JP3826797B2 - Evaporative fuel processing device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel vapor processing apparatus for a vehicle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a vehicle such as an automobile is provided with a fuel supply system of an internal combustion engine mounted as a prime mover, for example, an evaporative fuel processing device that processes evaporative fuel generated in a fuel tank without releasing it into the atmosphere.
[0003]
The evaporative fuel processing apparatus includes a canister that adsorbs evaporative fuel generated in a fuel tank, an atmospheric passage that introduces air into the canister, and a purge passage that sends evaporative fuel in the canister together with the air to the intake system of the internal combustion engine. I have. Then, using the negative pressure generated in the intake system of the internal combustion engine during engine operation, air is introduced from the air inlet to the canister, and the evaporated fuel in the canister together with the air enters the intake system of the internal combustion engine through the purge passage. Sent out. The evaporated fuel sent to the intake system in this way is processed without being burned by the internal combustion engine and released into the atmosphere.
[0004]
The air inlet of the evaporative fuel processing device is provided in the cross member of the vehicle so as to prevent water and dust from entering as much as possible when evaporative fuel is processed as described above, for example, as disclosed in JP-A-11-062726. It is conceivable to provide it. However, since the cross member is close to the road surface and is susceptible to water and dust, and the interior of the cross member is not completely shut off from the outside, water and dust cannot enter from the air inlet. It cannot be completely prevented.
[0005]
For this reason, it has been considered to provide an air inlet in the fuel inlet box of the vehicle. The fuel inlet box is provided with a fuel filler opening for supplying fuel to the fuel tank, and is opened or closed by opening and closing the fuel lid. During normal times such as when the vehicle is running, the fuel lid is closed and the fuel inlet box is closed. At this time, since the air inlet is opened in a closed space in the box, the entry of water and dust into the air inlet is accurately suppressed. On the other hand, when fuel is supplied to the fuel tank, the fuel lid is opened, the fuel inlet box is opened, and fuel is supplied from the fuel supply port.
[0006]
[Problems to be solved by the invention]
By providing the air inlet in the fuel inlet box as described above, it is possible to accurately prevent water and dust from entering from the air inlet when the vehicle is running.
[0007]
However, when the inside of the fuel inlet box is washed with water at the time of car washing, the fuel lid is opened and the box is opened, and water for washing is applied to the air inlet. Since the air inlet is normally provided in the fuel inlet box at a position where it is difficult for water to be washed, water does not enter from the air inlet as long as the internal combustion engine is stopped and the above-described cleaning is performed. .
[0008]
However, if the car is washed while the internal combustion engine is in operation, the fuel vapor processing is performed while the fuel inlet box is being washed, and the negative pressure generated in the intake system at that time causes the intake air to enter the atmosphere inlet. It can also happen that the splashed water is sucked into the atmospheric passage along with the air. If the water sucked into the air passage in this way passes through the canister and the purge passage and enters the intake system of the internal combustion engine, it may lead to deterioration of the operating state or failure of the engine.
[0009]
In addition, if water is left in the air passage in a cold region or the like, the water freezes and blocks the air passage. In this state, if air is introduced into the canister using the negative pressure generated in the intake system of the internal combustion engine, air is sucked into the canister from the fuel tank side. There is a risk of deformation.
[0010]
The present invention has been made in view of such circumstances, and its object is to open the fuel lid and clean the inside of the fuel inlet box while the internal combustion engine is operated, and to introduce the air inlet in the box. Another object of the present invention is to provide an evaporative fuel treatment device for a vehicle that can prevent water from entering the atmosphere passageway.
[0011]
[Means for Solving the Problems]
In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, according to the first aspect of the present invention, the evaporated fuel generated in the fuel supply system of the internal combustion engine mounted on the vehicle is adsorbed to the canister, and the negative fuel generated in the intake system of the engine during engine operation. Using pressure, air is introduced into the canister through an air passage from an air inlet provided in the fuel inlet box of the vehicle, and the evaporated fuel in the canister is supplied together with the air to the intake system through a purge passage. In the evaporative fuel processing apparatus for the vehicle to be sent out, when the open state of the fuel lid for opening / closing the fuel inlet box is detected, and when the open state of the fuel lid is detected by the detection means, And prohibiting means for prohibiting the introduction of air.
[0012]
According to the above configuration, when the fuel lid is opened and the inside of the fuel inlet box is cleaned while the internal combustion engine is in operation, the introduction of air from the atmosphere introduction port is prohibited because the fuel lid is open, and the introduction of the air is prohibited. As a result, water can be prevented from entering through the air inlet.
[0013]
The invention according to claim 2 is the gist of the invention according to claim 1, wherein the prohibiting means is configured to block at least one of the purge passage and the atmospheric passage.
[0014]
According to the above configuration, by introducing at least one of the purge passage and the atmosphere passage into a blocked state, the introduction of air from the atmosphere introduction port is prohibited, and water enters the atmosphere passage as the air is introduced. Can be accurately suppressed. Even if water enters the atmospheric passage, at least one of the purge passage and the atmospheric passage is shut off as described above, so that the internal combustion engine is caused by the negative pressure generated in the intake system during engine operation. It is possible to accurately prevent water from entering the intake system.
[0015]
According to a third aspect of the invention, in the first or second aspect of the invention, the prohibiting means does not execute the prohibition of introducing air from the air inlet when the vehicle is running.
[0016]
Since the fuel lid is not opened for cleaning when the vehicle is running, water does not enter the atmosphere passage together with the air introduced from the atmosphere introduction port. Therefore, according to the above configuration, it is possible to avoid unnecessary prohibition of the introduction of air from the atmosphere introduction port by the prohibiting unit.
[0017]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the internal combustion engine is in a stopped state, the prohibiting means does not prohibit the introduction of air from the air inlet. It was.
[0018]
Since no negative pressure is generated in the intake system when the internal combustion engine is in a stopped state, air is not introduced from the air inlet using the negative pressure, and water is introduced into the air passage as the air is introduced. There is no entry. Therefore, according to the above configuration, it is possible to avoid unnecessary prohibition of the introduction of air from the atmosphere introduction port by the prohibiting unit.
[0019]
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, air in the fuel tank is fed into the canister when fuel is supplied to a fuel tank of a vehicle, and the atmospheric passage is provided. Released the air from the canister to the outside.
[0020]
As the fuel is supplied to the fuel tank, the air in the tank is normally pushed out to the canister, where the evaporated fuel is removed and then discharged to the outside through the atmospheric passage. At this time, if the water that has entered the atmosphere passage is frozen and the passage is blocked, the air in the fuel tank will not be released to the outside, and the fuel will not enter quickly even if it tries to refuel the fuel tank. . However, it is possible to suppress the occurrence of the above problems by suppressing water from entering the atmospheric passage.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in an evaporative fuel processing apparatus for an automobile will be described with reference to FIGS. 1 and 2.
[0022]
As shown in FIG. 1, in an engine 1 mounted on an automobile, fuel in a fuel tank 2 is sent out to a fuel injection valve 4 by a fuel pump 3 and then injected into an intake passage 5.
[0023]
The fuel tank 2 is connected to a fuel supply passage 7 extending to a fuel inlet box 6 provided in the vehicle body of the automobile. The fuel inlet box 6 is opened and closed by opening and closing the fuel lid 6a. An opening portion of the fuel supply passage 7 located in the fuel inlet box 6 serves as a fuel supply port 7 a for supplying fuel into the fuel tank 2.
[0024]
Further, the automobile is provided with an evaporative fuel processing device that processes evaporative fuel generated in the fuel supply system of the engine 1 such as the fuel tank 2. This apparatus includes a canister 8 provided with an adsorbent for adsorbing evaporated fuel. The canister 8 includes a vapor passage 9 for introducing the evaporated fuel generated in the fuel tank 2 into the canister 8, an atmospheric passage 10 for introducing air into the canister 8, and a throttle in the intake passage 5 with the evaporated fuel in the canister 8 together with air. A purge passage 12 is connected to the downstream side of the valve 11.
[0025]
The atmospheric passage 10 extends to the fuel inlet box 6. An opening portion of the air passage 10 located in the fuel inlet box 6 serves as an air introduction port 10 a that opens to the inside of a cylindrical cover 15 provided so as to surround the oil supply passage 7. The cover 15 is provided with a plurality of slits (not shown) that connect the inside and the outside. The air in the fuel inlet box 6 enters the inside of the cover 15 through these slits, and further flows into the atmosphere passage 10 from the atmosphere introduction port 10a.
[0026]
The evaporated fuel generated in the fuel tank 2 passes through the vapor passage 9 and is once adsorbed by the adsorbent in the canister 8. In this state, air is introduced into the canister 8 through the atmospheric passage 10 by the action of negative pressure generated downstream of the throttle valve 11 in the intake passage 5 during engine operation. The vaporized fuel in the canister 8 together with the air is sent to the intake passage 5 as purge gas through the purge passage 12 due to the negative pressure, and is combusted and processed in the engine 1.
[0027]
A purge control valve 14 that is opened and closed to adjust the flow rate of the purge gas is provided in the middle of the purge passage 12. A canister shut-off valve 13 is provided in the middle of the air passage 10 to communicate and block the passage 10 when diagnosing an abnormality such as leakage in the canister 8. The canister cutoff valve 13 and the purge control valve 14 are driven and controlled by an electronic control device 16 mounted on the automobile. The electronic control device 16 includes detection from various sensors such as an open / close sensor 17 that detects the open / close state of the fuel lid 6a, a rotational speed sensor 18 that detects the rotational speed of the engine 1, and a vehicle speed sensor 19 that detects the vehicle speed of the automobile. A signal is input.
[0028]
The electronic control device 16 controls the purge control valve 14 to send an appropriate amount of purge gas to the intake passage 5 when the engine is in an engine operating state in which purge gas can be sent to the intake passage 5. Further, at the time of the abnormality diagnosis, for example, the canister cutoff valve 13 is closed and the purge control valve 14 is opened during engine operation, and a negative pressure is generated in the canister 8. Thereafter, the purge control valve 14 is closed, and the abnormality diagnosis is performed based on the change in the internal pressure of the canister 8 until a predetermined time elapses from that point.
[0029]
Further, when fuel is supplied to the fuel tank 2, the electronic control unit 16 keeps the canister shut-off valve 13 open. If the canister shut-off valve 13 is opened in this way, the air present in the fuel tank 2 is pushed out to the canister 8 through the vapor passage 9 during refueling, and after the evaporated fuel is removed there, the air is sent through the atmospheric passage 10 to the atmosphere. It is discharged to the outside from the introduction port 10a. As described above, by releasing the air in the fuel tank 2 to the outside during refueling, fuel can be quickly supplied to the fuel tank 2.
[0030]
By the way, since the air introduction port 10a of the air passage 10 in the evaporative fuel processing apparatus is provided in a closed space in the fuel inlet box 6 of the automobile, the air introduction port is used when a normal automobile is running. The entry of water and dust from 10a is accurately suppressed. However, when the inside of the fuel inlet box 6 is washed by opening the fuel lid 6a at the time of washing the car, water flows into the box 6. Therefore, the air introduction port 10a is opened inside the cover 15, and the water is prevented from entering the air passage 10 from the air introduction port 10a.
[0031]
However, if the car is washed while the engine 1 is in operation, the process of the evaporated fuel is performed when the inside of the fuel inlet box 6 is washed, and the air inlet port is caused by the negative pressure generated in the intake passage 5 at that time. It may also occur that water applied to 10a is sucked into the air passage 10 together with air. As described above, when the water sucked into the atmospheric passage 10 passes through the canister 8 and the purge passage 12 and enters the intake passage 5, it leads to deterioration of the operating state of the engine 1 or failure.
[0032]
Further, if water is left in the atmosphere passage 10 in a cold region or the like, the water freezes and closes the atmosphere passage 10. When the engine 1 is operated in this state, when the air in the canister 8 and the evaporated fuel are sucked using the negative pressure generated in the intake passage 5, air is sucked into the canister 8 from the fuel tank 2 side. There is a possibility that the fuel tank 2 is deformed by the negative pressure generated inside. Further, when the water is frozen in the atmospheric passage 10 as described above, the air in the fuel tank 2 is not released to the outside through the canister 8 and the atmospheric passage 10, so that fuel is supplied to the fuel tank 2. When trying to do so, the same refueling cannot be performed quickly.
[0033]
As described above, when water enters the atmosphere passage 10 from the atmosphere introduction port 10a, the above-described various problems occur. Therefore, in the present embodiment, in order to prevent water from entering the atmosphere passage 10, the introduction of air from the atmosphere introduction port 10a is prohibited by the procedure according to the flowchart of FIG. 2 showing the atmosphere introduction prohibition routine, as described above. Suppresses the occurrence of troubles.
[0034]
The air introduction prohibition routine is executed through the electronic control device 16 by, for example, a time interruption every predetermined time. In this atmospheric introduction prohibition routine, it is determined whether or not to prohibit the introduction of air from the atmospheric introduction port 10a according to the result of the determination shown below.
[0035]
Whether or not the automobile is stopped, that is, whether or not the vehicle speed obtained based on the detection signal from the vehicle speed sensor 19 is, for example, “0” (S101)
Whether or not the engine is in operation, that is, whether or not the engine rotation speed obtained based on the detection signal from the rotation speed sensor 18 is a predetermined value or more (S102)
Whether or not the fuel lid 6a is open, that is, whether or not the signal from the open / close sensor 17 corresponds to when the fuel lid 6a is open (S103)
Here, when the vehicle is running (S101: NO), the fuel lid 6a is not opened and the fuel inlet box 6 is not cleaned, and water does not enter the air inlet 10a.
[0036]
Further, when the engine 1 is in a stopped state (S102: NO), no negative pressure is generated in the intake passage 5, and the negative pressure acts on the canister 8 and the atmospheric passage 10 (atmospheric inlet 10a). The air around the air inlet 10a is not sucked into the air passage 10 together with water.
[0037]
Furthermore, when the fuel lid 6a is closed (S103: NO), water does not easily enter the fuel inlet box 6, and therefore the water does not enter the air inlet 10a.
[0038]
Accordingly, when a negative determination is made in any one of the above steps S101 to S103, the possibility that water enters the atmospheric passage 10 from the atmospheric introduction port 10a is extremely low, and therefore air introduction from the atmospheric introduction port 10a is not performed. There is no ban. Therefore, if the engine 1 is operated in this case, the evaporated fuel is processed as usual.
[0039]
On the other hand, when all of the above steps S101 to S103 are affirmative, since there is a high possibility that water will enter from the atmosphere introduction port 10a, the introduction of air from the atmosphere introduction port 10a is prohibited and accompanying the introduction of the atmosphere. Ingress of water from the air inlet 10a is suppressed. For example, the prohibition of introducing air from the atmosphere introduction port 10a is realized by closing the purge control valve 14 so that the negative pressure generated in the intake passage 5 does not act on the canister 8 and the atmosphere passage 10 side.
[0040]
According to the embodiment described in detail above, the following effects can be obtained.
(1) When the fuel lid 6a is open and the fuel inlet box 6 is open, the purge control valve 14 is closed, and the introduction of air from the atmosphere introduction port 10a using the negative pressure of the intake passage 5 is prohibited. Therefore, when the fuel lid 6a is opened and the inside of the fuel inlet box 6 is cleaned while the engine 1 is in operation, it is possible to prevent water from entering the atmosphere passage 10 as air is introduced into the atmosphere introduction port 10a. it can. Therefore, it is possible to suppress the water that has entered the atmospheric passage 10 from passing through the canister 8 and the purge passage 12 and into the intake passage 5 of the engine 1 to deteriorate the operating state of the engine 1. Even if water enters the atmospheric passage 10, the purge control valve 14 is closed as described above, so that the water is prevented from entering the intake passage 5 from the purge passage 12. be able to.
[0041]
(2) If the air is left in the atmosphere passage 10 in a cold region or the like, the water freezes and blocks the atmosphere passage 10. In this case, when fuel is supplied to the fuel tank 2, the air in the fuel tank 2 cannot be released to the outside through the vapor passage 9, the canister 8, and the atmospheric passage 10. Therefore, even if it is going to supply fuel to the fuel tank 2, the fuel will not enter quickly. Further, when air is introduced into the canister 8 using the negative pressure of the intake passage 5 in a state where the air passage 10 is blocked as described above, air is sucked into the canister 8 from the fuel tank 2 side. Therefore, the fuel tank 2 may be deformed by the negative pressure generated inside. As described above, various troubles occur when water enters the atmospheric passage 10, but since the entry of water into the atmospheric passage 10 at the time of car washing is suppressed, the occurrence of the above-described problems can be suppressed. become.
[0042]
(3) When the automobile is running, the fuel lid 6a is not opened and the fuel inlet box 6 is not cleaned, and water does not enter the air inlet 10a. Therefore, by prohibiting the introduction of air from the air inlet 10a when the automobile is running, it is possible to avoid the prohibition from being performed wastefully.
[0043]
(4) When the engine 1 is in a stopped state, no negative pressure is generated in the intake passage, and water does not enter the atmospheric passage 10 with the introduction of air from the atmospheric introduction port 10a using the negative pressure. . Therefore, when the engine 1 is stopped, by prohibiting the introduction of air from the air inlet 10a, the prohibition can be avoided.
[0044]
In addition, the said embodiment can also be changed as follows, for example.
Although the introduction of the atmosphere from the atmosphere introduction port 10a is realized by closing the purge control valve 14, it may be realized by closing the canister shut-off valve 13 instead. In this case, it is preferable to provide a shut-off valve that shuts off the vapor passage 9 so that the pressure in the fuel tank 2 does not decrease excessively when the canister shut-off valve 13 is closed as described above. Further, the prohibition of introduction of the atmosphere from the atmosphere introduction port 10a may be realized by closing both the purge control valve 14 and the canister cutoff valve 13.
[0045]
The conditions for prohibiting the introduction of air from the air inlet 10a do not necessarily include the conditions that the automobile is stopped (S101) and the engine 1 is operating (S102).
[0046]
In addition to using the atmospheric passage 10 as a passage for introducing air into the canister 8, the air passage 10 is also used as a passage for releasing the air in the fuel tank 2 to the outside, but the present invention is not limited to this. That is, a passage for releasing the air in the fuel tank 2 to the outside may be provided separately from the atmospheric passage 10, and the atmospheric passage 10 may be used only for introducing air into the canister 8.
[0047]
Whether or not the engine 1 is in operation is determined based on the engine rotation speed, but may be determined based on on / off of an ignition switch of the automobile instead.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the configuration of an evaporative fuel processing apparatus in the present embodiment. FIG. 2 is a flowchart showing a procedure for prohibiting the introduction of air from an air inlet.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Fuel tank, 3 ... Fuel pump, 4 ... Fuel injection valve, 5 ... Intake passage, 6 ... Fuel inlet box, 6a ... Fuel lid, 7 ... Fuel supply passage, 7a ... Fuel supply port, 8 ... Canister, 9 DESCRIPTION OF SYMBOLS: Vapor passage, 10 ... Atmospheric passage, 10a ... Atmospheric introduction port, 11 ... Throttle valve, 12 ... Purge passage, 13 ... Canister shut-off valve, 14 ... Purge control valve, 15 ... Cover, 16 ... Electronic control device, 17 ... Open / close Sensor, 18 ... rotational speed sensor, 19 ... vehicle speed sensor.

Claims (5)

The fuel vapor generated in the fuel supply system of the internal combustion engine mounted on the vehicle is adsorbed by the canister, and the negative pressure generated in the intake system of the engine during engine operation is used in the fuel inlet box of the vehicle. In an evaporative fuel processing apparatus for a vehicle that introduces air into the canister from an atmospheric inlet through an atmospheric passage, and sends the evaporated fuel in the canister together with the air to the intake system through a purge passage.
Detecting means for detecting an open / closed state of the fuel lid for opening / closing the fuel inlet box;
A prohibiting means for prohibiting the introduction of air from the atmosphere inlet when the detection means detects an open state of the fuel lid;
An evaporative fuel processing device for a vehicle, comprising: The evaporated fuel processing apparatus for a vehicle according to claim 1, wherein the prohibiting unit shuts off at least one of the purge passage and the atmospheric passage. The evaporative fuel processing device for a vehicle according to claim 1, wherein the prohibiting unit does not execute prohibition of introducing air from the air inlet when the vehicle is running. The evaporative fuel processing apparatus for a vehicle according to any one of claims 1 to 3, wherein the prohibiting means does not execute prohibition of introducing air from the atmosphere inlet when the internal combustion engine is in a stopped state. 5. The canister is supplied with air in the fuel tank when fuel is supplied to a fuel tank of a vehicle, and the atmospheric passage discharges the air from the canister to the outside. An evaporative fuel processing apparatus for a vehicle according to claim 1.

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