JP2022154288A - Fuel supply device - Google Patents

Abstract

To properly detect an abnormality of a fuel supply device.SOLUTION: A fuel supply device has: an injector arranged at an engine; a first fuel pump connected to the injector via a fuel supply path; a second fuel supply pump arranged at the fuel supply path; an air-fuel ratio sensor arranged at an exhaust system of the engine; and a control system having a processor and a memory which are connected to each other so as to be communicative with each other. The control system calculates an estimation work rate of the first fuel supply pump on the basis of an operation status of the injector, and the control system calculates an actual work rate of the first fuel supply pump on the basis of an operation status of the first fuel supply pump. When the actual work rate exceeds the estimation work rate, and the air-fuel ratio is shifted to a lean side rather than a threshold, the control system stops the first fuel supply pump.SELECTED DRAWING: Figure 7

Description

The present invention relates to a fuel supply system for supplying fuel to an engine.

An engine, which is an internal combustion engine, is provided with a fuel supply system including a low-pressure fuel pump, a high-pressure fuel pump, and the like. Fuel in the fuel tank is supplied to the injector through a low-pressure fuel pump and a high-pressure fuel pump (see Patent Documents 1 and 2).

JP-A-2010-53741 JP 2006-161675 A

Incidentally, when an abnormality such as fuel leakage occurs in the fuel supply system, it is necessary to take measures such as stopping the engine. Therefore, it is required to appropriately detect an abnormality in the fuel supply device.

SUMMARY OF THE INVENTION An object of the present invention is to appropriately detect an abnormality in a fuel supply system.

A fuel supply device of one embodiment is a fuel supply device that supplies fuel to an engine, and includes an injector that is provided in the engine and injects fuel, and is connected to the injector via a fuel supply path to pressure-feed the fuel. A first fuel pump, a second fuel pump provided in the fuel supply path for pumping fuel, and an air-fuel ratio sensor provided in the exhaust system of the engine for detecting an air-fuel ratio are connected so as to be able to communicate with each other. a control system, comprising a processor and memory, for controlling the injector, the first fuel pump and the second fuel pump, wherein the control system controls the operation of the first fuel pump based on operating conditions of the injector; , the control system calculates an actual power of the first fuel pump based on the operating state of the first fuel pump, and the control system determines that the actual power is the estimated When the power exceeds the power and the air-fuel ratio is leaner than the threshold, the first fuel pump is stopped.

One embodiment of the fuel delivery system has a control system with a processor and memory. The control system calculates an estimated power of the first fuel pump based on the operating state of the injector, and the control system calculates the actual power of the first fuel pump based on the operating state of the first fuel pump. , the control system stops the first fuel pump when the actual power exceeds the estimated power and the air-fuel ratio is leaner than the threshold. As a result, it is possible to appropriately detect an abnormality in the fuel supply device.

1 is a diagram showing a configuration example of a vehicle equipped with a fuel supply system according to an embodiment of the invention; FIG. It is a figure which shows the structural example of a fuel supply apparatus. FIG. 4 is a diagram showing the operating state of the high-pressure fuel pump; FIG. 4 is a diagram showing the operating state of the high-pressure fuel pump; FIG. 4 is a diagram showing the operating state of the high-pressure fuel pump; It is the figure which showed simply the structure of each control unit. FIG. 4 is a diagram showing an example of the relationship between the fuel pressure in the distribution pipe and the rotation speed of the low-pressure fuel pump; 4 is a flow chart showing an example of an execution procedure of abnormality determination control; 4 is a flow chart showing an example of an execution procedure of abnormality determination control; It is a figure which shows the example of the execution condition of abnormality determination control. It is a figure which shows the example of the execution condition of abnormality determination control. FIG. 5 is a diagram showing an example of thresholds compared with the air-fuel ratio; FIG. 4 is a diagram showing the operating state of the fuel system when the air-fuel ratio is rich; FIG. 4 is a diagram showing the operating state of the fuel system when the air-fuel ratio is lean;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or substantially the same configurations and elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[Vehicle configuration]
FIG. 1 is a diagram showing a configuration example of a vehicle 11 equipped with a fuel supply system 10 according to an embodiment of the invention. As shown in FIG. 1 , a vehicle 11 is equipped with a powertrain 14 having an engine 12 and a transmission 13 . A wheel 18 is connected to an output shaft 15 of the transmission 13 via a propeller shaft 16 and a differential mechanism 17 . The vehicle 11 is also provided with a fuel tank 19 that stores fuel such as gasoline. The fuel tank 19 and the engine 12 are connected to each other via a fuel supply path 20 .

[engine]
FIG. 2 is a diagram showing a configuration example of the fuel supply device 10. As shown in FIG. As shown in FIG. 2 , the engine 12 has a cylinder block 22 containing pistons 21 and a cylinder head 23 mounted on the cylinder block 22 . An intake port 30 communicating with the combustion chamber 24 is formed in the cylinder head 23, and an exhaust port 40 communicating with the combustion chamber 24 is formed. An intake valve 31 for opening and closing the intake port 30 is assembled to the cylinder head 23, and an exhaust valve 41 for opening and closing the exhaust port 40 is assembled. Further, the cylinder head 23 is provided with an intake camshaft 32 that drives the intake valves 31 and is provided with an exhaust camshaft 42 that drives the exhaust valves 41 . The intake camshaft 32 and the exhaust camshaft 42 are connected to a crankshaft (not shown) via a timing chain or the like.

An intake pipe 33 is connected to the intake port 30 of the cylinder head 23 , and an exhaust pipe 43 is connected to the exhaust port 40 of the cylinder head 23 . An intake pipe 33 forming an intake system 34 of the engine 12 is connected to a throttle valve 35 for adjusting the amount of intake air, and to an air cleaner box 36 for removing dust from the intake air. An intake pipe 33 of the engine 12 is provided with an airflow sensor 37 for detecting the amount of intake air. An exhaust pipe 43 forming an exhaust system 44 of the engine 12 is provided with an air-fuel ratio sensor 45 for detecting the air-fuel ratio from the oxygen concentration of the exhaust gas. It should be noted that the air-fuel ratio is the mass ratio of air and fuel supplied into the combustion chamber 24 .

[Fuel system]
Engine 12 has a fuel system 50 that supplies fuel to combustion chamber 24 . The fuel system 50 has a fuel tank 19 that stores fuel such as gasoline, and an injector 51 that injects fuel into the combustion chamber 24 . The fuel system 50 also has a low-pressure fuel pump (first fuel pump) 52 provided in the fuel tank 19 and a high-pressure fuel pump (second fuel pump) 54 connected to a distribution pipe 53 of the injector 51. ing. The low-pressure fuel pump 52 and the high-pressure fuel pump 54 are connected via a fuel pipe 55 , and the high-pressure fuel pump 54 and the injector 51 are connected via a fuel pipe 56 and a distribution pipe 53 . That is, the low pressure fuel pump 52 and the injector 51 are connected via the fuel supply path 20 composed of the fuel pipe 55 , the high pressure fuel pump 54 , the fuel pipe 56 and the distribution pipe 53 . An electromagnetic valve (not shown) for opening and closing the nozzle is incorporated in the injector 51, and the amount of fuel injection is controlled by this electromagnetic valve. A return pipe 58 having a pressure regulating valve 57 is connected to the distribution pipe 53 .

The high-pressure fuel pump 54 has a pump body 61 in which a pressurization chamber 60 is formed, and a plunger 62 which is assembled to the pump body 61 so as to reciprocate. A suction port 63 and a discharge port 64 communicating with the pressurizing chamber 60 are formed in the pump body 61 . A fuel pipe 55 on the side of the low-pressure fuel pump 52 is connected to a suction port 63 of the pump body 61 , and a fuel pipe 56 on the side of the injector 51 is connected to a discharge port 64 of the pump body 61 via a check valve 65 . It is connected. The high-pressure fuel pump 54 also has a pump cam 66 attached to the intake camshaft 32 and a lifter 67 sandwiched between the pump cam 66 and the plunger 62 . Further, the high-pressure fuel pump 54 has an electromagnetic valve 68 that opens and closes the intake port 63 , that is, opens and closes the pressurization chamber 60 . When the pump cam 66 is driven by engine operation, the plunger 62 follows the pump cam 66 and reciprocates. At this time, the operation of the high-pressure fuel pump 54 can be controlled by opening and closing the intake port 63 with the solenoid valve 68 .

3A to 3C are diagrams showing how the high-pressure fuel pump 54 operates. As shown in FIGS. 3A and 3B, when fuel is pumped by the high-pressure fuel pump 54, the opening/closing control of the solenoid valve 68 is executed in accordance with the reciprocating motion of the plunger 62. FIG. That is, as shown in FIG. 3A, the suction port 63 is opened by the solenoid valve 68 when the plunger 62 moves downward toward the bottom dead center. In this way, by opening the intake port 63 in accordance with the expansion of the pressurization chamber 60 , fuel can flow into the pressurization chamber 60 from the fuel pipe 55 . Subsequently, as shown in FIG. 3B, the suction port 63 is closed by the electromagnetic valve 68 when the plunger 62 moves upward toward the top dead center. In this way, by closing the intake port 63 in accordance with the contraction of the pressurization chamber 60, the fuel in the pressurization chamber 60 can be pressurized by the plunger 62, and the check valve 65 and the fuel pipe 56 lead to the distribution pipe. High pressure fuel can be pumped to 53 .

On the other hand, as shown in FIG. 3C, when stopping the pressurization of fuel by the high-pressure fuel pump 54, the intake port 63 is kept open by the solenoid valve 68. As shown in FIG. By opening the pressurization chamber 60 of the high-pressure fuel pump 54 in this way, even if the pump cam 66 rotates and the plunger 62 rises, the fuel can be returned from the pressurization chamber 60 to the fuel pipe 55. The pressurization of fuel by the high-pressure fuel pump 54 can be stopped. Even in the situation shown in FIG. 3C, the fuel pressure-fed from the low-pressure fuel pump 52 is supplied to the injector 51 through the pressurization chamber 60 and the check valve 65 .

[Control system]
As shown in FIG. 2, the fuel supply device 10 is provided with a control system 70 comprising a plurality of electronic control units for controlling the fuel system 50 described above. As an electronic control unit that constitutes the control system 70, there is an engine control unit CU1 that controls the throttle valve 35, the injector 51, the low-pressure fuel pump 52, the high-pressure fuel pump 54, and the like. As an electronic control unit that configures the control system 70, there is a vehicle control unit CU2 that outputs a control signal to the engine control unit CU1. These control units CU1 and CU2 are communicably connected to each other via an in-vehicle network 71 such as CAN (Controller Area Network). The vehicle control unit CU2 sets operation targets for the engine 12 and the fuel system 50 based on input information from the engine control unit CU1 and various sensors described later. Then, it generates control signals according to the operation targets of the engine 12 and the fuel system 50, and outputs these control signals to the engine control unit CU1.

Sensors connected to the vehicle control unit CU2 include a vehicle speed sensor 72 that detects the vehicle speed, which is the running speed of the vehicle 11, an accelerator sensor 73 that detects the amount of operation of the accelerator pedal, and an amount of operation of the brake pedal. There is a brake sensor 74 . A start switch 75 operated by the driver when starting the control system 70 is connected to the vehicle control unit CU2. Further, the vehicle control unit CU2 is connected to a warning light 76 that lights up when an abnormality occurs in the fuel system 50, and to a communication unit 77 that communicates with a server or the like outside the vehicle when an abnormality occurs in the fuel system 50.

A low pressure sensor 80 and a high pressure sensor 81 for detecting the pressure of fuel are also connected to the engine control unit CU1. The low pressure sensor 80 is attached to the fuel pipe 55 to which fuel is supplied from the low pressure fuel pump 52 . A high-pressure sensor (pressure sensor) 81 is attached to the distribution pipe 53 to which fuel is supplied from the high-pressure fuel pump 54 . The location where the high-pressure sensor 81 is attached is not limited to the distribution pipe 53, and may be the fuel pipe 56 as well. That is, the high-pressure sensor 81 may be attached to the fuel supply path 20 located between the injector 51 and the high-pressure fuel pump 54 .

FIG. 4 is a diagram simply showing the configuration of each of the control units CU1 and CU2. As shown in FIG. 4, each control unit CU1, CU2 has a microcontroller 92 in which a processor 90, a memory 91 and the like are incorporated. A predetermined program is stored in the memory 91 and the instruction set of the program is executed by the processor 90 . Processor 90 and memory 91 are communicably connected to each other. Although one processor 90 and one memory 91 are incorporated in the microcontroller 92 in the illustrated example, the present invention is not limited to this, and a plurality of processors 90 may be incorporated in the microcontroller 92. A plurality of memories 91 may be incorporated in the controller 92 .

Each control unit CU1, CU2 is provided with an input conversion circuit 93, a drive circuit 94, a communication circuit 95, an external memory 96, a power supply circuit 97, and the like. The input conversion circuit 93 converts signals input from various sensors into signals that can be input to the microcontroller 92 . A drive circuit 94 generates drive signals for actuators such as the throttle valve 35 described above based on signals output from the microcontroller 92 . A communication circuit 95 converts signals output from the microcontroller 92 into communication signals directed to other control units. The communication circuit 95 also converts communication signals received from other control units into signals that can be input to the microcontroller 92 . Furthermore, the power supply circuit 97 supplies a stable power supply voltage to the microcontroller 92, the input conversion circuit 93, the drive circuit 94, the communication circuit 95, the external memory 96, and the like. In addition, the external memory 96 such as a non-volatile memory stores data to be retained even when the power is off.

[Drive control of low-pressure fuel pump]
Drive control of the low-pressure fuel pump 52 will be described. The fuel system 50 is provided with a low-pressure fuel pump 52 such as a trochoid pump or a Wesco pump driven by an electric motor. The control system 70 controls the rotation speed of the low-pressure fuel pump 52 by controlling the electric motor so as to maintain the fuel pressure (hereinafter referred to as fuel pressure) in the distribution pipe 53 within a predetermined range. is doing.

FIG. 5 is a diagram showing an example of the relationship between the fuel pressure in the distribution pipe 53 and the rotational speed of the low-pressure fuel pump 52. As shown in FIG. As shown in FIG. 5, the control system 70 controls the rotation speed of the low-pressure fuel pump 52 so that the fuel pressure in the distribution pipe 53 falls within a predetermined target range Xa. That is, the control system 70 reduces the rotational speed of the low-pressure fuel pump 52 (arrow b1) when the fuel pressure increases due to a decrease in the fuel injection amount (arrow a1). On the other hand, the control system 70 increases the rotation speed of the low-pressure fuel pump 52 (arrow b2) when the fuel pressure decreases due to an increase in the fuel injection amount (arrow a2). Thus, the control system 70 controls the rotation speed of the low-pressure fuel pump 52 based on the fuel pressure acting on the injector 51 . As a result, the power consumption of the low-pressure fuel pump 52 can be suppressed, so the energy efficiency of the vehicle 11 can be enhanced. In the example shown in FIG. 5, the target rotational speed of the low-pressure fuel pump 52 is changed continuously, but the present invention is not limited to this, and the target rotational speed of the low-pressure fuel pump 52 is changed stepwise. can be

[Abnormality judgment control]
Next, the abnormality determination control for determining abnormality of the fuel system 50 will be described. 6 and 7 are flowcharts showing an example of the procedure for executing abnormality determination control. In the flow charts shown in FIGS. 6 and 7, they are connected to each other at points A. In FIG. 8 and 9 are diagrams showing an example of the execution status of abnormality determination control. It should be noted that each step shown in the flow charts of FIGS. 6 and 7 shows processing executed by one or more processors 90 that make up the control system 70 . The abnormality determination control shown in FIGS. 6 and 7 is executed by the control system 70 at predetermined intervals after the start switch 75 is operated by the driver and the control system 70 including the vehicle control unit CU2 is activated. It is the control that is performed.

As shown in FIG. 6, at step S10, the control system 70 calculates an estimated fuel pressure P1 based on the operating conditions of the low-pressure fuel pump 52, the high-pressure fuel pump 54, and the injector 51. FIG. This estimated fuel pressure P1 is the fuel pressure in the distribution pipe 53 estimated from the operating state of the fuel system 50 . For example, the higher the rotation speed of the low-pressure fuel pump 52, the higher the calculated estimated fuel pressure P1. The estimated fuel pressure P1 is calculated higher as the power consumption of the low-pressure fuel pump 52 increases. Also, the higher the rotational speed of the pump cam 66 of the high-pressure fuel pump 54, the higher the calculated estimated fuel pressure P1. Furthermore, the estimated fuel pressure P1 is calculated higher as the fuel injection amount of the injector 51 decreases. When calculating the estimated fuel pressure P1, a predetermined arithmetic expression may be used, or predetermined fuel pressure data created in advance based on the rotational speed of the low-pressure fuel pump 52, power consumption, and the like may be used.

In subsequent step S11, the control system 70 acquires the actual fuel pressure P2 from the high pressure sensor 81. FIG. This actual fuel pressure P2 is the actual fuel pressure in the distribution pipe 53 and the actual fuel pressure acting on the injector 51 . When the actual fuel pressure P2 is obtained in step S11, the control system 70 proceeds to step S12 and determines whether or not the value obtained by subtracting the actual fuel pressure P2 from the estimated fuel pressure P1 exceeds a predetermined threshold value Px. In step S12, the situation where the value obtained by subtracting the actual fuel pressure P2 from the estimated fuel pressure P1 is less than or equal to the threshold value Px is the situation shown as Cases 1 and 2 in FIG. That is, the actual fuel pressure P2 exceeds the estimated fuel pressure P1, or even if the actual fuel pressure P2 falls below the estimated fuel pressure P1, the difference between the estimated fuel pressure P1 and the actual fuel pressure P2 is equal to or less than the threshold value Px. In this case, since the actual fuel pressure P2 is sufficiently secured, the control system 70 determines that the fuel system 50 is normal, and exits the routine. A positive value equal to or greater than 0 can be set as the threshold value Px.

On the other hand, in step S12, the situation where the value obtained by subtracting the actual fuel pressure P2 from the estimated fuel pressure P1 exceeds the threshold value Px is the situation shown as case 3 in FIG. That is, the actual fuel pressure P2 is below the estimated fuel pressure P1, and the difference between the estimated fuel pressure P1 and the actual fuel pressure P2 is above the threshold value Px. In this case, since the actual fuel pressure P2 has decreased excessively, the control system 70 determines that there is a risk of fuel leakage in the fuel system 50, and proceeds to step S13. In step S13, the control system 70 turns on the warning light 76 to notify the driver of the fuel system abnormality. In subsequent step S14, the control system 70 opens the intake port 63 of the high-pressure fuel pump 54 to open the pressurization chamber 60, thereby stopping pressurization of fuel by the high-pressure fuel pump 54. FIG. In step S14, the low-pressure fuel pump 52 continues pumping the fuel, and the fuel supply from the low-pressure fuel pump 52 to the injector 51 is continued.

Next, the control system 70 proceeds to step S15 to determine whether or not various devices such as the pumps 52 and 54 provided in the fuel system 50 are normal, that is, whether or not there are abnormal signals emitted from the various devices. In step S15, if no abnormal signal is output from the various devices, the control system 70 determines that the various devices are normal, and proceeds to step S16. In step S16, control system 70 determines whether high pressure sensor 81 and low pressure sensor 80 are normal. In step S16, pressurization by the high-pressure fuel pump 54 is stopped, so the fuel pressures before and after the high-pressure fuel pump 54 become equal. Therefore, in step S16, the control system 70 determines whether or not the fuel pressure detected by both pressure sensors 80, 81 falls within a predetermined range. If the fuel pressures detected by both pressure sensors 80 and 81 fall within a predetermined range, control system 70 determines that both pressure sensors 80 and 81 are normal, and proceeds to step S17. On the other hand, when an abnormality signal from various devices is detected in step S15, or when the fuel pressure detected by both pressure sensors 80 and 81 deviates from a predetermined range in step S16, the control system 70 continues the abnormality determination control. is difficult and exits the routine.

As shown in FIG. 7, in step S17, the control system 70 calculates an estimated power W1 of the low-pressure fuel pump 52 based on the operating state of the injector 51. As shown in FIG. This estimated power W1 is the power of the low-pressure fuel pump 52 estimated from the operating conditions of the injector 51 . In step S17, the control system 70 calculates the fuel injection amount per unit time from the operating state of the injector 51, and calculates the estimated power W1 of the low-pressure fuel pump 52 based on this fuel injection amount per unit time. That is, as the fuel injection amount of the injector 51 increases, the fuel pumping amount of the low-pressure fuel pump 52 increases, so the control system 70 calculates the estimated power W1 higher as the fuel injection amount increases. When calculating the estimated power W1, a predetermined arithmetic expression may be used, or predetermined power data prepared in advance based on the fuel injection amount or the like may be used.

Subsequently, the control system 70 proceeds to step S<b>18 to calculate the actual power W<b>2 of the low-pressure fuel pump 52 based on the operation status of the low-pressure fuel pump 52 . In step S18, the control system 70 calculates the actual power W2 of the low-pressure fuel pump 52 based on the rotational speed of the low-pressure fuel pump 52, power consumption, and the like. For example, the higher the rotation speed of the low-pressure fuel pump 52, the higher the calculated actual power W2, and the higher the power consumption of the low-pressure fuel pump 52, the higher the calculated actual power W2. When calculating the actual power W2, a predetermined arithmetic expression may be used, or predetermined power data prepared in advance based on the rotational speed of the low-pressure fuel pump 52, power consumption, etc. may be used. .

When the actual power W2 is calculated in step S18, the control system 70 proceeds to step S19 and determines whether or not the value obtained by subtracting the estimated power W1 from the actual power W2 exceeds a predetermined threshold value Wx. . The situation in which the value obtained by subtracting the estimated power W1 from the actual power W2 in step S19 is equal to or less than the threshold value Wx is the situation shown as Cases 4 and 5 in FIG. In other words, even if the actual power W2 is lower than the estimated power W1, or even if the actual power W2 exceeds the estimated power W1, the difference between the actual power W2 and the estimated power W1 is equal to or less than the threshold value Wx. is. In this case, since the actual power W2 of the low-pressure fuel pump 52 has not excessively increased, the control system 70 determines that the fuel system 50 is normal, and exits the routine.

On the other hand, in step S19, the situation where the value obtained by subtracting the estimated power W1 from the actual power W2 exceeds the threshold value Wx is the situation shown as case 6 in FIG. That is, the actual power W2 exceeds the estimated power W1, and the difference between the actual power W2 and the estimated power W1 exceeds the threshold value Wx. In this case, since the actual power W2 of the low-pressure fuel pump 52 has increased excessively, the control system 70 determines that there is a risk of fuel leakage in the fuel system 50, and proceeds to step S20. In step S20, the control system 70 determines whether or not the air-fuel ratio detected by the air-fuel ratio sensor 45 is below a predetermined threshold α.

FIG. 10 is a diagram showing an example of the threshold α to be compared with the air-fuel ratio. As shown in FIG. 10, the threshold α to be compared with the air-fuel ratio is set to be leaner than the stoichiometric air-fuel ratio. The air-fuel ratio is the mass ratio of the air and fuel supplied into the combustion chamber 24, and is the ratio of the mass of fuel to the mass of air. In other words, changing the air-fuel ratio to the lean side means that the air ratio increases, which means that the value of the air-fuel ratio increases. Further, the fact that the air-fuel ratio changes to the rich side means that the air ratio decreases, which means that the value of the air-fuel ratio decreases. Also, the theoretical air-fuel ratio when the fuel is gasoline is 14.7.

FIG. 11 is a diagram showing the operating state of the fuel system 50 when the air-fuel ratio is rich, and FIG. 12 is a diagram showing the operating state of the fuel system 50 when the air-fuel ratio is lean. The situation in which the process proceeds from step S20 in FIG. 7 to "Yes" is a situation in which the value obtained by subtracting the estimated power W1 from the actual power W2 exceeds the threshold Wx and the air-fuel ratio is equal to or greater than the threshold α. In other words, the amount of fuel discharged from the low-pressure fuel pump 52 is large relative to the amount of fuel injected from the injector 51, and the amount of fuel supplied to the combustion chamber 24 is large. Therefore, as indicated by an arrow X1 in FIG. 11, it is assumed that fuel is leaking from the injector 51 into the cylinder. Therefore, the control system 70 proceeds to step S21 and continues the fuel supply from the low-pressure fuel pump 52 to the injector 51, thereby maintaining the operating state of the engine 12. FIG. Thus, in a situation where no fuel is leaking out of the engine 12, the operating state of the engine 12 is maintained in order to allow the vehicle to be moved to a maintenance shop or the like.

On the other hand, if it is determined in step S20 of FIG. 7 that the air-fuel ratio exceeds the threshold value α, the control system 70 proceeds to step S22 and stops the low-pressure fuel pump 52 . That is, the situation in which the process proceeds to "No" from step S20 in FIG. 7 is a situation in which the value obtained by subtracting the estimated power W1 from the actual power W2 exceeds the threshold Wx and the air-fuel ratio is below the threshold α. In other words, the amount of fuel discharged from the low-pressure fuel pump 52 is large relative to the amount of fuel injected from the injector 51, and the amount of fuel supplied to the combustion chamber 24 is small. Therefore, as indicated by arrows X2 and X3 in FIG.

Therefore, the control system 70 proceeds to step S22 to stop the low-pressure fuel pump 52, and proceeds to step S23 to stop the engine 12. In addition, the control system 70 proceeds to step S24 and notifies the occupants in the vehicle of evacuation using a warning sound, a display display, or the like. After that, the control system 70 proceeds to step S25 and determines whether or not the evacuation of the occupant has been completed. If it is determined in step S25 that the evacuation of the occupant has not been completed, the control system 70 proceeds to step S26, uses the communication unit 77 to notify the emergency contact such as the police, and exits the routine. In step S25, the control system 70 allows the occupant to evacuate from the vehicle compartment based on a signal from a seat sensor (not shown) that detects the seating of the occupant and a signal from a door sensor (not shown) that detects opening and closing of the vehicle body door. determine whether or not

As described above, the control system 70 determines that the actual power W2 of the low-pressure fuel pump 52 exceeds the estimated power W1, the difference between the actual power W2 and the estimated power W1 exceeds the threshold value Wx, and the air-fuel ratio is below the threshold value α, the low-pressure fuel pump 52 is stopped on the assumption that fuel is leaking from the fuel supply path 20 . As a result, an abnormality of the fuel supply device 10 can be detected appropriately, and an abnormality of the fuel supply device 10 can be appropriately dealt with. A positive value equal to or greater than 0 can be set as the threshold value Wx. That is, the control system 70 can be controlled to stop the low-pressure fuel pump 52 when the actual power W2 of the low-pressure fuel pump 52 exceeds the estimated power W1 and the air-fuel ratio is below the threshold value α. Further, the threshold value α to be compared with the air-fuel ratio is set to be leaner than the stoichiometric air-fuel ratio as shown in FIG. 10, but is not limited to this. For example, as the threshold α, a threshold that matches the stoichiometric air-fuel ratio may be set, or a threshold that is richer than the stoichiometric air-fuel ratio may be set.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. In the above description, the control system 70 is composed of the plurality of control units CU1 and CU2, but it is not limited to this. For example, the control system 70 may be configured with one control unit. Also, in the above description, gasoline is exemplified as the fuel, but the fuel is not limited to this. For example, the fuel may be light oil, ethanol, or a mixture of gasoline and ethanol. Also, in the illustrated example, the low-pressure fuel pump 52 is installed inside the fuel tank 19 , but the present invention is not limited to this, and the low-pressure fuel pump 52 may be installed outside the fuel tank 19 . Also, in the above description, the pump cam 66 of the high-pressure fuel pump 54 is driven by the intake cam shaft 32, but the present invention is not limited to this, and the pump cam 66 may be driven using another rotating shaft.

10 fuel supply device 11 vehicle 12 engine 20 fuel supply path 44 exhaust system 45 air-fuel ratio sensor 51 injector 52 low-pressure fuel pump (first fuel pump)
54 high-pressure fuel pump (second fuel pump)
60 pressurizing chamber 61 pump body 68 solenoid valve 70 control system 81 high pressure sensor (pressure sensor)
90 Processor 91 Memory W1 Estimated Power W2 Actual Power Wx Threshold α Threshold P1 Estimated Fuel Pressure P2 Actual Fuel Pressure Px Threshold

Claims (5)

A fuel supply device for supplying fuel to an engine,
an injector provided in the engine for injecting fuel;
a first fuel pump connected to the injector via a fuel supply path and pumping fuel;
a second fuel pump provided in the fuel supply path for pumping the fuel;
an air-fuel ratio sensor provided in the exhaust system of the engine for detecting an air-fuel ratio;
a control system comprising a processor and memory communicatively coupled to each other for controlling the injector, the first fuel pump and the second fuel pump;
has
the control system calculates an estimated power of the first fuel pump based on the operating status of the injector;
The control system calculates an actual power of the first fuel pump based on the operation status of the first fuel pump,
The control system stops the first fuel pump when the actual power exceeds the estimated power and the air-fuel ratio is leaner than a threshold.
fuel supply. The fuel supply device according to claim 1,
A threshold value to be compared with the air-fuel ratio is set to be leaner than the stoichiometric air-fuel ratio,
fuel supply. In the fuel supply device according to claim 1 or 2,
When the actual power exceeds the estimated power, the difference between the actual power and the estimated power exceeds a threshold, and the air-fuel ratio is leaner than the threshold, the control system controls the stopping the first fuel pump;
fuel supply. In the fuel supply device according to any one of claims 1 to 3,
The control system controls the rotation speed of the first fuel pump based on the fuel pressure acting on the injector.
fuel supply. In the fuel supply device according to any one of claims 1 to 4,
The second fuel pump includes a pump body in which a pressurization chamber for pressurizing fuel is formed, and an electromagnetic valve attached to the pump body for opening and closing the pressurization chamber,
The control system calculates an estimated fuel pressure based on operating conditions of the first fuel pump, the second fuel pump and the injectors, and calculates an estimated fuel pressure from a pressure sensor located between the injectors and the second fuel pump. get fuel pressure,
The control system opens the pressure chamber of the second fuel pump when the actual fuel pressure is lower than the estimated fuel pressure and a difference between the estimated fuel pressure and the actual fuel pressure exceeds a threshold.
fuel supply.

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