U.S. patent number 3,678,663 [Application Number 05/068,839] was granted by the patent office on 1972-07-25 for air cleaner remote from engine and having integrated fuel vapor adsorption means.
This patent grant is currently assigned to Ford Motor Company. Invention is credited to Gunnar W. Hansen.
United States Patent |
3,678,663 |
Hansen |
July 25, 1972 |
AIR CLEANER REMOTE FROM ENGINE AND HAVING INTEGRATED FUEL VAPOR
ADSORPTION MEANS
Abstract
The engine air cleaner is positioned remote from but connected
to the engine in essentially a side-by-side relationship. The air
cleaner is vertically disposed to define a lower reservoir that
traps excess fuel vapors flowing thereinto from the carburetor, and
contains a vapor adsorption means to store the vapors and
subsequently return them to the engine.
Inventors: |
Hansen; Gunnar W. (Ypsilanti,
MI) |
Assignee: |
Ford Motor Company (Dearborn,
MI)
|
Family
ID: |
22085040 |
Appl.
No.: |
05/068,839 |
Filed: |
September 2, 1970 |
Current U.S.
Class: |
96/141;
55/DIG.28 |
Current CPC
Class: |
F02M
25/08 (20130101); F02M 35/04 (20130101); Y10S
55/28 (20130101) |
Current International
Class: |
F02M
35/02 (20060101); F02M 35/04 (20060101); B01d
053/04 () |
Field of
Search: |
;55/74,316,387,DIG.28
;123/136 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hart; Charles N.
Claims
I claim:
1. An engine air cleaner assembly that is remotely located from the
air inlet portion of an engine carburetor but connected thereto by
duct means, comprising an essentially vertically disposed casing
having a horizontal axis and an air inlet adjacent the top thereof
on one side and an outlet on the other side connected to the duct
means, and a depending body portion, a filter element extending
from top to bottom of the casing for axial flow through the casing
and means for creating flow through the casing in essentially a
U-shaped path, the lower portion of said assembly constituting a
vapor trap type reservoir for containment of excess fuel vapors
adapted to pass thereinto from said outlet, and fuel vapor
adsorption means associated with the said reservoir in the
depending portion for storing the fuel vapors flowing at times by
gravity into said reservoir from said outlet and carburetor, said
fuel vapors being purged from said adsorption means upon air flow
in a normal direction from said air cleaner assembly to said outlet
during normal engine operation.
2. A system as in claim 1, including baffle means extending between
said casing air inlet and said outlet to divert fuel vapors into
said reservoir.
3. A system as in claim 1, said vapor adsorption means comprising
an activated carbon bed.
4. A system as in claim 1, said adsorption means comprising an
activated carbon bed having a fresh air inlet at one end and being
operatively associated with the fuel vapors at the other end.
Description
This invention relates, in general, to an air cleaner assembly for
a motor vehicle. More particularly, it relates to one that is
remotely located from a carburetor air horn air inlet opening, and
has integrally associated therewith a vapor adsorption device.
Present day demands for lower hood lines make it increasingly
difficult to use conventional engine constructions having a
carburetor and air cleaner superimposed thereon. This invention
seeks to remedy the above situation by locating the air cleaner
remote from the carburetor inlet, and construct it of a unique
design that minimizes the escape of excess fuel vapors into the
atmosphere.
The invention consists of an essentially vertically disposed air
cleaner assembly having essentially a side-by-side relationship to
the engine carburetor air horn. The air cleaner contains a filter
element to provide a clean supply of air to the engine; it also is
constructed to serve as a natural trap for excess fuel vapors
emitted from the carburetor fuel bowl during the hot soak cycle of
the engine. The construction is such that the fuel vapors flow by
gravity into the air cleaner assembly into an adsorption device for
storage and subsequent recirculation through the engine during
normal operation.
It is a primary object of the invention, therefore, to provide an
air cleaner assembly that is remotely located from the engine; and,
is of a unique design that satisfies engine air requirements, while
at the same time acts to trap excess fuel vapors emitted from the
carburetor fuel bowl so that undesirable elements will not be
emitted into the atmosphere.
Another object of the invention is to provide an air cleaner
assembly of a design permitting the use of lower profile vehicle
hoods, one that is relatively simple in construction, and one that
is relatively inexpensive to manufacture.
Other objects, features and advantages of the invention will become
more apparent upon reference to the succeeding detailed description
thereof, and to the drawings illustrating the preferred embodiments
thereof; wherein,
FIG. 1 is a cross sectional view of a portion of an engine air
filter assembly and fuel vapor emission control system embodying
the invention;
FIG. 2 is a top view on a reduced scale of the assembly shown in
FIG. 1; and,
FIG. 3 is a cross sectional view of a modification of the FIG. 1
showing.
FIG. 1 shows an air cleaner assembly adapted to be mounted adjacent
and connected to a portion 10 of the intake manifold for an
internal combustion engine. Secured on top of manifold 10 is a
downdraft type carburetor indicated schematically at 12. It has the
usual float bowl 14 containing liquid fuel 16 and a fuel vapor
space 18 thereabove. The carburetor contains the usual air horn
fresh air inlet portion 20 into which, in this case, excess fuel
vapors from the float bowl space 18 are vented through a tube 21.
As thus far described, the construction is known and conventional
and further details thereof are believed to be unnecessary to an
understanding of the invention.
The air cleaner assembly includes a main outer rectangular or
square shaped closed shell 22 defined by two cup-shaped portions 24
and 26 that are clamped in a sealing manner around a sheet-like
filter element 28. The latter may be of the known paper or other
suitable types for filtering particles from air passing
therethrough in an axial direction. The filter 28 is vertically
disposed and extends across shell or casing 22 so as to force all
air passing axially from one side of the casing to the other to be
filtered.
The air supply to casing 22 is provided by an inlet duct 30 secured
to casing 22 adjacent its upper portion. The duct is open at its
nonadjacent end to a suitable source of air at essentially
atmospheric pressure. This may be engine air compartment air or air
delivered directly thereto by ducting from outside the vehicle, as
the case may be. The duct 30 is shown as containing a hot air
branch 32 that is adapted to be connected to an exhaust manifold
heat stove (not shown) in a known manner and controlled by a
pivotal valve 34. The latter would proportion the degree of hot or
cold air being supplied to the air cleaner casing 22 from ducts 32
or 30 by movement of the valve from the position shown in a known
manner by a temperature sensitive device (not shown) against the
force of a return spring.
Casing 22 is connected to the inlet of the carburetor air horn by a
duct 36. The latter includes a horizontally disposed carburetor
connected section 38 joined in end-to-end relationship to an
inclined duct portion 40 that opens into casing 22, as shown.
The air cleaner, in this case, also contains a flat plate baffle
element 41 that acts as a fuel vapor flow barrier, in a manner to
be described.
As thus far described, it will be clear that during normal engine
operation, the engine suction will draw fresh air through supply
inlet 30, through the filter element 28 to be cleaned, and
therefrom through the ducting 40 and 38 into the carburetor and
engine proper. During a hot soak cycle of the engine, the engine
heat may increase the vapor pressure in float bowl space 18 to a
point where the vapors are forced through the vent 21. These fuel
vapors will flow leftwardly in duct 38 and thence by gravity
through the duct 40 into the lower portion of the air cleaner
casing 22, which constitutes in effect, a reservoir. The baffle 41
will prevent a flow of the vapors from the duct 40 directly into
the air inlet duct 30 and out into the atmosphere. Since the vapors
flow like water, however, the baffle may be unnecessary.
It will be seen that the vertically disposed air cleaner casing 22,
with its connecting ducting to the carburetor, acts as a trap to
contain the heavier than air fuel vapors therein. However, the main
purpose of the trap is to guide the vapors into an adsorption means
that has a storage capacity of say 50-100 times the volume of
reservoir 22, that will essentially prevent a spillover of the
vapors into the inlet duct 30.
More particularly, connected to the lower side portion of casing 22
is a bed of activated carbon 44. The bed is located within a
U-shaped trough 46 having a perforated metal side and bottom wall
48 and a corrugated or wavy non-perforated side wall 50. The latter
provides air bypass passages 52 (FIG. 2) between the portions
secured to casing 22 for a purpose to be described. A tube 54 can
be connected to the bed 44 so that excess fuel vapors from any
other source, such as, for example, the fuel tank of the vehicle
(not shown), may be routed to the carbon bed.
The carbon bed adsorbs excess fuel vapors on the carbon particles
which are purged of these vapors by the flow of fresh air through
the carbon bed during normal operation on the engine. That is, when
the engine has been started, the suction will draw air through the
air cleaner assembly from inlet duct 30 in the normal manner. A
portion of the air will flow from duct 30 through filter 28 to duct
40, bypassing the carbon bed 44. Another portion of air will flow
through passages 52 around the carbon bed, pick up any fuel vapors
that are in the bottom of casing 22 and carry them through the
filter to the duct 40. In this case, additional vapors, such as
crankcase blowby, may be vented to the lower space 56 via a tube
58. Finally, the remaining air portion will pass through bed 44,
purging it of the stored fuel vapors, and carry them through the
air filter element 28 and into the carburetor. The carbon bed in
this case is located above the crankcase vapor space so as not to
contaminate the carbon with oil mist, etc., that is contained in
the crankcase vapors.
The carbon bed increases the storage capacity of the assembly. If
the volume of the reservoir 22 were relied upon alone to contain
excess fuel vapors, it would fill in a short period with fuel
vapors during a hot soak to a level where the vapors would pass out
through inlet 30. However, the adsorption device, with its
multitude of carbon particles providing an infinite contact and
adsorbent area, can adsorb a quantity of fuel vapors equal to
50-100 times the volume in the reservoir 22.
It should be noted that the restriction to flow through filter
element 28 will be chosen so as to force an adequate supply of
purge air to flow through the carbon bed 44. The cross sectional
areas of passages 52 and the clearance spaces between the wall 46
of the trough and the filter 28 also will be controlled to assure
adequate purge flow while at the same time assuring an adequate
supply of air to meet all engine requirements, without undue
restriction.
FIG. 3 shows a modified construction of the adsorption means in
which a carbon embedded mat 60 having low air restriction
characteristics is used. Due to the lack of loose carbon particles,
the metal trough 46 of the FIG. 1 embodiment can be eliminated. The
operation otherwise is the same as described in connection with the
FIG. 1 embodiment.
From the foregoing, it will be seen that the invention provides an
air cleaner assembly that is remotely located from the engine
proper and yet operatively connected thereto to satisfy all the
engine air requirements; and, one that also traps excess full
vapors and subsequently redirects them back into the engine to be
consumed therein and thus not be vented freely to the
atmosphere.
It will also be seen that the invention eliminates the need for a
carbon canister to be located outside of the air cleaner. Further,
it will be seen that a hot air purge is available during cold
engine starts due to the hot air duct 32 of the air supply system
providing substantially all of the engine requirements during cold
starts.
* * * * *