JP2012207566A - Leak detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the leak detection of an individual fuel tank in an early stage after the stop of an internal combustion engine without installing a decompression pump at each fuel tank with respect to a plurality of the fuel tanks which communicate with each other via a fuel communication passage, and without discharging fuel vapor.SOLUTION: Fuel is moved between the fuel tanks by sealing an evaporated fuel passage (S106), blocking a gap between the fuel tanks (S108), switching a changeover valve (S110), and driving the fuel pump (S112). Then, the leak detection is performed on the basis of change amounts of internal pressure Pf1, Pf2 of each fuel tank (S116, S118). By this, each leak state can be detected without installing the decompression pumps at the two fuel tanks, respectively. The two fuel tanks are sealed and the fuel vapor is not discharged to the outside by the detection itself. Furthermore, the internal pressure Pf1, Pf2 is actively changed by the fuel pump, a leak can be detected in an early stage after the stop of the internal combustion engine.

Description

  The present invention relates to a leak detection device in a fuel storage mechanism that stores a fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path.

  There is known an internal combustion engine provided with a plurality of fuel tanks as fuel storage parts, or an internal combustion engine provided with a plurality of fuel storage parts in one fuel tank (see, for example, Patent Document 1).

  There is known an apparatus that detects the presence or absence of a hole in a fuel tank, which is a fuel storage part of an internal combustion engine, based on the purge line pressure (see, for example, Patent Document 2).

Japanese Patent Laying-Open No. 2008-8278 (pages 6-8, FIGS. 1-5) JP-A-2006-177199 (pages 4-6, FIGS. 1-4)

  It is conceivable to perform leak detection as shown in Patent Document 2 for a fuel storage mechanism that stores fuel to be supplied to the internal combustion engine by providing a plurality of fuel storage parts as in Patent Document 1. However, in this case, the pressure sensor detects leaks in the whole of the plurality of fuel storage parts connected by the communication pipe, and even if it is found that there is a leak as a whole, any fuel is detected. It is not the detection which discriminate | determined whether it is a leak about a storage part.

  Further, in the method of Patent Document 2, it is due to a natural drop in the fuel temperature when the internal combustion engine is stopped, and the presence or absence of leakage cannot be detected immediately after the internal combustion engine is stopped, and a long internal combustion engine stop time is required. For this reason, in a hybrid vehicle or the like that intermittently drives or stops the internal combustion engine, even if the internal combustion engine stops, the chance may not be utilized.

  In order to detect leaks early after the internal combustion engine stops without waiting for the natural decrease in the fuel temperature, separate decompression pumps are provided in a plurality of fuel storage units, and the pressure in the fuel storage unit is immediately reduced when the internal combustion engine is stopped. Is also possible. However, it is necessary to provide a decompression pump for each fuel storage section, and when these decompression pumps are driven, fuel vapor is discharged from the fuel storage section when a leak is detected. Not right.

  The present invention is capable of detecting leaks in individual fuel storage parts without providing a decompression pump for each fuel storage part and discharging fuel vapor for a plurality of fuel storage parts communicated by a fuel communication path. It is intended to be possible at an early stage after the internal combustion engine is stopped.

In the following, means for achieving the above-mentioned purpose, and its operation and effect are described.
The leak detection device according to claim 1 is a leak detection device in a fuel storage mechanism that stores a fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path, A pressure-feeding pump that moves the fuel between the parts, a first internal pressure sensor that detects an internal pressure of the outflow-side fuel storage part from which the fuel flows out by the pressure-feeding pump, and an inflow-side fuel storage in which the fuel is fed from the pressure-feeding pump A second internal pressure sensor for detecting an internal pressure of the fuel tank, an on-off valve of the fuel communication passage, a passage between the outflow side fuel storage portion and the inflow side fuel storage portion, and the outside, and the open / close valve is closed. When the fuel movement is executed by driving the pressure feed pump, the leak state of the outflow side fuel reservoir is detected based on the internal pressure state detected by the first internal pressure sensor. Characterized in that a leakage detecting means for detecting a leak condition of the inflow-side fuel reservoir on the basis of the detected internal pressure state by the second pressure sensor.

  The leak detection means seals the flow path between the outflow side fuel storage section and the inflow side fuel storage section and the outside, and closes the open / close valve of the fuel communication path, and moves the fuel between the fuel storage sections by the pump. Execute. Here, the pressure feed pump is not a pump for pressurizing or depressurizing the inside of the fuel storage unit, but moves the fuel between the fuel storage units which are components in the fuel storage mechanism. For this reason, the entire fuel storage mechanism subject to leak detection can maintain a closed system.

  In the fuel movement between the fuel reservoirs, the open / close valve of the fuel communication passage is closed, so that the pressure at the outflow side fuel reservoir where the fuel flows out is reduced by reducing the fuel amount. In the inflow side fuel storage part into which the fuel is poured, the pressure is increased by increasing the amount of fuel.

For this reason, if a leak exists in the outflow side fuel storage part, it will affect the pressure reduction, and if a leak exists in the inflow side fuel storage part, it will affect the pressure increase.
Therefore, the internal pressure state of the outflow side fuel storage part can be detected by the first internal pressure sensor, and the leak state of the outflow side fuel storage part can be detected based on the internal pressure state.

Similarly, the internal pressure state of the inflow side fuel storage portion can be detected by the second internal pressure sensor, and the leak state of the inflow side fuel storage portion can be detected based on the internal pressure state.
This makes it possible to detect leaks in a plurality of fuel reservoirs without providing a pumping pump in each fuel reservoir.

In addition, since each fuel storage section has the on-off valve closed, the internal pressure state of each fuel storage section is completely independent, and leak detection of each fuel storage section is possible.
Furthermore, this leak detection can be executed early after the internal combustion engine is stopped because the internal pressure change of the fuel reservoir is positively caused by the pump.

At the time of leak detection, only the fuel movement between the fuel storage portions is performed, and the entire fuel storage mechanism can be maintained in a sealed state. Therefore, there is no discharge of fuel vapor due to execution of leak detection itself.
In the leak detection device according to claim 2, in the leak detection device according to claim 1, the pressure feed pump also serves as a fuel pump for supplying fuel to an internal combustion engine, and the fuel discharge side of the pressure feed pump has the A fuel movement path for executing fuel movement and an internal combustion engine supply path for supplying fuel to the internal combustion engine are connected via a switching valve, and the leak detection means functions when the internal combustion engine is stopped. In the present invention, when the fuel moves, the switching valve is switched so that the fuel discharge side of the pressure feed pump is used as the fuel movement path.

  By using the fuel pump as the pressure pump while the internal combustion engine is stopped, it is not necessary to provide a separate pressure pump for detecting the leak. That is, only by providing the fuel movement path and the switching valve, the fuel can be moved between the fuel reservoirs, and the configuration is simplified.

  The leak detection device according to claim 3, wherein the leak detection means is based on an internal pressure state detected by the first internal pressure sensor during driving of the pumping pump. Then, the leak state of the outflow side fuel storage part is detected.

  In the outflow side fuel storage part, when the pump is driven and the fuel moves between the fuel storage parts, the internal pressure thereof decreases. If there is a leak in the outflow side fuel storage part, outside air enters and the degree of decrease in internal pressure is reduced.

As a result, it is possible to detect the leak state of the outflow side fuel storage part based on the internal pressure state detected by the first internal pressure sensor during the driving of the pressure feed pump.
The leak detection device according to claim 4, wherein the leak detection means is detected by the second internal pressure sensor while the pump is being driven. The leak state of the inflow side fuel storage part is detected based on the internal pressure state.

  In the inflow side fuel storage part, when the pump is driven and the fuel moves between the fuel storage parts, the internal pressure rises. If there is a leak in the inflow side fuel storage part, the gas in the fuel storage part leaks to the outside, and the degree of increase in the internal pressure is reduced.

As a result, it is possible to detect the leak state of the inflow side fuel storage portion based on the internal pressure state detected by the second internal pressure sensor during the driving of the pressure feed pump.
According to a fifth aspect of the present invention, in the leak detection device according to the first or second aspect, the leak detection means is detected by the first internal pressure sensor before or after driving the pressure pump. The leak state of the outflow side fuel storage part is detected based on the internal pressure state.

  In the outflow side fuel storage part, when the fuel moves between the fuel storage parts and the pumping pump stops driving, the internal pressure once decreased by the movement rises slightly due to the vapor supply from the liquid fuel, but it is higher than before the fuel movement. Stay low.

If there is a leak in the outflow side fuel storage part, the internal pressure once lowered by the fuel movement returns to the internal pressure before the fuel movement quickly by the intrusion of the outside air.
As a result, the leakage state of the outflow side fuel storage part can be detected based on the internal pressure state detected by the first internal pressure sensor before and after driving the pressure feed pump.

  Further, even if the internal pressure state after driving the pump is limited, the internal pressure state varies in changing state such as the changing speed depending on the presence or absence of leakage. From this, it is also possible to detect the leak state of the outflow side fuel storage part also based on the internal pressure state detected by the first internal pressure sensor immediately after the pumping pump is stopped.

  In the leak detection device according to claim 6, in the leak detection device according to any one of claims 1 to 5, the leak detection means includes the second internal pressure before and after driving the pumping pump or after driving. A leak state of the inflow side fuel storage part is detected based on an internal pressure state detected by a sensor.

  In the inflow side fuel reservoir, when the fuel moves between the fuel reservoirs and the pumping pump stops driving, the internal pressure once increased by the movement is slightly reduced by the condensation of the fuel vapor, but is higher than before the fuel movement To maintain.

If there is a leak in the inflow side fuel storage part, the internal pressure once increased by the fuel movement returns to the internal pressure before the fuel movement because the gas in the fuel storage part leaks outside.
Thus, the leakage state of the inflow side fuel storage part can be detected based on the internal pressure state detected by the second internal pressure sensor before and after driving the pressure feed pump.

  Further, even if the internal pressure state after driving the pump is limited, the internal pressure state varies in changing state such as the changing speed depending on the presence or absence of leakage. From this, it is possible to detect the leak state of the inflow side fuel storage part also based on the internal pressure state detected by the second internal pressure sensor immediately after the pumping pump is stopped.

  According to a seventh aspect of the present invention, there is provided the leak detection device according to the first or second aspect, wherein the leak detection means is in an internal pressure state detected by the first internal pressure sensor while the pump is being driven. Based on the first pumping side detection process for detecting the leak state of the outflow side fuel storage section and the first pumping side detection process, it was detected that the leak state could not be detected or that no leak occurred. A second pumping side detection process for detecting a leak state of the outflow side fuel storage unit based on an internal pressure state detected by the first internal pressure sensor before, after or after driving the pumping pump. It is characterized by doing.

  Since the first pumping side detection process detects the leak state based on the internal pressure state when the pump is driven and the fuel moves between the fuel storing portions with respect to the outflow side fuel storing portion. Presence or absence of leak can be detected at an early stage.

  However, in the leak state detection by the first pressure-feeding side detection process, since the fuel is moving, the internal pressure state of the outflow side fuel storage part may not be stable and leak detection may not be possible. In addition, during fuel movement, even if a leak occurs, if the leak is not large to some extent, it may be difficult to appear as a decrease in internal pressure.

  Accordingly, when the leak state cannot be detected in the first pumping side detection process or when it is detected that no leak has occurred, the pumping pump is driven before and after the pumping pump is driven by the second pumping side detection process. Based on the internal pressure state detected by the first internal pressure sensor before and after stopping, the leak state of the outflow side fuel storage part is detected.

  In this way, when the fuel movement is stopped before and after the driving of the pressure feed pump, the inside of the outflow side fuel storage part is in a stable state, so that the internal pressure state can be detected with high accuracy, and these internal pressure states can be detected. It is possible to accurately detect leaks by comparing.

  Furthermore, even if the internal pressure state is limited to the internal pressure state detected by the first internal pressure sensor after the pumping pump is driven, the internal pressure state varies in changing state such as the changing speed depending on the presence or absence of leakage. From this, it is possible to accurately detect the leak even when based on the internal pressure state detected by the first internal pressure sensor after driving the pressure pump.

In addition, since the pumping pump is stopped, no special driving process is required, so that the speed of the process is not hindered.
This makes it possible to achieve both rapidity and accuracy of leak detection for the outflow side fuel reservoir.

  The leak detection device according to claim 8, wherein the leak detection means is an internal pressure detected by the second internal pressure sensor during driving of the pump. In the first pressure-feed side detection process for detecting the leak state of the inflow-side fuel storage unit based on the state and the first pressure-feed side detection process, the leak state cannot be detected or no leak has occurred. Is detected, based on the internal pressure state detected by the second internal pressure sensor before and after driving the pressure pump, or the second pressure-feed side that detects the leak state of the inflow side fuel storage unit And a detection process.

  The first pressure-feed side detection process detects the leak state based on the internal pressure state when the pump is driven and the fuel moves between the fuel storage portions with respect to the inflow side fuel storage portion. The presence or absence of a leak can be detected early.

  However, in the leak state detection by the first pressure-feed side detection process, since the fuel is moving, the internal pressure state of the inflow side fuel storage part may not be stable and the leak detection may not be performed. In addition, during fuel movement, even if a leak occurs, if the leak is not large to a certain extent, it may be difficult to show an increase in internal pressure.

  Therefore, when the leak state cannot be detected in the first pressure-feed side detection process or when it is detected that no leak has occurred, the second pump-feed side detection process performs before and after driving of the pump, that is, the pressure pump is Based on the internal pressure state detected by the second internal pressure sensor before driving and after stopping, the leakage state of the inflow side fuel reservoir is detected.

  As described above, when the movement of the fuel is stopped before and after the pumping pump is driven, the inside of the inflow side fuel reservoir is in a stable state, so that the internal pressure state can be detected with high accuracy. By comparing the states, leak detection can be performed accurately.

  Furthermore, even if the internal pressure state is detected by the second internal pressure sensor after the pumping pump is driven, the internal pressure state varies in a changing state such as a changing speed depending on the presence or absence of a leak. From this, it is possible to accurately detect the leak even when based on the internal pressure state detected by the second internal pressure sensor after driving the pump.

In addition, since the pumping pump is stopped, no special driving process is required, so that the speed of the process is not hindered.
This makes it possible to achieve both quickness and accuracy of leak detection for the inflow side fuel storage section.

  In the leak detection device according to claim 9, in the leak detection device according to any one of claims 1 to 8, the leak detection means is configured so that the change rate of the internal pressure detected by the internal pressure sensor is within a reference range. In the case of convergence, the detection of a leak state is executed based on the amount of change in internal pressure between the internal pressure detected by the internal pressure sensor immediately before the start of driving the pressure feed pump or immediately after the start of driving and the converged internal pressure. And

  Thus, in a state where the change speed of the internal pressure (internal pressure change amount per unit time) converges to the reference range, that is, in a state where the internal pressure is stable, the leak state is determined based on the internal pressure change amount immediately before or after the fuel movement. Since detection is performed, more accurate leak detection can be performed.

  The leak detection device according to claim 10, wherein the leak detection unit is configured to detect a leak based on a change rate of an internal pressure detected by the internal pressure sensor. It is characterized by performing state detection.

Thus, before the internal pressure state is stabilized, the detection of the leak state may be executed based on the change speed of the internal pressure, and the leak detection can be performed more quickly.
The leak detection device according to claim 11 is a leak detection device in a fuel storage mechanism that stores a fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path. One of the pressure storage pump that performs the movement of the fuel between the sections, the outflow side fuel storage section where the fuel is flowed out by the pressure pump, and the inflow side fuel storage section where the fuel flows from the pressure pump An internal pressure sensor for detecting the internal pressure of the fuel, an on-off valve of the fuel communication passage, a passage between the outflow side fuel storage portion and the inflow side fuel storage portion and the outside, and the open / close valve in a closed state. The internal pressure detected by the internal pressure sensor when the stop of driving of the pressure feed pump and the opening of the on-off valve are executed after the fuel movement is performed by driving the pressure feed pump. Characterized in that a leakage detecting means performs the detection process of detecting a leak condition of the inflow-side fuel reservoir and the outflow-side fuel reservoir on the basis of the state.

  Here, the internal pressure sensor is not provided for detecting the internal pressure state of the outflow side fuel storage section and for detecting the internal pressure state of the inflow side fuel storage section, but detects the internal pressure of one of the fuel storage sections. Only things.

  As a detection process, the leak detection means first closes the passages of the outflow side fuel storage part and the inflow side fuel storage part and the outside, and closes the open / close valve of the fuel communication path to drive the pressure feed pump. Perform fuel transfer. After this fuel movement, the leakage state between the outflow side fuel storage part and the inflow side fuel storage part based on the internal pressure state detected by the internal pressure sensor by stopping the driving of the pressure feed pump and opening the on-off valve. Is detected.

  That is, immediately before the detection of the internal pressure state, the pressure feed pump moves the fuel between the fuel storage portions, so that the internal pressure is reduced in the outflow side fuel storage portion and the internal pressure is increased in the inflow side fuel storage portion. By opening the on-off valve that was closed during fuel movement in this state, the fuel returns from the inflow side fuel storage part to the outflow side fuel storage part due to the pressure difference between the fuel storage parts.

  Therefore, the internal pressure state of the fuel reservoir detected by the internal pressure sensor shows the opposite change. That is, when the internal pressure sensor detects the internal pressure state of the outflow side fuel storage part, the internal pressure has decreased due to the fuel movement by the pumping pump, but the fuel returns from the inflow side fuel storage part by opening the on-off valve. Then, it will turn upward toward the original internal pressure. When the internal pressure sensor detects the internal pressure state of the inflow side fuel storage part, the internal pressure has increased due to the fuel movement by the pressure pump, but the fuel returns to the outflow side fuel storage part by opening the on-off valve. As a result, the pressure starts to decrease toward the original internal pressure.

If neither the outflow side fuel storage part nor the inflow side fuel storage part has leaked, the internal pressure change described above occurs in the internal pressure sensor.
However, if there is a leak in either one of the fuel reservoirs, when the on-off valve is opened, the fuel is returned by the internal pressure of the fuel reservoir where there is no leak. In this case, when the internal pressure sensor detects the internal pressure of the fuel storage part where no leakage occurs, an internal pressure change with a width smaller than usual is generated.

  When the internal pressure sensor detects the internal pressure of the fuel storage section where the leak has occurred, the change in the internal pressure of the fuel storage section is already small or almost absent when the fuel is moved by the pressure pump. For this reason, an oscillating internal pressure change occurs immediately after the fuel is returned by the internal pressure of the fuel reservoir where no leakage occurs.

  Therefore, when there is a leak in one of the fuel reservoirs, it can be determined from the internal pressure change pattern whether the internal pressure sensor is on the side where the leak occurs or on the side where no leak occurs.

  When there is a leak in both of the fuel reservoirs, even if the on-off valve is opened after the fuel is moved by the pressure feed pump, there is almost no return of fuel due to the difference in internal pressure. In this case, even if the internal pressure sensor detects the internal pressure in any fuel storage portion, the internal pressure hardly changes.

  In this way, by opening the on-off valve of the fuel communication passage after the fuel is moved by the pressure feed pump, a plurality of fuel reservoirs can be provided even if there is only one internal pressure sensor and no pressure feed pump is provided in each fuel reservoir. Each leak state can be detected.

Furthermore, since this leak detection is based on the state in which the internal pressure change of the fuel reservoir is positively generated by the pressure feed pump, it can be executed early after the internal combustion engine is stopped.
At the time of detecting the leak, only the fuel movement between the fuel storage portions and the return thereof are performed, and the entire fuel storage mechanism can be maintained in a sealed state, so that there is no discharge of fuel vapor due to the leak detection execution itself.

  The leak detection device according to claim 12 is a leak detection device in a fuel storage mechanism that stores a fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication passage, One of the pressure storage pump that performs the movement of the fuel between the sections, the outflow side fuel storage section where the fuel is flowed out by the pressure pump, and the inflow side fuel storage section where the fuel flows from the pressure pump An internal pressure sensor for detecting the internal pressure of the fuel, an on-off valve of the fuel communication passage, a passage between the outflow side fuel storage portion and the inflow side fuel storage portion and the outside, and the open / close valve in a closed state. A first detection process for detecting a leakage state of the one fuel storage unit based on an internal pressure state detected by the internal pressure sensor when the fuel movement is executed by driving a pressure pump. And the outflow side fuel storage portion and the inflow side fuel based on the internal pressure state detected by the internal pressure sensor when the stoppage of the pumping pump and the opening / closing of the on-off valve are performed after the first detection process. Leakage detection means for executing a second detection process for detecting a leakage state of the other fuel storage part of the storage part is provided.

  Here, prior to the second detection process in which the leak detection means detects the leak state of the other fuel storage part in the same process as the detection process in claim 11, the leak state of one fuel storage part during fuel movement The 1st detection process which detects is performed.

  That is, as the first detection process, the fuel flow is controlled by blocking the passages of the outflow side fuel reservoir and the inflow side fuel reservoir and the outside, and closing the fuel communication passage on and off and driving the pressure pump. When the fuel is moved, the leak state of one fuel storage unit is detected based on the internal pressure state detected by the internal pressure sensor.

  As described above, by combining detection at the time of fuel movement and detection at the time of fuel return, a plurality of fuel storage units can be provided even if there is only one internal pressure sensor and no pump pump is provided in each fuel storage unit. Each leak state can be detected.

Furthermore, since this leak detection is based on the state in which the internal pressure change of the fuel reservoir is positively generated by the pressure feed pump, it can be executed early after the internal combustion engine is stopped.
At the time of detecting the leak, only the fuel movement between the fuel storage portions and the return thereof are performed, and the entire fuel storage mechanism can be maintained in a sealed state, so that there is no discharge of fuel vapor due to the leak detection execution itself.

  The leak detection device according to claim 13 is a leak detection device in a fuel storage mechanism that stores a fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path. A pump for performing fuel movement between the parts, a pump work detecting means for detecting the work of the pressure pump, an outflow side fuel storage part through which fuel is discharged by the pressure pump, and fuel from the pressure pump. An internal pressure sensor for detecting an internal pressure of any one of the inflow side fuel storage part to be poured, an on-off valve of the fuel communication path, the outflow side fuel storage part, the inflow side fuel storage part, and the outside The internal pressure state detected by the internal pressure sensor when the fuel movement is executed by driving the pressure feed pump with the on-off valve closed and the on-off valve closed. Leakage detection means for detecting the respective leak states of the outflow side fuel storage section and the inflow side fuel storage section based on the work volume detected by the pump work volume detection means. .

  The leak detection means closes the passage between the outflow side fuel storage section and the inflow side fuel storage section and the outside, and closes the open / close valve of the fuel communication path to drive the pressure feed pump to perform fuel movement. In addition, the leak state of one fuel reservoir is detected based on the internal pressure state detected by the internal pressure sensor.

  When the fuel is moved by the pressure pump, the work of the pressure pump is detected by the pump work detection means. The work volume of this pumping pump is such that the internal pressure of the outflow side fuel storage section is reduced and the internal pressure of the inflow side fuel storage section is increased unless both the outflow side fuel storage section and the inflow side fuel storage section are leaked. . Therefore, the differential pressure rapidly increases as the fuel moves. For this reason, the work volume of the pressure pump is a large value.

  If there is a leak in both the outflow side fuel storage part and the inflow side fuel storage part, the internal pressure of the outflow side fuel storage part is low or does not decrease, and the internal pressure of the inflow side fuel storage part is increased. The degree of is low or does not increase in pressure. Therefore, since the differential pressure hardly changes even when the fuel moves, the work amount of the pressure pump becomes a small value.

  If there is a leak in one of the outflow side fuel storage part and the inflow side fuel storage part and there is no leak in the other side, one of the internal pressure changes little or does not change as described above. On the other hand, the internal pressure change occurs as described above. Therefore, the differential pressure gradually increases as the fuel moves, but is not rapid. For this reason, the amount of work of the pressure pump is a medium value. In this case, the leaking side can be determined from the detection result of the internal pressure sensor that detects the internal pressure of any one of the fuel storage portions described above.

  In this way, even if there is only one internal pressure sensor, the work amount of the pumping pump is detected by the pump work amount detecting means, so that each of the fuel storage units can be provided for each of the fuel storage units without providing the pumping pump in each fuel storage unit. A leak state can be detected.

Furthermore, since this leak detection is based on the state in which the internal pressure change of the fuel reservoir is positively generated by the pressure feed pump, it can be executed early after the internal combustion engine is stopped.
At the time of leak detection, only the fuel movement between the fuel storage portions is performed, and the entire fuel storage mechanism can be maintained in a sealed state. Therefore, there is no discharge of fuel vapor due to execution of leak detection itself.

  15. The leak detection device according to claim 14, wherein the inflow side fuel for detecting the fuel level stored in the inflow side fuel storage portion is the leak detection device according to any one of claims 1 to 13. A level sensor is provided, and the leak detection means executes processing when the fuel level detected by the inflow side fuel level sensor is lower than an inflow reference level.

  In the inflow side fuel storage part, there must be a certain margin for fuel to flow. Therefore, the leak detection means executes the process on the assumption that there is a margin space when the fuel level detected by the inflow side fuel level sensor provided in the inflow side fuel reservoir is lower than the inflow reference level. .

As a result, highly accurate leak detection can be performed.
The leak detection device according to claim 15, wherein the outflow side fuel that is stored in the outflow side fuel storage portion is detected in the leak detection device according to any one of claims 1 to 14. A level sensor is provided, and the leak detection means executes processing when the fuel level detected by the outflow side fuel level sensor is higher than an outflow reference level.

  There must be some amount of fuel to be spilled in the outflow side fuel reservoir. Therefore, the leak detection means executes the process on the assumption that the necessary fuel amount is present when the fuel level detected by the outflow side fuel level sensor provided in the outflow side fuel storage unit is higher than the outflow reference level. ing.

As a result, highly accurate leak detection can be performed.
In the leak detection device according to claim 16, in the leak detection device according to any one of claims 1 to 15, in place of each internal pressure sensor that detects an internal pressure of the fuel storage portion, A strain sensor is disposed on the component member, and the leak detection unit detects a leak state of the fuel storage unit based on a strain amount of the component member detected by the strain sensor.

  Since the internal pressure state of the sealed fuel storage portion corresponds to the strain amount in the constituent members of the fuel storage portion, a strain sensor can be provided instead of the internal pressure sensor, and the strain amount can be used for leak detection instead of the internal pressure. .

  In the leak detection device according to claim 17, in the leak detection device according to any one of claims 1 to 15, separately from each internal pressure sensor that detects an internal pressure of the fuel storage section, or of each internal pressure sensor Instead, a fuel level sensor that detects the fuel level stored in the fuel storage unit is disposed, and the leak detection means detects the amount of change in the fuel level detected by the fuel level sensor before and after the pumping pump is driven. The leakage state of the fuel reservoir is detected based on the amount of deviation between the fuel change amount corresponding to the above and the amount of fuel movement by the pressure pump.

  When the internal pressure change of the fuel storage unit occurs due to the leak, the outer wall of the fuel storage unit bulges or shrinks. For this reason, even after the fuel is moved, the fuel level changes due to the leak state. Therefore, instead of the internal pressure, a deviation amount between the fuel movement amount and the fuel change amount detected by the fuel level sensor can be used for leak detection.

1 is a schematic diagram of an internal combustion engine and a fuel supply system thereof according to Embodiment 1. FIG. 3 is a flowchart of a leak detection process executed by the ECU according to the first embodiment. (A)-(c) The timing chart which shows an example of the leak detection process of Embodiment 1. FIG. 10 is a flowchart of leak detection processing executed by the ECU according to the second embodiment. 10 is a flowchart of leak detection processing executed by the ECU according to the third embodiment. 10 is a flowchart of leak detection processing executed by the ECU according to the fourth embodiment. 9 is a flowchart of a fuel pump after-leak detection process executed by the ECU according to the fourth embodiment. (A)-(c) The timing chart which shows an example of the leak detection process of Embodiment 4. FIG. Schematic of the internal combustion engine of Embodiment 5 and its fuel supply system. 10 is a flowchart of pre-leak detection preparation processing executed by the ECU according to the fifth embodiment. 10 is a flowchart of leak detection processing executed by the ECU according to the fifth embodiment. (A)-(d) The timing chart which shows an example of the pre-leak detection preparatory process of Embodiment 5, and a leak detection process. 10 is a flowchart of leak detection processing executed by an ECU according to the seventh embodiment. 10 is a flowchart of leak detection processing executed by an ECU according to the ninth embodiment. The structure explanatory view of the fuel tank of other embodiments.

[Embodiment 1]
<Structure> FIG. 1 shows an internal combustion engine 2 and its fuel supply system 4 to which the above-described invention is applied. The internal combustion engine 2 may be mounted on the vehicle alone as a vehicle drive source, or may be mounted on the vehicle together with the electric motor in a hybrid vehicle or a plug-in hybrid vehicle.

  A fuel injection valve 8 is disposed in each intake port 6 of the plurality of cylinders provided in the internal combustion engine 2. In these fuel injection valves 8, fuels FL 1 and FL 2 stored in two fuel tanks 12 and 14 (corresponding to a plurality of fuel storage portions) of the fuel storage mechanism 10 are supplied to the internal combustion engine by a fuel pump 16. It is pumped through path 18. By the fuel injection control, fuel is injected from the fuel injection valve 8 during intake at a predetermined timing, and is sucked into each cylinder and burned. As a result, the internal combustion engine 2 is driven.

  A first internal pressure sensor 20 is disposed in the main fuel tank 12 of the two fuel tanks 12, 14, and a second internal pressure sensor 22 is disposed in the sub fuel tank 14. These two internal pressure sensors 20, 22 detect the internal pressures Pf1, Pf2 in the upper spaces 12a, 14a of the fuel tanks 12, 14, respectively.

  Further, in the two fuel tanks 12, 14, fuel sender gauges 24, 26 are provided for detecting the fuel liquid level SGL1, SGL2 in the fuel tanks 12, 14 by the floats 24a, 26a.

  Refueling is performed from a fuel inlet pipe 28 provided in one fuel tank (hereinafter referred to as sub fuel tank) 14. The sub fuel tank 14 is connected to another fuel tank (hereinafter referred to as a main fuel tank) 12 by a fuel communication path 30 on the lower side thereof. An open / close valve 32 as an electromagnetic valve is provided in the middle of the fuel communication path 30.

  The upper space 12 a of the main fuel tank 12 is connected to a canister 36 by an evaporated fuel passage 34. In the evaporative fuel passage 34, an ORVR valve (Onboard referencing vapor recovery valve) 34 a and a COV (Cut Off Valve) 34 b are provided at the opening inside the main fuel tank 12.

  Further, the evaporative fuel passage 34 is provided with a block valve unit 35 including a block valve 35 a and a relief valve 35 b between the main fuel tank 12 and the canister 36. The block valve 35a is an electromagnetic valve that can be switched between an open state and a closed state. When the block valve 35a is opened, the upper space 12a of the main fuel tank 12 and the canister 36 communicate with each other through the evaporated fuel passage 34. To do. Thus, the fuel vapor generated in the upper space 12a of the main fuel tank 12 can be discharged to the canister 36 side. When the blocking valve 35a is closed, the evaporated fuel passage 34 is blocked, and the fuel vapor generated in the upper space 12a of the main fuel tank 12 cannot be discharged to the canister 36 side. That is, the inside of the main fuel tank 12 is sealed independently of the canister 36 and is in an airtight state. The relief valve 35b is opened when the difference between the pressure in the evaporated fuel passage 34 on the main fuel tank 12 side and the pressure in the evaporated fuel passage 34 on the canister 36 side is excessive, and the excessive differential pressure is eliminated. It is something to be made.

  The canister 36 includes an adsorbent such as activated carbon that adsorbs fuel therein, and adsorbs fuel vapor discharged from the upper space 12 a of the main fuel tank 12 through the evaporated fuel passage 34. An atmospheric passage 38 communicating with the atmospheric side is connected to the canister 36. The air passage 38 is provided with an air filter 38a on the way. Further, the atmosphere passage 38 is provided with an atmosphere release valve 40 as a normally open electromagnetic valve at a position closer to the canister 36 than the air filter 38a.

  With such a configuration, the fuel FL2 introduced from the fuel inlet pipe 28 into the sub fuel tank 14 can be supplied to the sub fuel tank 14 by opening the on-off valve 32 and the blocking valve 35a of the fuel communication passage 30 during refueling. 14, and also flows into the main fuel tank 12 through the fuel communication passage 30 and is stored in the main fuel tank 12.

  The canister 36 is connected to the intake passage 44 of the internal combustion engine 2 by a purge passage 42 at a position downstream of the throttle valve 46. A purge valve 48 as an electromagnetic valve is disposed in the purge passage 42. The purge is executed by opening the purge valve 48 and the air release valve 40.

In the intake passage 44, an air flow meter 54 is provided between the air filter 52 and the throttle valve 46 to detect the intake air amount GA supplied to the internal combustion engine 2.
In addition, an accelerator opening sensor provided on an accelerator pedal operated by a vehicle driver to detect an accelerator opening ACCP, an engine rotation speed sensor for detecting a rotation speed NE of a crankshaft of the internal combustion engine 2, an IGSW (ignition switch), Other sensors and switches are provided to output signals. Examples of other signals include cooling water temperature, intake air temperature, and vehicle speed.

  Detection signals from the internal pressure sensors 20 and 22 and the fuel sender gauges 24 and 26 are input to an electronic control unit (hereinafter referred to as an ECU) 60 that is configured around a microcomputer.

Then, based on such signal data and prestored data, the ECU 60 executes arithmetic processing to control the fuel injection valve 8, the throttle valve 46, and the like.
The fuel FL1 in the main fuel tank 12 is supplied to the fuel injection valve 8 via an internal combustion engine supply path 18, and the fuel discharge side of the fuel pump 16 is connected to the internal combustion engine supply path 18 via a switching valve 62. It is connected.

  This switching valve 62 can switch the fuel discharge side of the fuel pump 16 to a branch path 64 as a fuel movement path. This branch path 64 connects the fuel discharge side of the fuel pump 16 to the sub fuel tank 14.

The switching valve 62 normally feeds the fuel FL1 in the main fuel tank 12 discharged from the fuel pump 16 to the fuel injection valve 8 side via the internal combustion engine supply path 18. However, as will be described later, when the ECU 60 executes the leak detection processing as shown in FIG. 2 as the leak detection device, the ECU 60 switches the switching valve 62 and the fuel in the main fuel tank 12 discharged from the fuel pump 16. FL1 is pumped into the sub fuel tank 14 via the branch path 64.
<Operation> Next, the operation of the present embodiment will be described with reference to a flow chart of leak detection processing (FIG. 2). The process of FIG. 2 is periodically executed at a constant time. The steps in the flowchart corresponding to the individual processing contents are represented by “S˜”.

When this process is started, it is first determined whether or not a leak detection condition is satisfied (S102). Here, the leak detection conditions are as indicated by the following ac.
a. The internal combustion engine 2 is stopped.

  b. The main fuel liquid level SGL1 detected by the fuel sender gauge 24 provided in the main fuel tank 12 in a state before driving the fuel pump 16 is higher than the outflow reference level.

c. The sub fuel liquid level SGL2 detected by the fuel sender gauge 26 provided in the sub fuel tank 14 before the fuel pump 16 is driven is lower than the inflow reference level.
In step S102, the logical product of these conditions a, b, and c is set as a leak detection condition.

In addition to this, the following condition d may be added as a logical product.
d. A predetermined time has elapsed since the internal combustion engine 2 was stopped. (This predetermined time indicates a state in which the fuel temperature in each fuel tank 12, 14 is sufficiently lowered and the fuel vapor pressure is lowered to some extent.)
Alternatively, the next condition e may be added as a logical product to the conditions a, b, and c instead of or together with the condition d.

e. The vehicle has stopped running.
If the leak detection condition is not satisfied (NO in S102), the process is exited as it is. Thereafter, if the leak detection condition is not satisfied in the execution cycle of this process (NO in S102), the substantial leak detection process is not performed in the leak detection process (FIG. 2).

If the leak detection condition is satisfied (YES in S102), it is next determined whether or not the leak detection end setting is not set (S104).
If it is the first determination under the current leakage detection condition, the leak detection result indicating normal or abnormal has not yet been obtained (YES in S104). The provided blocking valve 35a is closed (S106). If the blockade valve 35a has already been closed, the process of maintaining the closed state is performed in step S106.

  Next, the on-off valve 32 provided in the fuel communication passage 30 communicating between the main fuel tank 12 and the sub fuel tank 14 is closed (S108). If the on-off valve 32 has already been closed, in step S108, a process for maintaining the closed state is performed.

  Next, the switching valve 62 is switched so that the fuel discharge side of the fuel pump 16 changes from the internal combustion engine supply path 18 side for supplying the fuel FL1 to the fuel injection valve 8 to the branch path 64 side (S110). If the switching valve 62 has already been switched to a state in which the fuel pump 16 and the branch path 64 are connected, in step S110, the switching state is maintained.

  Next, the fuel pump 16 is driven (S112). As a result, the fuel FL1 in the main fuel tank 12 is moved into the sub fuel tank 14 by the fuel pump 16. Accordingly, the amount of fuel FL2 in the sub fuel tank 14 increases. Then, the amount of fuel FL1 in the main fuel tank 12 is decreased by this increased amount.

  In this way, the main fuel tank 12 that is the outflow side fuel storage part and the sub fuel tank 14 that is the inflow side fuel storage part and the passage (evaporative fuel path 34) between the outside (here, the canister 36) are blocked, and further, the fuel connection. The passage 30 is blocked and the switching valve 62 is switched. By driving the fuel pump 16 in this state, the fuel FL 1 is moved from the main fuel tank 12 to the sub fuel tank 14.

  By this fuel movement, the upper space 12a of the main fuel tank 12 is expanded by the decrease of the fuel FL1, the internal pressure Pf1 is gradually lowered, and the upper space 14a of the sub fuel tank 14 is compressed by the increase of the fuel FL2, The internal pressure Pf2 gradually increases.

  Next, it is determined whether or not the drive time of the fuel pump 16 has passed the leak detection drive time (S114). The leak detection drive time is set until a leak state from the holes sufficiently appears in the internal pressures Pf1 and Pf2 when the main fuel tank 12 and the sub fuel tank 14 have holes. That is, the leak detection drive time is set as a leak detection time limit. Such a leak detection drive time may be set to a predetermined time in advance, or the length of the leak detection drive time may be set in accordance with the stop duration of the internal combustion engine 2 or the fuel. A temperature sensor may be arranged to set the length of the leak detection drive time according to the fuel temperature.

  If this is the first process after the leak detection condition is satisfied, the drive time for leak detection has not elapsed (NO in S114), and then from the internal pressure sensors 20 and 22 disposed in the fuel tanks 12 and 14, respectively. The detected internal pressures Pf1 and Pf2 are read into the working memory (S116).

  Then, whether or not the internal pressures Pf1 and Pf2 have converged, that is, the rate of change of the internal pressures Pf1 and Pf2 detected by the internal pressure sensors 20 and 22 (the amount of change in internal pressure per unit time) has converged to the reference range representing the stable state. It is determined whether or not (S117). Here, as the change rate of the internal pressures Pf1 and Pf2, the change amount of the internal pressure at one execution cycle interval of this process is used here.

  If it has not yet converged (NO in S117), the process is exited as it is. If it converges (YES in S117), the internal pressure Pf1, which is currently detected by the internal pressure sensors 20, 22, from the internal pressures Pf1, Pf2 detected by the internal pressure sensors 20, 22 immediately after the drive of the fuel pump 16 is started next. Leak detection is performed based on the amount of change in internal pressure to Pf2 (S118).

Here, when there is no hole in both the fuel tanks 12 and 14, the internal pressures Pf1 and Pf2 change as indicated by solid lines in FIGS. 3A and 3B due to fuel movement by the fuel pump 16.
That is, as shown in FIG. 3C, when the fuel FL1 in the main fuel tank 12 starts moving from the sub fuel tank 14 by driving the fuel pump 16 from the timing t0, the internal pressure Pf1 in the main fuel tank 12 is initially Decreases rapidly, and then the degree of decrease is moderate or almost no decrease. The internal pressure Pf2 of the sub fuel tank 14 rises rapidly at the initial stage of fuel movement, and then the degree of rise is moderate or almost no rise.

  When there is a hole in the main fuel tank 12, the internal pressure Pf1 changes as indicated by the alternate long and short dash line in FIG. That is, when the fuel movement is started from the timing t0, the internal pressure Pf1 of the main fuel tank 12 decreases at a lower speed than in the case where there is no hole in the initial stage, and thereafter, the degree of the decrease gradually or almost decreases. Disappear. Therefore, the amount of change in the internal pressure on the lower side of the internal pressure Pf1 is smaller than when the main fuel tank 12 has no hole (solid line). When the hole is large, the internal pressure Pf1 hardly decreases.

  When there is a hole in the sub fuel tank 14, the internal pressure Pf2 changes as indicated by the alternate long and short dash line in FIG. That is, when the fuel movement is started from the timing t0, the internal pressure Pf2 of the sub fuel tank 14 increases at a lower speed than in the case where there is no hole in the initial stage, and then the degree of increase is moderate or almost increased at an early stage. Disappear. Therefore, the amount of change in the internal pressure on the rising side of the internal pressure Pf2 is smaller than when the sub fuel tank 14 has no hole (solid line). When the hole is large, the internal pressure Pf2 hardly increases.

  As described above, the leak detection (S118) is not executed until the changes in the internal pressures Pf1 and Pf2 become gentle or almost no change (NO in S117). That is, the leak detection based on the change amount of the internal pressure is not completed during a period in which the conditions for the change speeds of the internal pressures Pf1, Pf2 detected by the internal pressure sensors 20, 22 to both converge to the reference range are not satisfied.

  Then, after the state in which the reference range convergence condition is not satisfied (NO in S117) continues, when the change speeds of the internal pressures Pf1, Pf2 both converge to the reference range at timing t1 (YES in S117), step The leak detection of S118 is executed.

  In this leak detection, the amount of change in internal pressure at timing t1 (internal pressures Pf1, Pf2 detected in step S116 immediately after the start of driving of the fuel pump 16 and internal pressures Pf1, Pf2 detected in step S116 in the current execution cycle). Pressure difference).

  When the absolute value of the differential pressure is large, that is, as shown by the solid lines in FIGS. 3A and 3B, the leak detection result is normal with no leak occurring. To do.

When the absolute value of the differential pressure is small, that is, as indicated by the alternate long and short dash line shown in FIGS. 3A and 3B, it is assumed that a leak has occurred as a leak detection result and is abnormal.
As described above, when YES is determined in step S117 and the leak detection (S118) as described above is completed in step S118, the leak detection end setting is made. Therefore, in the next execution cycle, the leak detection end setting state is set (NO in S104), so that the fuel movement between the fuel tanks 12 and 14 is stopped by stopping the fuel pump 16 (S120, t2 in FIG. 3). . Then, the switching valve 62, the on-off valve 32, and the blocking valve 35a are returned to the original state, that is, the state when the normal internal combustion engine is stopped (S122).

  In the example of FIG. 3, the switching valve 62 is returned to a state in which fuel is discharged from the fuel pump 16 to the internal combustion engine supply path 18 side, but the on-off valve 32 and the closing valve 35 a are kept closed as they are. An example is shown.

Thereafter, even if the leak detection condition is satisfied (YES in S102), since the leak detection end setting is made (NO in S104), the fuel movement by the fuel pump 16 is not performed.
In addition, while repeating the state determined as NO in step S117, the leakage detection drive time may elapse (YES in S114). In this case, assuming that the change speed of the internal pressures Pf1, Pf2 has not converged to the reference range for some reason, the leak detection end setting is made (S119), the fuel pump 16 is stopped (S120), The fuel movement between the fuel tanks 12 and 14 is stopped. Then, the switching valve 62, the on-off valve 32, and the blocking valve 35a are returned to their original states (S122).
<Relationship with Claims> In the configuration described above, the ECU 60 corresponds to the leak detection means, and the leak detection processing (FIG. 2) executed by the ECU 60 corresponds to the processing as the leak detection means.
<Effect> (1) In the leak detection process (FIG. 2), the evaporative fuel passage 34 is closed by closing the shutoff valve 35a (S106), the fuel tanks 12 and 14 are shut off from the outside, and the fuel communication passage is further closed. 30 on-off valve 32 is closed (S108), and the fuel tanks 12, 14 are also shut off.

  Then, by switching the switching valve 62 (S110), the fuel pump 16 disposed in the main fuel tank 12 discharges fuel to the sub fuel tank 14. In this state, the fuel pump 16 is driven (S112) to move the fuel from the main fuel tank 12 to the sub fuel tank 14.

  Then, as described with reference to FIG. 3, leak detection is performed based on the state of each internal pressure Pf1, Pf2 (S116, S118). Accordingly, it is possible to detect the leakage states of the main fuel tank 12 and the sub fuel tank 14 without providing a decompression pump in each of the fuel tanks 12 and 14.

  Since the fuel pump 16 used as a pressure feed pump moves the fuel between the fuel tanks 12 and 14, the entire fuel storage mechanism 10 as a leak detection target can maintain a closed system. Therefore, as long as there is no leak, there is no external discharge of fuel vapor due to the execution of the leak detection process (FIG. 2).

  Furthermore, when the leak is detected, the internal pressures Pf1 and Pf2 of the fuel tanks 12 and 14 are positively changed by the fuel pump 16, so that the leak detection can be executed early after the internal combustion engine is stopped.

  (2) For the fuel movement between the fuel tanks 12 and 14, instead of separately providing a pressure pump, a switching valve 62 and a branch path 64 are provided, and only the switching valve 62 is switched using the fuel pump 16. The fuel can be moved. Therefore, the leak detection process (FIG. 2) can be performed with a simple configuration.

  (3) With both the internal pressure change speeds converged to the reference range (YES in S117), a leak state is detected based on the internal pressure change amount at this time (S118). For this reason, more accurate leak detection can be performed.

(4) The leak detection conditions include the above conditions b and c (conditions of the fuel liquid level SGL1 and SGL2) as logical product conditions.
Since conditions are also set for the fuel liquid level SGL1 and SGL2 of the fuel tanks 12 and 14, in the leak detection process (FIG. 2), there is a certain margin space for the fuel to flow into the sub fuel tank 14. In the state, leak detection can be performed. Furthermore, leak detection can be performed in a state where there is a certain amount of fuel to flow out in the main fuel tank 12.

This makes it possible to perform highly accurate leak detection.
[Embodiment 2]
<Configuration> FIG. 4 shows the leak detection processing in this embodiment. In this leak detection process (FIG. 4), the amount of change (change) of the internal pressures Pf1 and Pf2 per unit time in the sudden change portions (timing t0 to ts) of the internal pressures Pf1 and Pf2 shown in FIGS. Speed). If the absolute value of the change amount (change speed) is larger than the reference change speed, no leak occurs, and if the absolute value is smaller, the leak is detected if a leak occurs.

The configuration of the present embodiment is the same as the configuration described in the first embodiment (FIG. 1) except that the ECU 60 executes the process of FIG. 4 as a leak detection process. To explain.
<Operation> The operation of the present embodiment will be described based on leak detection processing (FIG. 4). The process of FIG. 4 represents a process that is periodically executed at a fixed time.

The processes in steps S202 to S216 and S219 to S222 in FIG. 4 are the same processes as steps S102 to S116 and S119 to S122 in FIG.
When this process is started, it is first determined whether or not a leak detection condition is satisfied (S202). If the leak detection condition as described in FIG. 2 is not satisfied (NO in S202), the present process is left as it is, and the substantial process is not performed.

  If the leak detection condition is satisfied (YES in S202), it is next determined whether or not the leak detection end setting is not set (S204). Since the leak detection end setting is not initially set (YES in S204), the closing valve 35a of the evaporated fuel passage 34 is closed (S206), and the on-off valve 32 of the fuel communication passage 30 is closed (S208). The switching valve 62 is switched (S210), and the fuel pump 16 is driven (S212, t0 in FIG. 3).

  Then, it is determined whether or not the leak detection drive time has elapsed (S214). Since the leak detection drive time has not elapsed at the beginning (NO in S214), the internal pressures Pf1 and Pf2 as the detected values are read from the internal pressure sensors 20 and 22 (S216).

Then, a leak state is detected based on the changing speed of the internal pressures Pf1, Pf2 (S218).
Specifically, first, an absolute value at each change speed of the internal pressures Pf1 and Pf2 is calculated for each execution cycle, and a maximum value of each absolute value is obtained.

  If the maximum value in the absolute value of the change rate of the internal pressure Pf1 is greater than the reference change rate, it is assumed that no leak has occurred in the main fuel tank 12 as a leak detection result. If the maximum value is smaller than the reference change speed, it is assumed that a leak has occurred in the main fuel tank 12 as a leak detection result.

  Similarly, if the maximum value in the absolute value of the change rate of the internal pressure Pf2 is larger than the reference change rate, it is assumed that no leak has occurred in the sub fuel tank 14 as a leak detection result. If the maximum value is smaller than the reference change speed, it is assumed that a leak has occurred in the sub fuel tank 14 as a leak detection result.

  As described above, in step S218, the leak detection result is obtained for the two fuel tanks 12 and 14, the leak detection is completed, and the leak detection end setting is made. Therefore, in the next execution cycle, even if the leak detection condition is satisfied (YES in S202), since the leak detection end setting is made (NO in S204), the fuel pump 16 is stopped and the fuel tanks 12, 14 are set. The fuel movement between them is stopped (S220). Then, the switching valve 62, the on-off valve 32, and the blocking valve 35a are returned to their original states (S222).

In addition, when the leak detection drive time has elapsed before the leak detection is completed in step S218 (YES in S214), the above-described maximum value is not obtained for some reason. In this case, the leak detection end setting is performed (S219), and the fuel movement between the fuel tanks 12 and 14 is stopped by stopping the fuel pump 16 (S220), the switching valve 62, the on-off valve 32, the blockade. The valve 35a is returned to the original state (S222).
<Relationship with Claims> In the configuration described above, the ECU 60 corresponds to the leak detection means, and the leak detection processing (FIG. 4) executed by the ECU 60 corresponds to the processing as the leak detection means.
<Effect> (1) When the effects (1), (2), and (4) of the first embodiment are produced and the maximum value of the absolute value of the change rate of the internal pressures Pf1 and Pf2 is obtained, leak detection is performed. Is completed, and particularly rapid leak detection becomes possible.

[Embodiment 3]
<Configuration> FIG. 5 shows a leak detection process in the present embodiment. In this leak detection process (FIG. 5), the absolute value of the internal pressure change amount before and after the fuel pump 16 is driven is obtained. If the absolute value of this change amount is larger than the reference change amount, the leak is detected. If it is not present and is small, it is detected that there is a leak.

Since the configuration other than the leak detection process (FIG. 5) executed by the ECU 60 is the same as the configuration of FIG. 1 described in the first embodiment, the description will be given with reference to FIG.
<Operation> The operation of the present embodiment will be described based on leak detection processing (FIG. 5). The process of FIG. 5 represents a process that is periodically executed at a fixed time.

Note that the processing in steps S302 to S310, S314, S316, and S326 in FIG. 5 is the same as the processing in steps S102 to S112, S120, and S122 in FIG.
When this process is started, it is first determined whether or not a leak detection condition is satisfied (S302). If the leak detection condition as described in FIG. 2 is not satisfied (NO in S302), the internal pressures Pf1, Pf2 detected by the internal pressure sensors 20, 22 are read into the working memory (S303). And this processing is exited.

  Thereafter, as long as the leak detection condition is not satisfied (NO in S302), the reading of the internal pressures Pf1, Pf2 (S303) is repeated. This is a process for storing the internal pressures Pf1, Pf2 immediately before the fuel pump 16 is driven, and the contents of the work memory are updated each time it is read.

  If the leak detection condition is satisfied (YES in S302), it is next determined whether or not the leak detection end setting is not set (S304). Since the leak detection end setting is not initially set (YES in S304), the closing valve 35a of the evaporated fuel passage 34 is closed (S306), and the on-off valve 32 of the fuel communication passage 30 is closed (S308). Then, switching of the switching valve 62 (S310) is performed.

  Next, it is determined whether or not the reference drive time of the fuel pump 16 has elapsed (S312). This reference driving time is set to a time when the internal pressure change of the fuel tanks 12 and 14 is sufficiently generated if there is no leak. Since the reference driving time has not elapsed at the beginning (NO in S312), the driving of the fuel pump 16 is started (S314).

  Thereafter, as long as the leak detection condition is satisfied (YES in S302), the fuel pump 16 continues to be driven (S314, FIG. 3) until the reference drive time of the fuel pump 16 has elapsed (NO in S312). t0).

  When the reference driving time has elapsed (YES in S312), the fuel pump 16 is stopped (S316). Then, the internal pressures Pf1, Pf2 detected by the internal pressure sensors 20, 22 are read into the work memory (S318).

  Next, it is determined whether or not the internal pressures Pf1, Pf2 have converged (S320). When the fuel pump 16 is stopped, the internal pressures Pf1 and Pf2 change as shown after the timing t2 in FIG. 3. In step S320, whether the internal pressures Pf1 and Pf2 are stabilized after the change is finished. Determine whether.

If the internal pressures Pf1 and Pf2 have not converged (NO in S320), it is determined whether or not the leak detection time has elapsed (S322).
This leak detection time is equal to the internal pressures Pf1, Pf2 after the fuel pump 16 is driven (meaning a stopped state after the fuel pump 16 is driven), regardless of the presence or absence of holes in the main fuel tank 12 and the sub fuel tank 14. Sufficient time to stabilize is set. That is, this leak detection time is set as a leak detection time limit. Such a leak detection time may be set in advance to a certain time, or may be set according to the stop duration of the internal combustion engine 2 or according to the fuel temperature detected by arranging a fuel temperature sensor. May be.

  Since the leak detection time has not elapsed at the beginning (NO in S322), this processing is exited as it is. Thereafter, unless the internal pressures Pf1 and Pf2 converge (NO in S320) and the leak detection time has not elapsed (NO in S322), the reading of the internal pressures Pf1 and Pf2 (S318) is repeated.

  When the internal pressures Pf1 and Pf2 converge (YES in S320, corresponding to timing t3 in FIG. 3), that is, when the internal pressures Pf1 and Pf2 are stabilized, leak detection is performed (S324).

  In the leak detection in step S324, the internal pressure between the values of the internal pressures Pf1 and Pf2 read in step S303 before driving the fuel pump 16 and the values of the internal pressures Pf1 and Pf2 stabilized after driving the fuel pump 16 is obtained. The amount of change is required.

  As a leak detection result, it is assumed that no leak occurs if the absolute value of the internal pressure change amount is larger than the reference change amount, and that a leak occurs if the absolute value is small. When the leak detection result is output in this way, the leak detection end setting is made, and the present processing is exited.

  In the subsequent execution cycle, even if the leak detection condition is satisfied (YES in S302), since the leak detection end setting has already been made in step S324 (NO in S304), the switching valve 62, the on-off valve 32, The blocking valve 35a is returned to the original state, that is, the state when the internal combustion engine is stopped (S326).

  If the leak detection time elapses while repeating the state determined as NO in step S320 (YES in S322), in this case, it is assumed that the internal pressures Pf1 and Pf2 are not stabilized for some reason. Leak detection end setting is performed (S325), and the switching valve 62, the on-off valve 32, and the blocking valve 35a are returned to their original states (S326).

  If there is no hole in both the fuel tanks 12 and 14 in the leak detection in step S324, the internal pressure Pf1 of the main fuel tank 12 is changed by the fuel movement by driving the fuel pump 16 (t0 to t2) in FIG. As shown by the solid line in FIG. The internal pressure Pf2 of the sub fuel tank 14 changes to a high level as shown by the solid line in FIG.

  After the fuel pump 16 is driven (t2), the internal pressure Pf1 slightly rises as indicated by the solid line in the main fuel tank 12 due to fuel evaporation, but does not return to the state before the fuel pump 16 is driven. . In the sub fuel tank 14, the internal pressure Pf2 slightly decreases as indicated by the solid line due to the condensation of fuel vapor, but does not return to the state before the fuel pump 16 is driven.

  When there is a hole in the main fuel tank 12, the internal pressure Pf1 slightly decreases as indicated by the one-dot chain line in FIG. 3A due to fuel movement by driving the fuel pump 16 (t0 to t2). After the fuel pump 16 is driven (t2-), it returns to the original internal pressure Pf1 due to leakage.

  When the sub fuel tank 14 has a hole, the internal pressure Pf2 slightly rises as shown by a one-dot chain line in FIG. 3B due to fuel movement by driving the fuel pump 16 (t0 to t2). After the fuel pump 16 is driven (t2-), it returns to the original internal pressure Pf2 due to leakage.

Therefore, if the absolute value of the internal pressure change amount before and after driving the fuel pump 16 is larger than the reference change amount, it can be determined that no leak has occurred, and if it is smaller, it can be determined that the leak has occurred.
<Relationship with Claims> In the configuration described above, the ECU 60 corresponds to the leak detection means, and the leak detection processing (FIG. 5) executed by the ECU 60 corresponds to the processing as the leak detection means.
<Effects> (1) The effects (1) to (4) of the first embodiment can also be produced when the amount of change in internal pressure before and after driving the fuel pump 16 is used for leak detection.

[Embodiment 4]
<Configuration> FIGS. 6 and 7 show the leak detection processing in the present embodiment. This leak detection process (FIGS. 6 and 7) corresponds to a process in which the first embodiment and the third embodiment are combined.

FIG. 6 is a process equivalent to the leak detection process (FIG. 2) described in the first embodiment. FIG. 7 is a process equivalent to the leak detection process (FIG. 5) described in the third embodiment.
That is, in the process of FIG. 6, when one or both of the fuel tanks 12 and 14 cannot detect a leak due to an internal pressure state during driving of the fuel pump 16, or when it is detected that no leak has occurred. In the process of FIG. 7, the leak detection is executed again from the internal pressure state before and after the fuel pump 16 is driven.

Except for the leak detection process (FIGS. 6 and 7) executed by the ECU 60, the configuration is the same as that of FIG. 1 described in the first embodiment, and will be described with reference to FIG.
<Operation> The operation of the present embodiment will be described based on leak detection processing (FIGS. 6 and 7). The processes of FIGS. 6 and 7 represent processes that are periodically executed at a fixed time.

First, FIG. 6 will be described. The processing in steps S402 and S404 to S420 in FIG. 6 is the same as the processing in steps S102 to S120 in FIG.
When the process is started, it is first determined whether or not a leak detection condition is satisfied (S402). If the leak detection condition as described in FIG. 2 is not satisfied (NO in S402), the internal pressures Pf1, Pf2 detected by the internal pressure sensors 20, 22 are read into the working memory (S403). And this processing is exited.

  Thereafter, as long as the leak detection condition is not satisfied (NO in S402), the contents of the working memory are updated (S403) by reading the internal pressures Pf1, Pf2. This is a process for storing the internal pressures Pf1 and Pf2 immediately before the fuel pump 16 is driven.

  When the leak detection condition is satisfied (YES in S402), the processing from step S404 is performed, but the processing from step S404 to S420 is the same as the processing from step S104 to S120 in FIG. In particular, in step S404, it is determined whether or not the fuel pump driving leak detection end setting is not set, but is substantially the same as step S104 in FIG. The fuel pump driving leak detection end setting in step S419 is substantially the same as step S119 in FIG.

  Here, the stop process (S420) of the fuel pump 16 is performed when the fuel pump drive leak detection end setting is made (NO in S404) or when the fuel pump drive leak detection cannot be completed and the leak detection drive time elapses. If this is the case (YES in S414), the process is executed.

  When the fuel pump 16 is stopped (S420), the fuel pump after-leak detection process shown in FIG. 7 is executed (S422). The details of this fuel pump after-leak detection process are shown in FIG.

  When the leak detection process after driving the fuel pump (FIG. 7) is started, leak detection contents during the driving of the fuel pump 16 executed immediately before in the process of FIG. A determination is made under the logical sum condition (S452).

A. In one or both of the fuel tanks 12 and 14, leak detection could not be performed while the fuel pump 16 was being driven.
B. In one or both of the fuel tanks 12 and 14, it was detected that no leak occurred during the driving of the fuel pump 16.

  Therefore, if at least one of the two fuel tanks 12 and 14 cannot detect a leak while the fuel pump 16 is being driven, or if no leak occurs while the fuel pump 16 is being driven. In step S452, YES is determined.

  If it is detected that both the fuel tanks 12 and 14 are leaking while the fuel pump 16 is being driven, the leak is already clear for both of the fuel tanks 12 and 14, so the step In S452, NO is determined.

  If it is determined NO in step S452, the switching valve 62, the on-off valve 32, and the blocking valve 35a are returned to their original states, that is, the states when the internal combustion engine is stopped (S464). Thereafter, even if the leak detection condition is satisfied (YES in S402), the leak detection during fuel pump driving is completed because the leak detection during the driving of the fuel pump 16 is completed (NO in S404). In step S452, it is determined NO, so that the leak detection process is substantially ended.

If YES is determined in step S452, it is then determined whether or not the leak detection end setting after driving the fuel pump 16 is not set (S454).
Initially, it is immediately after the fuel pump 16 is stopped in step S420, and since leakage detection is started after the fuel pump is driven (YES in S454), the internal pressures Pf1, Pf2 detected by the internal pressure sensors 20, 22 are then set. The data is read into the working memory (S456).

  Then, it is determined whether or not the internal pressures Pf1 and Pf2 have converged (S458). This determination is the same as step S320 in FIG. 5, and it is determined whether or not the internal pressures Pf1 and Pf2 are stabilized.

  If it has not converged yet (NO in S458), it is determined whether or not the leak detection time after driving the pump has elapsed (S460). The leak detection time after driving the pump is the same as the leak detection time described in step S322 in FIG.

  Initially, since the leak detection time after driving the pump has not elapsed (NO in S460), the present process is exited. Thereafter, the internal pressures Pf1, Pf2 do not converge (NO in S458) and the internal pressures Pf1, Pf2 are read (S456) as long as the leak detection time after driving the pump does not elapse (NO in S460) while other conditions remain unchanged. ) Is repeated.

When the internal pressures Pf1, Pf2 converge (YES in S458), leak detection is performed (S462).
In the leak detection in step S462, the internal pressure between the values of the internal pressures Pf1 and Pf2 read in step S403 before driving the fuel pump 16 and the values of the internal pressures Pf1 and Pf2 stabilized after the fuel pump 16 is driven. The amount of change is required. As a leak detection result, it is assumed that no leak occurs if the absolute value of the internal pressure change amount is larger than the reference change amount, and if the absolute value is small, a leak occurs. As a result of the leak detection in this way, a leak detection end setting is made after driving the fuel pump, and this processing is exited.

  In the subsequent process execution cycle, even if the leak detection condition is satisfied (YES in S402), the leak detection end setting during fuel pump driving is already set, and the leak detection end setting after fuel pump driving is also set (in S404). NO, NO in S454). Therefore, the switching valve 62, the on-off valve 32, and the blocking valve 35a are returned to the original state, that is, the state when the normal internal combustion engine is stopped (S464).

  In addition, while repeating the state determined to be NO in step S458, the leak detection time after driving the fuel pump may elapse (YES in S460). In this case, since it is considered that the internal pressures Pf1 and Pf2 are not stabilized for some reason, the leak detection end setting after driving the fuel pump is performed (S463), and the switching valve 62, the on-off valve 32, and the blocking valve 35a are replaced with the original ones. The state is restored (S464).

  For example, when the main fuel tank 12 has a small hole, as indicated by a solid line in FIG. 8A, the fuel pump 16 is driven (t10 to t11) and before the leakage detection drive time elapses, If the internal pressure Pf1 is sufficiently lowered and stabilized, it may be determined that there is no leak in step S418.

  Similarly, when there is a small hole in the sub fuel tank 14, as indicated by the solid line in FIG. 8B, the fuel pump 16 is driven (t10 to t11) before the leakage detection drive time elapses. If the internal pressure Pf2 is sufficiently increased and stabilized, it may be determined in step S418 that no leak has occurred.

  Therefore, in this case, the fuel pump after-leak detection process (FIG. 7) is executed. Thus, in step S462, based on the amount of change in internal pressure between the internal pressures Pf1 and Pf2 before driving the fuel pump 16 (t10) and the internal pressures Pf1 and Pf2 after stabilization after driving the fuel pump 16 (t12). Thus, it is possible to accurately detect that a leak has occurred.

  Further, in the main fuel tank 12, as shown by a one-dot chain line in FIG. 8A, the internal pressure is increased until the drive time for leak detection elapses (YES in S414) by driving the fuel pump 16 (t10 to t13). Since the decrease in Pf1 does not converge continuously, leak detection may not be possible.

  In such a case, after the fuel pump 16 is stopped after the leakage detection drive time has elapsed (from t13), when the main fuel tank 12 has no hole, the internal pressure Pf1 rises slightly as indicated by the alternate long and short dash line and is stable. Turn into. When there is a hole in the main fuel tank 12, the internal pressure Pf1 rises to the internal pressure state before driving the fuel pump 16 and stabilizes as indicated by a two-dot chain line.

  Similarly, in the sub fuel tank 14 as well, as shown by the one-dot chain line in FIG. 8B, the drive time for leak detection elapses due to the drive of the fuel pump 16 (t10 to t13) (YES in S414). Until the internal pressure Pf2 continues to rise and does not converge, there are cases where leak detection cannot be performed.

  In such a case, after the fuel pump 16 stops after the elapse of the leak detection drive time (from t13), when the sub fuel tank 14 has no hole, the internal pressure Pf2 decreases slightly as indicated by the alternate long and short dash line. Turn into. When there is a hole in the sub fuel tank 14, the internal pressure Pf2 is lowered and stabilized to the internal pressure state before the fuel pump 16 is driven as indicated by a two-dot chain line.

Accordingly, accurate leak detection can be performed based on the amount of change in internal pressure between the internal pressures Pf1, Pf2 (t10) before driving the fuel pump 16 and the internal pressures Pf1, Pf2 (t14) after driving.
<Relationship with Claims> In the configuration described above, the ECU 60 corresponds to the leak detection means, and the leak detection processing (FIGS. 6 and 7) executed by the ECU 60 corresponds to the processing as the leak detection means.
<Effect> (1) The effects of (1) to (4) of the first embodiment can be produced by the leak detection process of FIG.

  (2) Even if leak detection cannot be performed by the processing in steps S402 to S420 in FIG. 6 or inaccurate leak detection is performed, leak detection processing after driving the fuel pump (S422: FIG. 7) Leak detection can be performed with high accuracy.

In addition, since the stop of the fuel pump 16 is used, a special fuel pump drive process is not required, and the speed of the process is not hindered.
Accordingly, both the quickness and accuracy of leak detection for the main fuel tank 12 and the sub fuel tank 14 can be achieved.

[Embodiment 5]
<Configuration> In this embodiment, one internal pressure sensor detects the leak state of each of the two fuel tanks.

FIG. 9 shows the fuel supply system 104 of the present embodiment. 9 is different from that shown in FIG. 1 in that the second internal pressure sensor 22 is not provided in the sub fuel tank 14.
Since the mechanical configuration is the same as the configuration of FIG. 1 except that the second internal pressure sensor 22 is not present, the same configuration as that of FIG. 1 is denoted by the same reference numeral. In addition, as a leak detection process performed by ECU60, the process shown in FIG.
<Operation> The operation of the present embodiment will be described with reference to FIGS.

First, the pre-leak detection preparation process (FIG. 10) will be described. The process of FIG. 10 represents a process that is periodically executed at a fixed time.
When the pre-leak detection preparation process (FIG. 10) is started, it is first determined whether or not the pre-leak detection preparation process has been set (S502). This pre-leak detection preparatory process is set in step S518 described later when the pre-leak detection preparatory process is completed, and is not set at a timing immediately after the internal combustion engine 2 is stopped.

  Therefore, if the internal combustion engine 2 is stopped and the pre-leak detection preparatory process has not yet been completed (YES in S502), it is next determined whether or not a leak detection condition is satisfied (S504).

This leak detection condition is as described in step S102 of FIG.
If the leak detection condition is not satisfied (NO in S504), the process is exited as it is.
If the leak detection condition is satisfied (YES in S504), the closing valve 35a of the evaporative fuel passage 34 is closed (S506), the on-off valve 32 of the fuel communication passage 30 is closed (S508), and the switching valve 62 is switched (S510). Then, the driving of the fuel pump 16 (S512) is executed. These processes (S506 to S512) are the same processes as steps S106 to S112 in FIG.

  Next, it is determined whether or not the fuel transfer from the main fuel tank 12 to the sub fuel tank 14 is completed by driving the fuel pump 16 (S514). Here, the completion of the fuel movement is determined by whether or not the driving time of the fuel pump 16 has passed a reference time for moving a certain amount of fuel. In addition to this, determination may be made based on whether or not the fuel movement amount has reached the reference amount based on one of the fuel liquid level SGL1 and SGL2 detected by the two fuel sender gauges 24 and 26.

Until the fuel transfer is completed (NO in S514), the present process is left as it is. As a result, the driving of the fuel pump 16 continues.
When the fuel movement from the main fuel tank 12 to the sub fuel tank 14 is completed (YES in S514), the fuel pump 16 is stopped (S516). Then, this pre-leak detection preparatory processing end setting is performed (S518).

As a result, NO is determined in step S502 in the next execution cycle, and the processing in step S504 and subsequent steps is not executed until the next stop of the internal combustion engine 2.
Next, the leak detection process (FIG. 11) will be described. The process of FIG. 11 represents a process that is periodically executed at a fixed time.

  When the leak detection process (FIG. 11) is started, it is first determined whether or not the leak detection process end setting has been made (S550). The leak detection process end setting is set when the leak detection process is completed in step S572, which will be described later, and is not set at a timing immediately after the internal combustion engine 2 is stopped.

  Therefore, if the internal combustion engine 2 is stopped and the leak detection process is not yet completed (YES in S550), it is next determined whether or not a leak detection condition is satisfied (S552). This leak detection condition is as described in step S102 of FIG.

If the leak detection condition is not satisfied (NO in S552), the process is exited as it is.
If the leak detection condition is satisfied (YES in S552), it is determined whether or not it is after the stop process (FIG. 10: S516) of the fuel pump 16 by the above-described pre-leak detection preparation process (FIG. 10) (S554). That is, it is determined whether or not the fuel pump 16 has completed the movement of fuel from the main fuel tank 12 to the sub fuel tank 14.

  At this determination timing, if the fuel pump 16 is still being driven by the pre-leak detection preparatory process (FIG. 10), it is not after the fuel pump 16 has stopped (NO in S554), so this process is exited as it is. As long as the fuel pump 16 is being driven, no substantial process is performed in the leak detection process (FIG. 11).

  When the fuel movement by the fuel pump 16 is completed in the pre-leak preparation process (FIG. 10) and the fuel pump 16 is stopped (FIG. 10: S516), YES is determined in step S554 of the leak detection process (FIG. 11). Will come to be.

  As a result, the on-off valve 32 of the fuel communication passage 30 is opened (S556). Immediately before the opening / closing valve 32 of the fuel communication passage 30 is opened, the fuel is transferred from the main fuel tank 12 to the sub fuel tank 14 by the fuel pump 16. Therefore, a differential pressure is generated in the fuel communication passage 30 with the on / off valve 32 of the fuel communication passage 30 interposed therebetween, with the sub fuel tank 14 side being the high pressure side and the main fuel tank 12 side being the low pressure side.

  When the on-off valve 32 is opened in this state, the fuel is automatically returned from the sub fuel tank 14 to the main fuel tank 12 due to the differential pressure, and finally the fuel pump 16 is driven by pre-leak detection preparatory processing (FIG. 10). (S512) It will be in the same state as before. Therefore, the internal pressure Pf1 in the main fuel tank 12 detected by the internal pressure sensor 20 is changed from the internal pressure state immediately after the fuel pump 16 is driven (reduced internal pressure) to the internal pressure state before the fuel pump 16 is driven. A change pattern appears.

  Here, a change pattern of the internal pressure Pf1 generated in the internal pressure sensor 20 of the main fuel tank 12 is shown in FIG. In the present embodiment, since no internal pressure sensor is arranged in the sub fuel tank 14, the in-vehicle ECU 60 does not detect the internal pressure of the sub fuel tank 14, but the sub fuel tank 14 detected experimentally. The internal pressure state is also shown.

  FIG. 12 (a) shows an internal pressure state when no leak occurs in the main fuel tank 12 and the sub fuel tank. Here, in the pre-leak detection preparatory process (FIG. 10), the fuel moves from the main fuel tank 12 to the sub fuel tank 14 by closing the on-off valve 32 and driving the fuel pump 16 (ta0 to ta1). As a result, the internal pressure Pf1 of the main fuel tank 12 is temporarily reduced (ta0 to ta1).

  Thereafter, the fuel pump 16 is stopped (FIG. 10: S516), and the on-off valve 32 is opened (S556), whereby the fuel returns from the sub fuel tank 14 to the main fuel tank 12 via the fuel communication passage 30. As a result, the internal pressure Pf1 of the main fuel tank 12 increases and returns to the state before the fuel movement.

  In FIG. 12 (a), the main fuel tank 12 has a low pressure and the sub fuel tank 14 has a high pressure due to the pre-leak detection preparation process (FIG. 10). Therefore, the differential pressure is large, the fuel flow speed in the fuel communication passage 30 is high, and the internal pressure Pf1 of the main fuel tank 12 is quickly recovered. In this case, the increase in the internal pressure Pf1 of the main fuel tank 12 is rapid as shown by the change pattern immediately after the timing ta1.

  FIG. 12B shows the internal pressure state when the main fuel tank 12 is not leaked but the sub fuel tank 14 is leaked. Here, the fuel moves from the main fuel tank 12 to the sub fuel tank 14 by closing the on-off valve 32 and driving the fuel pump 16 (tb0 to tb1) in the pre-leak detection preparatory process (FIG. 10). The internal pressure Pf1 of the tank 12 temporarily decreases as in the case of FIG.

  Thereafter, when the fuel pump 16 is stopped and the on-off valve 32 is opened, the internal pressure Pf1 of the main fuel tank 12 increases due to the return of fuel as described above. However, since a leak occurs on the sub fuel tank 14 side, the pressure is hardly increased when the fuel pump 16 is driven (tb0 to tb1). For this reason, the differential pressure with respect to the main fuel tank 12 side becomes small, the fuel returns in the fuel communication passage 30 at a low speed, and the return amount becomes small. Therefore, the internal pressure Pf1 of the main fuel tank 12 rises slowly and does not completely return to the original internal pressure.

In this case, the increase in the internal pressure Pf1 of the main fuel tank 12 becomes a slow and incomplete return state as shown by the change pattern immediately after the timing tb1.
FIG. 12C shows the internal pressure state when the main fuel tank 12 has a leak but the sub fuel tank 14 has no leak. Here, in the pre-leak detection preparatory process (FIG. 10), the fuel moves from the main fuel tank 12 to the sub fuel tank 14 by closing the on-off valve 32 and driving the fuel pump 16 (tc0 to tc1). Since a leak occurs at 12, the internal pressure Pf1 hardly decreases compared to the case of FIG.

  Thereafter, when the fuel pump 16 is stopped and the on-off valve 32 is opened, the internal pressure Pf2 of the sub fuel tank 14 that does not leak is increased, so that the fuel is supplied to the main fuel tank 12 by the internal pressure Pf2 of the sub fuel tank 14. Return to. However, since leakage occurs on the main fuel tank 12 side, the differential pressure with respect to the sub fuel tank 14 side becomes small, the fuel returns at a low speed in the fuel communication path 30, and the return amount also becomes small. Even if such fuel return occurs, the internal pressure Pf1 slightly rises temporarily because of leakage on the main fuel tank 12 side, but immediately decreases and returns to the internal pressure before the fuel movement.

In this case, the internal pressure Pf1 of the main fuel tank 12 changes in a vibrating manner as shown by the change pattern immediately after the timing tc1.
FIG. 12D shows the internal pressure state when leakage occurs in both the main fuel tank 12 and the sub fuel tank 14. Here, the fuel moves from the main fuel tank 12 to the sub fuel tank 14 by closing the on-off valve 32 and driving the fuel pump 16 (td0 to td1) in the pre-leak detection preparation process (FIG. 10). However, since the main fuel tank 12 leaks, the internal pressure Pf1 hardly decreases compared to the case of FIG.

  Thereafter, the fuel pump 16 is stopped and the on-off valve 32 is opened. However, since not only the main fuel tank 12 but also the sub fuel tank 14 is leaked, there is almost no differential pressure, and the fuel communication passage 30 is opened. There is almost no return of fuel through. Therefore, the internal pressure Pf1 of the main fuel tank 12 hardly changes.

  Therefore, after opening the on-off valve 32 in step S556, the internal pressure Pf1 detected by the internal pressure sensor 20 provided in the main fuel tank 12 is read into the working memory and sequentially accumulated (S558). Then, it is determined whether or not the internal pressure Pf1 has converged (S560). That is, it is determined whether or not the internal pressure Pf1 is stabilized.

  Until convergence (NO in S560), as long as the leak detection condition is satisfied, step S558 is repeated, and the internal pressure Pf1 detected by the internal pressure sensor 20 is repeatedly read and sequentially stored.

  When the internal pressure Pf1 converges (YES in S560), the change pattern of the internal pressure Pf1 continuously read in step S558 is classified (S562). That is, it is determined which of the change patterns of the internal pressure Pf1 shown in (a) to (d) of FIG.

In the case of the pattern 1 in FIG. 12A, it is detected that there is no leakage in the main fuel tank 12 and the sub fuel tank 14 (S564).
In the case of pattern 2 in FIG. 12B, it is detected that there is no leak in the main fuel tank 12, but there is a leak in the sub fuel tank 14 (S566).

In the case of Pattern 3 in FIG. 12C, it is detected that the main fuel tank 12 has leaked and the sub fuel tank 14 has not leaked (S568).
In the case of pattern 4 in FIG. 12D, it is detected that both the main fuel tank 12 and the sub fuel tank 14 are leaking (S570).

  As described above, when classified into any of the patterns, the leak detection processing end setting is made (S572), and the switching valve 62, the on-off valve 32, and the blocking valve 35a are in the original state, that is, when the normal internal combustion engine is stopped. (S574), and the process exits.

In the next execution cycle, since the leak detection process end setting is made (NO in S550), the substantial process in the leak detection process (FIG. 11) ends.
<Relationship with Claims> In the configuration described above, the ECU 60 corresponds to the leak detection means, and the pre-leak detection preparation process (FIG. 10) and the leak detection process (FIG. 11) executed by the ECU 60 are the processes as the leak detection means. Equivalent to.
<Effect> (1) Here, the internal pressure sensor 20 is provided only on the main fuel tank 12 side which is the outflow side fuel storage section. As described above, even when the internal pressure Pf1 of only one of the two fuel tanks 12 and 14 is detected, after the fuel is actively moved by the fuel pump 16, the on-off valve 32 is opened and the fuel is returned by the differential pressure. 12 shows a characteristic change pattern of the internal pressure Pf1 depending on whether or not there is a leak and which of the fuel tanks 12 and 14 is leaking, as shown in FIG.

  Therefore, the change pattern of the internal pressure Pf1 by the internal pressure sensor 20 provided only on the fuel tank 12 side is determined for each of the two fuel tanks 12 and 14 without providing a pressure reducing pump or the like for each of the fuel tanks 12 and 14. A leak condition can be detected.

  Furthermore, since this leak detection is performed using the state in which the internal pressure change between the fuel tanks 12 and 14 is positively generated by the fuel pump 16, it can be performed early after the internal combustion engine 2 is stopped.

  In addition, when the leak is detected, only the fuel is moved and returned between the fuel tanks 12 and 14, and the entire fuel storage mechanism 10 can be maintained in a sealed state. Therefore, no fuel vapor is discharged due to the leak detection itself.

[Embodiment 6]
<Structure> In the present embodiment, in FIG. 9, the internal pressure sensor 20 in the main fuel tank 12 is not provided, and the internal pressure sensor 22 is provided in the sub fuel tank 14 as shown in FIG. It is assumed that Pf2 is detected.
<Operation> FIG. 10 is executed as the pre-leak detection preparation process, and the internal pressure Pf2 of the sub fuel tank 14 is used instead of the internal pressure Pf1 of the main fuel tank 12 in FIG.

As a result, as shown in FIG. 12, the internal pressure Pf2 of the sub fuel tank 14 also has a characteristic internal pressure depending on whether there is a leak and which of the fuel tanks 12, 14 is leaking. A change pattern of Pf2 can be obtained.
<Effect> (1) Even if the internal pressure sensor 22 is provided only on the sub fuel tank 14 side, the same effect as in the fifth embodiment is produced.

[Embodiment 7]
<Configuration> In the present embodiment, a timing at which fuel is positively moved between fuel tanks by using a single internal pressure sensor, and a timing at which fuel is returned by a differential pressure between the fuel tanks thereafter. Is used to detect the respective leak states in the two fuel tanks.

FIG. 13 shows the leak detection process in this embodiment. The process of FIG. 13 represents a process that is periodically executed at a fixed time.
Further, the leak detection process (FIG. 11) described in the fifth embodiment is used as the leak detection process after opening and closing of the fuel pump in step S622 in FIG. The mechanical configuration is the same as that shown in FIG. Therefore, description will be made with reference to FIGS.

  FIG. 13 will be described. When this process is started, it is first determined whether or not the leak detection condition as described in FIG. 2 is satisfied (S602). If the leak detection condition is not satisfied (NO in S602), the process is exited.

  When the leak detection condition is satisfied (YES in S602), the processing from step S604 is performed, but the processing from step S604 to S620 is the same as steps S104 to S120 in FIG. 2 except that only the internal pressure Pf1 is used. The same process. In particular, in step S604, it is determined whether or not the fuel pump driving leak detection end setting is not set, but is substantially the same as step S104 in FIG.

  Therefore, the fuel pump 16 is stopped when the leak detection is completed based on the amount of change in the internal pressure of the main fuel tank 12 in step S618 (NO in S604) or after the drive time for leak detection has elapsed (YES in S614). Then, after the fuel pump is driven, the on-off valve open state leak detection process is executed (S622).

  This process uses the leak detection process (FIG. 11) described in the fifth embodiment. Therefore, this time, the change pattern of the internal pressure Pf1 is detected at the timing when the fuel returns due to the differential pressure between the fuel tanks 12, 14, and the leak state of the individual fuel tanks 12, 14 is detected based on the change pattern. (S556-570).

  If the leak detection is completed in step S618 in FIG. 13, the leak state has already been found for the main fuel tank 12. Therefore, in this case, steps S564 to S570 in FIG. 11 are actually equivalent to detecting the leak state of the sub fuel tank 14.

If it is determined YES in step S614 in FIG. 13 and the leak detection is not completed for the fuel tank 12, steps S564 to S570 in FIG. Is equivalent to detecting.
<Relationship with Claims> In the configuration described above, the ECU 60 corresponds to the leak detection means, and the leak detection processing (FIGS. 13 and 11) executed by the ECU 60 corresponds to the processing as the leak detection means.
<Effect> (1) The effect of the fifth embodiment is produced. Further, prior to the leak detection process (corresponding to the second detection process) of FIG. 11 performed at the fuel return timing, as the first detection process, the fuel movement is actively executed by the fuel pump 16. The leakage state of the main fuel tank 12 is detected based on the internal pressure Pf1 (FIG. 13).

By executing the first detection process (FIG. 13), leak detection by the second detection process (FIG. 11) can be made more reliable without requiring a special processing time.
[Embodiment 8]
<Structure> In the present embodiment, in FIG. 9, the main fuel tank 12 is not provided with the internal pressure sensor 20, but the sub fuel tank 14 is provided with the internal pressure sensor 22 as shown in FIG. Only the internal pressure Pf2 is detected.
<Operation> As the leak detection processing, the above-described FIGS. 13 and 11 shown in the seventh embodiment are executed. During this processing, the internal pressure Pf2 of the fuel tank 14 is used instead of the internal pressure Pf1 of the fuel tank 12. .
<Effect> (1) Even if the internal pressure sensor 22 is provided only on the sub fuel tank 14 side, the same effect as in the seventh embodiment is produced.

[Embodiment 9]
<Configuration> The mechanical configuration of the present embodiment is the same as the configuration of FIG. In the present embodiment, the internal pressure Pf1 obtained from one internal pressure sensor 20 provided in the main fuel tank 12 and the work amount for moving a constant amount of fuel between the fuel tanks 12 and 14 by the fuel pump 16 are 2 Each leak state in the two fuel tanks 12 and 14 is detected.

Hereinafter, a description will be given with reference to FIG. However, in order to detect the amount of work of the fuel pump 16, the ECU 60 is provided with an ammeter that measures the current flowing through the electric motor in the fuel pump 16 when the fuel pump 16 is driven.
<Operation> The operation of the present embodiment will be described based on the leak detection processing of FIG. The process of FIG. 14 represents a process that is periodically executed at a fixed time.

  When the leak detection process (FIG. 14) is started, it is first determined whether or not the leak detection condition as described in step S102 of FIG. 2 is satisfied (S702). If the leak detection condition is not satisfied (NO in S702), the fuel level level SGL1 that is the detected value of the fuel sender gauge 24 in the fuel tank 12 is read into the working memory (S703). And this processing is exited. Step S703 is a process of updating the work memory every time the fuel liquid level SGL1 is read in order to store the fuel liquid level SGL1 in the fuel tank 12 immediately before the leak detection.

  If the leak detection condition is satisfied (YES in S702), the processes from Steps S704 to S714 and S720 are the same as those in Steps S104 to S114 and S119 in FIG.

  Therefore, if the leak detection condition is satisfied (YES in S702) and the leak detection end setting is not set (YES in S704), the closing valve is closed (S706), the on-off valve 32 is closed (S708), and the switching valve 62 is switched (S710), and the fuel pump 16 is driven (S712). Then, it is determined whether or not the leak detection drive time has elapsed (S714).

  Initially, since the leak detection drive time has not elapsed (NO in S714), the work amount W (J) of the fuel pump 16 is then calculated by integration for each execution cycle of this process (S715). . Here, the amount of power consumed during one execution cycle of this process (the amount of work for one execution cycle) is calculated based on the amount of current flowing through the fuel pump 16, the applied voltage, and the execution cycle. The process of integrating the amount of electric power for each execution cycle is executed.

  Then, the internal pressure Pf1 of the main fuel tank 12 is read (S716), and it is determined whether or not the internal pressure Pf1 has converged (S717). Steps S716 and 717 are the same as steps S616 and S617 in FIG. That is, until the internal pressure Pf1 converges (NO in S717), an integration process for power consumption for driving the fuel pump 16 (S715) and the internal pressure Pf1 are read (S716), and a process for determining the convergence (S717). continue.

  When the internal pressure Pf1 converges (YES in S717), the fuel level SGL1 when the internal pressure Pf1 converges is read into the working memory (S718). From the difference between this value and the fuel level SGL1 immediately before the leak detection in step S703, the fuel amount Mf (g) moved from the main fuel tank 12 to the sub fuel tank 14 by the fuel pump 16 is determined.

Next, based on the work amount W / Mf of the fuel pump 16 per unit fuel movement amount and the internal pressure Pf1, leak detection is performed as follows (S719).
When neither the main fuel tank 12 nor the sub fuel tank 14 has leaked, the fuel movement by the fuel pump 16 reduces the internal pressure Pf1 on the main fuel tank 12 side and the internal pressure Pf2 on the sub fuel tank 14 side. Since it is necessary to move the fuel against high pressure, the work amount W / Mf of the fuel pump 16 per unit fuel movement amount becomes large.

  When both the main fuel tank 12 and the sub fuel tank 14 are leaking, the internal pressure Pf1 on the main fuel tank 12 side is difficult to decrease or does not decrease, and the internal pressure Pf2 on the sub fuel tank 14 side is increased. It is difficult or does not increase pressure. Therefore, the work amount W / Mf of the fuel pump 16 per unit fuel movement amount is small.

  When a leak occurs only in either the main fuel tank 12 or the sub fuel tank 14, the internal pressure Pf1 on the main fuel tank 12 side is difficult to decrease or does not decrease, or the internal pressure on the sub fuel tank 14 side. Pf2 is either difficult to increase in pressure or not increased in pressure. Therefore, the work amount W / Mf of the fuel pump 16 per unit fuel movement amount is moderate.

  Therefore, depending on the amount of work W / Mf of the fuel pump 16, the main fuel tank 12 and the sub fuel tank 14 are not leaked, both are leaked, and only one is leaked. Can be determined.

  However, if only the work amount is leaking in only one of the main fuel tank 12 and the sub fuel tank 14, it is impossible to determine which fuel tank 12 or 14 is leaking.

  In this case, if the value of the internal pressure Pf1 on the main fuel tank 12 side is sufficiently reduced, it can be determined that the main fuel tank 12 is not leaking and the sub fuel tank 14 is leaking. .

  Conversely, when the value of the internal pressure Pf1 on the main fuel tank 12 side is hardly lowered or not lowered at all, the main fuel tank 12 is leaked and the sub fuel tank 14 is leaked. It can be determined that there is no.

In step S719, when the leak state is found and the leak detection is completed as described above, the leak detection end setting is performed and the process is exited.
In the next processing execution cycle, even if the leak detection condition is satisfied (YES in S702), since the leak detection end setting is made (NO in S704), the fuel pump 16 is stopped (S722), and the switching valve 62 is set. Then, the on-off valve 32 and the blocking valve 35a are returned to the original state, that is, the state when the normal internal combustion engine is stopped (S724), and this processing is exited.
<Relationship with Claims> In the configuration described above, the ECU 60 corresponds to the pump work detection means and the leak detection means, and step S715 of the leak detection process (FIG. 14) executed by the ECU 60 is a process as the pump work detection means. In addition, the other steps correspond to processing as leak detection means.
<Effect> (1) As described above, even if there is only one internal pressure sensor 20, by detecting the work amount of the fuel pump 16, it is possible to detect the presence or absence of leakage for each of the plurality of fuel tanks 12, 14 with one fuel pump 16. .

Furthermore, this leak detection can be performed early after the internal combustion engine is stopped because the fuel pump 16 actively changes the internal pressure of the fuel tanks 12 and 14.
At the time of leak detection, only the fuel movement between the fuel tanks 12 and 14 is performed, and the entire fuel storage mechanism 10 can be maintained in a sealed state. Therefore, there is no discharge of fuel vapor due to the execution of leak detection itself.

[Embodiment 10]
<Structure> In this embodiment, in FIG. 14, the main fuel tank 12 is not provided with the internal pressure sensor 20, but the sub fuel tank 14 is provided with the internal pressure sensor 22 as shown in FIG. Only the internal pressure Pf2 is detected.
<Operation> Therefore, in the present embodiment, the internal pressure Pf2 obtained from one internal pressure sensor 22 provided in the sub fuel tank 14 and the work amount for moving a fixed amount of fuel between the fuel tanks 12 and 14 by the fuel pump 16. Thus, the respective leak states in the two fuel tanks 12 and 14 are detected.
<Effect> (1) Even if the internal pressure sensor 22 is provided only on the sub fuel tank 14 side, the same effect as in the ninth embodiment is produced.

[Other embodiments]
In the first embodiment, the leak detection is performed based on the amount of change in the internal pressure from the fuel tank internal pressures Pf1 and Pf2 immediately after the start of driving the fuel pump, but from the fuel tank internal pressures Pf1 and Pf2 immediately before the start of driving the fuel pump. Even if leak detection is executed based on the amount of change in internal pressure, the leak state can be detected in the same manner.

  In the leak detection means in the third embodiment (FIG. 5) and the leak detection process after driving the fuel pump in the fourth embodiment (FIG. 7), depending on the amount of change between the internal pressures detected before and after the fuel pump is driven. Leak was detected (S324, S462). As described above, the leak may be detected not by the internal pressure state before and after driving the fuel pump but by the internal pressure state after driving the fuel pump. That is, as shown after the timing t2 in FIG. 3, the change state of the internal pressure differs after the fuel pump is stopped depending on the presence or absence of leakage. In the case of the solid line where no leak occurs, the change is very slow, but in the case of the one-dot chain line where the leak occurs, a rapid change occurs. By detecting such a change state after the fuel pump is driven (stop state after the drive is executed), leak detection can be performed.

  In each of the above embodiments, the internal pressure of the fuel tank is detected by providing an internal pressure sensor. However, a tank generated by the internal pressure of the fuel tank by attaching a strain sensor to a constituent member of the fuel tank, for example, a wall portion The amount of distortion of the wall portion may be detected and the value itself may be used as the internal pressure. Alternatively, the strain amount may be converted into an internal pressure.

  After the fuel movement between the two fuel tanks by the fuel pump, the amount of distortion of the tank wall caused by the internal pressure of the fuel tank appears in the difference between the amount of fuel change detected by the fuel sender gauge and the actual amount of moving fuel.

  Accordingly, a means for detecting the amount of fuel moved by the fuel pump is separately provided, and a deviation amount between the amount of the moved fuel and the fuel change amount determined by the change in the fuel level is obtained, and this deviation amount is determined by the internal pressure. The physical quantity corresponding to the change may be used for detecting the leak state.

  As shown in FIGS. 1 and 9, the fuel storage mechanism 10 of each embodiment is composed of two fuel tanks 12 and 14, but more fuel tanks such as three fuel tanks and four fuel tanks The fuel tank may be provided as a fuel storage mechanism for one internal combustion engine. By moving the fuel from the main fuel tank with the fuel pump to two or more sub fuel tanks as in the above embodiments, the main fuel tank and the sub fuel tanks can individually detect leaks. Become.

  A plurality of fuel storage portions of the fuel storage mechanism are not formed as the fuel tanks 12 and 14 separated into a plurality as shown in FIGS. 1 and 9, but inside the one fuel tank 112 as shown in FIG. A plurality of fuel storage portions 112a and 112b may be provided by being divided by the partition wall 114.

  The sub fuel tank 14 shown in FIGS. 1 and 9 has a configuration in which a canister is not arranged, but a canister similar to the main fuel tank 12 may be arranged, and a trapper is arranged instead of the canister. May be. Thus, when a canister or trapper is arranged with respect to the sub fuel tank 14, a blocking valve is arranged in a passage connecting the sub fuel tank 14 and the canister or trapper, and when the leak is detected, the main fuel tank 12 side Similar to the closing valve 35a, the closing valve on the sub fuel tank 14 side is also closed.

  Thus, in the configuration in which the canister or trapper is connected to the sub fuel tank 14 via the block valve, the fuel inlet pipe 28 may be attached to the main fuel tank 12 side instead of the sub fuel tank 14 side.

  In the ninth and tenth embodiments, instead of using the fuel level SGL1 by the fuel sender gauge 24 on the main fuel tank 12 side, the fuel level SGL2 by the fuel sender gauge 26 on the sub fuel tank 14 side is used. The amount of moving fuel may be obtained. Alternatively, the moving fuel amount may be obtained from each of the two fuel liquid level SGL1, SGL2, and the average value thereof may be used.

  In each of the embodiments, as shown in FIGS. 1 and 9, the fuel pump 16 is diverted to a pressure pump by switching the switching valve 62 to the branch path 64. Instead of this, without providing the switching valve 62 and the branch path 64, a pressure pump and a movement path for moving one fuel of the fuel tanks 12 and 14 to the other are provided separately, and each of the above-mentioned pumps is driven by driving the pressure pump. You may perform leak detection similar to embodiment. In this case as well, leak detection can be performed with one pump in the two fuel tanks 12 and 14.

  The fuel temperature may be detected by arranging a fuel temperature sensor in the fuel tank, and control thresholds such as a leak detection drive time and a leak detection time may be adjusted according to the fuel temperature.

  DESCRIPTION OF SYMBOLS 2 ... Internal combustion engine, 4 ... Fuel supply system, 6 ... Intake port, 8 ... Fuel injection valve, 10 ... Fuel storage mechanism, 12 ... Main fuel tank, 12a ... Upper space, 14 ... Sub fuel tank, 14a ... Upper space, DESCRIPTION OF SYMBOLS 16 ... Fuel pump, 18 ... Internal combustion engine supply path, 20 ... 1st internal pressure sensor, 22 ... 2nd internal pressure sensor, 24, 26 ... Fuel sender gauge, 24a, 26a ... Float, 28 ... Fuel inlet pipe, 30 ... Fuel connection Passage, 32 ... Open / close valve, 34 ... Evaporative fuel passage, 34a ... ORVR valve, 34b ... COV, 35 ... Sealing valve unit, 35a ... Sealing valve, 35b ... Relief valve, 36 ... Canister, 38 ... Atmospheric passage, 38a ... Air Filter, 40 ... Air release valve, 42 ... Purge passage, 44 ... Intake passage, 46 ... Throttle valve, 48 ... Purge valve, 52 ... Air filter 54 ... Air flow meter, 60 ... ECU, 62 ... Switching valve, 64 ... Branch path, 104 ... Fuel supply system, 112 ... Fuel tank, 112a, 112b ... Fuel reservoir, 114 ... Bulkhead, FL1, FL2 ... Fuel, Pf1: internal pressure on the main fuel tank side, Pf2: internal pressure on the sub fuel tank side.

Claims (17)

A leak detection device in a fuel storage mechanism that stores fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path,
A pump for performing fuel movement between the fuel reservoirs; and
A first internal pressure sensor for detecting an internal pressure of an outflow side fuel storage part from which fuel is poured out by the pressure pump;
A second internal pressure sensor for detecting an internal pressure of the inflow side fuel storage part into which fuel is poured from the pressure feed pump;
An on-off valve for the fuel communication path;
When the movement of the fuel is executed by blocking the passage between the outflow side fuel storage part and the inflow side fuel storage part and the outside, and driving the pressure pump with the on-off valve closed. The leak state of the outflow side fuel storage part is detected based on the internal pressure state detected by the first internal pressure sensor, and the leak state of the inflow side fuel storage part is detected based on the internal pressure state detected by the second internal pressure sensor. Leak detection means for detecting;
A leak detection apparatus comprising: 2. The leak detection device according to claim 1, wherein the pressure feed pump also serves as a fuel pump that supplies fuel to an internal combustion engine, and a fuel movement path for performing movement of the fuel on a fuel discharge side of the pressure feed pump. And an internal combustion engine supply path for supplying fuel to the internal combustion engine through a switching valve,
The leak detection means functions when the internal combustion engine is stopped, and switches the switching valve when the fuel moves, so that the fuel discharge side of the pressure feed pump is used as the fuel movement path. Leak detection device. 3. The leak detection device according to claim 1, wherein the leak detection unit is configured to detect a leak state of the outflow side fuel storage unit based on an internal pressure state detected by the first internal pressure sensor during driving of the pressure pump. Leak detection device characterized by detecting 4. The leak detection device according to claim 1, wherein the leak detection unit is configured to detect the inflow side fuel based on an internal pressure state detected by the second internal pressure sensor during driving of the pressure feed pump. 5. A leak detection apparatus for detecting a leak state of a storage unit. 3. The leak detection device according to claim 1, wherein the leak detection unit is configured to store the outflow side fuel storage based on an internal pressure state detected by the first internal pressure sensor before and after driving the pressure feed pump or after driving. A leak detection apparatus for detecting a leak state of a part. The leak detection device according to any one of claims 1 to 5, wherein the leak detection means is based on an internal pressure state detected by the second internal pressure sensor before or after driving the pressure feed pump or after driving. A leak detection apparatus for detecting a leak state of the inflow side fuel storage section. The leak detection device according to claim 1 or 2, wherein the leak detection means includes:
A first pumping side detection process for detecting a leak state of the outflow side fuel storage unit based on an internal pressure state detected by the first internal pressure sensor during driving of the pumping pump;
In the first pressure-feeding side detection process, when the leak state cannot be detected or when it is detected that no leak has occurred, it is detected by the first internal pressure sensor before or after driving the pump. A second pumping side detection process for detecting a leak state of the outflow side fuel storage unit based on an internal pressure state;
The leak detection apparatus characterized by performing. The leak detection device according to claim 1, 2, or 7, wherein the leak detection means includes:
A first pressure-feed side detection process for detecting a leak state of the inflow-side fuel reservoir based on an internal pressure state detected by the second internal pressure sensor during driving of the pressure pump;
In the first pressure-feeding side detection process, when the leak state cannot be detected or when it is detected that no leak has occurred, it is detected by the second internal pressure sensor before or after driving the pump. A second pressure-feeding side detection process for detecting a leak state of the inflow side fuel storage unit based on the internal pressure state;
The leak detection apparatus characterized by performing. The leak detection device according to any one of claims 1 to 8, wherein the leak detection means starts driving the pumping pump when an internal pressure change rate detected by the internal pressure sensor converges to a reference range. A leak detection apparatus, wherein a leak state is detected based on an amount of change in internal pressure between an internal pressure detected by the internal pressure sensor immediately before or immediately after the start of driving and the converged internal pressure. 9. The leak detection device according to claim 1, wherein the leak detection unit performs detection of a leak state based on a change rate of an internal pressure detected by the internal pressure sensor. Leak detection device. A leak detection device in a fuel storage mechanism that stores fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path,
A pump for performing fuel movement between the fuel reservoirs; and
An internal pressure sensor for detecting an internal pressure of one of the outflow side fuel storage part from which the fuel is flowed out by the pressure feed pump and the inflow side fuel storage part from which the fuel is poured from the pressure feed pump;
An on-off valve for the fuel communication path;
After the movement of the fuel is performed by blocking the passage between the outflow side fuel storage section and the inflow side fuel storage section and the outside, and driving the pressure feed pump with the on-off valve closed, the pressure feed is performed. Detection for detecting a leakage state between the outflow side fuel storage part and the inflow side fuel storage part based on an internal pressure state detected by the internal pressure sensor when the pump is stopped and the on-off valve is opened. Leak detection means for executing processing;
A leak detection apparatus comprising: A leak detection device in a fuel storage mechanism that stores fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path,
A pump for performing fuel movement between the fuel reservoirs; and
An internal pressure sensor for detecting an internal pressure of one of the outflow side fuel storage part from which the fuel is flowed out by the pressure feed pump and the inflow side fuel storage part from which the fuel is poured from the pressure feed pump;
An on-off valve for the fuel communication path;
The internal pressure when the movement of the fuel is executed by blocking the passage between the outflow side fuel storage section and the inflow side fuel storage section and the outside, and driving the pressure feed pump with the on-off valve closed. A first detection process for detecting a leak state of the one fuel storage unit based on an internal pressure state detected by the sensor, and a stop of driving of the pressure pump and opening of the on-off valve are executed after the first detection process. And a second detection process for detecting a leak state of the other fuel storage part of the outflow side fuel storage part and the inflow side fuel storage part based on the internal pressure state detected by the internal pressure sensor Leak detection means to
A leak detection apparatus comprising: A leak detection device in a fuel storage mechanism that stores fuel to be supplied to an internal combustion engine by including a plurality of fuel storage portions communicated by a fuel communication path,
A pump for performing fuel movement between the fuel reservoirs; and
Pump work detection means for detecting the work of the pumping pump;
An internal pressure sensor for detecting an internal pressure of one of the outflow side fuel storage part from which the fuel is flowed out by the pressure feed pump and the inflow side fuel storage part from which the fuel is poured from the pressure feed pump;
An on-off valve for the fuel communication path;
The internal pressure when the movement of the fuel is executed by blocking the passage between the outflow side fuel storage section and the inflow side fuel storage section and the outside, and driving the pressure feed pump with the on-off valve closed. Leak detection for detecting respective leak states of the outflow side fuel storage part and the inflow side fuel storage part based on the internal pressure state detected by the sensor and the work amount detected by the pump work amount detection means Means,
A leak detection apparatus comprising: The leak detection device according to any one of claims 1 to 13, wherein the inflow side fuel storage unit is provided with an inflow side fuel level sensor that detects a stored fuel level,
The leak detection device according to claim 1, wherein the leak detection means executes processing when the fuel level detected by the inflow side fuel level sensor is lower than an inflow reference level. The leak detection device according to any one of claims 1 to 14, wherein the outflow side fuel storage unit is provided with an outflow side fuel level sensor that detects a stored fuel level.
The leak detection device according to claim 1, wherein the leak detection means executes processing when the fuel level detected by the outflow side fuel level sensor is higher than an outflow reference level. The leak detection device according to any one of claims 1 to 15, wherein a strain sensor is disposed on a constituent member of the fuel storage unit instead of each internal pressure sensor that detects an internal pressure of the fuel storage unit.
The leak detection device, wherein the leak detection unit detects a leak state of the fuel storage unit based on a strain amount of the constituent member detected by the strain sensor. The leak detection device according to any one of claims 1 to 15, wherein the fuel is stored in the fuel storage unit separately from, or instead of, each internal pressure sensor that detects an internal pressure of the fuel storage unit. A fuel level sensor to detect the fuel level
The leak detection means is configured to detect the fuel based on a deviation between a fuel change amount corresponding to a fuel level change amount detected by the fuel level sensor before and after driving the pressure feed pump and a fuel movement amount by the pressure feed pump. A leak detection apparatus for detecting a leak state of a storage unit.

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