JP2007009849A - Oil supply detection device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an oil supply state from being erroneously detected due to the occurrence of abnormality in a tank internal pressure detection area. <P>SOLUTION: The start of oil supply is determined based on the variation of the remaining amount of fuel. When the start of oil supply is not detected based on the remaining amount of fuel, it is detected based on the variation of a tank internal pressure. If any abnormality such as leak in the tank internal pressure detection area, the detection of the start of oil supply based on the tank internal pressure is prohibited. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle fuel supply detection device for detecting a fuel supply state to a fuel tank mounted on a vehicle.

In Patent Document 1, an electromagnetic on-off valve is provided in a communication pipe that communicates a canister that adsorbs evaporated fuel generated in a fuel tank and the fuel tank, and the electromagnetic on-off valve is controlled to open when it is determined that refueling has started. There is a disclosure of a tank internal pressure control system.
Moreover, in the said patent document 1, the determination of the said oil supply start is performed based on the change speed of the detected value of a tank internal pressure.
Japanese Patent Laid-Open No. 11-030157

By the way, when determining the start of refueling based on the change in the tank internal pressure as described above, if there is an abnormality such as a leak in the detection area of the tank internal pressure, the tank internal pressure changes due to the influence of the leak. There has been a problem that the determination accuracy of the refueling start is lowered, and the control based on the refueling start determination may be erroneously executed.
The present invention has been made in view of the above problems, and provides a vehicle fuel supply detection device that can prevent erroneous detection of the fuel supply state due to the occurrence of an abnormality in the pressure detection area in the fuel tank. Objective.

Therefore, the fuel supply detection device for a vehicle according to the first aspect of the invention detects the fuel supply state based on the detected value of the pressure in the fuel tank, while diagnosing whether there is an abnormality in the pressure detection area in the fuel tank. When the occurrence of abnormality is diagnosed, the detection of the refueling state based on the detected value of the pressure in the fuel tank is cancelled.
According to this configuration, if there is no abnormality in the tank pressure detection area (for example, the occurrence of a leak in the detection area or the valve that closes the area), the oil supply state is detected based on the detection value of the tank pressure. However, when the occurrence of an abnormality in the area is diagnosed, detection of the refueling state based on the detected value of the tank internal pressure is cancelled.

Therefore, in a state where an abnormality in the tank internal pressure detection area affects the pressure detection value, it is possible to prevent the oil supply state from being detected by detecting the oil supply state based on the tank internal pressure detection value.
In a second aspect of the present invention, when the refueling state is detected based on the detected value of the fuel level in the fuel tank, and the refueling state is not detected based on the detected value of the fuel level, the pressure in the tank The oil supply state is detected based on the detection value.

  According to such a configuration, since the fuel level in the fuel tank increases and changes due to fueling, the fuel level is detected based on the detected value of the fuel level, but even if the fuel level is not detected from the fuel level, the fuel level Since there is a possibility that the oil supply state has not been detected due to a gauge failure or the like, in this case, it is confirmed whether or not the oil supply state is based on the tank internal pressure.

Therefore, even if the fuel level gauge breaks down, it is possible to detect the refueling state, and it is possible to prevent erroneous detection of the refueling state when an abnormality occurs in the pressure detection area.
In a third aspect of the invention, the fuel supply state is detected on condition that the fuel filler lid and / or the fuel cap of the fuel tank is opened.

According to this configuration, the fuel supply is performed by opening the fuel filler lid and further removing the fuel cap. Therefore, when the fuel filler lid and / or the fuel cap is opened, the fuel supply is performed based on the fuel level or the tank internal pressure. Let the state be detected.
Therefore, for example, based on the fuel level and the tank internal pressure when the fuel filler lid and the fueling cap are closed, the fueling state can be prevented from being erroneously detected.

Embodiments of the present invention will be described below.
The system configuration of the vehicle engine in the embodiment is shown in FIG.
In FIG. 1, an engine 1 is a gasoline internal combustion engine, and air is sucked into a combustion chamber 4 through a throttle valve 2 and an intake valve 3, while fuel is injected from a fuel injection valve 5, thereby causing a combustion chamber. An air-fuel mixture is formed in 4.

The air-fuel mixture in the combustion chamber 4 is ignited and burned by spark ignition by the spark plug 6, and the combustion exhaust is discharged from the combustion chamber 4 through the exhaust valve 7.
The fuel injection valve 5 is supplied with fuel (gasoline) in a fuel tank 10 mounted on the vehicle together with the engine 1.
A fuel pump 11 is installed in the fuel tank 10, and fuel sucked by the fuel pump 11 is supplied to the fuel injection valve 5 through a fuel supply pipe (not shown).

The fuel tank 10 includes a mechanical valve 25 for releasing the pressure when the pressure in the tank becomes abnormally high, or a mechanical valve for closing the tank when the fuel is full. 26 etc. are provided.
Fuel injection by the fuel injection valve 5 and ignition by the spark plug 6 are controlled by an engine control module (hereinafter referred to as ECM) 12.

The ECM 12 includes a microcomputer, receives detection signals from various sensors, determines a fuel injection timing and a fuel injection amount by arithmetic processing based on the detection signals, and sends an injection control signal to the fuel injection valve. 5, the ignition timing is determined, and the ignition control signal is output to the power transistor that controls the energization of the ignition coil.
As the various sensors, an air flow meter 31 for detecting the intake air amount of the engine 1 on the upstream side of the throttle valve 2, a crank angle sensor 32 for detecting the rotation angle of the crankshaft, and the like are provided.

Further, an evaporative fuel processing device 15 for processing fuel vapor generated in the fuel tank 10 is provided.
The evaporative fuel processing device 15 once collects the fuel vapor generated in the fuel tank 10 by adsorbing it on the adsorbent (activated carbon) in the canister 17 via the fuel vapor introduction path 16 and removes it from the canister 17. The separated fuel vapor is supplied to the intake passage on the downstream side of the throttle valve 2 of the engine 1 through the purge passage 18.

The canister 17 is formed with a fresh air introduction port 17a. When the negative suction pressure of the engine 1 acts on the canister 17 through the purge passage 18, the canister 17 is caused by the fresh air introduced from the fresh air introduction port 17a. The fuel vapor adsorbed by the engine 17 is desorbed, and the desorbed fuel vapor is supplied to the engine 1 through the purge passage 18 and combusted.
A purge control valve 19, which is a normally closed solenoid valve, is interposed in the purge passage 18, and the purge flow rate is controlled by the opening degree of the purge control valve 19.

The fresh air introduction port 17a is provided with an atmospheric release valve 20, which is a normally closed solenoid valve. When purging is performed, the atmospheric release valve 20 is controlled to open and the purge control valve 19 is opened. The purge is performed by adjusting the opening degree of.
When the purge control valve 19 and the atmosphere release valve 20 are closed, the area including the fuel tank 10, the fuel vapor introduction passage 16, the canister 17, and the purge passage 18 upstream of the purge control valve 19 is closed. A pressure sensor 21 is provided for detecting the pressure (tank pressure) in the closed area.

The fuel pump 11, purge control valve 19, and air release valve 20 are controlled by a fuel system control module (hereinafter referred to as FCM) 22.
The FCM 22 includes a microcomputer, and is configured to be capable of mutual communication with the ECM 12. The FCM 22 inputs a detection signal of the pressure sensor 21, detects a detection signal of the fuel level gauge 23, and supplies fuel to the fuel tank 10. A signal of the open / close switch 24 for detecting the open / closed state of the mouth cap 27 (or the fuel filler lid 28) is input.

The FCM 22 receives the purge request signal from the ECM 12 and controls the purge control valve 19 and the atmosphere release valve 20 to perform the purge process, and also detects the blockage area (pressure detection) from the detection result of the pressure sensor 21. A leak diagnosis in the area) is performed, and the result of the leak diagnosis and information on the remaining fuel amount are transmitted to the ECM 12.
The leak diagnosis is performed based on, for example, a pressure increase characteristic in an area closed by the purge control valve 19 and the atmosphere release valve 20 immediately after the engine is stopped, and further, the pressure increased to a predetermined pressure. This is based on the pressure drop characteristics in a confined state.

  In addition, an air pump for supplying and pressurizing air in the closed area is provided, and air is supplied and pressurized in the closed area in a state where the fuel temperature is sufficiently lowered after the engine is stopped. The leak diagnosis can be performed based on the rising characteristic of the tank, and further, the leak diagnosis can be performed based on the pressure decreasing characteristic after stopping the pressurization of the tank internal pressure that has been raised to a predetermined value by the air pump.

Further, by opening the purge control valve 19 while the air release valve 20 is closed during engine operation, the tank is made negative pressure, and in this negative pressure state, the purge control valve 19 is closed and the negative pressure is confined. The leak diagnosis can be performed based on the pressure drop characteristic.
Further, the FCM 22 has a function of detecting the start of fuel supply (fuel supply state) to the fuel tank 10, and controls the opening of the atmosphere release valve 20 based on the detection result, whereby the fuel tank 10 is connected via the canister 17. The inside of the tank is opened to the atmosphere to prevent the tank internal pressure from increasing along with refueling and making it difficult to refuel.

In order to realize the above-described refueling start detection function, battery power is continuously supplied to the FCM 22 even after the ignition switch is turned off.
The flowchart of FIG. 2 shows 1st Embodiment of the said fueling start detection (fueling state detection).
The routine shown in the flowchart of FIG. 2 is executed every predetermined time. First, in step S1, the current value and the previous value of the fuel level (remaining fuel amount) detected by the fuel level gauge 23 are calculated. (Fuel remaining amount deviation = remaining amount current value-remaining amount previous value) is calculated.

In the next step S2, it is determined whether or not the remaining fuel amount deviation is greater than or equal to a preset value A stored in advance, that is, whether or not the remaining fuel amount is increasing at a predetermined speed or higher.
Here, when refueling into the fuel tank 10 is started, the remaining amount of fuel increases and changes. If it is determined that the remaining fuel amount deviation is greater than or equal to the set value A, the process proceeds to step S6. Then, the start of fuel supply (fuel supply state) to the fuel tank 10 is determined.

When the start of refueling is determined in step S6, the FCM 22 outputs an open drive signal to the atmosphere release valve 20 so that the inside of the fuel tank 10 is opened to the atmosphere via the canister 17 and continues until the tank is full. Switch to a state where regular refueling is possible.
If the atmosphere release valve 20 is kept closed even after the start of refueling, the air escape path in the tank is closed, so that the pressure in the tank increases as the amount of refueling increases, making refueling difficult. Therefore, when the start of refueling is determined, the atmosphere release valve 20 is controlled to be opened so that continuous refueling is possible.

When the atmosphere release valve 20 is controlled to open based on the start of refueling, the open state is maintained while the refueling state continues, and the output of the open drive signal is stopped after the refueling is completed, and the atmosphere release valve 20 is closed. return.
The completion of refueling can be determined as the time when the change in the remaining amount of fuel has stopped or when it has become full when the start of refueling has been determined based on the change in the remaining amount of fuel. The elapsed time can be detected as the completion of refueling.

Furthermore, it is possible to determine the completion of refueling by detecting an increase in tank internal pressure due to a full tank.
Note that it is not necessary to operate the FCM 22 in the normal mode from when the engine is stopped to when the output of the open drive signal to the atmosphere release valve 20 is started, and whether or not refueling is started in the low power consumption mode. It is possible to return to the normal mode after determining the start of refueling, and to output the open drive signal to the atmosphere release valve 20, and to determine the completion of refueling and to open the atmosphere release valve. After the output of the open drive signal to 20 is stopped, the mode can be shifted to the low power consumption mode again.

On the other hand, if it is determined in step S2 that the remaining fuel amount deviation is less than the set value A, the process proceeds to step S3, where it is determined whether or not there is a leak as a result of the leak diagnosis.
The presence / absence of a leak is information indicating the presence / absence of an abnormality in the closed area, which is a pressure detection area. As the presence / absence of an abnormality in the blocked area, failure of the purge control valve 19 (adherence, etc.) in addition to the presence of the leak. May be diagnosed.

If it is determined in step S3 that there is no leak and it is determined that there is no abnormality in the blocked area, the process proceeds to step S4.
In step S4, a deviation between the current value of the tank internal pressure detected by the pressure sensor 21 and the previous value (tank internal pressure deviation = tank internal pressure current value−tank internal pressure previous value) is calculated.
In the next step S5, it is determined whether or not the tank internal pressure deviation is equal to or greater than a predetermined value B.

Here, when fuel supply is performed with the atmosphere release valve 20 closed, the tank internal pressure rises and changes. If it is determined in step S5 that the tank internal pressure deviation is greater than or equal to the predetermined value B, the process proceeds to step S6. The process proceeds to determine the start of fuel supply to the fuel tank 10.
Therefore, even if the refueling is actually started but the start of refueling is not determined from the fuel remaining amount deviation due to the failure of the fuel level gauge 23, for example, the refueling with the air release valve 20 closed is performed. It can be determined that refueling has been started by increasing the tank internal pressure.

Further, if it is determined in step S5 that the tank internal pressure deviation is less than the predetermined value B, an increase in the remaining amount of fuel is not detected, and an increase in the tank internal pressure is not detected. It progresses to step S7 and it determines with refueling not being started.
If it is determined that refueling has not started, it is not necessary to open the atmosphere release valve 20, so the atmosphere release valve 20 is left in a closed state.

On the other hand, if it is determined in step S3 that the occurrence of leak has been diagnosed and the blocked area is abnormal, the process proceeds to step S7, where it is determined that refueling has not started.
When an abnormality such as a leak occurs in the closed area, the tank internal pressure detected by the pressure sensor 21 is affected by the abnormal state, and the reliability of the determination result as to whether or not refueling is started is determined. Sex is reduced.

Therefore, by canceling the determination process in steps S4 and S5 and proceeding directly to step S7 to determine that refueling is not performed, the start of refueling is erroneously determined in a state where refueling is not performed, and the atmosphere release It is avoided that the valve 20 is controlled to be opened.
Further, by preventing the start of refueling from being determined when an abnormality occurs, the atmosphere release valve 20 is maintained in the closed state, so that refueling can be restricted and a large amount of fuel vapor is prevented from flowing to the canister 17 side. it can.

In addition, when progressing from step S3 to step S7, it is preferable to display or sound an alarm recommending that the vehicle driver stop refueling.
Further, in the case of determining whether or not refueling is performed on the basis of the tank internal pressure deviation, the tank internal pressure changes due to the evaporation of fuel, so that the fuel temperature is detected and the predetermined value B or the tank internal pressure is detected. Correcting the deviation according to the fuel temperature or canceling the refueling start determination based on the tank internal pressure deviation according to the fuel temperature to suppress the deterioration of the refueling start detection accuracy due to the fuel evaporation. Is preferred.

  By the way, in the said embodiment, it was set as the structure which determines the start of refueling based on the change of fuel remaining amount or tank internal pressure, but when actually refueling, before that, the fuel filler lid 28 is opened, and further, Since the fuel supply is started by inserting the fuel supply gun into the fuel supply port after the fuel supply cap 27 of the fuel tank 10 is opened, the fuel supply is not started when the fuel filler lid 28 and the fuel supply cap 27 are closed.

Accordingly, if the fuel filler lid 28 and the fueling cap 27 are opened as a precondition for the fueling start determination, the accuracy of the fueling start determination based on the change in the remaining fuel amount or the tank internal pressure can be improved.
The second embodiment of the refueling start detection (refueling state detection) shown in the flowchart of FIG. 3 is an embodiment in which the fuel filler lid 28 and the refueling cap 27 are opened as a precondition for the start of refueling.

In the flowchart of FIG. 3, steps S12 to S18 perform the same processing as steps S1 to S7 in the flowchart of FIG. 2, and thus detailed description thereof is omitted here.
In step S11, it is determined from the signal from the opening / closing switch 24 whether the fuel cap 27 of the fuel tank 10 is open.

And when the oil supply cap 27 is closed, since oil supply is not started in this state, it progresses to step S18 and determines with oil supply not being started.
Accordingly, it is possible to avoid erroneous determination of the start of refueling from the remaining amount of fuel and the tank internal pressure even though the refueling cap 27 is closed and refueling cannot be started.
On the other hand, when the refueling cap 27 is open, there is a possibility that refueling may be started. Therefore, the process proceeds to step S12 and subsequent steps, and the start of refueling is determined based on the change in the remaining fuel amount or the tank internal pressure.

The open / close states of the fuel cap 27 and the fuel filler lid 28 are individually detected, and only when the fuel cap 27 is open and the fuel filler lid 28 is open, the fuel supply start determination is performed, and the fuel cap 27 and the fuel When at least one of the filler lid 28 is closed, it can be configured not to determine the start of refueling.
Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(A) A vehicle fuel supply detection device for detecting fuel supply to the fuel tank based on a detected value of the pressure in the fuel tank,
A fuel supply detection apparatus for a vehicle, which detects a fuel temperature in the fuel tank and corrects a fuel supply detection characteristic based on a detected value of the pressure in the fuel tank in accordance with the fuel temperature.

According to this configuration, the internal pressure of the tank changes due to the generation of the fuel vapor, and the generation state of the fuel vapor can be estimated from the fuel temperature. Therefore, by correcting the detection characteristic of the fuel supply based on the detection value of the tank internal pressure according to the fuel temperature, In addition, the influence of the fuel vapor can be eliminated and the fuel supply state can be detected.
(B) In the vehicle fuel supply detection device according to any one of claims 1 to 3,
A vehicle fuel supply detection apparatus that diagnoses whether there is a leak in the detection area based on a detected value of the pressure in the fuel tank as an abnormality in the detection area.

According to such a configuration, when a leak occurs, the detection of the oil supply state based on the tank internal pressure is canceled, thereby preventing the tank internal pressure from being affected by the leak and erroneously detecting the oil supply state.
(C) The vehicle oil supply detection device according to any one of claims 1 to 3,
When the start of refueling is detected by the refueling detection device, opening control of an air release valve interposed in a fresh air inlet of a canister that adsorbs fuel vapor generated in the fuel tank is performed. Vehicle refueling control device.

According to such a configuration, when the start of refueling is detected, the tank is opened to the atmosphere via the canister by opening the air release valve interposed in the fresh air inlet of the canister, and the tank pressure is increased by refueling. To prevent the refueling from becoming difficult.
(D) In the vehicle fuel supply control device according to claim (c),
An oil supply control device for a vehicle, wherein the air release valve is a normally closed electromagnetic valve.

  According to this configuration, the air release valve is driven to open only during refueling after the engine is stopped, thereby saving power consumption while the engine is stopped.

The system diagram of the engine in an embodiment. The flowchart which shows 1st Embodiment of the fuel supply start determination in embodiment. The flowchart which shows 2nd Embodiment of the fuel supply start determination in embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 10 ... Fuel tank, 11 ... Fuel pump, 12 ... Engine control module (ECM), 15 ... Evaporative fuel processing apparatus, 16 ... Fuel vapor introduction path, 17 ... Canister, 17a ... Fresh air inlet, 18 ... Purge passageway, 19 ... Purge control valve, 20 ... Air release valve, 24 ... Open / close switch, 22 ... Fuel system control module (FCM), 27 ... Fueling cap, 28 ... Fuel filler lid

Claims (3)

A vehicle fuel supply detection device for detecting a fuel supply state to a fuel tank,
While detecting the refueling state based on the detected value of the pressure in the fuel tank,
A vehicle characterized by diagnosing the presence or absence of an abnormality in the pressure detection area in the fuel tank, and canceling the detection of the fueling state based on the detected value of the pressure in the fuel tank when the occurrence of the abnormality is diagnosed Oiling detection device. The fuel supply state is detected based on the detected value of the fuel level in the fuel tank, and when the fuel supply state is not detected based on the detected value of the fuel level, the fuel supply is performed based on the detected value of the pressure in the fuel tank. The vehicle fuel supply detection device according to claim 1, wherein the state is detected. The vehicle fuel supply detection device according to claim 1 or 2, wherein a fuel supply state is detected on condition that a fuel filler lid and / or a fuel supply cap of the fuel tank is opened.

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