JP2022133738A - Abnormality detection system - Google Patents

Abstract

To provide a technique which can accurately detect an abnormality of a fuel supply device, in the fuel supply device in which a pressure regulator is arranged.SOLUTION: An abnormality detection device comprises: a fuel pump for discharging fuel by the rotation of a motor; a fuel supply passage for supplying the fuel discharged from the fuel pump to an engine; a discharge passage for discharging a part of the fuel flowing in the fuel supply passage; a pressure regulator for opening and closing the discharge passage, and discharging the fuel from the discharge passage by being brought into an open state from a closed state when the pressure of the fuel in the fuel supply passage reaches prescribed allowable pressure or higher; and a control part. When the pressure regulator is in the open state, the control part detects a characteristic value indicating an operation state of the fuel pump, and detects an abnormality of the fuel supply device by comparing the detected characteristic value and a preset threshold.SELECTED DRAWING: Figure 1

Description

The technology disclosed herein relates to an anomaly detection system. In particular, it relates to a system for detecting an abnormality in a fuel supply system.

Patent Document 1 discloses a system for detecting an abnormality in a fuel pump that discharges fuel in a fuel supply device. This system detects characteristic values that indicate the operating state of the fuel pump (for example, the current or voltage applied to the fuel pump motor) and compares the detected characteristic values with a judgment threshold for judging deterioration of the fuel pump. By doing so, it is determined whether or not there is an abnormality in the fuel pump.

JP 2020-45832 A

In general, when the rotation speed of the fuel pump motor changes, the pressure of the fuel discharged from the fuel pump (that is, the pressure in the fuel supply passage that supplies the fuel discharged from the fuel pump to the engine) changes greatly. . That is, the current and voltage applied to the motor of the fuel pump change sharply with respect to the rotation speed of the motor of the fuel pump. For this reason, in the technique disclosed in Patent Document 1, the set determination threshold may deviate from an appropriate value, and the accuracy of detecting an abnormality in the fuel supply device may deteriorate. This specification provides a technique capable of detecting an abnormality in a fuel supply device with high accuracy.

The anomaly detection system disclosed herein detects an anomaly in a fuel supply system. The abnormality detection system includes a fuel pump that discharges fuel by rotation of a motor, a fuel supply passage that supplies the fuel discharged from the fuel pump to the engine, and a discharge that discharges a portion of the fuel flowing through the fuel supply passage. A pressure regulating device for opening and closing a passage and the discharge passage, wherein when the pressure of the fuel in the fuel supply passage exceeds a predetermined allowable pressure, the closed state is changed to the open state to discharge the fuel from the discharge passage. A pressure regulator and a controller are provided. The control unit detects a characteristic value indicating an operating state of the fuel pump when the pressure regulating device is in an open state, and compares the detected characteristic value with a preset threshold value to detect the Detects abnormalities in the fuel supply system.

In the above configuration, when the pressure of the fuel in the fuel supply passage becomes equal to or higher than the allowable pressure, the pressure regulating device is opened to prevent the pressure in the fuel supply passage from rising excessively. Then, the control unit detects the characteristic value of the fuel pump when the pressure regulating device is in the open state. That is, in this abnormality detection system, the characteristic value of the fuel pump is detected when the rate of change thereof is relatively small. Therefore, by comparing the detected characteristic value with a preset threshold value, an abnormality of the fuel supply device can be detected with high accuracy.

The characteristic value may include a plurality of types of values indicating operating states of the fuel pump. The control unit may store characteristic value relationship information indicating a relationship between a first characteristic value and a second characteristic value different from the first characteristic value, The threshold may be set based on the characteristic value relationship information.

In the above configuration, the threshold is set based on the relationship between the two characteristic values that indicate the operating state of the fuel pump. For example, a threshold can be easily set for a graph mapped according to the stored characteristic value relationship information.

The control unit detects a first measurement point at which the detected first characteristic value is a first value, and a first measurement point at which the detected first characteristic value is a second value different from the first value. The second characteristic value and the threshold may be compared at a second measurement point. The control unit, when an abnormality is detected at at least one of the first measurement point and the second measurement point, the difference between the second characteristic value and the threshold value at the first measurement point, and the An abnormal location of the fuel supply device may be specified based on a difference between the second characteristic value and the threshold at a second measurement point.

In the above configuration, for example, when the difference at the first measurement point and the difference at the second measurement point are substantially equal, it is assumed that the second characteristic value transitions with a substantially constant difference from the threshold. can judge. On the other hand, for example, when the difference at the first measurement point and the difference at the second measurement point are equal to or greater than a predetermined value, it is assumed that the second characteristic value is transitioning at a rate of change different from the rate of change of the threshold. can judge. As described above, in the above configuration, by comparing the characteristic value and the threshold value at two different measurement points, the mode of abnormality occurring in the fuel supply system (for example, deterioration of the fuel pump, abnormality of the pressure regulator, etc.) can be determined. ) can be specified.

The control unit indicates a relationship between an open period during which the pressure regulating device should be in the open state when the fuel pump operates, a closed period during which the pressure regulating device is in the closed state, and the characteristic value. Period-related information may be stored, and the threshold may be set based on the period-related information.

In the above configuration, the period-related information indicates the relationship between the open period, the closed period, and the characteristic value. In other words, the period-related information indicates changes in characteristic values over time. Therefore, by setting the threshold value based on the period-related information, it is possible to detect an abnormality in the fuel supply device by detecting only a single characteristic value.

The control unit detects the characteristic value indicating the operating state of the fuel pump when the pressure regulating device is in the closed state, and compares the detected characteristic value with the threshold value to control the fuel supply. Abnormality of the device may be detected.

In the above configuration, the characteristic value detected during the closed period in which the pressure regulator should be closed is compared with the threshold value. According to this configuration, for example, it is possible to detect an abnormality in which the pressure regulating device is in the open state even though it is in the closed period.

The discharge passage may have a first discharge passage connected to the fuel supply passage, and a second discharge passage connected to the fuel supply passage at a position different from the first discharge passage. The pressure adjustment device may include a first pressure adjustment device that opens and closes the first discharge passage, and a second pressure adjustment device that opens and closes the second discharge passage. The first pressure regulating device may be opened when the pressure of the fuel in the fuel supply passage reaches or exceeds a predetermined first allowable pressure. The second pressure regulating device may be opened when the pressure of the fuel in the fuel supply passage reaches or exceeds a predetermined second allowable pressure different from the first allowable pressure. The control unit detects the characteristic value when the first pressure regulating device or the second pressure regulating device is in an open state, and compares the detected characteristic value with the threshold value to control the fuel pressure. Abnormality of the supply device may be detected.

With this configuration, an abnormality in the fuel supply system can be accurately detected even in a fuel supply system having two pressure regulating devices.

1 is a schematic diagram of a fuel supply device according to Embodiment 1. FIG. FIG. 4 is a diagram showing an example of input signals input to the FPC; 3A and 3B are a graph showing the relationship between the discharge flow rate of the fuel pump and the pressure of the fuel in the fuel supply passage; 5 is a graph showing an example of detecting an abnormality in the fuel supply system based on the relationship between the number of revolutions of the motor of the fuel pump and the current of the motor; 7 is a graph showing another example of detecting an abnormality in the fuel supply system based on the relationship between the number of revolutions of the motor of the fuel pump and the current of the motor; 5 is a graph showing an example of detecting an abnormality in the fuel supply system based on the relationship between the driving time of the fuel pump and the current of the motor; FIG. 5 is a schematic diagram of a fuel supply device according to a second embodiment; 3A and 3B are a graph showing the relationship between the discharge flow rate of the fuel pump and the pressure of the fuel in the fuel supply passage; 5 is a graph showing an example of detecting an abnormality in the fuel supply system based on the relationship between the number of revolutions of the motor of the fuel pump and the current of the motor; 7 is a graph showing another example of detecting an abnormality in the fuel supply system based on the relationship between the number of revolutions of the motor of the fuel pump and the current of the motor; 7 is a graph showing another example of detecting an abnormality in the fuel supply system based on the relationship between the number of revolutions of the motor of the fuel pump and the current of the motor;

(Example 1)
A fuel supply device 1 according to Embodiment 1 will be described with reference to the drawings. FIG. 1 is a schematic diagram of a fuel supply device 1 according to a first embodiment. As shown in FIG. 1 , the fuel supply device 1 includes a fuel pump 10 , a fuel supply passage 30 , a high pressure pump 44 and a fuel injection device 42 . The fuel supply system 1 also includes an FPC (Fuel Pump Controller) 52 and an ECU (Engine Control Unit) 50 .

The fuel supply system 1 is mounted on a vehicle having an engine 40 . The fuel supply system 1 is mounted, for example, on a direct-injection gasoline automobile that directly injects high-pressure fuel into the cylinders of the engine 40 . The fuel supply device 1 is a device for supplying fuel to an engine 40 of a vehicle.

The fuel pump 10 is located within the fuel tank 12 and has an inlet 102 and an outlet 104 . The fuel tank 12 stores liquid fuel (for example, gasoline) to be supplied to the engine 40 . The fuel pump 10 sucks the fuel in the fuel tank 12 from the suction port 102 and discharges it from the discharge port 104 . A fuel supply passage 30 is connected to a discharge port 104 of the fuel pump 10 . The fuel pump 10 discharges the fuel in the fuel tank 12 to the fuel supply passage 30 .

The fuel pump 10 includes, for example, a motor 16 and an impeller (not shown). When the motor 16 rotates, the impeller rotates to draw in and discharge fuel from the fuel tank 12 . The motor 16 is, for example, a brushless motor and a three-phase motor. The motor 16 includes a plurality (for example, three) of coils (not shown), and rotates when currents flow through the coils in sequence. The current of the motor 16 (that is, the current applied to the motor 16) is detected by a current sensor (not shown). The current sensor includes a detection resistor (not shown) and detects the current of the motor 16 based on the resistance value of the resistor. In the fuel pump 10, the higher the current of the motor 16, the higher the rotational speed of the motor 16 (that is, the higher the rotational speed), and the more the flow rate of the fuel discharged from the fuel pump 10 increases. The smaller the current of the motor 16, the smaller the rotational speed of the motor 16 (that is, the lower the rotational speed), and the smaller the discharge flow rate of the fuel pump 10.

Motor 16 of fuel pump 10 is driven by FPC 52 . The FPC 52 has a drive circuit 56 for driving the motor 16 to rotate. A drive circuit 56 of the FPC 52 controls the motor 16 based on an input signal input from the ECU 50 . The drive circuit 56 includes a power supply 64 and a plurality of (eg, six) switches 62 . By sequentially switching on and off of the plurality of switches 62 of the drive circuit 56 , current flows through the plurality of coils of the motor 16 in sequence. This causes the motor 16 to rotate. Since the principle of rotation of the motor 16 is well known, detailed explanation is omitted.

The current of the motor 16 of the fuel pump 10 depends on the duty ratio of the input signal input from the ECU 50 to the FPC 52 . FIG. 2 is a diagram showing an example of input signals input to the FPC 52. As shown in FIG. The input signal shown in FIG. 2 is a signal for switching on and off any one switch 62 of the FPC 52 . As shown in FIG. 2, the larger the duty ratio of the input signal input to the FPC 52, the larger the ON time ratio of the switch 62, and the smaller the duty ratio, the smaller the ON time ratio of the switch 62. The current of the motor 16 increases as the duty ratio of the input signal input to the FPC 52 increases, and decreases as the duty ratio of the input signal decreases. The rotation speed of the motor 16 also depends on the duty ratio of the input signal input from the ECU 50 to the FPC 52 . The rotation speed of the motor 16 increases as the duty ratio of the input signal input to the FPC 52 increases, and decreases as the duty ratio of the input signal decreases. The discharge flow rate of the fuel pump 10 corresponds to the rotation speed of the motor 16 .

As shown in FIG. 1 , the fuel supply passage 30 is connected at its upstream end to the discharge port 104 of the fuel pump 10 . Fuel discharged from the fuel pump 10 flows through the fuel supply passage 30 . A downstream end of the fuel supply passage 30 is connected to a fuel injection device 42 attached to the engine 40 . The fuel supply passage 30 supplies the fuel discharged from the fuel pump 10 to the fuel injection device 42 . Fuel is injected from the fuel injection device 42 to the engine 40 .

A check valve 24 and a high-pressure pump 44 are provided in the fuel supply passage 30 . The check valve 24 allows fuel to flow from the upstream side (the fuel pump 10 side) to the downstream side (the engine 40 side) of the check valve 24, and allows the fuel to flow from the downstream side of the check valve 24 to the upstream side. is prohibited from flowing. The high-pressure pump 44 pressurizes and discharges the fuel supplied through the fuel supply passage 30 . The high-pressure pump 44 discharges fuel at a pressure higher than that of the fuel pump 10 . High-pressure fuel is injected from the fuel injection device 42 to the engine 40 while the high-pressure pump 44 is operating.

A first discharge passage 32 is connected to the fuel supply passage 30 . As the pressure of fuel in the fuel supply passage 30 increases, the pressure of fuel in the first discharge passage 32 also increases accordingly. As the pressure of fuel in the fuel supply passage 30 decreases, the pressure of fuel in the first discharge passage 32 also decreases accordingly.

The first discharge passage 32 is connected at its upstream end to the fuel supply passage 30 on the downstream side (engine 40 side) of the check valve 24 . Part of the fuel flowing through the fuel supply passage 30 on the downstream side of the check valve 24 flows into the first discharge passage 32 . A downstream end of the first discharge passage 32 is arranged inside the fuel tank 12 . The fuel that has flowed through the first discharge passage 32 is discharged into the fuel tank 12 from the downstream end of the first discharge passage 32 . The first discharge passage 32 is a passage for discharging part of the fuel flowing through the fuel supply passage 30 on the downstream side of the check valve 24 into the fuel tank 12 .

A first pressure regulating device 20 is provided in the first discharge passage 32 . The first pressure regulating device 20 is composed of, for example, an on-off valve that opens and closes the first discharge passage 32 . The first pressure regulating device 20 is opened when the pressure of the fuel in the first discharge passage 32 on the upstream side (on the fuel supply passage 30 side) of the first pressure regulating device 20 reaches or exceeds a predetermined first allowable pressure. , the closed state when the pressure becomes less than the first allowable pressure. The predetermined first allowable pressure can be set as appropriate. When the first pressure regulating device 20 is opened, part of the fuel in the fuel supply passage 30 on the downstream side of the check valve 24 is discharged into the fuel tank 12 through the first discharge passage 32 . This prevents the pressure of the fuel in the fuel supply passage 30 from becoming excessively high. When the first pressure regulating device 20 is closed, fuel is no longer discharged through the first discharge passage 32 .

The ECU 50 of the fuel supply device 1 includes, for example, a CPU and a memory 54 (ROM and RAM), and executes predetermined control and processing based on programs stored in the memory 54 . The ECU 50 inputs an input signal for rotationally driving the motor 16 of the fuel pump 10 to the FPC 52 . Specifically, the ECU 50 inputs to the FPC 52 an input signal for switching on and off the plurality of switches 62 in the drive circuit 56 of the FPC 52 . The ECU 50 inputs an input signal with a predetermined duty ratio to the FPC 52 .

[Operation of fuel supply device 1]
Next, operation of the fuel supply device 1 will be described. In the fuel supply system 1 described above, the fuel pump 10 in the fuel tank 12 sucks the fuel in the fuel tank 12 and discharges it to the fuel supply passage 30 . The fuel discharged from the fuel pump 10 to the fuel supply passage 30 flows through the fuel supply passage 30 and is supplied to the high pressure pump 44 . The high-pressure pump 44 pressurizes the supplied fuel and discharges it. Fuel discharged from the high-pressure pump 44 is injected from the fuel injection device 42 to the engine 40 . Fuel is thereby supplied to the engine 40 .

3 shows (a) a graph showing the relationship between the discharge flow rate (horizontal axis) of the fuel pump 10 and the pressure (vertical axis) of the fuel in the fuel supply passage 30, and (b) the motor 16 of the fuel pump 10. 2 is a graph showing the relationship between the number of revolutions (horizontal axis) of the fuel pump 10 and the current of the motor 16 of the fuel pump 10 (vertical axis). The discharge flow rate of the fuel pump 10 corresponds to the rotation speed of the motor 16 of the fuel pump 10 . Also, the number of rotations of the motor 16 of the fuel pump 10 corresponds to the duty ratio of the input signal input to the FPC 52 .

As shown in FIG. 3A, in the fuel supply system 1, the higher the discharge flow rate of the fuel pump 10, the higher the pressure of the fuel in the fuel supply passage 30, and the lower the discharge flow rate of the fuel pump 10, the higher the pressure of the fuel supply passage 30. The pressure of the fuel inside becomes low. Further, in the fuel supply device 1, as shown in FIG. 3B, the higher the rotational speed of the motor 16 (the higher the discharge flow rate of the fuel pump 10), the higher the current of the motor 16. Further, the smaller the rotation speed of the motor 16 (the smaller the discharge flow rate of the fuel pump 10), the smaller the current of the motor 16.

3(a), when the discharge flow rate of the fuel pump 10 is less than the first allowable discharge flow rate F1, the first pressure The adjusting device 20 is closed, and the fuel pressure in the fuel supply passage 30 is relatively low. In the fuel supply system 1, when the discharge flow rate of the fuel pump 10 becomes equal to or higher than the first allowable discharge flow rate F1, the pressure of the fuel in the fuel supply passage 30 becomes equal to or higher than the first allowable pressure P1. The first pressure regulating device 20 that opens and closes the discharge passage 32 is opened. When the first pressure regulating device 20 is opened, part of the fuel flowing through the fuel supply passage 30 is discharged into the fuel tank 12 through the first discharge passage 32 . This suppresses the pressure of the fuel in the fuel supply passage 30 from increasing.

In this fuel supply system 1, as shown in FIG. 3B, when the discharge flow rate of the fuel pump 10 is the first allowable discharge flow rate F1, the rotation speed and current of the motor 16 of the fuel pump 10 are respectively R1 , I1. When the number of revolutions of the motor 16 becomes R1 or more and the discharge flow rate of the fuel pump 10 becomes equal to or more than the first allowable discharge flow rate F1, the current of the motor 16 becomes I1 or more.

In the fuel supply system 1, when the discharge flow rate of the fuel pump 10 decreases, the operation is reversed to the above operation. The ECU 50 of the fuel supply system 1 stores the graph shown in FIG. 3(b) in the memory 54 as characteristic value relation information. The characteristic value relation information is generated in advance by a preliminary test of the fuel supply device 1 or the like. Note that the characteristic value relation information may be generated while the fuel supply device 1 is operating.

[Fuel supply device 1 abnormality detection]
In this embodiment, when an abnormality occurs in the fuel supply device 1, the abnormality can be detected. A mode of detecting an abnormality in the fuel supply device 1 will be described. The ECU 50 detects an abnormality of the fuel supply system 1 based on the characteristic value relational information stored in the memory 54 during operation of the fuel supply system 1 . First, the example shown in FIG. 4 will be described. FIG. 4 shows a graph _GS1 represented by characteristic value relationship information and a graph G1 showing an example of the relationship between characteristic values actually detected when the fuel supply system ₁ is operating. First, the ECU 50 sets a threshold T1 for the graph _GS1 . As shown in FIG. 4, the threshold T1 is set for the open period of the first pressure regulator 20 . The open period is a period during which the first pressure regulating device 20 should be in the open state when the first pressure regulating device 20 is normal. The closed period is a period during which the first pressure regulating device 20 should be in the closed state when the first pressure regulating device 20 is normal. The threshold T1 is set such that the current for a given number of revolutions of the motor 16 is a value higher than the graph _GS1 by a predetermined value A1.

When the fuel supply device 1 starts operating, the ECU 50 detects the actual rotation speed and current of the motor 16 during the open period of the first pressure regulating device 20 . Specifically, the rotation speed and current of the motor 16 are detected at two different measurement points M1 and M2 within the open period of the first pressure regulating device 20 . In a vehicle equipped with the fuel supply device 1, electric power is supplied to the ECU 50 when an ignition switch (not shown) is turned on. At this time, an input signal for rotationally driving the motor 16 that is input from the ECU 50 to the FPC 52 is set in advance. Further, as described above, the rotation speed of the motor 16 corresponds to the discharge flow rate of the fuel pump 10, and the discharge flow rate correlates with the pressure in the fuel supply passage 30 (see FIG. 3(a)). Therefore, the ECU 50 can calculate the time from when the ignition switch is turned on until the pressure in the fuel supply passage 30 reaches a predetermined pressure based on the input signal input to the FPC 52 . That is, the ECU 50 can specify the timing at which the first pressure regulating device 20 should change from the closed state to the open state, and therefore can specify the closed period and the open period of the first pressure regulating device 20 .

Here, when there is no abnormality in the fuel supply device 1, a characteristic value having a relationship substantially equal to the relationship indicated by the graph _GS1 is detected. In the graph G1 shown in FIG. ₄ , the current with respect to the rotation speed of the motor 16 exceeds the threshold value T1 at both measurement points M1 and M2. Therefore, the ECU 50 detects that the fuel supply device 1 is abnormal. Also, the difference d1 between the threshold T1 at the measurement _point M1 and the current in the graph G1 is substantially _equal to the difference d2 between the threshold T1 at the measurement point M2 and the current in the graph G1. That is, the slope of the threshold value T1 and the slope of the graph G1 in the open period are substantially _equal . That is, in the example shown in FIG. 4, compared to the case where the fuel supply device 1 is normal, the current of the motor 16 with respect to the number of revolutions of the motor 16 is always a substantially constant value (that is, d1 (=d2)). It's getting bigger. Therefore, the ECU 50 can determine that the detected abnormality is caused by deterioration of the fuel pump 10, for example.

Next, the example shown in FIG. 5 will be described. 5 differs from _FIG . 4 in a graph G2 showing an example of the relationship between characteristic values actually detected when the fuel supply system 1 is in operation. In the graph G2 shown in _FIG . 5, the current with respect to the rotation speed of the motor 16 exceeds the threshold value T1 at both measurement points M1 and M2. Therefore, the ECU 50 detects that the fuel supply device 1 is abnormal. Here, in the example shown in _FIG . 5, the difference d3 between the threshold T1 at the measurement point M1 and the current in the graph G2 is different from the difference d4 between the threshold T1 at the measurement point _M2 and the current in the graph G2. Specifically, the rate of change of the current of the motor 16 with respect to the number of revolutions of the motor 16 is greater than when the fuel supply device 1 is normal. In other words, the pressure in the fuel supply passage 30 continues to rise even during the open period. Therefore, for example, when the difference between d3 and d4 is greater than a predetermined value, the ECU 50 determines that the detected abnormality is caused by, for example, an abnormality in the first pressure regulating device 20 (for example, the on-off valve is stuck closed). It can be determined that

Further, as described below, an abnormality in the fuel supply system 1 can be detected in a manner different from the manner described above. As described above, the ECU 50 can specify the closed period and open period of the first pressure regulating device 20 after the ignition switch is turned on. Furthermore, the ECU 50 can identify changes in current applied to the motor 16 during the closed period and the open period based on the input signal input to the FPC 52 . A graph _{GS2 of FIG. 6 is a graph GS2 showing} changes in the current of the motor 16 with respect to the operation time of the fuel supply device 1 specified based on the above.

In graph _GS2 of FIG. 6, the ignition switch is turned on at timing t0. A period from timing t0 to timing t1 is a closing period in which the first pressure regulating device 20 is closed because the current of the motor 16 is relatively low (that is, the pressure in the fuel supply passage 30 is relatively low). . After that, at timing t1, when the current of the motor 16 reaches I1, the pressure in the fuel supply passage 30 reaches the first allowable pressure P1, so the first pressure regulating device 20 changes from the closed state to the open state. After timing t1, the pressure in the fuel supply passage 30 is kept substantially constant because the first pressure regulating device 20 is in the open state, and the current of the motor 16 changes at a substantially constant value I1. The ECU 50 stores this graph _GS2 in the memory 54 as period relation information.

The ECU 50 sets a threshold T2 for this graph _GS2 . The threshold T2 is set for the open period of the first pressure regulator 20 . The threshold T2 is set to a value that is greater than the current value I1 during the open period by a predetermined value. The ECU 50 detects that the fuel supply device 1 is abnormal when the detected current value exceeds the threshold value T2 during the open period. Note that the current of the motor 16 may be detected at two different timings, similar to the examples shown in FIGS.

A graph G3 in FIG. ₆ shows an example of an abnormality in which the detected current of the motor 16 changes with a substantially constant difference from the threshold value T2 during the open period. In this case, similarly to the example shown in FIG. 4, the ECU 50 can determine that the detected abnormality is caused by deterioration of the fuel pump 10, for example.

A graph G4 in FIG. ₆ shows an example of an abnormality in which the detected current of the motor 16 changes with a substantially constant slope during the open period. That is, it shows an example in which the difference between the current of the motor 16 and the threshold T2 gradually increases after the current of the motor 16 exceeds the threshold T2. In this case, similarly to the example shown in FIG. 5, the ECU 50 may determine that the detected abnormality is caused by, for example, an abnormality of the first pressure regulating device 20 (for example, the on-off valve is stuck closed). can.

Further, the ECU 50 sets a threshold T3 for the graph _GS2 . The threshold T3 is set for the closing period of the first pressure regulator 20 . The threshold value T3 is set so that the rate of increase of the current in the closed period is lower than that of the graph _GS2 . That is, the slope of the threshold T3 is smaller than the slope of the graph _GS2 . The ECU 50 detects that the fuel supply device 1 is abnormal when the detected current value is below the threshold value T3 during the closed period.

A graph G5 in FIG. ₆ shows an example of an abnormality in which the detected current of the motor 16 changes with a slope smaller than the slope of the threshold value T3 during the closed period. That is, the graph G5 shows a state in which the current of the motor 16 is difficult to rise immediately after the ignition switch is turned _on . _In other words, graph G5 indicates a state in which the pressure in fuel supply passage 30 is difficult to rise. Therefore, the ECU 50 can determine that the detected abnormality is caused by, for example, the abnormality of the first pressure regulating device 20 (for example, the on-off valve is stuck open).

In the fuel supply device 1 described above, the first pressure regulating device 20 suppresses an excessive increase in the pressure of the fuel in the fuel supply passage 30 . Then, the ECU 50 detects the characteristic value of the fuel pump 10 when the first pressure regulating device 20 is in the open state. That is, in this embodiment, the characteristic value of the fuel pump 10 is detected when the rate of change thereof is relatively small. Therefore, by comparing the detected characteristic value with preset threshold values T1, T2, etc., an abnormality of the fuel supply device 1 can be detected with high accuracy.

Further, in this embodiment, as shown in FIGS. 4 and 5, based on a graph _GS1 showing the relationship between two characteristic values (that is, the rotation speed and the current of the motor 16) indicating the operating state of the fuel pump 10, A threshold T1 is set. Therefore, the threshold T1 can be easily set.

Further, in this embodiment, by comparing the difference between the current of the motor 16 at the measurement point M1 and the threshold value T1 and the difference between the current of the motor 16 and the threshold value T1 at the measurement point M2, the It is possible to specify the mode of the abnormality (for example, deterioration of the fuel pump 10, abnormality of the first pressure regulating device 20, etc.).

Further, in this embodiment, as shown in FIG. 6, the threshold T2 is set based on period relation information indicating the relation between the open period and the closed period of the first pressure regulating device 20 and the current of the motor 16. , an abnormality of the fuel supply device 1 can be detected. By setting the threshold value T2 based on the period-related information in this way, it is possible to detect an abnormality in the fuel supply device 1 by detecting only a single characteristic value (that is, the current of the motor 16). .

Further, in this embodiment, by comparing the characteristic value (current of the motor 16) detected during the closed period of the first pressure regulating device 20 with the threshold value T3, the first pressure regulating device 20 is in the closed period. However, it is possible to detect an abnormality (for example, an on-off valve stuck open) that is in an open state.

(Example 2)

Next, a fuel supply device 110 according to a second embodiment will be described. The second embodiment differs from the first embodiment in the configuration of the passage connecting the fuel pump 10 and the engine 40 . Specifically, as shown in FIG. 7, a second discharge passage 34 is provided that is connected to the fuel supply passage 30 at a position different from that of the first discharge passage 32 . As the pressure of the fuel in the fuel supply passage 30 increases, the pressure of the fuel in the second discharge passage 34 also increases accordingly. As the pressure of fuel in the fuel supply passage 30 decreases, the pressure of fuel in the second discharge passage 34 also decreases accordingly.

The second discharge passage 34 is connected at its upstream end to the fuel supply passage 30 on the upstream side (fuel pump 10 side) of the check valve 24 . Part of the fuel flowing through the fuel supply passage 30 on the upstream side of the check valve 24 flows into the second discharge passage 34 . A downstream end of the second discharge passage 34 is arranged inside the fuel tank 12 . The fuel that has flowed through the second discharge passage 34 is discharged from the downstream end of the second discharge passage 34 into the fuel tank 12 . The second discharge passage 34 is a passage for discharging part of the fuel flowing through the fuel supply passage 30 on the upstream side of the check valve 24 into the fuel tank 12 .

A second pressure regulating device 22 is provided in the second discharge passage 34 . The second pressure regulating device 22 is composed of, for example, an on-off valve that opens and closes the second discharge passage 34 . The second pressure regulating device 22 is opened when the pressure of the fuel in the second discharge passage 34 on the upstream side (on the side of the fuel supply passage 30) of the second pressure regulating device 22 reaches or exceeds a predetermined second allowable pressure. , the closed state when the pressure becomes less than the second allowable pressure. The predetermined second allowable pressure can be set as appropriate. The second allowable pressure is a pressure lower than the first allowable pressure described above. When the second pressure regulating device 22 is opened, part of the fuel in the fuel supply passage 30 on the upstream side of the check valve 24 is discharged into the fuel tank 12 through the second discharge passage 34 . This prevents the pressure of the fuel in the fuel supply passage 30 from becoming excessively high. When the second pressure regulating device 22 is closed, fuel is no longer discharged through the second discharge passage 34 .

A throttle 26 is provided in the second discharge passage 34 on the downstream side (fuel tank 12 side) of the second pressure regulating device 22 . The throttle 26 limits the flow of fuel through the second discharge passage 34 . The throttle 26 restricts the flow of fuel flowing from the upstream side (the fuel supply passage 30 side) to the downstream side (the fuel tank 12 side) of the throttle 26 . The pressure of fuel in the second discharge passage 34 on the upstream side of the throttle 26 is higher than the pressure of fuel in the second discharge passage 34 on the downstream side of the throttle 26 (or in the fuel tank 12). As the flow rate of fuel flowing through the second discharge passage 34 increases, the pressure of the fuel in the second discharge passage 34 on the upstream side of the throttle 26 increases. The throttle 26 increases the pressure of fuel in the fuel supply passage 30 by restricting the flow of fuel through the second discharge passage 34 . The fuel pressure increase rate can be appropriately set based on the opening diameter of the throttle 26 .

[Operation of fuel supply device 110]
8 shows (a) a graph showing the relationship between the discharge flow rate (horizontal axis) of the fuel pump 10 and the pressure (vertical axis) of the fuel in the fuel supply passage 30, and (b) the motor 16 of the fuel pump 10. 2 is a graph showing the relationship between the number of revolutions (horizontal axis) of the fuel pump 10 and the current of the motor 16 of the fuel pump 10 (vertical axis). Note that the scale of the horizontal axis relative to the vertical axis in FIG. 8 is different from the scale of the horizontal axis relative to the vertical axis in FIG.

In the fuel supply device 110, as shown in FIG. 8A, when the discharge flow rate of the fuel pump 10 is less than the second allowable discharge flow rate F2, the first pressure regulating device 20 and the second pressure regulating device 22 are closed. , and the pressure of the fuel in the fuel supply passage 30 is relatively low. In the fuel supply device 110, when the discharge flow rate of the fuel pump 10 becomes equal to or higher than the second allowable discharge flow rate F2, the pressure of the fuel in the fuel supply passage 30 becomes equal to or higher than the second allowable pressure P2. The second pressure regulating device 22 that opens and closes the discharge passage 34 is opened. When the second pressure regulating device 22 is opened, part of the fuel flowing through the fuel supply passage 30 is discharged into the fuel tank 12 through the second discharge passage 34 . This suppresses the pressure of the fuel in the fuel supply passage 30 from increasing.

In this fuel supply device 110, as shown in FIG. 8B, when the discharge flow rate of the fuel pump 10 is the second allowable discharge flow rate F2, the rotation speed and current of the motor 16 of the fuel pump 10 are respectively R2 , I2. When the rotation speed of the motor 16 becomes R2 or more and the discharge flow rate of the fuel pump 10 becomes equal to or more than the second allowable discharge flow rate F2, the current of the motor 16 becomes I2 or more.

Further, in the fuel supply device 110, as shown in FIG. 8A, when the discharge flow rate of the fuel pump 10 becomes equal to or higher than the third allowable discharge flow rate F3 when the second pressure regulating device 22 is in the open state, the fuel supply passage The pressure of the fuel in 30 is further increased. In the fuel supply device 110, the flow of fuel flowing through the second discharge passage 34 is restricted by the restrictor 26 provided in the second discharge passage 34, so that the flow of fuel in the second discharge passage 34 and the fuel supply passage 30 is restricted. pressure rises.

In this fuel supply device 110, as shown in FIG. 8B, when the discharge flow rate of the fuel pump 10 is the third allowable discharge flow rate F3, the rotation speed and current of the motor 16 of the fuel pump 10 are respectively R3 , I3. When the rotation speed of the motor 16 becomes R3 or more and the discharge flow rate of the fuel pump 10 becomes equal to or more than the third allowable discharge flow rate F3, the current of the motor 16 becomes I3 or more.

Furthermore, in the fuel supply device 110, as shown in FIG. 8A, when the discharge flow rate of the fuel pump 10 becomes equal to or greater than the fourth allowable discharge flow rate F4 (=the first allowable discharge flow rate F1 in the first embodiment), The pressure of the fuel in the fuel supply passage 30 becomes equal to or higher than the first allowable pressure P1, and the pressure causes the first pressure regulating device 20 that opens and closes the first discharge passage 32 to open. When the first pressure regulating device 20 is opened, part of the fuel flowing through the fuel supply passage 30 is discharged into the fuel tank 12 through the first discharge passage 32 . This suppresses the pressure of the fuel in the fuel supply passage 30 from increasing.

In this fuel supply device 110, as shown in FIG. 8B, when the discharge flow rate of the fuel pump 10 is the fourth allowable discharge flow rate F4, the rotation speed and current of the motor 16 of the fuel pump 10 are respectively R4 (=R1 in Example 1) and I4 (=I1 in Example 1). When the rotation speed of the motor 16 becomes R4 or more and the discharge flow rate of the fuel pump 10 becomes equal to or more than the fourth allowable discharge flow rate F4, the current of the motor 16 becomes I4 or more.

[Detection of Abnormality in Fuel Supply Device 110]
The ECU 50 of the fuel supply device 110 stores the graph shown in FIG. 8B in the memory 54 as characteristic value relation information. First, the example shown in FIG. 9 will be described. FIG. ₉ shows a graph _GS3 represented by the characteristic value relationship information and a graph G6 showing an example of the relationship between characteristic values actually detected when the fuel supply device 110 is operating. First, the ECU 50 sets a threshold T4 for the graph _GS3 . As shown in FIG. 4, the threshold T4 is set for the first open period and the second open period. The first open period is a period during which the second pressure regulating device 22 should be open, and the second open period is a period during which the first pressure regulating device 20 and the second pressure regulating device 22 should be open. . The threshold value T4 is set such that the current for a given number of rotations of the motor 16 is higher than the graph _GS3 by a predetermined value.

When the fuel supply device 110 starts operating, the ECU 50 detects the actual rotation speed and current of the motor 16 during the first open period and the second open period. Specifically, the rotation speed and current of the motor 16 are detected at the measurement point M3 in the first open period and the measurement point M4 in the second open period.

In the graph G6 shown in FIG. ₉ , the current with respect to the rotation speed of the motor 16 exceeds the threshold value T4 at both measurement points M3 and M4. Therefore, the ECU 50 detects that the fuel supply device 110 is abnormal. Also, the difference d5 between the threshold T4 at the measurement point M3 and the current in the graph _G6 is substantially equal to the difference d6 between the threshold T4 at the measurement point M4 and the current in the graph _G6 . That is, in the example shown in FIG. 9, compared to the case where the fuel supply device 110 is normal, the current of the motor 16 with respect to the rotation speed of the motor 16 is always a substantially constant value (that is, d5 (=d6)). It's getting bigger. Therefore, the ECU 50 can determine that the detected abnormality is caused by deterioration of the fuel pump 10 .

Next, the example shown in FIG. 10 will be described. 10 differs from FIG. ₉ in graph G7 showing an example of the relationship between characteristic values actually detected when the fuel supply device 110 is in operation. _In the graph G7 shown in FIG. 10, the current with respect to the rotation speed of the motor 16 exceeds the threshold value T4 at both measurement points M3 and M4. Therefore, the ECU 50 detects that the fuel supply device 110 is abnormal. Here, in the example shown in FIG. ₁₀ , the difference d7 between the threshold T4 at the measurement point M3 and the current in the graph G7 is different from the difference d8 between the threshold T4 at the measurement point M4 and the graph _G7 . Specifically, the difference d7 in the first open period is greater than the difference d8 in the second open period. That is, compared to when the fuel supply device 110 is normal, the current value of the motor 16 with respect to the number of revolutions of the motor 16 becomes significantly larger in the first open period in which the second pressure regulating device 22 should be in the open state. there is In other words, the pressure in the fuel supply passage 30 continues to rise during the first open period. Therefore, for example, when d7 is larger than d8 by a predetermined difference or more, the ECU 50 determines that the detected abnormality is caused by an abnormality in the second pressure regulating device 22 (for example, the on-off valve is stuck closed). can be determined to be

Next, the example shown in FIG. 11 will be described. 11 differs from FIGS. ₉ and 10 in a graph G8 showing an example of the relationship between characteristic values actually detected when the fuel supply device 110 is in operation. _In the graph G8 shown in FIG. 11, the current relative to the rotation speed of the motor 16 does not exceed the threshold value T4 at the measurement point M3, whereas the current relative to the rotation speed of the motor 16 exceeds the threshold value T4 at the measurement point M4. Over. Therefore, the ECU 50 detects that the fuel supply device 110 is abnormal. In the example shown in FIG. 11, compared to the case where the fuel supply device 110 is normal, in the second open period in which the second pressure regulating device 22 should be in the open state and the first pressure regulating device 20 should be in the open state. , the current of the motor 16 with respect to the rotation speed of the motor 16 exceeds the threshold value T4. In other words, the pressure in the fuel supply passage 30 continues to rise during the second open period. Therefore, the ECU 50, for example, determines that the second pressure regulating device 22 is normal, while the detected abnormality is caused by an abnormality in the first pressure regulating device 20 (for example, the on-off valve is stuck closed). can be determined to exist.

As in the first embodiment, it is also possible to detect that an abnormality has occurred in the fuel supply device 110 based on the identified period-related information.

The fuel supply device 110 described above includes two types of pressure regulating devices, a first pressure regulating device 20 and a second pressure regulating device 22 . In the present embodiment, there is a first open period during which only the second pressure regulating device 22 is open, and a second open period during which the first pressure regulating device 20 is open in addition to the second pressure regulating device 22. By detecting the characteristic values at the two measurement points M3 and M4, the mode of abnormality occurring in the fuel supply device 110 (for example, deterioration of the fuel pump 10, abnormality of the first pressure regulating device 20, second abnormality of the pressure adjusting device 22, etc.) can be specified with high accuracy.

[Correspondence]
The ECU 50 and the FPC 52 are examples of the "controller". The rotation speed and current of the motor 16 are examples of the "characteristic value". The rotation speed of the motor 16 and the current of the motor 16 are examples of the "first characteristic value" and the "second characteristic value", respectively. The graph G _S1 shown in FIG. 4 and the like and the graph G _S3 shown in FIG. 9 and the like are examples of the “characteristic value relation information”. A graph _GS2 shown in FIG. 6 is an example of "period related information". The measurement points M1 and M3 are examples of the "first measurement point", and the measurement points M2 and M4 are examples of the "second measurement point".

Although one embodiment has been described above, specific aspects are not limited to the above embodiment. In the following description, the same reference numerals are given to the same configurations as those in the above description, and the description thereof is omitted.

[Modification]
In each of the above-described embodiments, the characteristic value relationship information indicating the relationship between the number of rotations of the motor 16 and the current of the motor 16 is used. However, values used as characteristic values are not limited to these. For example, the voltage applied to the motor 16 or the output voltage of the motor 16 may be used as the characteristic value. For example, the vertical axis in FIGS. 3 and 8 can be appropriately selected from the current applied to the motor 16, the voltage applied to the motor 16, and the output voltage of the motor 16. FIG.

In the above-described embodiment, the characteristic values are detected at two measurement points for the graph showing the characteristic value relationship information. However, the number of measurement points for detecting characteristic values may be only one. Even with such a configuration, an abnormality in the fuel supply device 1, 110 can be detected with high accuracy by detecting the characteristic value during the open period. Also, the relationship between the two characteristic values may be detected over time during the operation of the fuel supply device 1,110. With such a configuration, since it is possible to grasp in detail the transition of the graph of the actually detected characteristic value with respect to the graph indicated by the characteristic value relation information, it is possible to identify the abnormal location of the fuel supply device 1 with higher accuracy. can.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or in the drawings exhibit technical utility either singly or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technique illustrated in this specification or drawings can simultaneously achieve a plurality of purposes, and achieving one of them has technical utility in itself.

1: fuel supply device, 10: fuel pump, 12: fuel tank, 16: motor, 20: first pressure regulator, 22: second pressure regulator, 24: check valve, 26: throttle, 30: fuel supply Passage 32: First discharge passage 34: Second discharge passage 40: Engine 42: Fuel injection device 44: High pressure pump 50: ECU 52: FPC 54: Memory

Claims (6)

An abnormality detection system for detecting an abnormality in a fuel supply device,
a fuel pump that discharges fuel by rotation of a motor;
a fuel supply passage for supplying the fuel discharged from the fuel pump to the engine;
a discharge passage for discharging a part of the fuel flowing through the fuel supply passage;
A pressure regulating device for opening and closing the discharge passage, wherein the pressure regulating device opens from a closed state to an open state to discharge fuel from the discharge passage when the pressure of the fuel in the fuel supply passage exceeds a predetermined allowable pressure. When,
a control unit;
and
The control unit
When the pressure regulating device is in an open state, a characteristic value indicating the operating state of the fuel pump is detected, and the abnormality of the fuel supply device is detected by comparing the detected characteristic value with a preset threshold value. to detect the
Anomaly detection system. The anomaly detection system according to claim 1,
The characteristic value includes a plurality of types of values indicating the operating state of the fuel pump,
The control unit
storing characteristic value relationship information indicating a relationship between a first characteristic value and a second characteristic value different from the first characteristic value among the characteristic values;
An anomaly detection system, wherein the threshold is set based on the characteristic value relationship information. The anomaly detection system according to claim 2,
The control unit
At a first measurement point where the detected first characteristic value is a first value and at a second measurement point where the detected first characteristic value is a second value different from the first value , comparing said second characteristic value with said threshold,
When an abnormality is detected at at least one of the first measurement point and the second measurement point, the difference between the second characteristic value and the threshold value at the first measurement point, and at the second measurement point An abnormality detection system that identifies an abnormal location of the fuel supply device based on the difference between the second characteristic value and the threshold value. The abnormality detection system according to any one of claims 1 to 3,
The control unit
storing period relation information indicating a relationship between an open period in which the pressure regulating device should be in the open state, a closed period in which the pressure regulating device is in the closed state, and the characteristic value;
An anomaly detection system, wherein the threshold is set based on the period-related information. The anomaly detection system according to claim 4,
The control unit
An abnormality detection system that detects an abnormality of the fuel supply device by detecting the characteristic value indicating the operating state of the fuel pump during the closed period and comparing the detected characteristic value with the threshold value. The abnormality detection system according to any one of claims 1 to 5,
The discharge passage has a first discharge passage connected to the fuel supply passage and a second discharge passage connected to the fuel supply passage at a position different from the first discharge passage,
The pressure regulating device has a first pressure regulating device that opens and closes the first discharge passage, and a second pressure regulating device that opens and closes the second discharge passage,
The first pressure regulating device is opened when the pressure of the fuel in the fuel supply passage reaches or exceeds a predetermined first allowable pressure,
The second pressure regulating device is opened when the pressure of the fuel in the fuel supply passage reaches or exceeds a predetermined second allowable pressure different from the first allowable pressure,
The control unit
When the first pressure regulating device or the second pressure regulating device is in an open state, the characteristic value is detected, and an abnormality of the fuel supply device is detected by comparing the detected characteristic value with the threshold value. To detect,
Anomaly detection system.

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