Canister for vehicle

Details Canister for vehicle Canister for vehicle

2001-07-17

2002-10-08

Miller, Carl S. (Department: 3747)

Internal-combustion engines

Charge forming device

Having fuel vapor recovery and storage system

C123S1980DA

Reexamination Certificate

active

06460516

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a canister for a vehicle, and more particularly to a canister serving as evaporated fuel adsorbing means used for treating evaporated fuel from a fuel system in an internal combustion engine mounted on a vehicle.
DESCRIPTION OF THE PRIOR ART
In conventional, in the vehicle, there has been employed an evaporated fuel treating apparatus for preventing evaporated fuel from a fuel system such as a fuel tank or the like from being discharged to an atmospheric air, and a structure shown in
FIG. 7
has been, for example, known as means for adsorbing and collecting the evaporated fuel.
A canister
101
shown in
FIG. 7
is structured such as to introduce an evaporated fuel generated within a fuel tank
103
from an introduction port
104
so as to flow through a first adsorbing material layer
105
constituted by adsorbent such as activated carbon or the like, a communicating chamber
106
, a second adsorbing material layer
107
and a third adsorbing material layer
108
, adsorb and collect the evaporated fuel to each of the adsorbing material layers
105
,
107
and
108
and discharge air from an atmospheric air port
110
through a chamber
109
at a time when an engine
102
stops, and, at a time when the engine
102
is operated, such as to apply a negative pressure generated in an intake manifold
111
to a purge port
112
of the canister
101
so as to purge the evaporated fuel adsorbed and collected to each of the adsorbing material layers
105
,
107
and
108
to the engine
102
from the purge port
112
. In the drawing, reference numeral
113
denotes a filter and reference numeral
114
denotes an air cleaner.
In the conventional canister, when the engine
102
stops, the evaporated fuel is adsorbed to each of the adsorbing material layers
105
,
107
and
108
in the canister
101
, however, an adsorbing state immediately after the engine stops corresponds to a state, as shown in
FIG. 8
, that concentration of adsorption is high in the first adsorbing material layer
105
, concentration of adsorption is middle in the second adsorbing material layer
107
and concentration of adsorption is low in the third adsorbing material layer
108
. In this case, in the first adsorbing material layer
105
and the second adsorbing material layer
107
in
FIG. 8
, the adsorbing material layer having high concentration is expressed by a narrowly hatched portion.
Then, since the evaporated fuel adsorbed to each of the adsorbing material layers
105
,
107
and
108
tends to uniformly diffuse to a whole together with passage of time after the engine stops, the concentration of the evaporated fuel within the third adsorbing material layer
108
becomes gradually higher as shown in
FIG. 9
, so that all of the adsorbing material layers
105
,
107
and
108
have the substantially uniform concentration. In
FIG. 9
, intervals between the hatched lines expressed within the respective adsorbing material layers
105
,
107
and
108
are set to the same interval, thereby showing a uniform concentration state. When the concentration of the third adsorbing material layer
108
becomes high as mentioned above, a little amount of evaporated fuel adsorbed to the third adsorbing material layer
108
may leak to the chamber
109
even if the adsorbing material layer
108
can yet adsorb some evaporated fuel, so that there is a risk that the evaporated fuel leaks to the atmospheric air through the atmospheric air port
110
and the canister dose not have an ability to adsorb and collect the sufficient evaporated fuel.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a canister for a vehicle which can further reduce a leakage of an evaporated fuel to an atmospheric air and can sufficiently adsorb and collect the evaporated fuel.
In order to solve the problem mentioned above, in accordance with the present invention, there is provided a canister for a vehicle comprising:
an introduction port for an evaporated fuel provided in a casing;
an atmospheric air port for the evaporated fuel provided in the casing; and
an adsorbing material layer communicating between the introduction port and the atmospheric air port,
wherein a chamber is provided between the atmospheric air port and a surface on a side of the atmospheric air port in the adsorbing material layer, and a leakage preventing adsorbing material layer is arranged within the chamber so that a space layer is formed between the leakage preventing adsorbing material layer and the surface on the side of the atmospheric air port in the adsorbing material layer and another space layer is formed between the leakage preventing adsorbing material layer and the atmospheric air port.
In accordance with the present invention, when the engine stops, the evaporated fuel generated from an evaporated fuel generating source is adsorbed and collected to the adsorbent in the adsorbing material layer within the canister from the introduction port. At this time, immediately after the engine stops, the closer to the introduction port a part in the adsorbing material layer within the canister is, the higher concentration of adsorption is. However, in correspondence to passage of time after the engine stops, the evaporated fuel diffuses to a whole of the adsorbing material layers within the canister and leaks out from the surface on the side of the atmospheric air port in the adsorbing material layer only at a little amount.
At this time, since the space layer is provided between the surface on the side of the atmospheric air port in the adsorbing material layer and the leakage preventing adsorbing material layer, the leakage of the evaporated fuel can be restricted by this space layer.
Further, it is possible to adsorb and collect and the evaporated fuel leaking within the space layer by providing the leakage preventing adsorbing material layer.
Accordingly, it is possible to significantly reduce an amount of the evaporated fuel within the adsorbing material layers which is discharged to the atmospheric air through the atmospheric air port.
Further, in accordance with the present invention, the leakage preventing adsorbing material layer may be formed by a filter including adsorbent to which an adsorbent is penetrated.
In accordance with this structure, since an amount of the evaporated fuel leaking from the surface on the side of the atmospheric air port in the adsorbing material layer is a little as mentioned above, an amount of the leakage preventing adsorbent required for adsorbing the leaking evaporated fuel can be reduced. Accordingly, as well as the function can be sufficiently achieved by the leakage preventing adsorbent penetrating into the filter in the manner mentioned above, the leakage preventing adsorbing material layer can be constituted only by placing the filter into which the leakage preventing adsorbent penetrates, so that a structure for assembling the leakage preventing adsorbent becomes simple and an operation for assembling becomes significantly easily performed.


REFERENCES:
patent: 4306894 (1981-12-01), Fukami et al.
patent: 5207808 (1993-05-01), Haruta et al.
patent: 5337721 (1994-08-01), Kasuya et al.
patent: 5564398 (1996-10-01), Maeda et al.
patent: 5647332 (1997-07-01), Hyodo et al.
patent: 5875765 (1999-03-01), Norton
patent: 61-97566 (1986-06-01), None
patent: 11-200963 (1999-07-01), None

Affiliated with

Also associated with

Rating

Canister for vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Canister for vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Canister for vehicle will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2942128