU is an electronic control unit having a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like. In the ECU, programs stored in the ROM are loaded into the RAM and executed by the CPU to perform various controls. The ECU may consist of a plurality of electronic control units.

Here the fuel is also slightly pressurized by the feed pump 3 . Therefore, the fuel is pressurized by the feed pump 3 and heated when passing through the feed pump 3 . The pressurization of the fuel by the feed pump 3 is, for example, about 1 MPa. When the feed pump 3 is normal, as shown in FIG. 3, the temperature rise when the fuel passes through the feed pump 3 is not greatly affected by the passage of time. That is, the temperature T1 of the fuel supplied to the feed pump 3 and the temperature T2 of the fuel discharged from the feed pump 3 are maintained within a predetermined range over time.

However, if foreign matter is mixed in the fuel, the foreign matter gets caught in the feed pump 3 and the feed pump 3 generates heat. As a result, the temperature T2 of the fuel discharged from the feed pump 3 becomes higher than the temperature T1 of the fuel supplied to the feed pump 3, as shown in FIG. The tendency for the temperature T2 to become higher than the temperature T1 increases with the lapse of time. Therefore, by comparing the temperature T1 of the fuel supplied from the fuel tank 2 to the feed pump 3 and the temperature T2 of the fuel supplied from the feed pump 3 to the fuel filter 5, it is possible to determine whether the feed pump 3 is abnormal. It is possible to determine whether

Therefore, when the fuel temperature T2 detected by the second temperature sensor 9 is less than the fuel temperature T1 detected by the first temperature sensor 8 and not equal to or higher than a predetermined threshold value T, the abnormality determination unit 10 determines that the feed pump 3 is operating normally. It is determined that On the other hand, when the fuel temperature T2 detected by the second temperature sensor 9 is higher than the fuel temperature T1 detected by the first temperature sensor 8 by a predetermined threshold value T or more, the abnormality determination unit 10 determines that the feed pump 3 is Judged as abnormal. It should be noted that the predetermined threshold value T can be appropriately set according to the specification of the engine, the criteria for judging abnormality of the feed pump 3, and the like.

If the feed pump 3 malfunctions, there is a high possibility that the compressing pump 4 and the supply pump 12 malfunction as well. Therefore, when the abnormality detection device 1 determines that the feed pump 3 is abnormal, it may also determine that the pressure-feeding pump 4 and the supply pump 12 are abnormal.

The abnormality processing unit 11 performs abnormality processing for reducing the rotation of the engine when the abnormality determination unit determines that the feed pump is abnormal. As the abnormality processing, the engine ECU is controlled to reduce the engine speed or the engine speed to a predetermined value or less, and the display device or the audio output device instructs the driver to reduce the engine speed or the vehicle speed. A process of notifying with an image or sound, or the like can be mentioned. The abnormality processing unit 11 is configured by an ECU, for example. When the abnormality determination unit 10 and the abnormality processing unit 11 are configured by an ECU, the abnormality determination unit 10 and the abnormality processing unit 11 may be configured by the same ECU, or may be configured by different ECUs. .

Next, the processing operation of the abnormality detection device 1 of this embodiment will be described with reference to FIG.

As shown in FIG. 5, the first temperature sensor 8 detects the temperature T1 of the fuel supplied from the fuel tank 2 to the feed pump 3 (step S1). Also, the second temperature sensor 9 detects the temperature T2 of the fuel supplied from the feed pump 3 to the fuel filter 5 (step S2).

Next, the abnormality determination unit 10 determines abnormality of the feed pump 3 based on the fuel temperature T1 detected by the first temperature sensor 8 and the fuel temperature T2 detected by the second temperature sensor 9 . That is, the abnormality determination unit 10 determines whether or not the value obtained by subtracting the fuel temperature T1 detected by the first temperature sensor 8 from the fuel temperature T2 detected by the second temperature sensor 9 is equal to or greater than the predetermined threshold value T. Determine (step S3). Then, when it is determined in step S3 that the value obtained by subtracting the temperature T1 from the temperature T2 is less than the predetermined threshold value T (step S3: NO), the process is temporarily terminated, and the above process is repeated again from step S1. On the other hand, if it is determined in step S3 that the value obtained by subtracting the temperature T1 from the temperature T2 is equal to or greater than the predetermined threshold value T (step S3: YES), the abnormality determination unit 10 determines that the feed pump 3 is abnormal. The processing unit 11 performs abnormality processing (step S4). Then, the process is terminated once, and the above process is repeated again from step S1.

As described above, the abnormality detection device 1 of this embodiment compares the temperature T1 of the fuel supplied from the fuel tank 2 to the feed pump 3 with the temperature T2 of the fuel supplied from the feed pump 3 to the fuel filter 5. Thus, it is possible to determine whether or not the feed pump 3 is abnormal. That is, if the fuel temperature T2 detected by the second temperature sensor 9 is higher than the fuel temperature T1 detected by the first temperature sensor 8 by a predetermined threshold T or more, it is determined that the feed pump 3 is abnormal. be able to. As a result, an abnormality of the feed pump 3 can be detected early.

Further, on the upstream and downstream sides of the feed pump 3, the temperature of the fuel may change as the distance from the feed pump 3 increases. By detecting the temperature, the abnormality detection accuracy of the feed pump 3 can be further improved.

Also, by attaching the first temperature sensor 8 and the second temperature sensor 9 to the feed pump 3, the first temperature sensor 8 and the second temperature sensor 9 detect the temperature of the fuel at the inlet and outlet of the feed pump 3. can do. Therefore, it is possible to further improve the accuracy of detecting an abnormality of the feed pump 3, and furthermore, it is possible to reduce the size of the device.

Further, when it is determined that the feed pump 3 is abnormal, the abnormality processing section for reducing the rotation of the engine can be performed, so that the occurrence of engine malfunction due to the abnormality of the feed pump 3 can be suppressed.

Further, by providing the pressure pump 4 and the common rail 6, it is possible to supply the fuel of uniform pressure to the plurality of fuel injection devices 7. FIG.

When the compressing pump 4 is provided, the abnormality of the compressing pump 4 can be detected by comparing the temperature of the fuel on the upstream side and the downstream side of the compressing pump 4 . However, the temperature that the feed pump 3 raises by pressurizing the fuel is much smaller than the temperature that the pressure feed pump 4 raises by pressurizing the fuel. For this reason, compared with the case of detecting an abnormality of the pressure-feeding pump 4 by comparing the temperature of the fuel on the upstream side and the downstream side of the pressure-feeding pump 4, as in the present embodiment, it is possible to Abnormality detection accuracy can be significantly increased by comparing the temperature of the fuel to detect the abnormality of the feed pump 3 .

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be modified or applied to other things within the scope of not changing the gist of each claim. may

DESCRIPTION OF SYMBOLS 1... Abnormality detection apparatus 2... Fuel tank 3... Feed pump 4... Pressure feed pump 5... Fuel filter 6... Common rail 7... Fuel injection device 8... First temperature sensor 9... Second temperature sensor DESCRIPTION OF SYMBOLS 10... Abnormality determination part 11... Abnormality process part 12... Supply pump 13... Flow path (first flow path) 14... Flow path 15... Flow path 16... Flow path (second flow path) 17... Flow path 18... Flow path 19... Flow path 20... Flow path 21... Flow path.

Claims (6)

a fuel tank;
a feed pump communicating with the fuel tank and sucking up fuel from the fuel tank;
a fuel filter communicating with the feed pump and filtering the fuel sucked up by the feed pump;
a first temperature sensor that detects the temperature of the fuel supplied from the fuel tank to the feed pump;
a second temperature sensor that detects the temperature of the fuel supplied from the feed pump to the fuel filter;
an abnormality determination unit that determines abnormality of the feed pump based on the temperature of the fuel detected by the first temperature sensor and the temperature of the fuel detected by the second temperature sensor;
Anomaly detector. the first temperature sensor detects the temperature of the fuel in the vicinity of the feed pump in a first flow path of the fuel flowing from the fuel tank to the feed pump;
the second temperature sensor detects the temperature of the fuel in the vicinity of the feed pump in a second flow path of the fuel flowing from the feed pump to the fuel filter;
The abnormality detection device according to claim 1. wherein the first temperature sensor and the second temperature sensor are attached to the feed pump;
The abnormality detection device according to claim 1 . Further comprising an abnormality processing unit that performs abnormality processing for reducing engine speed when the abnormality determination unit determines that the feed pump is abnormal,
The abnormality detection device according to any one of claims 1 to 3. a pumping pump communicating with the feed pump and pumping the fuel filtered by the fuel filter;
a common rail that is communicated with the pressure-feeding pump and supplies the fuel pressure-fed from the pressure-feeding pump to a plurality of fuel injection devices;
The abnormality detection device according to any one of claims 1 to 4. a first flow path formed between the fuel tank and the feed pump for the feed pump to draw the fuel from the fuel tank;
a second flow path formed between the feed pump and the fuel filter for supplying the fuel delivered from the feed pump to the fuel filter;
a third flow path formed between the fuel filter and the feed pump for returning the fuel filtered by the fuel filter to the feed pump;
The abnormality detection device according to any one of claims 1 to 5.

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