Canister

Details Canister Canister

2001-05-09

2003-02-25

Smith, Duane S. (Department: 1724)

Gas separation: apparatus

Solid sorbent apparatus

Plural solid sorbent beds

C096S135000, C096S139000, C096S143000, C096S152000, C123S519000

Reexamination Certificate

active

06524374

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to a canister located in an evaporated fuel processing device.
RELATED ART
Conventionally, as a canister which is located in an evaporated fuel processing device for preventing evaporated fuel (vapor) in a fuel tank on an automobile from leaking into the atmosphere, there has been proposed a canister of such a type that copes with an ORVR (Onboard Refueling Vapor Recovery) regulation, in which a plate is arranged in a absorbent charging chamber of the canister, and a constriction passage is formed in the plate in order to trap and process vapor in the fuel tank, in particular during refueling, without the vapor leaking into the atmosphere. This canister is disclosed in, for example, JP-A-06-249088 and JP-A-08-189428.
In such an ORVR regulation type canister, a conventional structure of the canister in which the above-mentioned plate is vertically arranged is shown in
FIGS. 4
to
6
.
The canister
1
shown in
FIGS. 4
to
6
, is composed of a main chamber
3
in which absorbent
2
including active carbon is charged, and a subchamber
4
in which the absorbent
2
is charged, and further, the subchamber
4
is partitioned into a first subchamber
4
a
and a second subchamber
4
b
by a plate
5
having constriction passages. The main chamber
3
and the first subchamber
4
a
are communicated with each other through a diffusion chamber
6
.
The main chamber
3
and the subchamber
4
are arranged in a horizontal direction, and the plate
5
is arranged in a vertical direction.
A vapor introduction port
7
for sucking vapor (gasoline vapor) generated in a fuel tank during refueling, and a purge port
8
communicated with an air intake part of an engine are provided to the main chamber
3
on the side remote from the diffusion chamber
6
. Further, there are shown absorbent holding filters
9
,
10
, an absorbent holding plate
11
, and an absorbent holding spring
12
.
An absorbent holding filter
13
, an absorbent holding plate
14
and an absorbent holding spring
15
are provided in the first subchamber
4
a
on the diffusion chamber
6
side.
An atmospheric port
16
opened to the atmosphere is provided to the second subchamber
4
b
on the side remote from the plate
5
. Reference
17
in the figures denotes an absorbent holding filter
17
.
Several filter support pins
18
are projected from opposite surfaces of the plate
5
, as arranged in FIG.
6
. Filters
19
,
20
for the plate are arranged at tip end faces of the filter support pins
18
on both surfaces of the plate, and the absorbent
2
is held by these filters
19
,
20
while communication passages
21
,
22
are defined between adjacent filter support pins
18
. A constriction passage
23
which is a circular through-hole as shown in
FIGS. 5 and 6
is formed in the plate
5
, being located in its center upper part.
With this arrangement, at a time other than refueling, during resting of an engine, when liquid fuel in the fuel tank is evaporated so that the internal pressure becomes higher than a predetermined value, vapor in the fuel tank is introduced through the vapor introduction port
7
into the main chamber
3
in the canister
1
, and the fuel component thereof is trapped by the absorbent
2
. Then, the vapor has been introduced into the first subchamber
4
a
from the diffusion chamber
6
and a fuel component which has not yet trapped in the main chamber
3
is absorbed by the absorbent
2
in the first subchamber
4
a.
Further, the vapor passes through the filter
19
and ascends flowing through the communication passages
21
between the filter support pins
18
and between the plate
5
and the filter
19
, and thereafter, passes through the constriction passage
23
. Further, the vapor passes through the communication passages
22
and the filter
20
, and enters into the second subchamber
4
b
in which a fuel component is trapped by the absorbent
2
in the second subchamber
4
b.
The vapor which is purified, substantially similar to the air after the fuel component is trapped, passes through the filter
17
, and is vented into the atmosphere from the atmospheric port
16
.
In such a case that is other than refueling, since the constriction passage
23
is formed at a position in the upper part of the plate
5
, the vapor comes up from the lower side to the upper side as indicated by the arrows shown in
FIG. 6
, and the stream of the vapor is restrained and further, the discharge of the vapor from the atmospheric port
16
is restrained by the constriction passage
23
.
Further, during refueling, the vapor whose pressure becomes higher in the fuel tank than that obtained in the case other than refueling, is introduced into the main chamber
3
from the vapor introduction port
7
due to its high positive pressure. The thus introduced vapor flows through the canister
1
so that the fuel component is trapped in the absorbent
2
in the chambers, similarly to above, and accordingly, the vapor having substantially become a purified gas which is similar to the air is vented into the atmosphere from the atmospheric port
16
.
By the way, the volume of the vapor flowing into the canister
1
during refueling, is extremely large in comparison with that obtained in the case of other than refueling when the engine is rested. Accordingly, the air flow resistance among the filter support pins
18
of the plate
5
becomes higher during refueling. Therefore, if the flow distance among the filter support pins
18
is long, and if the flow resistance of the constriction passage
23
is high, the function of preventing the vapor from being discharged into the atmosphere become higher in the case of other than refueling, but the refueling speed becomes lower than usual so that the time of refueling is longer. On the contrary, if the above-mentioned passage resistance becomes lower in order to shorten the time of refueling, vapor which contains a fuel components by a large quantity is discharged into the atmosphere in the case of other than refueling. Accordingly, it is difficult that enhancing the prevention of discharge of vapor is consistent with the shortening of the time of refueling.
As the conventional plate
5
shown in
FIG. 6
, in the one in which a single constriction passage
23
is formed in the center upper part thereof, vapor which has flown into the first subchamber
4
a
from the diffusion chamber
6
comes up from the lower side to the upper side as indicated by the arrows in
FIG. 6
, and in particular, the vapor which flows on the opposite sides as indicated by the arrows A
1
, A
2
has a long flowing distance to the constriction passage
23
, and accordingly, it is difficult to shorten the time of refueling.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is, as comparative with the conventional canister with the plate shown in
FIG. 6
, to provide a canister which can maintain the discharge of vapor into the atmosphere in the case of other than refueling, similar to the conventional canister
5
, and further, which can aim at shortening the time of refueling.
To the end, according to the present invention, there is provided a canister which introduces vapor generated in a fuel tank thereinto through a vapor introduction port and then causes the vapor to flow through a chamber charged therein with an absorbent so as to purify the vapor, substantially similar to the air before it is vented from an atmospheric port, and in which a plate is vertically arranged in the chamber charged therein with the absorbent, the plate being formed in its upper part with a constriction passage means and being formed on its opposite surfaces with filter support pins having tip end faces at which filters are arranged,
wherein the constriction passage means is composed of a plurality of constriction passages which are arranged in a horizontal direction only in the upper part of the plate.
According to the present invention, during refueling, the volume and the pressure of vapor introduced into the canister are higher than

Affiliated with

Also associated with

Rating

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3140883