JP2022100039A - Fuel supply device - Google Patents

Abstract

To provide a technique capable of controlling fuel pressure by using a simple configuration while suppressing electric power consumption.SOLUTION: A control section stores relation information indicating a relation between rotational frequency or voltage and an electric current of a motor corresponding to a discharge flow rate of fuel discharged from a fuel pump and a first change point at which the characteristics of the relation information change corresponding to an allowable discharge flow rate, and can control the rotational frequency, the voltage or the electric current of the motor on the basis of the stored relation information and first change point. When a temperature of fuel is lower than a predetermined reference temperature, the control section controls the rotational frequency, the voltage or the electric current of the motor on the basis of the relation information in a region less than the first change point.SELECTED DRAWING: Figure 1

Description

The techniques disclosed herein relate to fuel supply equipment.

Patent Document 1 discloses a fuel supply device. The fuel supply device of Patent Document 1 includes a fuel pump that discharges fuel, a fuel supply passage that supplies fuel discharged from the fuel pump to the fuel injection device, and an discharge passage that discharges a part of the fuel flowing through the fuel supply passage. It is a pressure regulator that opens and closes the discharge passage, and when the pressure of the fuel in the fuel supply passage exceeds a predetermined allowable pressure, it is opened and a part of the fuel in the fuel supply passage is discharged from the discharge passage. It is equipped with a pressure regulator.

Japanese Unexamined Patent Publication No. 2017-002803

The fuel supply device may be equipped with two types of pressure regulators. For example, the fuel supply device has a first pressure regulator that opens when the fuel pressure in the fuel supply passage exceeds the low pressure first allowable pressure, and a second allowable pressure in which the fuel pressure in the fuel supply passage becomes high. It may be equipped with a second pressure adjusting device that opens when the pressure exceeds the pressure. In this configuration, when the fuel is discharged from the fuel pump, the pressure of the fuel in the fuel supply passage is not known, so that the discharge flow rate of the fuel pump may be unnecessarily increased. As a result, the power consumption of the fuel pump may be unnecessarily large. It is also conceivable to use a pressure sensor to detect the pressure of the fuel in the fuel supply passage, but using the pressure sensor complicates the configuration and increases the cost. Therefore, the present specification provides a technique capable of controlling the fuel pressure with a simple configuration while suppressing power consumption.

The fuel supply device disclosed in the present specification is a fuel that supplies fuel to a fuel pump that discharges fuel by rotation of a motor and a high-pressure pump that discharges fuel at a higher pressure than the fuel pump. The supply passage, the first discharge passage for discharging a part of the fuel flowing through the fuel supply passage, the second discharge passage for discharging a part of the fuel flowing through the fuel supply passage, and the first discharge passage are opened and closed. The first pressure adjusting device, which is an open state when the pressure of the fuel in the fuel supply passage becomes equal to or higher than a predetermined first allowable pressure, and discharges the fuel from the first discharging passage. When the discharge flow rate of the fuel discharged from the fuel pump becomes equal to or higher than a predetermined allowable discharge flow rate when the first pressure adjusting device is in the open state, the fuel flow is restricted by limiting the flow of the fuel flowing through the first discharge passage. A flow limiting unit that raises the pressure of the fuel in the supply passage and a second pressure adjusting device that opens and closes the second discharge passage, and the pressure of the fuel in the fuel supply passage is higher than the first allowable pressure. It includes the second pressure adjusting device that is opened when the pressure exceeds a predetermined second allowable pressure and discharges fuel from the second discharge passage, and a control unit that controls the motor of the fuel pump. The control unit has relationship information indicating the relationship between the rotation speed or voltage and the current of the motor corresponding to the discharge flow rate of the fuel discharged from the fuel pump, and the characteristics of the relationship information corresponding to the allowable discharge flow rate. The first change point in which the motor changes is stored, and the rotation speed, voltage, or current of the motor can be controlled based on the stored relationship information and the first change point. When the temperature of the fuel is lower than the predetermined reference temperature, the control unit controls the rotation speed, voltage, or current of the motor based on the relational information in the region below the first change point.

According to this configuration, when the fuel is discharged from the fuel pump, the motor of the fuel pump can be controlled according to the required discharge flow rate. As a result, it is possible to prevent the discharge flow rate of the fuel from increasing unnecessarily, and it is possible to suppress the power consumption of the fuel pump from increasing unnecessarily. In addition, it is possible to prevent the fuel pressure from becoming unnecessarily high. For example, when supplying low pressure fuel to a high pressure pump, the rotation speed, voltage or current of the motor is controlled so that the discharge flow rate is small. This makes it possible to reduce the power consumption of the fuel pump and supply low pressure fuel to the high pressure pump. The fuel pressure can be adjusted to an appropriate pressure without using a pressure sensor.

Further, when the temperature of the fuel is low, the fuel is unlikely to evaporate, so that the pressure of the fuel in the fuel supply passage can be lowered. Therefore, when the fuel temperature is lower than the predetermined reference temperature, the motor is controlled based on the relational information in the region below the first change point. This makes it possible to control the motor in a region where the pressure of the fuel discharged from the fuel pump is low. As a result, the power consumption of the fuel pump can be suppressed. Even if the pressure of the fuel discharged from the fuel pump is low, the high pressure fuel can be discharged from the high pressure pump. From the above, according to the above fuel supply device, it is possible to control the fuel pressure with a simple configuration while suppressing power consumption.

The control unit has a second change in which the characteristics of the related information change according to the discharge flow rate of the fuel discharged from the fuel pump when the pressure of the fuel in the fuel supply passage becomes the second allowable pressure. You may remember the points. When the temperature of the fuel is equal to or higher than the reference temperature, the control unit may control the rotation speed, voltage, or current of the motor based on the relational information in the region of the second change point or higher.

In configurations with high pressure pumps, the heat of the high pressure pumps can increase the temperature of the fuel in the fuel supply passages. When the temperature of the fuel is high, the fuel tends to evaporate. Therefore, when the fuel temperature is equal to or higher than a predetermined reference temperature, the motor is controlled based on the relational information in the region of the second change point or higher. According to this configuration, the motor can be controlled in a region where the pressure of the fuel discharged from the fuel pump is high. As a result, the pressure of the fuel in the fuel supply passage can be increased, and the fuel can be made difficult to evaporate.

The control unit may control the rotation speed, voltage, or current of the motor based on the relational information in the region above the predetermined reference point calculated from the first change point. The reference point is a second change in which the characteristics of the related information change according to the discharge flow rate of the fuel discharged from the fuel pump when the pressure of the fuel in the fuel supply passage becomes the second allowable pressure. It may be located in the area above the point.

According to this configuration, the motor can be controlled in a region where the pressure of the fuel discharged from the fuel pump is high. As a result, the pressure of the fuel in the fuel supply passage can be increased, and the fuel can be made difficult to evaporate.

Even if the control unit corrects the stored relationship information based on the relationship between the rotation speed or voltage and the current of the motor corresponding to the discharge flow rate when the fuel pump actually discharges fuel. good.

According to this configuration, the actual fuel properties and the state of the fuel pump when the fuel pump operates can be reflected in the related information. By controlling the motor of the fuel pump based on this related information, the discharge flow rate of the fuel pump can be controlled with high accuracy.

The control unit corrects the stored first change point based on the relationship between the rotation speed or the voltage and the current of the motor corresponding to the discharge flow rate when the fuel pump actually discharges the fuel. You may.

According to this configuration, the actual fuel properties and the state of the fuel pump when the fuel pump operates can be reflected in the first change point. By controlling the motor of the fuel pump based on this first change point, the discharge flow rate of the fuel pump can be controlled with high accuracy.

The control unit includes a first graph showing the relationship between the rotation speed or voltage and current of the motor corresponding to a discharge flow rate lower than the allowable discharge flow rate when the fuel pump actually discharges fuel, and the allowable discharge rate. Stored based on the difference between the graph change point of the second graph showing the relationship between the rotation speed or voltage and the current of the motor corresponding to the discharge flow rate equal to or higher than the flow rate, and the stored first change point. The first change point may be corrected.

According to this configuration, the correction of the first change point can be performed with high accuracy.

The control unit may calculate the graph change point based on the intersection of the extrapolated line of the first graph and the extrapolated line of the second graph.

Even if the first graph and the second graph are curves, the correction of the first change point can be performed with high accuracy.

The fuel supply device may be mounted on a vehicle equipped with an engine. The control unit may correct the stored related information at least once during the operation of the engine.

According to this configuration, it is possible to reflect the actual properties of the fuel during the operation of the engine and the state of the fuel pump in the related information.

It is a schematic diagram of the fuel supply device which concerns on Example. It is a figure which shows an example of the input signal input to FPC. (A) 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, and (b) a graph showing the relationship between the discharge flow rate of the fuel pump and the current of the motor. It is a graph which shows the relationship between the discharge flow rate of a fuel pump, and the current of a motor. It is a figure explaining the relational information correction processing which concerns on Example. It is a flowchart of the relational information correction processing which concerns on Example. It is a figure which shows an example of the method of calculating a graph change point. It is a schematic diagram of the fuel supply device which concerns on the modification. It is a graph which shows the relationship between the discharge flow rate of a fuel pump and the current of a motor which concerns on a modification.

The fuel supply device 1 according to the embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram of the fuel supply device 1 according to the 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. Further, the fuel supply device 1 includes an FPC (Fuel Pump Controler) 52 and an ECU (Engine Control Unit) 50.

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

The fuel supply device 1 includes a temperature sensor 46 arranged in the engine room of the vehicle. The temperature sensor 46 is, for example, a water temperature sensor, an oil temperature sensor, an intake air temperature sensor, or the like. The water temperature sensor can detect the temperature of the cooling water of the engine 40. The oil temperature sensor 46 can detect the temperature of the oil in the engine 40. The intake air temperature sensor can detect the temperature of the air sucked into the engine 40. Information on the detected temperature of the temperature sensor 46 is transmitted to the ECU 50.

The fuel pump 10 is arranged in the fuel tank 12 and includes a suction port 102 and a discharge port 104. The fuel tank 12 stores liquid fuel (for example, gasoline) for supplying 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 the 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), and the impeller rotates due to the rotation of the motor 16 to suck in and discharge the fuel in the fuel tank 12. The motor 16 is, for example, a sensorless brushless motor or a brushless motor with a sensor, and is a three-phase motor. The motor 16 includes a plurality of (for example, three) coils (not shown), and rotates when a current flows through the plurality of coils in order. The current of the motor 16 (current flowing through a plurality of coils) is detected by a current sensor (not shown). The current sensor includes a resistance for detection (not shown), and detects the current of the motor 16 (current flowing through a plurality of coils) based on the resistance value of the resistance. In the fuel pump 10, the larger the current of the motor 16, the higher the rotation speed of the motor 16 (that is, the higher the rotation speed), and the higher the flow rate of the fuel discharged from the fuel pump 10. The smaller the current of the motor 16, the smaller the rotation speed of the motor 16 (that is, the slower the rotation speed), and the smaller the discharge flow rate of the fuel pump 10. When the motor 16 is a sensorless motor, the rotation speed of the motor 16 is detected, for example, based on the induced voltage at the time of rotation of the motor 16.

The motor 16 of the fuel pump 10 is driven by the FPC 52. The FPC 52 includes a drive circuit 56 for rotationally driving the motor 16. The drive circuit 56 of the FPC 52 controls the motor 16 based on the input signal input from the ECU 50. The drive circuit 56 includes a power supply 64 and a plurality of (for example, six) switches 62. By switching the on and off of the plurality of switches 62 of the drive circuit 56 in order, a current flows through the plurality of coils of the motor 16 in order. This causes the motor 16 to rotate. Since the principle of rotation of the motor 16 is well known, detailed description thereof will be 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 an input signal input to the FPC 52. The input signal shown in FIG. 2 is a signal for switching on and off of 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 ratio of the on-time of the switch 62, and the smaller the duty ratio, the smaller the ratio of the on-time 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 upstream end of the fuel supply passage 30 is connected to the discharge port 104 of the fuel pump 10. The fuel discharged from the fuel pump 10 flows through the fuel supply passage 30. The downstream end of the fuel supply passage 30 is connected to the 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 into 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 (fuel pump 10 side) to the downstream side (engine 40 side) of the check valve 24, and the fuel flows from the downstream side to the upstream side of the check valve 24. Is prohibited from flowing. The high-pressure pump 44 boosts and discharges the fuel supplied through the fuel supply passage 30. The high-pressure pump 44 discharges fuel at a higher pressure than the fuel pump 10. When the high-pressure pump 44 is operating, high-pressure fuel is injected from the fuel injection device 42 into the engine 40.

A first discharge passage 32 and a second discharge passage 34 are connected to the fuel supply passage 30. As the pressure of the fuel in the fuel supply passage 30 increases, the pressure of the fuel in the first discharge passage 32 and the pressure of the fuel in the second discharge passage 34 also increase. When the pressure of the fuel in the fuel supply passage 30 becomes low, the pressure of the fuel in the first discharge passage 32 and the pressure of the fuel in the second discharge passage 34 also become low.

The upstream end of the first discharge passage 32 is connected to the fuel supply passage 30 on the upstream side (fuel pump 10 side) of the check valve 24. A part of the fuel flowing through the fuel supply passage 30 on the upstream side of the check valve 24 flows into the first discharge passage 32. The downstream end of the first discharge passage 32 is arranged in 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 a 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 first pressure adjusting device 20 is provided in the first discharge passage 32. The first pressure adjusting device 20 is composed of, for example, an on-off valve that opens and closes the first discharge passage 32. The first pressure adjusting device 20 is opened when the pressure of the fuel in the first discharging passage 32 on the upstream side (fuel supply passage 30 side) of the first pressure adjusting device 20 becomes equal to or higher than the predetermined first allowable pressure. , When the pressure becomes less than the first allowable pressure, the closed state is obtained. The predetermined first allowable pressure can be appropriately set. The first allowable pressure is a pressure lower than the second allowable pressure described later. When the first pressure adjusting device 20 is opened, a 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 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 adjusting device 20 is closed, fuel is not discharged through the first discharge passage 32.

A throttle 26 (an example of a flow limiting unit) is provided in the first discharge passage 32 on the downstream side (fuel tank 12 side) of the first pressure adjusting device 20. The throttle 26 limits the flow of fuel through the first discharge passage 32. The throttle 26 limits the flow of fuel flowing from the upstream side (fuel supply passage 30 side) to the downstream side (fuel tank 12 side) of the throttle 26. The pressure of the fuel in the first discharge passage 32 on the upstream side of the throttle 26 is higher than the pressure of the fuel in the first discharge passage 32 (or in the fuel tank 12) on the downstream side of the throttle 26. As the flow rate of the fuel flowing through the first discharge passage 32 increases, the pressure of the fuel in the first discharge passage 32 on the upstream side of the throttle 26 increases. The throttle 26 increases the pressure of the fuel in the fuel supply passage 30 by limiting the flow of the fuel through the first discharge passage 32. The rate of increase in fuel pressure can be appropriately set based on the opening diameter of the throttle 26.

The upstream end of the second discharge passage 34 is connected to the fuel supply passage 30 on the downstream side (engine 40 side) of the check valve 24. A part of the fuel flowing through the fuel supply passage 30 on the downstream side of the check valve 24 flows into the second discharge passage 34. The downstream end of the second discharge passage 34 is arranged in the fuel tank 12. The fuel that has flowed through the second discharge passage 34 is discharged into the fuel tank 12 from the downstream end of the second discharge passage 34. The second discharge passage 34 is a passage for discharging a 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 second pressure adjusting device 22 is provided in the second discharge passage 34. The second pressure adjusting device 22 is composed of, for example, an on-off valve that opens and closes the second discharge passage 34. The second pressure adjusting device 22 is opened when the pressure of the fuel in the second discharge passage 34 on the upstream side (fuel supply passage 30 side) of the second pressure adjusting device 22 becomes equal to or higher than the predetermined second allowable pressure. , When the pressure becomes less than the second allowable pressure, the closed state is obtained. The predetermined second allowable pressure can be appropriately set. The second allowable pressure is a pressure higher than the first allowable pressure in the first pressure adjusting device 20 described above. When the second pressure adjusting device 22 is opened, a 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 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 adjusting device 22 is closed, fuel is not discharged through the second discharge passage 34.

The ECU 50 of the fuel supply device 1 includes, for example, a CPU and a memory 54 (ROM or RAM), and executes predetermined control or processing based on a program 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 an input signal for switching on / off of a plurality of switches 62 in the drive circuit 56 of the FPC 52 to the FPC 52. The ECU 50 inputs an input signal having a predetermined duty ratio to the FPC 52. Further, the ECU 50 can estimate the temperature of the fuel in the fuel supply passage 30 supplied to the high pressure pump 44 based on the detected temperature of the temperature sensor 46.

[Operation of fuel supply device 1]
Next, the operation of the fuel supply device 1 will be described. In the fuel supply device 1 described above, the fuel pump 10 in the fuel tank 12 sucks in the fuel in the fuel tank 12 and discharges it into 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 increases the pressure of the supplied fuel and discharges the fuel. The fuel discharged from the high-pressure pump 44 is injected from the fuel injection device 42 into the engine 40. As a result, fuel is supplied to the engine 40.

3A and 3B are a graph showing the relationship between (a) the discharge flow rate (X-axis) of the fuel pump 10 and the fuel pressure (Y-axis) in the fuel supply passage 30, and (b) the discharge flow rate of the fuel pump 10. It is a graph which shows the relationship between (X-axis) and the current (Y-axis) of a motor 16. The discharge flow rate (X-axis) of the fuel pump 10 corresponds to the rotation speed of the motor 16 of the fuel pump 10. Further, the rotation speed 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 device 1, the larger the discharge flow rate of the fuel pump 10, the higher the pressure of the fuel in the fuel supply passage 30, and the smaller the discharge flow rate of the fuel pump 10, the higher 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 larger the duty ratio of the input signal input to the FPC 52, the larger the rotation speed of the motor 16, and the larger the discharge flow rate of the fuel pump 10, the more the motor. The current of 16 becomes large. Further, the smaller the duty ratio of the input signal, the smaller the rotation speed of the motor 16, and the smaller the discharge flow rate of the fuel pump 10, the smaller the current of the motor 16.

Explaining the operation of the fuel supply device 1 in more detail, in the fuel supply device 1, as shown in FIG. 3A, 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 and the second pressure adjusting device 22 are closed, and the pressure of the fuel in the fuel supply passage 30 is relatively low. In the fuel supply device 1, when the discharge flow rate of the fuel pump 10 becomes the first allowable discharge flow rate F1 or more, the pressure of the fuel in the fuel supply passage 30 becomes the first allowable pressure P1 or more, and the pressure causes the first. The first pressure adjusting device 20 that opens and closes the discharge passage 32 is opened. When the first pressure adjusting device 20 is opened, a part of the fuel flowing through the fuel supply passage 30 is discharged into the fuel tank 12 through the first discharge passage 32. As a result, it is possible to prevent the pressure of the fuel in the fuel supply passage 30 from increasing.

In this fuel supply device 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 current of the motor 16 of the fuel pump 10 is C1. Further, as shown in FIG. 4, the duty ratio of the input signal at that time is D1, and the rotation speed of the motor 16 is R1. When the duty ratio of the input signal becomes D1 or more, the rotation speed of the motor 16 becomes R1 or more, and the discharge flow rate of the fuel pump 10 becomes the first allowable discharge flow rate F1 or more, the current of the motor 16 becomes C1 or more.

Further, in the fuel supply device 1, as shown in FIG. 3A, when the discharge flow rate of the fuel pump 10 becomes the second allowable discharge flow rate F2 or more when the first pressure adjusting device 20 is in the open state, the fuel supply passage. The pressure of the fuel in 30 becomes higher. In the fuel supply device 1, the flow of fuel flowing through the first discharge passage 32 is restricted by the throttle 26 provided in the first discharge passage 32, whereby the fuel in the first discharge passage 32 and the fuel supply passage 30 is restricted. The pressure rises.

In this fuel supply device 1, as shown in FIG. 3B, when the discharge flow rate of the fuel pump 10 is the second allowable discharge flow rate F2, the current of the motor 16 of the fuel pump 10 is C2. Further, as shown in FIG. 4, the duty ratio of the input signal at that time is D2, and the rotation speed of the motor 16 is R2. When the duty ratio of the input signal becomes D2 or more, the rotation speed of the motor 16 becomes R2 or more, and the discharge flow rate of the fuel pump 10 becomes the second allowable discharge flow rate F2 or more, the current of the motor 16 becomes C2 or more.

Further, in the fuel supply device 1, as shown in FIG. 3A, when the discharge flow rate of the fuel pump 10 becomes the third allowable discharge flow rate F3 or more, the pressure of the fuel in the fuel supply passage 30 becomes the second allowable rate. The pressure becomes P2 or higher, and the pressure causes the second pressure adjusting device 22 that opens and closes the second discharge passage 34 to open. When the second pressure adjusting device 22 is opened, a part of the fuel flowing through the fuel supply passage 30 is discharged into the fuel tank 12 through the second discharge passage 34. As a result, it is possible to prevent the pressure of the fuel in the fuel supply passage 30 from increasing.

In this fuel supply device 1, as shown in FIG. 3B, when the discharge flow rate of the fuel pump 10 is the third allowable discharge flow rate F3, the current of the motor 16 of the fuel pump 10 is C3. Further, as shown in FIG. 4, the duty ratio of the input signal at that time is D3, and the rotation speed of the motor 16 is R3. When the duty ratio of the input signal becomes D3 or more, the rotation speed of the motor 16 becomes R3 or more, and the discharge flow rate of the fuel pump 10 becomes the third allowable discharge flow rate F3 or more, the current of the motor 16 becomes C3 or more.

In the fuel supply device 1 described above, when the discharge flow rate of the fuel pump 10 decreases, the operation is opposite to the above operation. The ECU 50 of the fuel supply device 1 can store the graph shown in FIG. 3B as related information in the memory 54 during the operation of the fuel supply device 1.

[Control of fuel supply device 1]
Next, the control of the fuel supply device 1 will be described. In the fuel supply device 1, the ECU 50 controls the discharge flow rate of the fuel pump 10 by inputting a predetermined input signal to the FPC 52. The ECU 50 controls the pressure of the fuel in the fuel supply passage 30 supplied to the high-pressure pump 44 by controlling the discharge flow rate of the fuel pump 10.

The ECU 50 stores the graph shown in FIG. 4 in the memory 54 as related information. The relationship information is generated, for example, during the operation of the fuel supply device 1. In the variant, the relationship information may be generated based on experimentation or analysis. Further, the relational information may be the relational information after the relational information correction processing (see FIG. 6) described later is executed. The ECU 50 inputs an input signal to the FPC 52 based on the relational information shown in FIG. As shown in FIG. 4, the larger the duty ratio of the input signal input to the FPC 52, the higher the rotation speed of the motor 16 of the fuel pump 10 and the larger the discharge flow rate of the fuel pump 10. In addition, the current of the motor 16 becomes large. The smaller the duty ratio of the input signal, the smaller the rotation speed of the motor 16 of the fuel pump 10, and the smaller the discharge flow rate of the fuel pump 10. Further, the current of the motor 16 becomes small.

The ECU 50 stores the low-side change point T1, the intermediate change point T2, and the high-side change point T3 in which the characteristics of the related information change in the memory 54. The low side change point T1, the intermediate change point T2, and the high side change point T3 are points where the slope and intercept of the graph of the relational information change. The low side change point T1 is a point where the characteristics of the related information change according to the first allowable discharge flow rate F1. The intermediate change point T2 is a point where the characteristics of the related information change according to the second allowable discharge flow rate F2. The high side change point T3 is a point where the characteristics of the related information change in accordance with the third allowable discharge flow rate F3.

The ECU 50 stores the first reference value D1, the second reference value D2, and the third reference value D3 in the memory 54 regarding the duty ratio of the input signal input to the FPC 52. The first reference value D1, the second reference value D2, and the third reference value D3 correspond to the low side change point T1, the intermediate change point T2, and the high side change point T3, respectively. The first reference value D1 is the duty ratio of the input signal corresponding to the first allowable discharge flow rate F1. Similarly, the second reference value D2 is the duty ratio of the input signal corresponding to the second allowable discharge flow rate F2, and the third reference value D3 is the duty ratio of the input signal corresponding to the third allowable discharge flow rate F3.

The ECU 50 further stores in the memory 54 the rotation speed of the motor 16 corresponding to each change point T1, T2, T3, the discharge flow rate of the fuel pump 10, and the current of the motor 16.

In the fuel supply device 1, the ECU 50 determines the discharge flow rate of the fuel pump 10 based on, for example, information regarding the load of the engine 40. For example, the ECU 50 determines the discharge flow rate of the fuel pump 10 based on the air-fuel ratio of the exhaust gas discharged from the engine 40. The ECU 50 inputs a duty ratio input signal corresponding to the determined discharge flow rate of the fuel pump 10 to the FPC 52 based on the relational information shown in FIG.

For example, when the fuel of the first allowable discharge flow rate F1 is discharged from the fuel pump 10, the ECU 50 inputs an input signal of the duty ratio D1 corresponding to the first allowable discharge flow rate F1 to the FPC 52. In the fuel supply device 1, fuel having a discharge flow rate (for example, F1) corresponding to the duty ratio (for example, D1) of the input signal is discharged from the fuel pump 10. The fuel discharged from the fuel pump 10 flows through the fuel supply passage 30 and is supplied to the high pressure pump 44. The high-pressure pump 44 boosts and discharges the supplied fuel. The fuel discharged from the high-pressure pump 44 is injected from the fuel injection device 42 into the engine 40.

Further, the ECU 50 may determine an input signal to be input to the FPC 52 based on the reference values D1-D4 stored in the memory 54. For example, when the ECU 50 discharges fuel having a discharge flow rate less than the second allowable discharge flow rate F2 from the fuel pump 10, the ECU 50 determines an input signal to be input to the FPC 52 as an input signal having a duty ratio less than the second reference value D2. .. The ECU 50 inputs an input signal having a duty ratio less than the determined second reference value D2 to the FPC 52.

Further, the ECU 50 determines the input signal to be input to the FPC 52 as the input signal having the duty ratio of the third reference value D3 or more when the fuel having the discharge flow rate of the third allowable discharge flow rate F3 or more is discharged from the fuel pump 10. .. The ECU 50 inputs an input signal having a duty ratio equal to or higher than the determined third reference value D3 to the FPC 52.

The ECU 50 may determine the discharge flow rate of the fuel pump 10 based on the temperature of the fuel in the fuel supply passage 30 supplied to the high pressure pump 44. Specifically, when the fuel temperature is less than a predetermined reference temperature (for example, 70 ° C.), the ECU 50 determines the discharge flow rate of the fuel pump 10 to be less than the second allowable discharge flow rate F2. The predetermined reference temperature can be appropriately set according to the type and properties of the fuel. The fuel temperature is estimated by the ECU 50 based on the temperature detected by the temperature sensor 46.

When the fuel temperature is lower than the predetermined reference temperature, the ECU 50 controls the motor 16 of the fuel pump 10 based on the relational information in the region below the intermediate change point T2 corresponding to the second allowable discharge flow rate F2. The ECU 50 inputs an input signal having a duty ratio less than the second reference value D2 corresponding to the intermediate change point T2 to the FPC 52. As a result, the rotation speed of the motor 16 of the fuel pump 10 becomes a rotation speed less than the rotation speed R2 corresponding to the intermediate change point T2. Further, the discharge flow rate of the fuel pump 10 becomes a discharge flow rate less than the second allowable discharge flow rate F2 corresponding to the intermediate change point T2. Further, the current of the motor 16 becomes a current less than the current C2 corresponding to the intermediate change point T2. Then, the pressure of the fuel in the fuel supply passage 30 supplied to the high-pressure pump 44 is suppressed to be low (see FIG. 3).

When the motor 16 is a sensorless motor, the FPC 52 is directed toward a target rotation speed set by the duty ratio of the input signal instructed by the ECU 50 based on the rotation speed of the motor 16 detected based on the induced voltage. The motor 16 is controlled at any time. As a result, the ECU 50 sets the rotation speed of the motor 16 so that the discharge flow rate of the fuel pump 10 is less than the second allowable discharge flow rate F2 (that is, the rotation speed of the motor 16 is less than R2). Feedback control is performed at any time.

In the modification, the FPC 52 may control the duty ratio of the input signal at any time based on the current of the motor 16 detected by the current sensor. As a result, the FPC 52 feeds back the current of the motor 16 at any time so that the discharge flow rate of the fuel pump 10 becomes less than the second allowable discharge flow rate F2 (that is, the current of the motor 16 becomes less than C2). Control. Further, the FPC 52 aims at the target rotation speed set by the duty ratio of the input signal instructed by the ECU 50 based on the current of the motor 16 detected by the current sensor and the rotation speed-current map stored in the ECU 50. The motor 16 may be controlled at any time.

When the fuel temperature is equal to or higher than a predetermined reference temperature, the ECU 50 controls the motor 16 of the fuel pump 10 based on the relationship information in the region of the high side change point T3 or higher corresponding to the third allowable discharge flow rate F3. The ECU 50 inputs an input signal having a duty ratio of the third reference value D3 or more corresponding to the high side change point T3 to the FPC 52. As a result, the rotation speed of the motor 16 of the fuel pump 10 becomes the rotation speed of the rotation speed R3 or more corresponding to the high side change point T3. Further, the discharge flow rate of the fuel pump 10 becomes a discharge flow rate equal to or higher than the third allowable discharge flow rate F3 corresponding to the high side change point T3. Further, the current of the motor 16 becomes a current equal to or higher than the current C3 corresponding to the high side change point T3. Then, the pressure of the fuel in the fuel supply passage 30 supplied to the high-pressure pump 44 becomes a pressure equal to or higher than the second allowable pressure P2 corresponding to the high-side change point T3 (see FIG. 3).

[effect]
According to the fuel supply device 1 described above, when the fuel is discharged from the fuel pump 10, an input signal corresponding to a required discharge flow rate can be input to the FPC 52. As a result, it is possible to suppress the discharge flow rate of the fuel pump 10 from becoming unnecessarily large, and it is possible to suppress the power consumption of the fuel pump 10 from becoming unnecessarily large. In addition, it is possible to prevent the fuel pressure from becoming unnecessarily high. For example, when injecting low pressure fuel from the fuel injection device 42, the power consumption of the fuel pump 10 is reduced by inputting an input signal corresponding to a small discharge flow rate to the FPC 52 based on the related information. Low pressure fuel can be injected. The fuel pressure can be appropriately controlled without using a separate pressure sensor. Therefore, according to the fuel supply device 1 described above, it is possible to control the fuel pressure with a simple configuration while suppressing power consumption.

Further, when the temperature of the fuel is low, the fuel is unlikely to evaporate, so that the pressure of the fuel in the fuel supply passage 30 can be lowered. Therefore, when the fuel temperature is lower than the predetermined reference temperature, the ECU 50 controls the motor 16 based on the relational information in the region below the intermediate change point T2. The intermediate change point T2 is a point where the characteristics of the related information change according to the second allowable discharge flow rate F2. According to this configuration, the motor 16 can be controlled in a region where the pressure of the fuel discharged from the fuel pump 10 is low. As a result, the power consumption of the fuel pump 10 can be suppressed. Even if the pressure of the fuel discharged from the fuel pump 10 is low, the high pressure fuel can be discharged from the high pressure pump 44. Therefore, it is possible to control the fuel pressure with a simple configuration while suppressing power consumption.

In the fuel supply device 1, the pressure of the fuel can be controlled to some extent by the presence of the first pressure adjusting device 20 and the second pressure adjusting device 22, but further by inputting an input signal to the FPC 52 based on the related information. The fuel pressure can be controlled accurately. In addition, power consumption can be suppressed.

When the fuel temperature is equal to or higher than the reference temperature, the ECU 50 controls the motor 16 based on the relational information in the region of the high side change point T3 or higher. The high side change point T3 is a point where the characteristics of the related information change in accordance with the third allowable discharge flow rate F3. The third allowable discharge flow rate F3 is the discharge flow rate of the fuel pump 10 when the pressure of the fuel in the fuel supply passage 30 becomes the second allowable pressure P2. According to this configuration, the motor 16 can be controlled in a region where the pressure of the fuel discharged from the fuel pump 10 is high. As a result, the pressure of the fuel in the fuel supply passage 30 can be increased, and the fuel can be made difficult to evaporate.

[Relationship information correction processing]
Next, the relational information correction process executed by the fuel supply device 1 will be described. The relationship information correction process is a process for correcting the relationship information (see FIG. 4) stored in the memory 54.

In the fuel supply device 1, the relationship between the discharge flow rate of the fuel pump 10 and the current of the motor 16 may change, for example, depending on the properties of the fuel, the degree of deterioration of the fuel pump 10, and the like. That is, the relationship between the rotation speed of the motor 16 of the fuel pump 10 and the current of the motor 16 and the relationship between the duty ratio of the input signal and the current of the motor 16 may change. Therefore, these relationships may differ between the past and the present. For example, even if the discharge flow rate of the fuel pump 10, the rotation speed of the motor 16, and the duty ratio of the input signal are the same in the past and present, the current current of the motor 16 may be larger than the past current. In this case, in the fuel supply device 1, the ECU 50 can correct the related information stored in the memory 54.

Here, as shown in FIG. 5, it is assumed that the ECU 50 stores the relational information Hn _-1 before the correction. The relationship information H _n-1 before correction is, for example, information generated when the fuel pump 10 has discharged fuel in the past. Alternatively, the relationship information H _n-1 before correction may be information generated based on an experiment or analysis. Further, the relational information Hn _-1 before the correction may be the relational information after the relational information correction processing (see FIG. 6) has been executed in the past.

The relationship information H _n-1 before correction includes information of a plurality of graphs G1 _n-1 , G2 _n-1 , G3 _n-1 , and G4 _n-1 . Graph G1 _n-1 is a graph in the range of less than the first allowable discharge flow rate F1. Further, the graph G2 _n-1 is a graph in the range of the first allowable discharge flow rate F1 or more and less than the second allowable discharge flow rate F2, and the graph G3 _n-1 is the second allowable discharge flow rate F2 or more and the third allowable discharge flow rate F2 or less. It is a graph in the range of less than the flow rate F3, and the graph G4 _n-1 is a graph in the range of the third allowable discharge flow rate F3 or more.

Further, the relationship information H _n-1 before correction includes information on a plurality of graph change points T1 _n-1 , T2 _n-1 , and T3 _n-1 . The graph change point T1 _n-1 is a portion where the graph G1 _n-1 changes to the graph G2 _n-1 . Further, the graph change point T2 _n-1 is a portion where the graph G2 _n-1 changes to the graph G3 _n-1 , and the graph change point T3 _n-1 changes from the graph G3 _n-1 to the graph G4 _n-1 . It's a changing part.

FIG. 6 is a flowchart of the related information correction process according to the embodiment. The relationship information correction process is started, for example, when the high-pressure pump 44 of the fuel supply device 1 is started, and is executed during the operation of the high-pressure pump 44. As shown in FIG. 6, in S2 of the relational information correction process, the ECU 50 determines whether or not a predetermined execution condition is satisfied. For example, when the engine 40 is operating and the fuel pump 10 is operating, a predetermined execution condition is satisfied. If YES in S2, the ECU 50 proceeds to S4, and if NO, waits.

In the following S4, the FPC 52 controls the fuel pump 10 so that the discharge flow rate of the fuel pump 10 becomes a predetermined target discharge flow rate. The target discharge flow rate is an arbitrary discharge flow rate. For example, the FPC 52 controls the fuel pump 10 with a discharge flow rate equal to or higher than the third allowable discharge flow rate F3 as a target discharge flow rate. When the discharge flow rate of the fuel pump 10 becomes the third allowable discharge flow rate F3 or more, the pressure of the fuel in the fuel supply passage 30 becomes the second allowable pressure P2 or more (see FIG. 3).

The discharge flow rate of the fuel pump 10 corresponds to the rotation speed of the motor 16. Therefore, in S4, the FPC 52 controls the motor 16 so that the rotation speed of the motor 16 becomes a predetermined target rotation speed. The target rotation speed corresponds to the target discharge flow rate. Further, in S4, the ECU 50 specifies the duty ratio of the input signal when the discharge flow rate of the fuel pump 10 reaches the target discharge flow rate (that is, when the rotation speed of the motor 16 reaches the target rotation speed).

In the following S6, the ECU 50 specifies the current of the motor 16 when the discharge flow rate of the fuel pump 10 reaches the target discharge flow rate (that is, when the rotation speed of the motor 16 reaches the target rotation speed). By the processing of S4 and S6, the relationship between the discharge flow rate of the fuel pump 10, the rotation speed of the motor 16, the duty ratio of the input signal, and the current of the motor 16 is specified. The ECU 50 stores the specified relationship in the memory 54.

In the following S8, the ECU 50 determines whether or not the current of the motor 16 specified in S6 is within a predetermined allowable range. The ECU 50 proceeds to S10 if YES in S8, and proceeds to S30 if NO in S8. In S30 after NO in S8, the ECU 50 turns on the warning light. The warning light is provided, for example, on the instrument panel of the vehicle. The processing of S8 may be omitted.

In S10 after YES in S8, the ECU 50 lowers the target discharge flow rate of the fuel pump 10 to set a new target discharge flow rate (that is, lowers the target rotation speed of the motor 16 to set a new target rotation speed). ). The target discharge flow rate and the target rotation speed reduction range can be set as appropriate. In the following S12, similarly to the above S4, the FPC 52 fuels the fuel pump 10 so that the discharge flow rate becomes the new target discharge flow rate (that is, the rotation speed of the motor 16 becomes the new target rotation speed). Control the pump 10. Further, in S12, the ECU 50 specifies the duty ratio of the input signal when the discharge flow rate of the fuel pump 10 reaches the target discharge flow rate (that is, when the rotation speed of the motor 16 reaches the target rotation speed). In the following S14, similarly to the above S6, the ECU 50 determines the current of the motor 16 when the discharge flow rate of the fuel pump 10 reaches the target discharge flow rate (that is, when the rotation speed of the motor 16 reaches the target rotation speed). To identify.

By the processing of S10, S12, and S14, the relationship between the discharge flow rate of the fuel pump 10, the rotation speed of the motor 16, the duty ratio of the input signal, and the current of the motor 16 is specified. The ECU 50 stores the specified relationship in the memory 54.

After that, the ECU 50 repeats the above processes of S10, S12, and S14 over a predetermined range. In the ECU 50, for example, the discharge flow rate of the fuel pump 10 is in the range of the third allowable discharge flow rate F3 or more (see FIG. 5), the range of less than the third allowable discharge flow rate F3 and the range of the second allowable discharge flow rate F2 or more, and the second allowable discharge flow rate. The processing of S10, S12, and S14 is repeated for the range of less than F2 and the first allowable discharge flow rate F1 or more, and the range of less than the first allowable discharge flow rate F1. The number of repetitions is not particularly limited.

In the following S16, the ECU 50 calculates a plurality of graphs G4 _n , G3 _n , G2 _n , and G1 _n (see FIG. 5). For example, the ECU 50 can calculate the graph G3 _n by repeating the processes of S10, S12, and S14 over a range in which the discharge flow rate of the fuel pump 10 is less than the third allowable discharge flow rate F3 and the second allowable discharge flow rate F2 or more. can. Further, the ECU 50 calculates the graph G2 _n by repeating the above processes of S10, S12, and S14 over a range in which the discharge flow rate of the fuel pump 10 is less than the second allowable discharge flow rate F2 and equal to or larger than the first allowable discharge flow rate F1. be able to. The ECU 50 calculates graphs G3 _n and G2 _n based on, for example, mathematical processing. The same applies to the other plurality of graphs G4 _n and G1 _n . In the modified example, the ECU 50 may be configured to calculate only a part of the graph. The ECU 50 does not necessarily have to calculate all the graphs G4 _n , G3 _n , G2 _n , and G1 _n .

In the following S18, the ECU 50 calculates a plurality of graph change points T3 _n , T2 _n , and T1 _n (see FIG. 5). For example, when the graphs G3 _n and G2 _n are straight lines, the ECU 50 calculates the intersection of the graphs G3 _n and G2 _n as the graph change point T2 _n . Further, as shown in FIG. 7, when the graphs G3 _n and G2 _n are curves, the ECU 50 sets the intersection of the extrapolation line L3 of the graph G3 _n and the extrapolation line L2 of the graph G2 _n as the graph change point T2. It may be calculated as _n . The ECU 50 calculates the graph change point _T2n based on, for example, mathematical processing. The same applies to the other plurality of graph change points T3 _n and T1 _n . In the modified example, the ECU 50 may be configured to calculate only a part of the graph change points. The ECU 50 does not necessarily have to calculate all the graph change points T3 _n , T2 _n , and T1 _n .

In the following S20, the ECU 50 corrects the relational information Hn _-1 stored in the memory 54 based on the information acquired in the processes of S16 and S18 described above. The ECU 50 can correct the relational information Hn _-1 based on, for example, mathematical processing. The method for correcting the relational information H _n-1 is not particularly limited.

For example, the ECU 50 is based on the difference between the current C2 n of the motor 16 corresponding to the graph change point T2 _n shown in FIG. 5 and the current C2 _{n -} 1 of the motor 16 corresponding to the graph change point T2 _n-1 . The relationship information H _n-1 may be corrected. The ECU 50 may translate the relationship information H _n-1 by the difference between C2 _n and C2 _n-1 . As a result, the ECU 50 can acquire the corrected relationship information _Hn . Further, the ECU 50 may correct the intermediate change point T2 _n-1 before correction to a new intermediate change point T2 _n .

Further, the ECU 50 may correct the relationship information H _n-1 based on the difference between the currents C2 _n and C2 _n-1 of the motor 16 and the difference between C3 _n and C3 _n-1 . For example, the ECU 50 may reflect the slope of the graph G3 _n in each of the graphs G1 _n-1 , G2 _n-1 , and G4 _n-1 at a predetermined ratio. As a result, the ECU 50 may acquire the corrected relationship information _Hn .

Further, the ECU 50 may correct the relational information H _n-1 based on the graph G4 _n . For example, the ECU 50 may reflect the difference between the graph G4 _n and the graph G4 _n-1 in each of the graphs G1 _n-1 , G2 _n-1 , and G3 _n-1 at a predetermined ratio.

[effect]
According to the fuel supply device 1 described above, the relational information Hn _-1 is corrected based on the relationship between the rotation speed and the current of the motor 16 corresponding to the discharge flow rate when the fuel pump 10 actually discharges the fuel. Therefore, the actual properties of the fuel and the state of the fuel pump 10 can be reflected in the corrected relationship information _Hn . By controlling the fuel pump 10 based on the corrected relationship information _Hn , the fuel pump 10 can be controlled with high accuracy. Therefore, it is possible to reliably aim at the pressure adjusting region of the first pressure adjusting device 20 and the pressure adjusting region of the second pressure adjusting device 22, and it is possible to accurately control the fuel discharge flow rate and the pressure.

Further, according to the fuel supply device 1 described above, the intermediate change point T2 _n-1 is set based on the relationship between the rotation speed and the current of the motor 16 corresponding to the discharge flow rate when the fuel pump 10 actually discharges the fuel. By making the correction, the actual properties of the fuel and the state of the fuel pump 10 can be reflected in the corrected intermediate change point T2 _n . By determining the input signal based on the corrected intermediate change point T2 _n , the fuel discharge flow rate and the pressure can be controlled with high accuracy.

Further, according to the fuel supply device 1 described above, the graph G3 _n is calculated by calculating the graph change point T2 _n based on the intersection of the extrapolation line L3 of the graph G3 _n and the extrapolation line L2 of the graph G2 _n . Even if the graph G2 _n is a curve, the intermediate change point T2 _n-1 can be corrected with high accuracy.

Further, in the fuel supply device 1, the ECU 50 may execute the above-mentioned relationship information correction process (see FIG. 6) a plurality of times while the engine 40 of the vehicle is operating. By correcting the relational information _n-1 at least once during the operation of the engine 40, the actual properties of the fuel during the operation of the engine 40 and the state of the fuel pump 10 can be reflected in the relational information _Hn .

[Correspondence]
The graphs shown in FIGS. 4 and 5 are examples of “relationship information”. The intermediate change point T2 is an example of the "first change point". The high side change point T3 is an example of the "second change point". Graph G2 _n is an example of the “first graph”. Graph G3 _n is an example of the “second graph”. The ECU 50 and the FPC 52 are examples of the control unit.

Although one embodiment has been described above, the specific embodiment is not limited to the above embodiment. In the following description, the same components as those in the above description will be designated by the same reference numerals and the description thereof will be omitted.

[Modification example]
(1) In the above embodiment, the second discharge passage 34 is connected to the fuel supply passage 30 on the downstream side of the check valve 24 (see FIG. 1), but in the modified example, as shown in FIG. The second discharge passage 34 may be connected to the fuel supply passage 30 on the upstream side of the check valve 24. Further, in the modified example, the fuel supply device 1 may include a plurality of (for example, two) first discharge passages 32. One first discharge passage 32 is connected to the fuel supply passage 30 on the upstream side of the check valve 24, and the other first discharge passage 32 is connected to the fuel supply passage 30 on the downstream side of the check valve 24. It may have been done.

(2) The temperature sensor 46 may be configured to directly detect the temperature of the fuel in the fuel supply passage 30 supplied to the high pressure pump 44. The ECU 50 may be configured to actually measure the temperature of the fuel in the fuel supply passage 30 supplied to the high-pressure pump 44 based on the detected temperature of the temperature sensor 46.

(3) In the above embodiment, the ECU 50 controls the discharge flow rate of the fuel pump 10 by controlling the rotation speed of the motor 16. In the modified example, the ECU 50 may be configured to control the discharge flow rate of the fuel pump 10 by controlling the voltage of the motor 16 (that is, the voltage applied to the motor 16). In this case, the rotation speed of the X-axis motor 16 in the graphs shown in FIGS. 3B, 4 and 5 is replaced with the voltage of the motor 16.

(4) As shown in FIG. 9, the ECU 50 may store a predetermined reference point V in the memory 54 for the related information. The predetermined reference point V is a point in the region of the high side change point T3 or higher in the relational information. The reference point V is calculated based on the intermediate change point T2. For example, the ECU 50 calculates the reference point V from the intermediate change point T2 during the control of the fuel supply device 1. The calculation method of the reference point V is not particularly limited.

The ECU 50 may store the fourth reference value D4 in the memory 54 for the duty ratio of the input signal input to the FPC 52. The fourth reference value D4 corresponds to the reference point V. The fourth reference value D4 is the duty ratio of the input signal corresponding to the predetermined discharge flow rate F4 equal to or higher than the third allowable discharge flow rate F3. The ECU 50 may further store the rotation speed of the motor 16 corresponding to the reference point V, the discharge flow rate of the fuel pump 10, and the current of the motor 16 in the memory 54.

When the fuel temperature is equal to or higher than a predetermined reference temperature, the ECU 50 may control the motor 16 of the fuel pump 10 based on the relational information in the region of the reference point V or higher. The ECU 50 inputs an input signal having a duty ratio of the fourth reference value D4 or more corresponding to the reference point V to the FPC 52. As a result, the rotation speed of the motor 16 of the fuel pump 10 becomes the rotation speed of the rotation speed R4 or more corresponding to the reference point V. Further, the discharge flow rate of the fuel pump 10 becomes a discharge flow rate equal to or higher than the discharge flow rate F4 corresponding to the reference point V. Further, the current of the motor 16 becomes a current equal to or higher than the current C4 corresponding to the reference point V. Then, the pressure of the fuel in the fuel supply passage 30 supplied to the high-pressure pump 44 becomes a pressure equal to or higher than the second allowable pressure P2 (see FIG. 3).

According to this configuration, the motor 16 can be controlled in a region where the pressure of the fuel discharged from the fuel pump 10 is high. As a result, the pressure of the fuel in the fuel supply passage 30 can be increased, and the fuel can be made difficult to evaporate.

(5) The ECU 50 does not have to store the low-side change point T1 and the high-side change point T3 in the memory 54.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples exemplified above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques exemplified in the present specification or the drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

1: Fuel supply device, 10: Fuel pump, 12: Fuel tank, 16: Motor, 20: First pressure regulator, 22: Second pressure regulator, 24: Check valve, 26: Squeeze, 30: Fuel supply Passage, 32: 1st discharge passage, 34: 2nd discharge passage, 36: branch passage, 40: engine, 42: fuel injection device, 44: high pressure pump, 46: temperature sensor, 50: ECU, 52: FPC, 54 :memory

Claims (8)

A fuel pump that discharges fuel by rotating the motor,
A fuel supply passage for supplying the fuel discharged from the fuel pump to a high-pressure pump that discharges the fuel at a higher pressure than the fuel pump.
A first discharge passage that discharges a part of the fuel flowing through the fuel supply passage, and
A second discharge passage that discharges a part of the fuel flowing through the fuel supply passage, and
It is a first pressure adjusting device that opens and closes the first discharge passage, and when the pressure of the fuel in the fuel supply passage becomes equal to or higher than a predetermined first allowable pressure, it is opened and the fuel is discharged from the first discharge passage. With the first pressure adjusting device
When the discharge flow rate of the fuel discharged from the fuel pump becomes equal to or higher than a predetermined allowable discharge flow rate when the first pressure adjusting device is in the open state, the fuel supply is performed by limiting the flow of fuel flowing through the first discharge passage. A flow limiting part that raises the pressure of fuel in the passage,
A second pressure adjusting device that opens and closes the second discharge passage, and is opened when the pressure of the fuel in the fuel supply passage becomes higher than the first allowable pressure and becomes a predetermined second allowable pressure or higher. The second pressure regulator that discharges fuel from the second discharge passage,
A control unit for controlling the motor of the fuel pump is provided.
The control unit has relational information indicating the relationship between the rotation speed or voltage and the current of the motor corresponding to the discharge flow rate of the fuel discharged from the fuel pump, and the characteristics of the relational information corresponding to the allowable discharge flow rate. The first change point in which the motor changes is stored, and the rotation speed, voltage, or current of the motor can be controlled based on the stored relationship information and the first change point.
When the temperature of the fuel is lower than a predetermined reference temperature, the control unit controls the rotation speed, voltage, or current of the motor based on the relational information in the region below the first change point. .. The fuel supply device according to claim 1.
The control unit has a second change in which the characteristics of the related information change according to the discharge flow rate of the fuel discharged from the fuel pump when the pressure of the fuel in the fuel supply passage becomes the second allowable pressure. When the point is stored and the fuel temperature is equal to or higher than the reference temperature, the fuel supply controls the rotation speed, voltage or current of the motor based on the relational information in the region of the second change point or higher. Device. The fuel supply device according to claim 1 or 2.
The control unit controls the rotation speed, voltage, or current of the motor based on the relational information in the region above the predetermined reference point calculated from the first change point.
The reference point is a second change in which the characteristics of the related information change according to the discharge flow rate of the fuel discharged from the fuel pump when the pressure of the fuel in the fuel supply passage becomes the second allowable pressure. A fuel supply system located in the area above the point. The fuel supply device according to any one of claims 1 to 3.
The control unit corrects the stored relational information based on the relation between the rotation speed or the voltage and the current of the motor corresponding to the discharge flow rate when the fuel pump actually discharges the fuel. Feeding device. The fuel supply device according to claim 4.
The control unit corrects the stored first change point based on the relationship between the rotation speed or the voltage and the current of the motor corresponding to the discharge flow rate when the fuel pump actually discharges the fuel. , Fuel supply device. The fuel supply device according to claim 5.
The control unit includes a first graph showing the relationship between the rotation speed or voltage and current of the motor corresponding to a discharge flow rate lower than the allowable discharge flow rate when the fuel pump actually discharges fuel, and the allowable discharge rate. Stored based on the difference between the graph change point of the second graph showing the relationship between the rotation speed or voltage and the current of the motor corresponding to the discharge flow rate equal to or higher than the flow rate, and the stored first change point. A fuel supply device that corrects the first change point. The fuel supply device according to claim 6.
The control unit is a fuel supply device that calculates the graph change point based on the intersection of the extrapolated line of the first graph and the extrapolated line of the second graph. The fuel supply device according to claim 4, which is mounted on a vehicle equipped with an engine.
The control unit is a fuel supply device that corrects the stored related information at least once during the operation of the engine.

Images