JP2003184662A - Evaporative fuel discharge control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent vapor from being emitted into the air through between tank shells of a multiple-layer fuel tank. <P>SOLUTION: In a state of no engine purge (during parking), if internal pressure of a fuel tank 10 is increased, vapor generated in the fuel tank 10 is relieved at a certain pressure or more and flows into a canister 26. Meanwhile, vapor, which flows into an air releasing part 40A of an air releasing line 40 formed near an oil feeing opening 10A of the fuel tank 10 from the canister 26 through the air releasing line 40 consisting of an air intake/exhaust line 30, a tank shell space 22, and pipe space 24, is adsorbed and held in a trap canister 50 placed in the air releasing part 40A of the air releasing line 40. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporative emission control device, and more particularly to an evaporative emission control device mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, in a fuel vapor emission control device installed in a vehicle such as an automobile, vaporized fuel (vapor) is collected in the middle of a line (communicating passage) connecting an intake line of an engine and a fuel tank. Some have a canister (evaporative fuel collecting device) that performs (adsorption and holding), one example of which is JP-A-2
No. 001-130272.

As shown in FIG. 5, in this fuel vapor emission suppressing device, the negative pressure of the intake system in the engine, specifically, the surge tank 1 communicating with the air cleaner 100 is used.
When the internal pressure of the canister 104 becomes negative due to the negative pressure in 02, the high temperature air in the inter-tank shell space 110 between the inner tank shell 106 and the outer tank shell 108 in the fuel tank 105 enters the outer tank shell 108. The formed exhaust port 112 flows into the canister 104. On the other hand, in the space 110 between the tank shells, which has a negative pressure,
Air having a low temperature is introduced from the inside of the air cleaner 100 or the vehicle interior 114 into the intake port 11 formed in the outer tank shell 108.
It is designed to flow through 6.

[0004]

However, in this evaporative emission control device, the vapor generated in the fuel tank 105 enters the tank shell-to-shell space 110 via the canister 104, and enters from the tank shell-to-shell space 110. May be released into the atmosphere.

In view of the above facts, it is an object of the present invention to provide an evaporated fuel emission control device capable of suppressing vapor release into the atmosphere through the tank shells of a multi-layer fuel tank.

[0006]

The present invention according to claim 1 has a fuel tank having a multi-layer structure, and an atmosphere opening line for opening the canister to the atmosphere through the tank shells of the fuel tank. In the evaporated fuel emission control device, vapor trap means is provided in the atmosphere opening portion of the atmosphere opening line.

Therefore, the vapor generated in the fuel tank flows from the canister to the atmosphere opening part of the atmosphere opening line through the atmosphere opening line passing through the tank shells of the fuel tank, but is provided in the atmosphere opening part of the atmosphere opening line. It is adsorbed and held by the vapor trap means. As a result, it is possible to suppress the release of vapor to the atmosphere through the tank shells of the multi-layer fuel tank.

According to a second aspect of the present invention, in the evaporative emission control device according to the first aspect, the atmosphere opening line reaches the vicinity of a fuel filler port of the fuel tank, and the atmosphere releasing portion is connected to the fuel filler port. It is characterized in that it is formed in the vicinity.

Therefore, in addition to the contents of the first aspect, the vapor generated in the fuel tank passes from the canister through the tank shell of the fuel tank to the atmosphere opening line reaching the vicinity of the fuel filler port of the fuel tank, It flows to the atmosphere opening part of the atmosphere opening line formed near the fuel filler port of the fuel tank,
It is adsorbed and held by the vapor trap means provided in the atmosphere opening portion of the atmosphere opening line. As a result, it is possible to prevent vapor from being released into the atmosphere from the atmosphere opening portion formed near the fuel filler opening.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an evaporated fuel emission suppressing device according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, in this embodiment, the fuel tank 10 includes an outer tank shell 12 and an inner tank shell 14.
And a double-walled resin fuel tank having a double-walled structure, and a double-walled resin inlet pipe (fuel filling pipe) having an outer pipe 16 and an inner pipe 18 on the side wall of the fuel tank 10. 20 are provided.

The outer tank shell 12 of the fuel tank 10
The inter-tank shell space 22 between the inner tank shell 14 and the inner tank shell 14, and the outer pipe 16 and the inner pipe 1 in the inlet pipe 20.
The space 24 between the pipes 8 and 8 communicates with each other.

The space 22 between the tank shells of the fuel tank 10 and the air intake / exhaust port 28 of the canister 26 are connected by an air intake / exhaust line 30, and a connecting portion 30A of the air intake / exhaust line 30 in the fuel tank 10 is connected.
And the connecting portion 20A of the inlet pipe 20 in the fuel tank 10 are connected to the farthest position in the tank shell space 22.

A float valve (cutoff valve) 32 for full tank detection and a float valve 34 for rollover are arranged in the fuel tank 10. The float valves 32, 34 are connected to the canister 26. A vapor line 36 (also called an evaporation line) is connected to the vapor line 36.

Air intake / exhaust line 30, space between tank shells 2
2 and the space between pipes 24 constitute an atmosphere opening line 40 for opening the canister 26 to the atmosphere, and the atmosphere opening portion 40A of this atmosphere opening line 40 is a space between the pipes 24.
Is formed near the opening side end, that is, in the vicinity of the fuel filler port 10A of the fuel tank 10.

As shown in FIG. 2, a ring-shaped lid 42 for closing the end portion of the inter-pipe space 24 is provided at the opening end portion 20A of the inlet pipe 20 which serves as a fuel filling port of the fuel tank. The lid 42 is formed with a round hole-shaped atmosphere opening portion 40A. A fuel cap 44 is detachably attached to the opening 18A of the inner pipe 18.

As shown in FIG. 1, the inlet pipe 2
A trap canister 5 as a vapor trap means is provided in the tip end portion 24A of the inter-pipe space 24, which is the mouth of 0.
0 is filled. An air filter 52 is filled in the entire space between the tank shell space 22 and the other portion 24B of the space 24 between pipes except the tip portion 24A.

The canister 26 has a purge line 54.
Is connected to a surge tank that communicates with an engine air cleaner, and a sub tank 60 is provided inside the fuel tank 10. A fuel pump 62 is arranged inside the sub tank 60, and a fuel supply pipe 64 leading to an injector of the engine is connected to the fuel pump 62.

Next, the operation of this embodiment will be described.

In the present embodiment, the vapor that has permeated from the inner tank shell 14 of the fuel tank 10 and the inner pipe 18 of the inlet pipe 20 passes through the atmosphere open line 40 by the engine purge, is adsorbed and held by the canister 26, and then from the canister 26. It is sent to the engine and processed.

As a result, the amount of vapor that permeates the outer tank shell 12 of the fuel tank 10 and the outer pipe 16 of the inlet pipe 20 can be reduced. In addition, the outer tank shell 12, the inner tank shell 14, and the inlet pipe 20 of the fuel tank 10.
Since the permeation performance of the inner pipe 14 and the outer pipe 16 can be reduced, cost reduction and weight reduction can be achieved.

Further, in the present embodiment, when the internal pressure of the fuel tank 10 rises in a state where the engine is not purged (during parking), the vapor generated in the fuel tank 10 is relieved at a certain pressure or more and is relieved in the canister 26. The air flows from the canister 26 through the atmosphere intake / exhaust line 30, the tank shell space 22, and the pipe space 24 to the atmosphere release line 40, and the atmosphere release portion of the atmosphere release line 40 formed near the fuel filler port 10A of the fuel tank 10. Although it flows to 40 A, it is adsorbed and held by the trap canister 50 provided in the atmosphere opening portion 40 A of the atmosphere opening line 40.

As a result, in this embodiment, the fuel tank 1
It is possible to suppress the release of vapor to the atmosphere from the atmosphere opening portion 40A formed near the fuel filler opening 10A through the space 22 between the tank shells of 0.

The vapor adsorbed and held by the trap canister 50 is adsorbed and held by the canister 26 through the atmosphere open line 40 by engine purging, and is sent from the canister 26 to the engine for processing.

Further, in this embodiment, the connecting portion 30A of the air intake / exhaust line 30 in the fuel tank 10 and the connecting portion 20A of the inlet pipe 20 in the fuel tank 10 are connected.
Are connected to the most distant position in the space 22 between the tank shells, so that the space 22 between the tank shells and the space 24 between the pipes
The vapor with the inside can be effectively collected in the canister 26.

Further, in this embodiment, the space 24 between the pipes is
Since the air filter 52 is filled in the entire region 24B other than the tip end portion 24A and the space 22 between the tank shells, the space between the pipe from the atmosphere opening portion 40A formed near the fuel filler port 10A by the air filter 52. 24 and the dust between the tank shell space 22 and water enter the canister 26.
You can suppress entering. Further, in order to fill the space 24 between pipes and the space 22 between tank shells with the air filter 52,
Compared with the case where the air filter 52 is arranged at another portion outside the space 24 between the pipes and the space 22 between the tank shells,
Space efficiency can be achieved, and since it is not necessary to set a mounting bracket or the like, weight and cost can be reduced.

Further, in this embodiment, the air filter 52 is used.
By using a material having a heat insulating property and a shock absorbing property in addition to the air filter performance, for example, a urethane foam material as the material of the, the temperature change in the fuel tank 10 can be suppressed and the impact at the time of a vehicle collision can be suppressed. Can also be absorbed. As a result,
The amount of vapor generated can be suppressed, fire resistance can be improved, and impact resistance can be improved.

In the above, the present invention has been described in detail with respect to specific embodiments, but the present invention is not limited to such embodiments, and various other embodiments within the scope of the present invention. It is obvious to a person skilled in the art that For example, in the above embodiment, the air filter 52
Was filled into the entire space of the space 22 between the tank shells and the other portion 24B in the space 24 between pipes except the tip portion 24A, but the filling position of the air filter 52 is not limited to this region, and the inside of the atmosphere open line 40 is filled. Other parts may be used. For example, as shown in FIG. 3, an air filter 52 may be filled between the lid 42 and the trap canister 50 in the inter-pipe space 24. In this case, the air filter 52 can also prevent dust, water, etc., which have entered the inter-pipe space 24 from the atmosphere opening portion 40A formed near the fuel supply port 10A, from entering the trap canister 50.

Further, in this embodiment, the fuel tank 10 is a resin fuel tank having a double wall structure composed of the outer tank shell 12 and the inner tank shell 14, and the inlet pipe 20 is also composed of the outer pipe 16 and the inner pipe 18. However, instead of this, the fuel tank 10 is replaced only by the outer tank shell 12 as shown in FIG.
A resin fuel tank having a double-walled structure including the inner tank shell 14 and the inner tank shell 14 may be used. In this case, the connecting portion 30A of the air intake / exhaust line 30 in the fuel tank 10,
The atmosphere opening part 40A of the atmosphere opening line 40 is set at the position of the outermost tank shell 12 at the farthest position, and the trap canister 50 is arranged at the part of the tank shell space 22 surrounding the atmosphere opening part 40A.

Further, in the present embodiment, the fuel tank 10 has the double wall structure composed of the outer tank shell 12 and the inner tank shell 14. However, the structure of the fuel tank 10 is not limited to this, and for example, a triple tank structure Other multilayer structures such as a structure may be used.

[0031]

According to the first aspect of the present invention, there is provided a fuel tank having a multi-layer structure, and an evaporative emission control device having an atmosphere opening line for opening the canister to the atmosphere through the tank shells of the fuel tank. In the above, since the vapor trap means is provided in the atmosphere opening portion of the atmosphere opening line, it has an excellent effect that it is possible to suppress the release of vapor to the atmosphere through the space between the tank shells of the multilayer fuel tank.

According to a second aspect of the present invention, in the evaporative emission control device according to the first aspect, the atmosphere opening line reaches the vicinity of the fuel filler port of the fuel tank, and the atmosphere releasing portion is formed near the fuel filler port. In addition to the effect of claim 1,
It has an excellent effect that vapor can be suppressed from being released to the atmosphere from the atmosphere opening portion formed in the vicinity of the fuel filler port.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an evaporated fuel emission suppressing device according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing the vicinity of the fuel tank filler port of the evaporated fuel emission control device according to the embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing an evaporated fuel emission suppressing device according to another embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view showing an evaporated fuel emission suppressing device according to another embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view showing a conventional evaporated fuel emission suppressing device.

[Explanation of symbols]

10 Fuel tank 10A Fuel tank filler port 12 outer tank shell 14 Inner tank shell 16 Outer pipe 18 Inner pipe 20 inlet pipe 20A inlet pipe open end 22 Space between tank shells 24 Space between pipes 26 canister 28 Canister air intake and exhaust 30 Air intake / exhaust line 36 Vapor Line 40 atmosphere release line 40A Open to the atmosphere 50 Trap canister (vapor trap means) 52 Air filter

Claims (2)

[Claims] 1. An evaporative emission control device, comprising: a fuel tank having a multi-layer structure; and an atmosphere release line that opens the canister to the atmosphere through the tank shells of the fuel tank. An evaporative emission control device, characterized in that a vapor trap means is provided at the opening. 2. The evaporative emission control device according to claim 1, wherein the atmosphere opening line reaches the vicinity of the fuel filler opening of the fuel tank, and the atmosphere opening part is formed near the fuel filler opening. .