JP3131306B2 - Evaporative fuel treatment system for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel vapor treatment system for a vehicle.

[0002]

2. Description of the Related Art In an engine, an evaporative fuel processing device is provided in order to prevent the evaporative fuel generated in a fuel tank from being released to the atmosphere. Intake system (intake passage)
It has been done to introduce. Such an evaporative fuel processing apparatus generally communicates a fuel tank with a downstream side of a throttle valve of an intake passage through a purge passage as an evaporative fuel supply passage, and an atmosphere opening is formed in the purge passage. The canister and the purge valve are provided in order from the fuel tank side to the intake passage side, and the evaporated fuel generated in the fuel tank is temporarily adsorbed in the canister, and the
By opening the di-valve, the evaporated fuel in the canister is introduced into the intake passage while introducing outside air into the canister from the atmosphere opening using the intake negative pressure on the downstream side of the throttle valve. On the other hand, when fuel vapor having a capacity equal to or greater than the capacity of the canister 21 is introduced into the canister from the fuel tank, a part of the fuel vapor is released to the atmosphere via the atmosphere opening.

[0003] Incidentally, the canister in the above-mentioned evaporative fuel treatment apparatus has been generally arranged in an engine room, but recently, as shown in Japanese Utility Model Publication No. 46-35932, effective use of dead space has been proposed. In view of the above, the arrangement of the canister cannot be established in the engine room with the arrangement of the canister in the recess of the spare tire pan or the enhancement of the capacity of the canister (enlarging the canister). In addition, the canister is being arranged below the rear body or the like. For this reason, in such a case, the canister approaches the vehicle cabin below the engine room, and a new measure is required for the odor when the fuel vapor is released from the canister. I have. As a countermeasure, considering the merchantability of the vehicle, it is preferable that the air opening be extended downward so that the opening is as far away from the vehicle compartment as possible, thereby promoting the diffusion of odor.

[0004]

However, as described above, when the air opening is extended downward, the opening approaches the road surface, and dust, muddy water and the like pass through the air opening to the canister. There is a risk of intrusion into

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a vehicle equipped with a canister other than an engine room. It is another object of the present invention to provide a fuel vapor treatment device for a vehicle, which can prevent intrusion of muddy water into a canister through an atmospheric opening.

[0006]

In order to achieve the above object, according to the present invention (first invention), a fuel tank and an intake system are communicated via a canister, and an air opening is formed in the canister. In the fuel vapor treatment device for a vehicle provided, the air opening is branched into a first opening and a second opening located below the first opening, and the air opening is provided. A switching valve mechanism for selecting the first and second openings, wherein the switching valve mechanism is provided when the pressure in the atmospheric opening is lower than the atmospheric pressure on the canister side with respect to the switching valve mechanism. While the communication between the canister and the atmosphere is interrupted at the second opening, the communication between the canister and the atmosphere is performed through the first opening, and the pressure in the atmosphere opening is higher than that of the switching valve mechanism. Large on the canister side When it is on the pressure or is, first
The configuration is such that communication between the canister and the atmosphere is interrupted at the opening, while communication between the canister and the atmosphere is performed through the second opening.

With the above arrangement, the second opening is located below the first opening, the position of the second opening is lowered, and when a part of the fuel vapor is released into the atmosphere, The communication between the canister and the atmosphere is blocked at the first opening, while the second opening is used, so that the diffusion of the odor based on the fuel vapor is promoted. For this reason, penetration of the odor into the cabin can be suppressed. In addition, when the evaporated fuel is introduced into the intake system (intake passage) for combustion processing, when introducing outside air into the canister,
The first opening at a position higher than the second opening is used, while the second opening is closed by the switching valve mechanism,
Dust, muddy water and the like do not enter through the second opening. Therefore, it is possible to prevent dust, muddy water and the like from entering the canister.

In order to achieve the above object, according to the present invention (second invention), in the first aspect, the canister is provided between a rear fender and a wheel house. is there. According to the above configuration, even if the canister is arranged between the rear fender and the wheel house, the same operation as in the first invention is produced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes an intake passage connected to an engine (not shown). The intake passage 1 is provided with an air cleaner 2, a throttle valve 3 and the like in order from the upstream side. .

In the intake passage 1, as shown in FIG.
A fuel tank 4 is connected via a purge passage 5.
One end of the purge passage 5 is connected to the intake passage 1 on the downstream side of the throttle valve 3, and the other end of the purge passage 5 is connected to an upper portion of the fuel tank 4. The canister 6 and the purge valve 7 are provided in the gas passage 5 in order from the fuel tank 4 side to the intake passage 1 side. The canister 6 has a function of temporarily adsorbing the evaporated fuel generated in the fuel tank 4. In the present embodiment, the canister 6 is provided below the floor panel as shown in FIG. 8 is disposed on the front side of the vehicle body. The purge valve 7 is
By opening and closing the gas passage 5, the function of the intake negative pressure on the canister 6 is adjusted, and based on this, the function of adjusting the supply (purge) of the evaporated fuel to the air intake passage 1 is provided.

As shown in FIGS. 1 and 2, the canister 6 has an atmosphere opening passage 10 as an atmosphere opening. The open-to-atmosphere passage 10 includes a common passage 11, a first passage 12 as a first opening, and a second passage 13 as a second opening, and these are, as shown in FIG. It is arranged between the rear wheel house 8 and the rear fender 9. The common passage 11 has one end opened to the internal space of the canister 6 and the other end opened downward. The first and second passages 1
2 and 13 are branched at the other end of the common passage 11 so as to be continuous. The first passage 12 once extends in the lateral direction and then extends upward, and the distal end opening thereof is again oriented in the lateral direction. Second passage 13
Is extended downward, and the tip opening is
It is located at a position lower than the distal end opening of the passage 12.

A switching valve mechanism 14 is provided at a branch between the first passage 12 and the second passage 13 as shown in FIG. As shown in FIG. 3, the switching valve mechanism 14 includes a main body 15 and first and second on-off valves 1 disposed in the main body 15.
6 and 17. The main body 15 has an internal space 18, and connection ports 19, 20, 21 communicating with the internal space are provided in the upper part, the side part, and the lower part, respectively. The upper connection port 19 is connected to the other end of the common passage 11, the side connection port 20 is connected to the first passage 12, and the lower connection port 21 is connected to the second passage 13. The first on-off valve 16 is provided at the side connection port 20 and has a function of opening and closing the side connection port 20. The first on-off valve 16 is provided in the internal space 18 of the main body 15. The side connection port 20 is set to be opened only when the pressure is lower than the atmospheric pressure, and the side connection port 20 is closed when the pressure in the internal space 18 of the main body 15 is equal to or higher than the atmospheric pressure. It has become. The second on-off valve 17 is provided at the lower connection port 21 and has a function of opening and closing the lower connection port 21. The second on-off valve 17 is configured such that the pressure in the internal space 18 of the main body 15 is reduced. The lower connection port 21 is set to be opened only when the pressure becomes equal to or higher than the atmospheric pressure including the atmospheric pressure. When the pressure in the internal space 18 of the main body 15 is lower than the atmospheric pressure, the lower connection port 21 is set based on the negative pressure. The lower connection port 21 is closed. In FIG. 2, reference numeral 22 denotes a rear door, and 23 denotes a bumper.

[0013] In such an evaporated fuel processing apparatus,
When the vehicle is running, the purge valve 7 is opened in order to feed the evaporated fuel into the intake passage, and the intake negative pressure downstream of the throttle valve 3 passes through the canister 6 to the internal space 18 of the switching valve mechanism 14. This causes the second on-off valve 17 to close the lower connection port 21 and the first on-off valve 16 to close the side connection port 20 based on the intake negative pressure.
Open. For this reason, in the evaporated fuel processing device,
The evaporative fuel in the canister 6 is introduced into the intake passage 1 while introducing outside air (indicated by an arrow in FIG. 3) into the canister 6 through the switching valve mechanism 14 from the distal end opening of the first passage 12, During that time, the lower connection port 21 is closed, so that dust, muddy water and the like can be prevented from entering the canister 6 through the second passage 13.

On the other hand, when the vehicle is stopped, the purge valve 7 is closed, and when fuel vapor having a capacity equal to or greater than the capacity of the canister 6 is introduced from the fuel tank 4 into the interior of the canister 4, the fuel based on the fuel vapor is corrected. The pressure acts on the internal space 18 of the switching valve mechanism 14, and based on the positive pressure, the first on-off valve 16 closes the side connection port 20 and the second on-off valve 1
7 opens the lower connection port 21. As a result, a part of the evaporated fuel is released into the atmosphere only from the distal end opening of the second passage 13 far from the vehicle interior, and is not released from the distal end opening of the first passage 12. Will be promoted.

Therefore, even if the canister 6 is disposed between the rear wheel house 8 and the rear fender 9 as described above, that is, other than the engine room, the canister 6 is disposed on the engine room. In the same manner as in the case where
It is possible to prevent dust and muddy water from entering the canister 6.

Although the embodiments have been described above, the present invention includes the following. Canister 6 with rear wheel house 8 and rear fender 9
To be placed between As a result, the space between the rear wheel house 8 and the rear fender 9 can be effectively used. Open the purge valve 7 during idling and set the idle
That you can do it.

[0017]

As described above, according to the first and second aspects of the present invention, even if the canister is provided in a place other than the engine room, it is possible to suppress the intrusion of the odor based on the evaporative fuel released into the passenger compartment. , Dust and muddy water can be prevented from entering the canister through the air opening.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an evaporated fuel processing apparatus according to an embodiment.

FIG. 2 is a perspective view showing the arrangement of a canister and the like.

FIG. 3 is an explanatory diagram illustrating a switching valve mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake passage 4 Fuel tank 6 Canister 8 Rear wheel house 9 Rear fender 10 Open air passage 12 First passage 13 Second passage 14 Switching valve mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-134060 (JP, A) JP-A-63-162329 (JP, A) JP-A-63-105517 (JP, U) JP-A-63-105517 104657 (JP, U) JP-A 63-159326 (JP, U) JP-A 1-148050 (JP, U) JP-A 1-138813 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B60K 15/077 F02M 25/08 301

Claims (2)

(57) [Claims] 1. An evaporative fuel treatment system for a vehicle in which a fuel tank and an intake system communicate with each other via a canister, and wherein the canister has an atmosphere opening, wherein the atmosphere opening is a first opening; And a second opening located below the first opening.
The air opening is provided with a switching valve mechanism for selecting the first and second openings. The switching valve mechanism is configured such that the pressure in the air opening is higher than the atmospheric pressure on the canister side with respect to the switching valve mechanism. Low , the canister and the atmosphere at the second opening.
Communication with the key, and the key through the first opening.
The canister communicates with the atmosphere. When the pressure in the atmosphere opening becomes higher than the atmospheric pressure on the canister side with respect to the switching valve mechanism, the canister is opened at the first opening.
And while blocking communication with the atmosphere, through the second opening
Evaporative fuel processing apparatus for a vehicle according to claim set and it so as to communicate the said canister and the atmosphere. 2. The evaporative fuel treatment device for a vehicle according to claim 1, wherein the canister is disposed between a rear fender and a wheel house.