JP2011038452A - Fuel supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply system capable of surely diagnosing failure of a second fuel supply means, in the fuel supply system having a first fuel supply means driven in ordinary operation and the second fuel supply means driven when satisfying a predetermined condition. <P>SOLUTION: This fuel supply system 1A includes: a first pump 70 driven in ordinary operation and supplying fuel in a fuel tank to an engine; a second pump 80 arranged separately from the first pump 70, driven when satisfying a predetermined condition and supplying the fuel in the fuel tank to the engine; an FI-ECU (Fuel Injection-Electronic Control Unit) 50A and an FPC (Fuel Pump Controller) 60 for controlling driving of the first pump 70 and the second pump 80. The FI-ECU 50A outputs a driving signal for driving the second pump 80 at least one time up to finishing warming-up from starting of the engine, and diagnoses failure of the second pump 80. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel supply system, and more specifically, includes a first fuel supply unit that is driven during normal operation, and a second fuel supply unit that is driven when a predetermined condition is satisfied, so that the failure of the second fuel supply unit is prevented. The present invention relates to a fuel supply system for diagnosis.

  As a technique for determining an abnormality in a fuel supply system that supplies fuel to an internal combustion engine, Patent Document 1 includes a plurality of fuel pumps, and a fuel pump control that switches and drives a fuel pump that is used every time the internal combustion engine is started. An apparatus is disclosed. When a specific fuel pump is used, the fuel pump control device determines that the specific fuel pump is abnormal if the number of consecutive failures in starting the internal combustion engine exceeds a predetermined number.

Japanese Patent Laid-Open No. 10-259769

  In such a fuel supply system having a plurality of fuel pumps, the first fuel pump is driven during normal operation, and the second fuel pump is driven only when necessary according to the operating state of the internal combustion engine. It is possible to make it. However, if the abnormality determination by the fuel pump control device disclosed in Patent Document 1 is applied in such a case, the abnormality of the second fuel pump cannot be determined when the second fuel pump is not driven. There is a fear.

  The present invention was devised to solve the above-described problem, and includes a fuel supply system including a first fuel supply unit that is driven during normal operation and a second fuel supply unit that is driven when a predetermined condition is satisfied. Then, it aims at providing the fuel supply system which can diagnose the failure of a 2nd fuel supply means reliably.

  In order to solve the above problems, a fuel supply system according to the present invention includes a first fuel supply unit that is driven during normal operation and supplies fuel in a fuel tank to an internal combustion engine, and the first fuel supply unit is separate from the first fuel supply unit. A second fuel supply means that is provided to supply fuel in the fuel tank to the internal combustion engine when a predetermined condition is satisfied; and driving the first fuel supply means and the second fuel supply means A system control means for controlling the fuel supply system, wherein the system control means drives the second fuel supply means at least once from the start of the internal combustion engine to the end of warm-up. Is output, and the failure of the second fuel supply means is diagnosed.

  According to such a configuration, the drive signal for driving the second fuel supply means is output from the start of the internal combustion engine to the end of warm-up, and the failure is diagnosed. Therefore, the failure of the second fuel supply means is reliably diagnosed. Can do.

  The fuel supply system further includes an operation state detection unit that detects an operation state of the internal combustion engine, and the system control unit is configured such that the operation state of the internal combustion engine detected by the operation state detection unit becomes a predetermined operation state. In this case, a drive signal for driving the second fuel supply means may be output to diagnose a failure of the second fuel supply means.

  The fuel supply system further includes temperature detection means for detecting the temperature of the internal combustion engine, and the system control means is configured to detect when the temperature of the internal combustion engine detected by the temperature detection means reaches a predetermined temperature. A configuration may be adopted in which a drive signal for driving the second fuel supply means is output to diagnose a failure of the second fuel supply means.

  Further, the system control means integrates the fuel injection amount or the number of times of fuel injection by the fuel injection means for injecting the fuel supplied from the fuel tank to the internal combustion engine, and the integrated fuel injection amount reaches a predetermined amount. Or when the accumulated number of fuel injections reaches a predetermined number, a drive signal for driving the second fuel supply means is output to diagnose a failure of the second fuel supply means It may be.

  In these, the predetermined operating state, the predetermined temperature, and the predetermined amount or the predetermined number of times are the operation state of the internal combustion engine, the temperature of the internal combustion engine, and the fuel injection amount at least once from the start of the internal combustion engine to the end of warm-up. Or it is set to the driving | running state and value which the frequency | count of fuel injection reaches, respectively.

  According to the present invention, it is possible to reliably diagnose a failure of the second fuel supply means.

It is an electric circuit diagram showing the principal part of the fuel supply system concerning a first embodiment of the present invention. It is a block diagram showing typically the principal part of the fuel supply system concerning a first embodiment of the present invention. It is a flowchart for demonstrating the failure diagnosis method by a failure diagnosis part. Vehicle speed, the rotational speed of the engine, the operation state of the accelerator pedal, the driving state of the first pump is a timing chart showing a drive state of the second pump. It is a block diagram which shows typically the principal part of the fuel supply system which concerns on 2nd embodiment of this invention. It is a timing chart which shows an example of vehicle speed, the number of rotations of an engine, the operation state of an accelerator pedal, the water temperature of an engine, the fuel injection quantity to an engine, the drive state of the 1st pump, and the drive state of the 2nd pump. It is a block diagram which shows typically the principal part of the fuel supply system which concerns on 3rd embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate, taking as an example the case where the fuel supply system of the present invention is applied to a vehicle. Similar parts are denoted by the same reference numerals, and redundant description is omitted.

<First embodiment>
First, a fuel supply system according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an electric circuit diagram showing the main part of the fuel supply system according to the first embodiment of the present invention. FIG. 2 is a block diagram schematically showing the main part of the fuel supply system according to the first embodiment of the present invention. FIG. 3 is a flowchart for explaining a failure diagnosis method by the failure diagnosis unit. FIG. 4 is a timing chart showing an example of vehicle speed, engine speed, accelerator pedal operation state, first pump drive state, and second pump drive state.

  As shown in FIG. 1, the fuel supply system 1A according to the first embodiment of the present invention includes a power supply control unit 10, a main relay 20, a first pump relay 30, a second pump relay 40, An FI-ECU (Fuel Injection Electronic Control Unit) 50A, an FPC (Fuel Pump Controller) 60, a first pump 70, and a second pump 80 are provided.

  The power supply control unit 10 is a starting means for starting the engine (internal combustion engine), and includes a first switch 11 provided between one end of the battery and the first pump relay 30, one end of the battery, and the second pump. And a second switch 12 provided between the relay 40 and the relay 40. The first switch 11 and the second switch 12 are, for example, ignition switches that are connected or opened by an operation by the driver. A fuse 91 is provided between the first switch 11 and the first pump relay 30, and a fuse 92 is provided between the second switch 12 and the second pump relay 40. Yes.

  The main relay 20 includes a switch 21 and a coil 22, the first pump relay 30 includes a switch 31 and a coil 32, and the second pump relay 40 includes a switch 41 and a coil 42.

  The FI-ECU 50A outputs a command signal to the FPC 60, controls driving of the second pump 80, and diagnoses a failure of the second pump 80. Here, the command signal is a signal for driving the first pump 70 in a predetermined mode, and is transmitted from the FI-ECU 50A to the FPC 60 via the wiring 93.

  The FPC 60 is a drive control unit that controls the drive of the first pump 70 based on a command signal output from the FI-ECU 50A. Further, the FPC 60 outputs a diagnosis signal to the system control means as a state signal indicating the state of the FPC 60. Here, the diagnosis signal is a signal indicating a logic state in the FPC 60, and is transmitted from the FPC 60 to the FI-ECU 50A via the wiring 94. The combination of the FI-ECU 50A and the FPC 60 is an example of the system control means in the claims.

  The first pump 70 is a first fuel supply means that is driven during normal operation and supplies the fuel in the fuel tank to the engine (internal combustion engine). The drive of the motor that is the drive source is controlled by the FPC 60.

  The second pump 80 is a second fuel supply unit that is separate from the first pump 70 that supplies the fuel in the fuel tank to the engine when a predetermined condition is satisfied. It is controlled by the FI-ECU 50A. When the predetermined condition here is satisfied, the engine speed reaches a second predetermined speed described later (when the driver depresses the accelerator pedal strongly and high load driving is required, the first For example, when the pump 70 fails, the second pump 80 is driven together with the first pump 70 to assist the first pump 70 or to be driven instead of the failed first pump 70. Here, the wiring 95 is for monitoring the voltage applied to the second pump 80, and the FI-ECU 50A monitors the voltage applied to the second pump 80, whereby the second pump 80 In addition, a shunt resistor is provided in series on the ground side of the second pump 80, and a wiring 95 is connected between the second pump 80 and the shunt resistor. May be configured to. Further, FI-ECU 50A by monitoring the current flowing through the second pump 80, second pump 80 may be a determining configuration whether or not the drive.

  As shown in FIG. 2, the fuel supply system 1 </ b> A further includes a rotation sensor 100 as an operation state detection unit that detects an operation state of the engine. The rotation sensor 100 detects the number of revolutions of the engine and outputs the detection result to the FI-ECU 50A.

  The FI-ECU 50A includes a command signal output unit 51, a second pump drive control unit 52, and a failure diagnosis unit 53 as functional blocks.

  The command signal output unit 51 determines that the first command signal for driving the first pump 70 in the first mode when the engine is started by the power supply control unit 10 and the engine start has failed in the first mode. A second command signal for driving the first pump 70 in the second mode, and a third command signal for driving the first pump 70 in the third mode after the second mode, Output. In the present embodiment, the first mode is a mode in which the first pump 70 is driven with a first output (Hi drive), and the second mode is a mode in which the first pump 70 is smaller than the first output. The second mode is a mode (Lo drive) for driving with the second output, and the third mode is a mode (OFF) for stopping the first pump 70.

  The second pump drive control unit 52 outputs a drive signal for driving the second pump 80 and drives the second pump 80 when a predetermined condition is satisfied. Moreover, the 2nd pump drive control part 52 stops the output of a drive signal as needed, and stops the 2nd pump 80. FIG. In the present embodiment, the drive signal is a current that flows to the coil 42, and the second pump drive control unit 52 connects the switch 41 by flowing a current as the drive signal to the coil 42, and the motor of the second pump 80. Drive. That is, the command signal output unit 51 and the second pump drive control unit 52 acquire the engine speed detected by the rotation sensor 100, and each (via the FPC 60) based on the acquired engine speed. The driving of the first pump 70 is controlled, and the driving of the second pump 80 is controlled.

  When the engine speed is smaller than the first predetermined speed (when the driver depresses the accelerator pedal lightly and low load driving is required), the command signal output unit 51 sends the first command signal to the FPC. Output (first fuel pump 70: Lo drive, second fuel pump: OFF). In addition, when the engine speed is equal to or higher than the first predetermined speed and smaller than the second predetermined speed (when the driver depresses the accelerator pedal slightly and a medium load traveling is required), a command is issued. The signal output unit 51 outputs a second command signal (first fuel pump 70: Hi drive, second pump: OFF). Further, when the engine speed is equal to or higher than the second predetermined speed (when the driver strongly depresses the accelerator pedal and high load traveling is required), the second pump drive control unit 52 outputs a drive signal. The second pump 80 is driven (first fuel pump 70: Hi drive, second pump: ON).

  The second pump drive control unit 52 performs at least one operation from the start of the engine to the end of warm-up, more specifically, from the output of the ignition ON signal (IGON signal) by the operation of the key, switch, etc. by the driver to the end of warm-up. The failure diagnosis unit 53 drives the second pump 80 at least once (if the second pump 80 is normal) from the start of the engine to the end of warm-up. Diagnose the failure. In the present embodiment, the failure diagnosis unit 53 acquires a voltage (monitoring voltage) applied to the second pump 80 through the wiring 95 in a state where the second pump 80 is driven, and based on the monitored voltage, the second It is diagnosed whether the pump 80 is out of order.

  Subsequently, an operation example of the fuel supply system 1A according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart for explaining a failure diagnosis method by the failure diagnosis unit. FIG. 4 is a timing chart showing an example of vehicle speed, engine speed, accelerator pedal operation state, engine water temperature, engine fuel injection amount, first pump drive state, and second pump drive state.

≪Failure diagnosis method≫
First, a failure diagnosis method for the second pump 80 by the failure diagnosis unit 53 will be described with reference to FIG. The rotational speed of the engine is not in the driving region of the second pump 80 (second predetermined rotational speed or higher) (No in step S1), and the second pump 80 has been driven in the current DC (driving cycle). More specifically, when the drive signal has been output (No in step S2), the second pump drive control unit 52 stops the second pump 80 (step S4). In addition, the engine speed is not the driving range of the second pump 80 (second predetermined speed or more) (No in step S1), and the second pump 80 is not driven at this DC (Yes in step S2). In addition, even when the power OFF failure diagnosis of the second pump 80 is not started (No in step S3), the second pump drive control unit 52 stops the second pump 80 (step S4). Here, the power OFF failure diagnosis refers to diagnosing whether the second pump 80 has a power OFF failure (the power is always OFF or disconnected). Is a diagnosis performed in a state in which is driven.

In step S3 of the present embodiment, the failure diagnosis unit 53 acquires the engine speed detected by the rotation speed sensor 100. In step S4, the failure diagnosis unit 53 acquires the acquired engine speed. The engine operating state is determined. In the present embodiment, the failure diagnosis unit 53 determines that the engine speed detected by the speed sensor 100 has reached the third predetermined speed NE _TH (for example, the engine speed is 1500 rpm or more). If so, power failure diagnosis of the second pump 80 is started. In a vehicle to which the fuel supply system 1A according to the present embodiment is applied, fast idle control is performed for warm-up when the engine is started. In the first idle control, when the engine is started, the engine speed is set to a higher speed (first idle speed) than the normal idle speed (700 to 800 rpm), thereby promoting engine warm-up. It is. Here, as the third predetermined rotation speed NE _TH , such a first idle rotation speed (for example, 1500 rpm) is preferably used.

  The failure diagnosis unit 53 acquires the voltage (monitoring voltage) applied to the second pump 80 in a state where the second pump 80 is stopped (if normal). If the acquired monitoring voltage is equal to or higher than the first predetermined voltage (No in step S6), the failure diagnosis unit 53 causes a power ON failure (always power is ON) in the second pump 80. When the acquired monitoring voltage is smaller than the first predetermined voltage (Yes in step S6), the failure diagnosis unit 53 determines that the second pump 80 is normal. Diagnose (step S8).

  On the other hand, when the engine speed is in the second pump drive region (second predetermined speed or higher) (Yes in step S1), the second pump drive control unit 52 drives the second pump 80. And In addition, the engine speed is not the driving range of the second pump 80 (second predetermined speed or more) (No in step S1), and the second pump 80 is not driven at this DC (Yes in step S2). In addition, when the power OFF failure diagnosis of the second pump 80 is started (Yes in step S4 after execution of step S3), the second pump drive control unit 52 sets the second pump 80 in the drive state. (Step S9).

  The failure diagnosis unit 53 acquires a voltage (monitoring voltage) applied to the second pump 80 in a state where the second pump 80 is operating (if it is normal). If the acquired monitoring voltage is greater than the second predetermined voltage (Yes in step S10), the failure diagnosis unit 53 diagnoses that the second pump 80 is normal (step S8), and the acquired monitoring voltage. Is equal to or lower than the second predetermined voltage (No in step S10), the failure diagnosis unit 53 diagnoses the second pump 80 as a power-off failure (always power is off or disconnected). (Step S11).

≪Operation example≫
Next, with reference to FIG. 4, an operation example of the fuel supply system 1A according to the first embodiment of the present invention will be described (see FIGS. 1 and 2 as appropriate). In FIG. 4, NE is the engine speed, and AP is the operating state of the accelerator pedal.

First, at time t ₀₁ , when the switches 11 and 12 are connected by an operation of a key, a switch, or the like by the driver, the command signal output unit 51 receives a start signal (ignition ON signal) output from the power supply control unit 10. Obtaining and energizing the coil 22 of the main relay 20 to connect the switch 21 (main relay 20: ON), and energizing the coil 32 of the first pump relay 30 to connect the switch 31 (for the first pump) Further, the first command signal is output to the FPC 60 (first pump: Hi drive, second pump: OFF), and engine warm-up (first idle control) is started. Subsequently, when the engine speed reaches the third predetermined speed NE _TH at time t ₀₂ , the failure diagnosis unit 53 determines that the power OFF failure diagnosis of the second pump 80 is started, and the second pump drive The controller 52 outputs a drive signal for a predetermined time (between times t _{02 and} t ₀₃ ) to drive the second pump 80.

Thereafter, at time t ₀₄ , the command signal output unit 51 outputs the second command signal to the FPC 60 (first fuel pump: Lo drive, second pump: OFF), and at time t ₀₅ , the warming up of the engine ends. To do. Thereafter, the driver depresses the accelerator pedal (AP) lightly, and the vehicle travels at a low load.

Thereafter, the driver depresses the accelerator pedal strongly, and the vehicle sequentially performs medium load traveling and high load traveling. That is, when the engine speed reaches the first predetermined speed at time t ₀₆ , the command signal output unit 51 outputs the first command signal (first pump 70: Hi drive, second pump: Further, at time _t07 , when the engine speed reaches the second predetermined speed, the second pump drive control unit 52 outputs a drive signal to drive the second pump 80 (first). Pump 70: Hi drive, second pump 80: ON).

Thereafter, the driver weakens the depression of the accelerator pedal, and the vehicle sequentially performs medium load traveling and low load traveling. That is, at time t _08, when the rotational speed of the engine is smaller than the second predetermined rotational speed, the second pump drive control unit 52 stops the output of the drive signal, the second pump 80 is stopped (first pump 70: Hi drive, second pump 80: OFF) Further, at time _t09 , when the engine speed becomes smaller than the first predetermined speed, the command signal output unit 51 outputs the second command signal. (First pump 70: Lo drive, second pump: OFF),

Then, at time t _10, the switch 11, 12 is opened by operation of the driver, with the first pump 70 and second pump 80 is stopped, the engine is stopped.

In this operation example, when the second pump 80 is not driven, the engine speed has reached the third predetermined speed NE _TH , so that the second pump drive control unit 52 outputs the drive signal at time t _{02 to} t ₀₃ . Is output to drive the second pump 80 to diagnose the power OFF failure of the second pump 80. The third predetermined rotational speed NE _TH is set to a rotational speed that reaches at least once from the start of the engine to the end of warm-up (time t _{01 to} t _{05 in} FIG. 4).

Since the fuel supply system 1A according to the first embodiment of the present invention always outputs a drive signal for driving the second pump 80 from the start of the engine to the end of warm-up, and diagnoses the failure of the second pump 80. The failure of the second pump 80 can be reliably diagnosed with a simple configuration. In addition, the fuel supply system 1A according to the first embodiment of the present invention provides a case where it is determined that the engine speed has reached the third predetermined speed NE _TH between the start of the engine and the end of warm-up. Since the drive signal for driving the second pump 80 is output and the failure of the second pump 80 is diagnosed, the fuel pressure in the fuel supply pipe connecting the fuel tank and the engine so that the fuel can be supplied fluctuates at the time of failure diagnosis. The influence on the operating state of the engine by doing can be suppressed.

<Second Embodiment>
Next, a fuel supply system according to the second embodiment of the present invention will be described with reference to FIGS. 5 and 6 focusing on differences from the fuel supply system 1A according to the first embodiment. FIG. 5 is a block diagram schematically showing the main part of the fuel supply system according to the second embodiment of the present invention. FIG. 6 is a timing chart showing an example of vehicle speed, engine speed, accelerator pedal operation state, engine water temperature, engine fuel injection amount, first pump drive state, and second pump drive state. In FIG. 6, TW is the coolant temperature of the engine. F is the fuel injection amount integrated by the injector drive control unit 54 (see FIG. 7), and is used in the third embodiment to be described later.

As shown in FIG. 5, the fuel supply system 1B according to the second embodiment of the present invention includes an FI-ECU 50B instead of the FI-ECU 50A, and further includes a temperature sensor 110. The temperature sensor 110 is temperature detection means for detecting the temperature of the engine, more specifically, the temperature of cooling water for cooling the engine. The second pump drive control unit 52 according to the present embodiment acquires the engine temperature (water temperature) detected by the temperature sensor 110 instead of the engine speed in step S3 of the flow of FIG. The engine temperature is compared with a predetermined temperature. When it is determined that the acquired temperature has reached a predetermined temperature TW _TH (see FIG. 6) (for example, the water temperature is 80 ° C. or higher), the second pump drive control unit 52 supplies power to the second pump 80. The OFF failure diagnosis is started (Yes in step S4 of the flow of FIG. 3), a drive signal for driving the second pump 80 is output, and the second pump 80 is set to the drive state (ON) (flow of FIG. 3). step S9, the time _t 05 _~t 11 in FIG. 6). The predetermined temperature TW _TH is from the start of the engine to the end of warm-up, more specifically, from the output of an ignition ON signal (IGON signal) by the driver's operation of a key, switch, etc. to the end of warm-up (time of FIG. 6). at least once t ₀₁ ~t ₀₅₎ is set to temperatures reached. Here, as the predetermined temperature TW _TH , the water temperature (for example, 80 ° C.) of the engine cooling water obtained at the end of the warm-up, which is obtained in advance, is preferably used.

The fuel supply system 1B according to the second embodiment of the present invention always outputs a drive signal for driving the second pump 80 from the start of the engine to the end of warm-up, and diagnoses the failure of the second pump 80. The failure of the second pump 80 can be reliably diagnosed with a simple configuration. The fuel supply system 1B according to the second embodiment of the present invention is for driving the second pump 80 when the temperature of the engine reaches a predetermined temperature TW _TH between the start of the engine and the end of warm-up. Since the drive signal is output and the failure of the second pump 80 is diagnosed, the operating state of the engine is stable at the time of failure diagnosis, and the fuel pressure in the fuel supply pipe connecting the fuel tank and the engine so that fuel can be supplied is The influence on the operating state of the engine due to the fluctuation can be suppressed.

<Third embodiment>
Next, a fuel supply system according to a third embodiment of the present invention will be described with reference to FIGS. 6 and 7 focusing on differences from the fuel supply system 1A according to the first embodiment. FIG. 7 is a block diagram schematically showing the main part of the fuel supply system according to the third embodiment of the present invention.

  As shown in FIG. 7, the fuel supply system 1B according to the third embodiment of the present invention includes an FI-ECU 50C instead of the FI-ECU 50A. The FI-ECU 50C further includes an injector drive control unit 54 that controls the drive of the fuel injector 120 that is fuel injection means for injecting the fuel supplied from the fuel tank into the engine. The injector drive control unit 54 accumulates the fuel injection amount or the number of fuel injections by the fuel injector 120 and outputs the accumulated fuel injection amount or the number of fuel injections to the second pump drive control unit 52.

The second pump drive control unit 52 according to the present embodiment obtains the fuel injection amount or the number of fuel injections integrated by the injector drive control unit 54 instead of the engine speed in step S3 of the flow of FIG. The obtained fuel injection amount or the number of fuel injections is compared with the predetermined amount or the predetermined number. When it is determined that the acquired fuel injection amount or the number of times of fuel injection has reached the predetermined amount or the predetermined number of times, in the example of FIG. 6, the acquired fuel injection amount has reached the predetermined amount _FTH (for example, obtained in advance). If it is determined that the fuel injection amount is equal to or greater than the amount of fuel injected at the end of engine warm-up), the second pump drive control unit 52 starts power-off failure diagnosis of the second pump 80 (flow in FIG. 3). In step S4, Yes), a drive signal for driving the second pump 80 is output, and the second pump 80 is set to the drive state (ON) (step S9 in the flow of FIG. 3, time t _05-in FIG. 6). t _11). The predetermined amount F _TH or the predetermined number of times is from the start of the engine to the end of warm-up, more specifically, from the output of an ignition ON signal (IGON signal) by the operation of the key, switch, etc. by the driver until the end of warm-up (see 6 at time t _{01 to} t ₀₆ ) at least once.

Since the fuel supply system 1C according to the third embodiment of the present invention always outputs a drive signal for driving the second pump 80 from the start of the engine to the end of warm-up, and diagnoses the failure of the second pump 80. The failure of the second pump 80 can be reliably diagnosed with a simple configuration. Further, in the fuel supply system 1C according to the third embodiment of the present invention, when the fuel injection amount or the number of fuel injections accumulated from the start of the engine to the end of warm-up reaches the predetermined amount _FTH or the predetermined number of times A drive signal for driving the second pump 80 is output to diagnose the failure of the second pump 80. Therefore, at the time of failure diagnosis, the engine operating state is stable and the fuel tank and the engine are supplied with fuel. The influence on the operating state of the engine due to the fluctuation of the fuel pressure in the fuel supply pipe to be connected can be suppressed.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the summary of this invention. For example, the failure diagnosis unit 53 outputs the diagnosis result to an external notification means (speaker, monitor, etc.) so that the notification means notifies the driver or the like of the failure part with characters, images, sounds, etc. It can also be. Further, the failure diagnosis unit 53 acquires the ignition ON signal, and starts the failure diagnosis of the second pump 80 based on the acquired ignition ON signal (for example, starts the failure diagnosis at time t ₀₁ in FIGS. 3 and 6). ) Configuration.

1A, 1B, 1C Fuel supply system 50A, 50B, 50C FI-ECU (system control means)
60 FPC (system control means)
70 First pump (first fuel supply means)
80 Second pump (second fuel supply means)
100 Rotation sensor (Operating state detection means)
110 Temperature sensor (temperature detection means)

Claims (4)

First fuel supply means that is driven during normal operation and supplies the fuel in the fuel tank to the internal combustion engine;
A second fuel supply means which is provided separately from the first fuel supply means and is driven when a predetermined condition is satisfied, and supplies the fuel in the fuel tank to the internal combustion engine;
System control means for controlling driving of the first fuel supply means and the second fuel supply means;
A fuel supply system comprising:
The system control means outputs a drive signal for driving the second fuel supply means at least once from the start of the internal combustion engine to the end of warm-up, and diagnoses a failure of the second fuel supply means. And fuel supply system. An operation state detecting means for detecting an operation state of the internal combustion engine;
The system control means outputs a drive signal for driving the second fuel supply means when the operating state of the internal combustion engine detected by the operating state detecting means becomes a predetermined operating state, The fuel supply system according to claim 1, wherein a failure of the two fuel supply means is diagnosed. Temperature detecting means for detecting the temperature of the internal combustion engine,
The system control means outputs a drive signal for driving the second fuel supply means when the temperature of the internal combustion engine detected by the temperature detection means reaches a predetermined temperature, and supplies the second fuel supply The fuel supply system according to claim 1, wherein a failure of the means is diagnosed. The system control means integrates the fuel injection amount or the number of times of fuel injection by the fuel injection means for injecting the fuel supplied from the fuel tank into the internal combustion engine, and the integrated fuel injection amount reaches a predetermined amount Alternatively, when the accumulated number of times of fuel injection reaches a predetermined number, a drive signal for driving the second fuel supply means is output to diagnose a failure of the second fuel supply means. The fuel supply system according to claim 1.

Images