JP6989459B2 - Evaporative fuel processing equipment - Google Patents

Description

The present disclosure relates to an evaporative fuel processing device that supplies evaporative fuel generated in a fuel tank to an internal combustion engine via an intake passage.

In the evaporative fuel processing device, when a purge pump is provided in the purge passage, if the passage on the upstream side of the purge pump (for example, the purge passage or the vapor passage) is clogged, the flow rate of the purge gas cannot be adjusted appropriately. , A / F roughness may occur. Therefore, it is required to detect the presence or absence of clogging of the passage on the upstream side of the purge pump. The "A / F roughness" is an air-fuel ratio roughness in which the air-fuel ratio in the combustion chamber of the engine fluctuates excessively.

Here, as a conventional technique for detecting the presence or absence of an abnormality in a passage in an evaporative fuel processing apparatus, Patent Document 1 describes fuel gas leakage, etc. in a fuel evaporation prevention apparatus for preventing evaporation of fuel gas generated in a fuel tank. A device for detecting an abnormality in the fuel is disclosed.

Japanese Unexamined Patent Publication No. 05-125997

In the apparatus disclosed in Patent Document 1, first, when the vehicle is stopped and in an idle operation state, the purge control valve and the canister block valve are fully closed, and the amount of pressure change under atmospheric pressure sealing is measured. Next, once the purge control valve is switched from the fully closed state to the fully open state, the negative pressure of the intake pipe is introduced into the closed section, and the amount of pressure change under the negative pressure sealing is measured. Then, based on the measured value of the pressure change amount under the atmospheric pressure sealing and the measured value of the pressure change amount under the negative pressure sealing, the presence or absence of an abnormality causing a leak in the closed section is detected.

However, in the apparatus disclosed in Patent Document 1 as described above, the presence or absence of an abnormality in the closed section is detected by measuring the amount of pressure change by setting two conditions under atmospheric pressure sealing and negative pressure sealing. Therefore, the control for performing the detection becomes complicated.

Therefore, the present disclosure has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an evaporative fuel processing apparatus capable of determining whether or not the passage on the upstream side of the purge pump is clogged with simple control. ..

One embodiment of the present disclosure made to solve the above problems is connected to a vapor passage connected to a fuel tank, a canister for storing evaporated fuel sent from the fuel tank through the vapor passage, and an internal combustion engine. It has a purge passage connected to the intake passage and the canister, a purge pump provided in the purge passage, an air passage connected to the canister, and an air shutoff valve for opening and closing the atmospheric passage, from the canister. In the evaporated fuel processing apparatus that executes the purge control for introducing the purge gas containing the evaporated fuel into the intake passage through the purge passage, the vapor passage and the passage on the upstream side of the purge pump in the purge passage are provided. It has a passage clogging determination unit that determines the presence or absence of clogging in the passage on the upstream side of the pump including the pump, and the passage clogging determination unit closes the air shutoff valve while the internal combustion engine is stopped or the purge control is stopped. Presence or absence of clogging in the pump upstream passage based on the increase in pressure in the pump upstream passage when the purge pump is driven and a positive pressure is applied to the pump upstream passage. The pressure in the upstream side passage of the pump is the upstream passage of the purge pump in the purge passage, the downstream passage of the atmospheric shutoff valve in the atmospheric passage, or the said. The pressure is detected by a pressure sensor provided in the vapor passage .

According to this aspect, it is possible to determine the presence or absence of clogging in the pump upstream passage based on the rising state of the pressure in the pump upstream passage only by applying a positive pressure to the pump upstream passage by the purge pump. Therefore, it is possible to determine whether or not the passage on the upstream side of the pump is clogged with simple control.

In the above aspect, the passage clogging determination unit determines that the pressure increase in the pump upstream passage is such that the pressure increase in the pressure in the pump upstream passage is less than a predetermined determination speed. It is preferable to determine that the side passage is not clogged.

According to this aspect, since the determination may be made based on the rate of increase in pressure in the pump upstream passage, it is possible to determine the presence or absence of clogging in the pump upstream passage in a short time. Therefore, when making a determination, the drive time of the purge pump can be shortened, so that power consumption can be suppressed.

Another aspect of the present disclosure made to solve the above problems is to connect to a vapor passage connected to a fuel tank, a canister for storing evaporated fuel sent from the fuel tank through the vapor passage, and an internal combustion engine. The canister has an intake passage, a purge passage connected to the canister, a purge pump provided in the purge passage, an air passage connected to the canister, and an air shutoff valve for opening and closing the atmospheric passage. In an evaporative fuel processing apparatus that executes a purge control for introducing a purge gas containing the evaporative fuel into the intake passage through the purge passage, the vapor passage, the passage on the upstream side of the purge pump in the purge passage, and the passage on the upstream side of the purge pump. It has a passage clogging determination unit for determining the presence or absence of clogging in the passage on the upstream side of the pump including the above, and the passage clogging determination unit closes the air shutoff valve while the internal combustion engine is stopped or the purge control is stopped. Based on the increase in pressure in the pump upstream passage when the purge pump is driven and a positive pressure is applied to the pump upstream passage, the blockage in the pump upstream passage is established. The presence / absence is determined, and the passage clogging determination unit determines that the pressure difference in the passage upstream of the pump is less than a predetermined value for each predetermined time as the state of increase in the pressure in the passage upstream of the pump. if saturating time to reach the saturating state is longer than the predetermined judging time, determining that clogging the pump upstream passage has not occurred, and wherein.

According to this aspect, since the determination is made by observing the transition of the pressure change in the pump upstream passage, it is possible to accurately determine whether or not the pump upstream passage is clogged.

In the above aspect, it is preferable that the predetermined determination speed or the predetermined determination time is defined corresponding to the remaining amount of fuel in the fuel tank.

According to this aspect, the presence or absence of clogging in the passage on the upstream side of the pump can be accurately determined regardless of the remaining amount of fuel in the fuel tank.

In the above aspect, it is preferable that the passage clogging determination unit drives the purge pump in the reverse rotation to apply a positive pressure to the passage on the upstream side of the pump.

According to this aspect, as a means for applying a positive pressure to the passage on the upstream side of the pump, the purge pump, which is an existing configuration in the evaporative fuel processing apparatus, is used without providing a new means, so that the cost is reduced. Can be reduced.

Other embodiments of the present disclosure made to solve the above problems are connected to a vapor passage connected to a fuel tank, a canister for storing evaporative fuel sent from the fuel tank through the vapor passage, and an internal combustion engine. The canister has an intake passage, a purge passage connected to the canister, a purge pump provided in the purge passage, an atmospheric passage connected to the canister, and an air shutoff valve for opening and closing the atmospheric passage. In an evaporative fuel processing apparatus that executes a purge control for introducing a purge gas containing the evaporative fuel into the intake passage through the purge passage, the vapor passage, the passage on the upstream side of the purge pump in the purge passage, and the passage on the upstream side of the purge pump. It has a passage clogging determination unit for determining the presence or absence of clogging in the pump upstream side passage including the pump, and the passage clogging determination unit closes the atmosphere shutoff valve while the internal combustion engine is stopped or the purge control is stopped. The clogging in the upstream passage of the pump is based on the increase of the pressure in the upstream passage of the pump when the purge pump is driven and a positive pressure is applied to the upstream passage of the pump. It has a switching valve for switching a passage to which the suction port and the discharge port of the purge pump are connected, and the passage clogging determination unit uses the switching valve to connect the suction port to the purge passage. By driving the purge pump in a forward rotation in a state where the discharge port is connected to the passage on the upstream side of the purge pump in the purge passage while being connected to the passage on the downstream side of the purge pump in the above. It is characterized by applying a positive pressure to the passage on the upstream side of the pump.

According to this aspect, it is not necessary to drive the purge pump in the reverse rotation. Therefore, as a purge pump, a pump capable of operating in one direction (only forward rotation is possible) can be used. Therefore, regardless of the type of pump used as the purge pump, it is possible to determine the presence or absence of clogging in the passage on the upstream side of the pump.

According to the evaporative fuel processing apparatus of the present disclosure, it is possible to determine whether or not the passage on the upstream side of the purge pump is clogged with simple control.

It is a schematic block diagram of the evaporative fuel processing system including the evaporative fuel processing apparatus of 1st and 2nd Embodiment and its periphery. It is a figure which shows the control flowchart in 1st Embodiment. It is a figure which shows an example of the map which defines the relationship between the remaining amount of a tank and a judgment value. It is a figure which shows an example of the control time chart in 1st Embodiment. It is a figure which shows the switching valve. It is a figure which shows the control flowchart in 2nd Embodiment. It is a figure which shows an example of the map which defines the relationship between the remaining amount of a tank, and the determination time. It is a figure which shows an example of the control time chart in 2nd Embodiment.

Hereinafter, embodiments of the evaporative fuel treatment apparatus of the present disclosure will be described.

[First Embodiment]
First, the first embodiment will be described.

<Overview of evaporative fuel treatment equipment>
The outline of the evaporative fuel processing apparatus 1 of this embodiment will be described. The evaporative fuel processing device 1 is used for a vehicle such as an automobile.

Here, as shown in FIG. 1, an intake passage IP for supplying air (intake air, intake air) to the engine ENG is connected to the engine ENG (internal combustion engine) mounted on the vehicle. The intake passage IP is provided with an electronic throttle THR (throttle valve) that opens and closes the intake passage IP to control the amount of air flowing into the engine ENG (intake air amount). An air cleaner AC for removing foreign matter from the air flowing into the intake passage IP is provided on the upstream side (upstream side in the flow direction of the intake air) of the electronic throttle THR in the intake passage IP. As a result, in the intake passage IP, air passes through the air cleaner AC and is sucked toward the engine ENG.

The evaporative fuel processing device 1 of the present embodiment is a device that supplies the evaporative fuel in the fuel tank FT to the engine ENG via the intake passage IP. As shown in FIG. 1, the evaporative fuel processing device 1 includes a canister 11, a purge passage 12, a purge pump 13, a purge control valve 14 (purge valve), an atmospheric passage 15, a vapor passage 16, and a control unit 17. It also has a filter 18, an atmosphere shutoff valve 19, a pressure sensor PS1 (first pressure sensor), a pressure sensor PS2 (second pressure sensor), and the like.

The canister 11 is connected to the fuel tank FT via the vapor passage 16, and stores the evaporated fuel flowing from the fuel tank FT through the vapor passage 16. Further, the canister 11 communicates with the purge passage 12 and the atmospheric passage 15.

The purge passage 12 is connected to the intake passage IP and the canister 11. As a result, the purge gas (gas containing evaporative fuel) flowing out of the canister 11 flows through the purge passage 12 and is introduced into the intake passage IP. In the example shown in FIG. 1, the purge passage 12 is connected to a position on the downstream side (downstream side in the flow direction of the intake air) of the electronic throttle THR in the intake passage IP, but is not limited to this, and is not limited to this. It may be connected to a position on the upstream side of the electronic throttle THR.

The purge pump 13 is provided in the purge passage 12 and controls the flow of the purge gas flowing through the purge passage 12. That is, the purge pump 13 sends the purge gas in the canister 11 to the purge passage 12, and supplies the purge gas sent to the purge passage 12 to the intake passage IP.

The purge control valve 14 is provided in the purge passage 12 at a position on the downstream side of the purge pump 13 (downstream in the flow direction of the purge gas when the purge control is executed), that is, at a position between the purge pump 13 and the intake passage IP. Has been done. The purge control valve 14 opens and closes the purge passage 12. When the purge control valve 14 is closed (when the valve is closed), the purge gas in the purge passage 12 is stopped by the purge control valve 14 and does not flow toward the intake passage IP. On the other hand, when the purge control valve 14 is opened (when the valve is open), the purge gas flows toward the intake passage IP.

One end of the atmospheric passage 15 is open to the atmosphere, and the other end is connected to the canister 11, so that the canister 11 communicates with the atmosphere. Then, air taken in from the atmosphere flows through the atmospheric passage 15.

The vapor passage 16 is connected to the fuel tank FT and the canister 11. As a result, the evaporated fuel of the fuel tank FT flows into the canister 11 through the vapor passage 16.

The control unit 17 is a part of an ECU (not shown) mounted on the vehicle, and is integrally arranged with other parts of the ECU (for example, a part that controls the engine ENG). The control unit 17 may be arranged separately from other parts of the ECU. The control unit 17 includes a CPU and memories such as ROM and RAM. The control unit 17 controls the evaporative fuel processing device 1 and the evaporative fuel processing system according to the program stored in the memory in advance. For example, the control unit 17 controls the purge pump 13 and the purge control valve 14. Further, the control unit 17 acquires the pressure detection result from the pressure sensor PS1 and the pressure sensor PS2.

In the present embodiment, the control unit 17 includes a passage clogging determination unit 21. The passage clogging determination unit 21 determines whether or not the passage 22 on the upstream side of the pump is clogged. Here, the "pump upstream passage 22" is a passage on the upstream side of the purge pump 13, and is in the vapor passage 16, the upstream passage 12a on the upstream side of the purge pump 13 in the purge passage 12, and the atmospheric passage 15. It is a passage including a downstream passage 15a on the downstream side of the air shutoff valve 19. The "upstream side of the purge pump 13" means the upstream side in the flow direction of the purge gas when the purge control is executed, that is, the canister 11 side. Further, the "downstream side of the atmosphere shutoff valve 19" means the downstream side in the flow direction of the atmosphere (air), the canister 11 side. Further, the passage clogging determination unit 21 may be provided independently of the control unit 17.

The filter 18 removes foreign matter from the atmosphere (air) flowing into the atmospheric passage 15. The atmospheric shutoff valve 19 opens and closes the atmospheric passage 15.

The pressure sensor PS1 and the pressure sensor PS2 detect the pressure in the pump upstream passage 22. In the example shown in FIG. 1, the pressure sensor PS1 is provided in the upstream passage 12a in the purge passage 12 of the pump upstream passage 22, and detects the pressure in the upstream passage 12a. Further, the pressure sensor PS2 is provided in the downstream passage 15a in the atmospheric passage 15 of the pump upstream passage 22, and detects the pressure in the downstream passage 15a. The position where the pressure sensor PS1 and the pressure sensor PS2 are provided is not limited to the position shown in FIG. 1, and may be provided at any position of the pump upstream passage 22 (for example, the vapor passage 16). Just do it.

In the evaporative fuel processing apparatus 1 having such a configuration, when the purge condition is satisfied during the operation of the engine ENG, the control unit 17 controls the purge pump 13 and the purge control valve 14, that is, the purge pump 13 rotates in the forward direction. The purge control valve 14 is opened while being driven by, and the purge control is executed. The purge control is a control for introducing the purge gas from the canister 11 to the intake passage IP via the purge passage 12.

Then, while the purge control is being executed, the engine ENG has the air sucked into the intake passage IP, the fuel injected from the fuel tank FT via the injector (not shown), and the intake passage IP by the purge control. With the purge gas supplied to, is supplied. Then, the control unit 17 adjusts the air-fuel ratio (A / F) of the engine ENG to the optimum air-fuel ratio (for example, the ideal air-fuel ratio) by adjusting the injection time of the injector, the valve opening time of the purge control valve 14, and the like. do.

<Control to determine the presence or absence of clogging in the passage on the upstream side of the pump>
When determining whether or not the pump upstream passage 22 including the vapor passage 16 is clogged as a vehicle self-diagnosis function (On-board diagnostics, OBD), if the determination is made while the vehicle is running, the effect of the determination operation. Therefore, the purge flow rate (purge gas flow rate) may decrease while the vehicle is running. Then, the air-fuel ratio of the engine ENG may not be adjusted to the optimum air-fuel ratio.

Therefore, in the present embodiment, control is performed to determine whether or not the pump upstream passage 22 including the vapor passage 16 is clogged while preventing the purge flow rate from decreasing while the vehicle is traveling.

Specifically, the passage clogging determination unit 21 of the control unit 17 controls based on the control chart shown in FIG.

As shown in FIG. 2, the passage clogging determination unit 21 opens the purge control valve 14 (opens the valve) immediately after the engine ENG is stopped (step S1: YES), while the atmospheric shutoff valve. 19 is closed (the valve is closed) (step S2).

Next, the passage clogging determination unit 21 drives the purge pump 13 in a reverse rotation at a predetermined rotation speed (for example, 20,000 rpm) (step S3). In this way, the passage clogging determination unit 21 drives the purge pump 13 in the reverse rotation to supply gas (intake air, etc.) to the pump upstream side passage 22 and apply positive pressure to the pump upstream side passage 22. Apply. As the purge pump 13, a pump (for example, a Wesco pump) capable of operating in two directions (forward rotation and reverse rotation) is used.

Next, the passage clogging determination unit 21 stores the pressure P (pressure P1, pressure P2, pressure P3) for each TA (for example, every 1 sec) for a predetermined time (step S4). Here, the pressure P is a detection value of the pressure sensor PS1. Further, it is assumed that the pressure P is detected in the order of pressure P1, pressure P2, and pressure P3 with the passage of time. The pressure P may be a detection value of the pressure sensor PS2.

Next, the passage clogging determination unit 21 determines a determination value X (predetermined determination speed) from the remaining tank remaining amount TR, which is the residual amount of fuel in the fuel tank FT, using, for example, the map shown in FIG. Step S5). As shown in FIG. 3, the determination value X is defined corresponding to the tank remaining amount TR, and is specified so as to increase as the tank remaining amount TR increases.

Next, the passage clogging determination unit 21 determines whether or not the pressure increase allowance ΔPA (increasing speed of the pressure P) is less than the determination value X (step S6). Here, ΔPA = (P2-P1), ΔPA = (P3-P1), or ΔPA = (P3-P2).

Then, when the pressure increase allowance ΔPA is less than the determination value X (step S6: YES), the passage clogging determination unit 21 determines that the hose forming the pump upstream passage 22 is not clogged (step S7). .. That is, when the pressure increase allowance ΔPA is less than the determination value X and the pressure P increase rate is normal, it is considered that the capacity of the gas that can flow into the pump upstream passage 22 is maintained, so that the passage is clogged. The determination unit 21 determines that the passage 22 on the upstream side of the pump is not clogged. When it is determined that the pump upstream passage 22 is not clogged in this way, it is considered that the vapor passage 16 which is a part of the pump upstream passage 22 is also not clogged.

In this way, the passage clogging determination unit 21 determines that the pump upstream side passage 22 is not clogged if the pressure rising speed in the pump upstream side passage 22 is less than a predetermined determination speed.

On the other hand, when the pressure increase allowance ΔPA is equal to or greater than the determination value X (step S6: NO), the passage clogging determination unit 21 determines that the hose forming the passage clogging determination unit 21 is clogged (step S8). .. That is, when the pressure rise margin ΔPA is equal to or higher than the determination value X and the pressure P rise speed is faster than usual, it is considered that the capacity of the gas that can flow into the pump upstream passage 22 is small, so that the passage is clogged. The determination unit 21 determines that the passage 22 on the upstream side of the pump is clogged. If it is determined that the pump upstream passage 22 is clogged in this way, there is a possibility that the vapor passage 16 which is a part of the pump upstream passage 22 is clogged.

In this way, the passage clogging determination unit 21 determines that the passage clogging determination unit 21 is clogged if the pressure rising speed in the pump upstream side passage 22 is equal to or higher than a predetermined determination speed.

Then, by performing control based on the control chart shown in FIG. 2, an example of the control time chart as shown in FIG. 4 is implemented. As shown in FIG. 4, if the pressure increase allowance ΔPA (= P3-P2) is less than the determination value X (for example, 3 kPa), it is determined that the passage clogging determination unit 21 is not clogged and is normal. On the other hand, if the pressure increase allowance ΔPA is equal to or higher than the determination value X, the passage clogging determination unit 21 is clogged and is determined to be abnormal. The pressure P1 is the pressure P at the time T1, the pressure P2 is the pressure P at the time T2, and the pressure P3 is the pressure P at the time T3.

As a modification, in step S3 of FIG. 2, the passage clogging determination unit 21 switches the passage to which the suction port 13a and the discharge port 13b of the purge pump 13 are connected by the switching valve 23 shown in FIG. 5, and pumps. Gas may be supplied to the upstream passage 22 and a positive pressure may be applied to the pump upstream passage 22.

Specifically, the switching valve 23 includes a first passage portion 24 and a second passage portion 25, and the first passage portion 24 or the second passage portion 25 may be arranged between the purge pump 13 and the purge passage 12. can.

The first passage portion 24 includes a first passage 24a and a second passage 24b. The first passage 24a connects the suction port 13a of the purge pump 13 to the upstream passage 12a in the purge passage 12. The second passage 24b has the discharge port 13b of the purge pump 13 on the downstream side passage 12b on the downstream side of the purge pump 13 in the purge passage 12 (downstream side in the flow direction of the purge gas when the purge control is executed, intake passage IP side). Connect to.

Further, the second passage portion 25 includes a first passage 25a and a second passage 25b. The first passage 25a connects the suction port 13a of the purge pump 13 to the downstream passage 12b. The second passage 25b connects the discharge port 13b of the purge pump 13 to the upstream passage 12a.

Then, the switching valve 23 switches the passage portion arranged between the purge pump 13 and the purge passage 12 to the first passage portion 24 or the second passage portion 25. As a result, the switching valve 23 can switch the passage to which the suction port 13a and the discharge port 13b of the purge pump 13 are connected to the upstream side passage 12a or the downstream side passage 12b.

In such a modified example, the passage clogging determination unit 21 connects the suction port 13a of the purge pump 13 to the downstream passage 12b in the purge passage 12 by the switching valve 23, while the discharge port of the purge pump 13 is connected. 13b is connected to the upstream passage 12a in the purge passage 12. Then, in this state, the passage clogging determination unit 21 can drive the purge pump 13 in a forward rotation to apply a positive pressure to the pump upstream side passage 22.

Further, as a modification, the passage clogging determination unit 21 may determine the presence or absence of clogging in the pump upstream side passage 22 while the purge control is stopped while the engine ENG is being driven.

<About the action and effect of this embodiment>
As described above, in the present embodiment, the passage clogging determination unit 21 closes the atmospheric shutoff valve 19 and drives the purge pump 13 while the engine ENG is stopped or the purge control is stopped. A positive pressure is applied to the upstream passage 22. Then, the passage clogging determination unit 21 determines the presence or absence of clogging in the pump upstream side passage 22 based on the pressure increase state in the pump upstream side passage 22 at this time.

In this way, simply by applying a positive pressure to the pump upstream passage 22 by the purge pump 13, it is determined whether or not the pump upstream passage 22 is clogged based on the pressure increase in the pump upstream passage 22. can. Therefore, it is possible to determine whether or not the pump upstream passage 22 is clogged with simple control.

Further, it is possible to determine whether or not the pump upstream passage 22 is clogged by using the existing configuration in the evaporative fuel processing apparatus 1 without adding a new configuration. Therefore, it is possible to determine whether or not the pump upstream passage 22 is clogged with a simple device configuration, so that the cost can be reduced.

Further, since the determination is made while the engine ENG is stopped or the purge control is stopped, the flow rate of the purge gas is not reduced when the purge control is performed while the vehicle is running, and the restriction of the determination timing is reduced. Further, since it is only necessary to apply a positive pressure to the pump upstream passage 22 by the purge pump 13 and see the pressure increase in the pump upstream passage 22 once, the pump upstream passage 22 is clogged in a short time. It is possible to complete the determination of the presence or absence of.

Further, in the present embodiment, the passage clogging determination unit 21 does not clog the pump upstream side passage 22 if the pressure increase allowance ΔPA is less than the determination value X as the pressure increase state in the pump upstream side passage 22. Is determined.

In this way, the determination may be made based on the pressure increase allowance ΔPA of the pressure in the pump upstream passage 22, so that the presence or absence of clogging in the pump upstream passage 22 can be determined in a short time. Therefore, when making a determination, the drive time of the purge pump 13 can be shortened, so that power consumption can be suppressed.

Further, since the determination value X is defined according to the remaining amount of fuel in the fuel tank FT, it is possible to accurately determine the presence or absence of clogging in the pump upstream side passage 22 regardless of the remaining amount of fuel in the fuel tank FT.

Further, the passage clogging determination unit 21 drives the purge pump 13 in the reverse rotation to apply a positive pressure to the pump upstream side passage 22. In this way, as a means for applying the positive pressure to the pump upstream passage 22, the purge pump 13 which is the existing configuration in the evaporative fuel processing apparatus 1 is used without providing a new means. The cost can be reduced.

Further, the passage clogging determination unit 21 connects the suction port 13a of the purge pump 13 to the downstream passage 12b in the purge passage 12 by the switching valve 23, while the discharge port 13b of the purge pump 13 is connected to the upstream side in the purge passage 12. While connected to the passage 12a, the purge pump 13 may be driven in a forward rotation to apply a positive pressure to the pump upstream passage 22.

As a result, the purge pump 13 does not have to rotate in the reverse direction. Therefore, as the purge pump 13, a pump capable of operating in one direction (only forward rotation is possible) (for example, a centrifugal pump) can also be used. Therefore, regardless of the type of pump used as the purge pump 13, it is possible to determine the presence or absence of clogging in the pump upstream passage 22.

[Second Embodiment]
Next, the second embodiment will be described, but the components equivalent to those of the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and the differences will be mainly described.

<Control to determine the presence or absence of clogging in the passage on the upstream side of the pump>
In the present embodiment, the passage clogging determination unit 21 controls based on the control chart shown in FIG.

As shown in FIG. 6, the difference from the control of the first embodiment shown in FIG. 2 is that in step S14, the passage clogging determination unit 21 has a pressure difference ΔPB for each TB for a predetermined time (pressure increase allowance for each predetermined time). (Step S14).

Next, the passage clogging determination unit 21 determines the determination time t (predetermined determination time) from the tank remaining amount TR, for example, using the map shown in FIG. 7 (step S15). As shown in FIG. 7, the determination time t is specified corresponding to the remaining tank remaining amount TR, and is specified so as to become shorter as the tank remaining amount TR increases.

Next, the passage clogging determination unit 21 stores the saturation time ST when (pressure difference ΔPB) <(predetermined value Y) (step S16). That is, the passage clogging determination unit 21 stores the saturating time ST, which is the time until the saturating state in which the pressure difference ΔPB becomes less than the predetermined value Y is reached.

Next, the passage clogging determination unit 21 determines whether or not the saturation time ST is longer than the determination time t (step S17).

Then, when the saturating time ST is longer than the determination time t (step S17: YES), the passage clogging determination unit 21 determines that the hose forming the pump upstream passage 22 is not clogged (step S18). That is, when the saturating time ST is longer than the determination time t and it takes a certain amount of time for the pressure difference ΔPB to reach the saturating state, it is considered that the capacity of the gas that can flow into the pump upstream passage 22 is maintained. Therefore, the passage clogging determination unit 21 determines that the passage on the upstream side of the pump is not clogged.

In this way, if the saturation time ST is longer than the predetermined determination time, the passage clogging determination unit 21 determines that the passage on the upstream side of the pump is not clogged.

On the other hand, when the saturation time ST is equal to or less than the determination time t (step S17: NO), the passage clogging determination unit 21 determines that the hose forming the pump upstream passage 22 is clogged (step S19). That is, when the saturating time ST is equal to or less than the determination time t and the pressure difference ΔPB reaches the saturating state immediately, it is considered that the capacity of the gas that can flow into the pump upstream passage 22 is small. The passage clogging determination unit 21 determines that the passage 22 on the upstream side of the pump is clogged.

In this way, the passage clogging determination unit 21 determines that the pump upstream side passage 22 is clogged if the saturation time ST is equal to or less than the predetermined determination time.

Then, by performing control based on the control chart shown in FIG. 6, an example of the control time chart as shown in FIG. 8 is implemented. As shown in FIG. 8, when the saturation time ST of the pressure difference ΔPB is time T11 to time T14 (when it is longer than the determination time t), it is considered that the pump upstream passage 22 is not clogged (normal). It is judged. On the other hand, when the saturation time ST of the pressure difference ΔPB is shortened to time T11 to time T12 (when the determination time is t or less), it is determined that the pump upstream passage 22 is clogged (abnormal). To.

If the passage clogging determination unit 21 exceeds the determination time t, the passage clogging determination unit 21 may determine normal and end the control.

<About the action and effect of this embodiment>
As described above, in the present embodiment, the passage clogging determination unit 21 determines that the pressure difference ΔPB in the pump upstream passage 22 for each predetermined time is less than the predetermined value Y as the pressure increase in the pump upstream passage 22. If the saturating time ST until reaching the saturating state is longer than the determination time t, it is determined that the pump upstream passage 22 is not clogged.

In this way, since the determination is made by observing the transition of the pressure change in the pump upstream side passage 22, it is possible to accurately determine whether or not the pump upstream side passage 22 is clogged.

It should be noted that the above-described embodiment is merely an example and does not limit the present disclosure in any way, and it goes without saying that various improvements and modifications can be made without departing from the gist thereof.

1 Evaporated fuel processing device 11 Canister 12 Purge passage 12a Upstream side passage 13 Purge pump 13a Suction port 13b Discharge port 14 Purge control valve 15 Atmospheric passage 15a Downstream side passage 16 Vapor passage 17 Control unit 19 Air shutoff valve 21 Passage clogging determination unit 22 Pump upstream side passage 23 Switching valve 24 1st passage 25 2nd passage PS1 Pressure sensor PS2 Pressure sensor ENG Engine IP Intake passage THR Electronic throttle FT Fuel tank TA Predetermined time P, P1, P2, P3 Pressure TR Tank remaining amount X Judgment value ΔPA Pressure rise allowance ΔPB (every predetermined time) Pressure difference TB Predetermined time t Judgment time Y Predetermined value ST Saturate time

Claims (6)

A vapor passage connected to a fuel tank, a canister for storing evaporated fuel sent from the fuel tank through the vapor passage, an intake passage connected to an internal combustion engine, a purge passage connected to the canister, and the purge passage. A purge pump provided in the canister, an air passage connected to the canister, and an air shutoff valve for opening and closing the air passage. In the evaporative fuel processing equipment that executes the purge control to introduce
It has a passage clogging determination unit for determining the presence or absence of clogging in the pump upstream passage including the vapor passage and the passage on the upstream side of the purge pump in the purge passage.
The passage clogging determination unit closes the atmosphere shutoff valve and drives the purge pump to the upstream passage of the pump while the internal combustion engine is stopped or the purge control is stopped. Based on the increase in pressure in the pump upstream passage when a positive pressure is applied, the presence or absence of clogging in the pump upstream passage is determined .
The pressure in the pump upstream passage is a pressure sensor provided in the upstream passage of the purge pump in the purge passage, the downstream passage of the atmospheric shutoff valve in the atmospheric passage, or the vapor passage. Being a detected pressure,
Evaporative fuel processing equipment featuring. In the evaporated fuel processing apparatus of claim 1,
In the passage clogging determination unit, if the pressure increase in the pump upstream passage is lower than the predetermined determination speed, the pump upstream passage is clogged. Judging that it is not,
Evaporative fuel processing equipment featuring. A vapor passage connected to a fuel tank, a canister for storing evaporated fuel sent from the fuel tank through the vapor passage, an intake passage connected to an internal combustion engine, a purge passage connected to the canister, and the purge passage. A purge pump provided in the canister, an air passage connected to the canister, and an air shutoff valve for opening and closing the air passage. In the evaporative fuel processing equipment that executes the purge control to introduce
It has a passage clogging determination unit for determining the presence or absence of clogging in the pump upstream passage including the vapor passage and the passage on the upstream side of the purge pump in the purge passage.
The passage clogging determination unit closes the atmosphere shutoff valve and drives the purge pump to the upstream passage of the pump while the internal combustion engine is stopped or the purge control is stopped. Based on the increase in pressure in the pump upstream passage when a positive pressure is applied, the presence or absence of clogging in the pump upstream passage is determined.
The passage clogging determination unit determines that the pressure increase in the pump upstream passage is such that the saturating time until the pressure difference in the pump upstream passage reaches a saturated state in which the pressure difference at predetermined time intervals is less than a predetermined value. If it is longer than the predetermined determination time, it is determined that the passage on the upstream side of the pump is not clogged.
Evaporative fuel processing equipment featuring. In the evaporative fuel processing apparatus according to claim 2 or 3.
The predetermined determination speed or the predetermined determination time shall be specified according to the remaining amount of fuel in the fuel tank.
Evaporative fuel processing equipment featuring. In the evaporative fuel processing apparatus according to any one of claims 1 to 4.
The passage clogging determination unit drives the purge pump in a reverse rotation to apply a positive pressure to the passage on the upstream side of the pump.
Evaporative fuel processing equipment featuring. A vapor passage connected to a fuel tank, a canister for storing evaporated fuel sent from the fuel tank through the vapor passage, an intake passage connected to an internal combustion engine, a purge passage connected to the canister, and the purge passage. A purge pump provided in the canister, an air passage connected to the canister, and an air shutoff valve for opening and closing the air passage. In the evaporative fuel processing equipment that executes the purge control to introduce
It has a passage clogging determination unit for determining the presence or absence of clogging in the pump upstream passage including the vapor passage and the passage on the upstream side of the purge pump in the purge passage.
The passage clogging determination unit closes the atmosphere shutoff valve and drives the purge pump to the upstream passage of the pump while the internal combustion engine is stopped or the purge control is stopped. Based on the increase in pressure in the pump upstream passage when a positive pressure is applied, the presence or absence of clogging in the pump upstream passage is determined.
It has a switching valve that switches the passages to which the suction port and the discharge port of the purge pump are connected.
The passage clogging determination unit connects the suction port to the passage on the downstream side of the purge pump in the purge passage by the switching valve, while the discharge port is connected to the passage on the upstream side of the purge pump in the purge passage. By driving the purge pump in a forward rotation while connected to, a positive pressure is applied to the passage on the upstream side of the pump.
Evaporative fuel processing equipment featuring.

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