close

Вход

Забыли?

вход по аккаунту

?

код для вставки
Oct 8, 1946.
'
G_. M. BlCKNELL
2,403,726
CARBURETOR
' Original Filed May 7, 1940
2 Sheets-Sheet 2
2,408,726
Patented Oct. 8, 1946
‘UNITED ‘STATES PATENT OFFICE.
Carter Carburetor Corporation, St. Louis, Mo.,
a corporation of Delaware
Application November 5, 1942, Serial No. 464,643,
which is a division of application Serial No.
333,759, May 7, 1940. Divided and this applica
tion September 6, 1943, Serial No. 501,437 ~ '
6 Claims. (01.261-69)
.
1
-
,
_ This invention relates to carburetors for in~
ternal combustion engines and more particularly
to improvements in downdraft carburetors of the
tubes 9 and I0,‘Venturi tube 9 b'eingarranged
todischarge near the throat of .venturi l3) and
venturi- in being arranged to discharge near‘ the
constriction 5.
plain tube type.
.
v
’ This application is a division of my application,
Serial No. 464,643, ?led November 5, 1942, which
is a division of my application, Serial No. 333,759,
?led May‘ '7, 1940 which has now issued as Patent
No. 2,328,504.
a
’
‘
The outlet I l of the mixing conduitiscontrolled
by a plate-type throttle valve l2 which is rigidly
attachedto a throttle'shaft 13 by means of screws
I'll; Throttle shaft I3 is journalled in the bosses
l5 and 15a. For operation of the throttle valve,
a ‘stamped throttle operating .lever i6 is rigidly
.
.
_ ‘
In devices, such as automotive carburetors, 10 attached to one end of the throttle shaft 13. The
which utilize a diaphragm for‘ actuating or seal
throttle lever. I6 is fabricated from sheet stock
ing'a metering valve or other movable part, it
by stamping and forming, and is provided at one
has been necessary ‘to completely dismantle the
end with a perforation I'l toreceive a remote
diaphragm in‘ order to inspect or replace the valve
control rod (not shown). The throttle lever is
15'
or part carried'thereby.
'
'
normally urged toward a throttle closing position
It is the main object-of the present invention
to facilitate applying and removing a valve or
other diaphragm operated device which is located
behind. the diaphragm.
by the usual throttle ‘pull back spring (not
shown), whichgenerally forms a part of the re
mote control linkage. Lever I6 is also provided
with a pairof parallel bent-up portions [8 and
. A‘ more detailed'object is to provide means for 20 i9 (Fig.2), which’ are‘ perforated and internally
sealingly attaching a metering valve to its actuat
screw‘ threaded .to receive a throttle lever adjust
ing diaphragm in a manner to permit insertion
and withdrawal of the valve through the dia
phragm and without the necessity of disassem
bling
the
diaphragm.
-
'
~
.
‘
Further objects and advantages of the present
invention will be hereinafter set forth in the fol
lowing speci?cation and accompanying drawings,
in which like numerals ‘indicate identical parts.
ing screw. 20. Provision of adjusting screw 2!!
permits a ?ne adjustment of the throttle‘ valve
when, in a- near closed or idling position. An
25 upper wing lug 2| on body casting l provides a
throttle closing limit abutment, and a lower. wing
lug 2m provides a throttle opening limit abut
ment.- JA- narrow tank 22 formed as part of lever
I6 abuts lug 21a as the throttle valve reaches its
30
Figrléis a vertical center section of an automo
tiv'e carburetor embodying the invention.
The air inlet passage25 is controlled by a plate
Fi€.'2is a horizontal section taken on line 2—-2
type choke valve 26 which is eccentrically mount
of Fig; 3.
ed for rotation with the choker shaft 21 which,
open
Fig. 3 is a vertical section taken on line 3-3
of Fig. 1.
35
_
Fig. 4 is a vertical section taken on line 4--4
limit..
-
.
.
in turn, is journalled in the bosses 28 and 29. A
pair of abutments 26a within the air inlet pas
sageway. and castv as an integral part of the air 7
horn} casting ii provide a wide open stop for the
5 is a detailed view of the metering rod
choke valve.‘ Referring to'Fig. 3, the left ‘end of
and attaching screw. ‘
,
~
choker shaft 21' projects into a casing 30 which
40
'In'the drawings, numeral l indicates a main
is cast as anintegral part ofthe airhorn casting
ofr‘ig. 1.
_
.
carburetor body casting having a suitable ?ange
2 formed at the lower end, thereof for attaching
6.‘ The casing 30, together with the cup-shaped
tothe constriction or: throat 5. The upper end
horizontal bore 83in which is retained a cylin
cover 3|. form a housingv which completely? en
a carburetor to the intake manifold of an internal
A
mixing
conduit
3
is
formed
closes'mechanism vfor the automatic control of
combustion engine.
'
in the main body casting, and an adjacent con 45 the choker valve 26. y
, ‘
'
Cast as'an integral part .of the fuel bowl cover '
stant level fuel chamber 4 is cast integral there
with, Aportionof the mixing conduit 3 has a
‘l is arcombination fuel inletand vent'boss. 82.
Boss 82 is provided with a comparatively large,
ventunrorm as indicated at 3a which converges
of body casting l is provided with a smooth ?ange
surface to whichis attached an air inlet casting
drically formed wire screen retainer 84. Fuel.
entering through" bore 83 passes through screen
84 and through a horizontal passage 89 ‘to a
verticalpassage 90, see Fig.4.v The lower end of
or air horn Grand a fuel bqwljcover 1 by means
ofv attachingscrews 8. Depending from the air
horn casting. 1 and projecting into the upper end 55 passageway.“ is screwthreaded to receive a
of the mixing conduitare two concentric Venturi
2,408,726
3
"
'
'
"
needle seat member 9I, through which is pro
vided a bore 92 to admit fuel to the fuel cham
ber 4. A conventional float 93 pivoted at 94 acts
move metering rod I09 to the left; that, nor
mally, the metering rod is urged to the right by
Fuel is supplied to the carburetor mixing conduit
to the right in a less restricting position in jet 96.
spring I25 and that a clockwise rotation of the
upon the needle valve 95 in a well known man
ner to maintain a constant level of fuel in cham 61 throttle shaft !3 (which is a throttle opening
movement) will forcibly. move the metering rod
ber 4 substantially as indicated by‘ the line :r—-x.
It will also be noted that a movement to the
right of diaphragm I I0 caused by a drop in mani
for normal and full speed and load operation ‘
of the engine through a metering jet 96, through
passages 91 and 98 and is discharged through 10 fold vacuum or throttle opening movement will
displace the fuel in chamber “1, causing an in
nozzle 99 into the primary Venturi tube 9. Fuel
creased pressure‘on jet 96 and also momentarily
for low speeds or idling operation is also metered '
raising the fuel level in the constant level cham
by jet 96 and passes into passage 9‘! from whence
ber. This enriching effect is highly desirable.
it passes through the idling jet tube I00 and suit
Fuel for acceleration is supplied to the mixing
able passages to the usual idling ports adjacent
the edge of the throttle when iclosed.
'
conduit under pressure by the diaphragm type
accelerating device generally indicated at I32,
;
The amount of fuel available for aspiration
from the main nozzle 99 and the idling ports is
varied in accordance with engine intake mani
fold vacuum and throttle position by a stepped
Figs. 2, 3 and 4, and which comprises a circu
lar chamber I 33 formed by a recess in the main
body casting and by the recessed cover I34 which
ax 20 is attached thereto by means of attaching screws
I35. A flexible diaphragm member I36 ?rmly
rod
clamped at its periphery between cover I34 and
net
the carburetor body is provided and forms a
the
partition in chamber I33. The diaphragm I36
rod I09 in accordance with manifold vacuum, a
?exible diaphragm member II 0 is rigidly at 25 is attached at its center to a horizontal plunger
I 31 which passes through the cover I 34 and
tached to rod I69 at its center by means of the
projects therefrom. A spring I38 hearing at
plunger member III. Referring to Fig. 3, the
one end against a retainer I39 and at its other
left hand side of diaphragm III) is subjected to
end against cover I34 normally urges the dia
intake manifold suction by reason of passages ‘
H2, H3, H4 and H5 which open as a port H5 in 30 phragm I36 and plunger I3‘! toward the right,
Fig. 3. which is an intake stroke. A rocker arm
the wall of the mixing conduit below the throttle
I40 pivoted at one end at MI and having at
and/or tapered metering rod I09 extending
ially into metering jet 96. As the metering
I09, Fig. 3, is moved toward the left, the
opening of jet 96 is decreased. To position
valve. The recess II ‘I in the carburetor body
casting and the generally cup-shaped cover plate
I I8 form a working chamber for the diaphragm.
The recess I I‘! communicates with the fuel cham
ber 4 through a large passage II'I'a, see Figure 2,
so that the pocket of fuel therein and the dia
phragm are in substantially unrestricted com
munication with the remainder of the bowl. The
tached at its other end at I50 a spring I 42 which
is connected to lever I28 moves the plunger and
diaphragm to the left (discharge stroke) as the
lever I28 is rotated clockwise (throttle opening
direction).
40 ‘provision in lieu of a non-yielding, link results in
a smooth yielding pressure being exerted upon
the diaphragm and is attached to the body cast
The central per
foration of cover plate II8. wherein is ?tted for
reciprocation the plunger III, is provided with a
packing gland I20; The plunger, I II passes
through a central perforation in diaphragm H0
and is ?rmly attached thereto by riveting or
.
stantially stronger than spring I38 and that its
cover plate II 8 ?rmly clamps the peripheryaof
ing by means of screws H9.
I
It will be understood that spring I 42 is sub
45
the plunger and diaphragm I36 which is desir
able.
The accelerating device further comprises inlet
passageways I 5| and I52, Figs. 2 and 3, leading
from the constant level fuel chamber 4 to the ex
pansible chamber I 33.
A cylindrically formed
wire mesh strainer I53 is provided and is re
spinning over the reduc d end of the plunger as
tained in passage I52 by the screw threaded inlet
>
Plunger I I I is further provided with a through 50 check plug I54. The inlet check plug I54 is pro
vided with a valve seat I55, a disc check‘valve
axial bore of sufficient size to permit the passing
I56 and a valve retainer I51. The fuel is dis
of the entire metering rod and is provided with
charged
from chamber I33 through passages I58,
internal screw threads I22a at its outer end. An
I59, diagonal passage I 60 and an accelerating
externally threaded sleeve I22, staked to the rod,
as at I23, Fig. 5, is secured in the plunger. It will 55 jet (not shown) into the mixing conduit. A dis
charge valve seat is formed at the lower end of
be seen from the foregoing that the metering rod
passage I59 at I62 by a reduction in diameter.
I09 may be removed or assembled without the
and a gravity seating ball check valve I63 is pro
necessity of removing the cover plate II 8 and
vided and adapted to engage seat I 62. The up
diaphragm IHJ. Metering .rod I09 is normally
urged to the right, Fig. 3, by the lever I24 which 60 per end of passage I59 is screw threaded and re_
ceives a screw plug I64 which is provided with
is acted upon by a spring I25. The lever I24 is
a downwardly extending stem I65 which limits
carried on pivot I26 which also forms a pivot for
the upward movement of ball check I63 When the
asecond lever I21 which is, in turn, connected
same is acted on by discharge pressure.
to a lever I 28 by means of a link I29. Lever I26
indicated at I -2 I.
A decided advantage gained by the present ar
rangement of the accelerating device is that, by
extending the discharge passageway upwardly
is rigidly attached to the throttle shaft I3.
' Relative motion of levers I24 and I 27 is pre
vented in‘ one direction by the ?nger vI3I carried
by lever I24. It will be understood that spring
I25 is so proportioned and calibrated with re
lation to the e?ective area of diaphragm I09
thatthe desired position of the metering rod for
a given manifold vacuum is attained. From the
foregoing, it will be seen that suf?cient‘ vacuum
applied to the left side of the diaphragm IIO will
70
from the very top of the expansible chamber I 33
to a point above the fuel level, pressures..which
frequently build up in chamber I33 clue to vapori
zation are-released without the forcing of fuel
from the chamber as occurs in many construc
tions. ' This advantage has particular signi?cance
I . due .to the importance of maintaining a full ~
' charge of fuel in the accelerating chamber.
mg, a. lateral. extension below the fuel level and
Referring to Fig. l, acomparativelyllarge veri
opening’ through the side .wall of said chamber,
a diaphragmoclosin'g said opening and acting
against the fluid in said chamber, a plate fixed
tical passageway IE9 is provided,.extending. from
the main fuel passage98 to apoint above the fuel
level. The upper part of this passage communi
cates with the mixing conduit through a tube I10.
This provision has the purpose of relieving vapor
pressures at theba'se of nozzle 99,. and its oper
ation is fully describedin my copending appli
cation, now Patent‘No. 2,234,946,
over
.
and plate opening, andmeans removable through
‘said plate opening and securing said metering
pin to said diaphragm whereby movement of said
diaphragm by suction regulates theflow of fuel
and 92 wherein a substantially constant level as
'
'\
and forming . a ' suction
axial of the. center of said diaphragm, a. suction
inlet passage83, screen 84, and passages 09,50
of the ?oat 93 on needle valve 95.
diaphragm
passage connecting said conduit and said cham
Ioe'r, a metering ori?ce in said main. fuel pas
sage, a metering pin for regulating the fuel pass
ing? through said ‘ori?ce, said metering pin ex
tending axially through said ori?ce,‘ diaphragm,
The operation of'the carburetor is astfollow's:
Fuel is supplied to the .float chamberA through
indicatedby line arr-m is maintained by the action
said
chamber therewith, said plate having an opening
15
Fuel for normal and high speed operation is
supplied to the mixing conduit from fuel chamber
through said jet.v
‘4 through metering jet 06, passages 91,.98and
nozzle 99. During comparatively light load oper
ation, the intake manifold suction will act on. dia
phragm I I0 to move. ‘metering rod I00 toward
the left, Fig. 3, that is, toward a more restricting
position. The position of the metering rod un
der these conditions will also be determined by
the throttle position. When sufficient load is ap
plied to the engine for any given throttle posi
.
2. The substanceof claim 1, further including
guide structure .for said metering pin in a por
tion of the carburetor wallspaced from Isaid
,
diaphragm. ’
,
.
' 3. Ina carburetor, a mixture, conduit,.,afuel
bowl forming a constant level ?oat chamber
formed on one wall of said conduit, the common
wall between said conduit and said chamber
being thickened, a main fuel nozzle passage ex
tending from the lower part of said bowl through
tion to cause a su?icient resulting drop in mani
said common wall and opening into said mixture
fold vacuum, spring I25 will urge the metering
conduit, a fuel nozzle arranged in said nozzle
rod toward the right to a less restricting posi
passage and extending into said mixing conduit,
3 0 a pocket formed in the wall of the lower part
tion.
Fuel for idling operation is supplied to the
of said float chamber and in open communica
mixing conduit from fuel chamber A through jet
tion therewith, a suction responsive diaphragm
06, passage 91, idling jet I03, idling tube I00, pas
sages l0! and I02, and is discharged into the mix
ing conduit near the upward opening edge of
throttle valve I2 through the usual idling ports
' forming
formed
(not shown) .
Fuel for acceleration is supplied under pres- ,
sure to the mixing conduit from the accelerat
ing chamber I33 duringv the discharge stroke of
diaphragm I35, through passages I58, I59, and
I60. The diaphragm I36 is actuated through its
discharge stroke by an opening movement of the
throttle valve by means of linkage comprising the
rocker arm I40, the spring I42, and lever I28.
When the throttle is suddenly opened from
nearly closed position, pressure in the carburetor
outlet and in diaphragm control passages H2
and H3 increases, causing rapid inward move
ment of diaphragm IIO by spring I25. This
forces liquid fuel back through open bowl com
munication I Ila, momentarily raising the level in
the bowl, and through main metering jet 90. Ad
ditional fuel is thus supplied to the mixture con
duit through the main nozzle, both because of the
raised level and consequent increased pressure in
the bowl and because of the extra charge of fuel
forced directly into the main nozzle passage. As
the throttle is opened, the distance diaphragm I I0
4. In a carburetor, a mixture conduit, a fuel
bowl forming a constant level ?oat chamber
formed on one wall of said conduit, the common
wall between said conduit and said chamber be
ing thickened, a main fuel nozzle passage ex
tending from the lower part of said bowl through
said common wall and opening into said mixture
conduit, a fuel nozzle arranged in said nozzle
50 passage and extending into said mixing conduit,
a pocket formed in the wall of the lower part
of said ?oat chamber and in open communica
tion therewith, a suction responsive diaphragm
forming one wall of said pocket, said thickened
common wall terminating short of said pocket at 55
can move because of a drop in suction to the car
one edge to provide open communication between
said pocket and said bowl, a passageway formed
in said thickened wall connecting said nozzle pas
60
buretor becomes progressively less, since the dia
phragm is impelled inwardly by lever I24 oper
ated by the throttle. This is an advantage be
cause less auxiliary pick-up fuel is needed for ac
celeration from a substantially open throttle posi
come within the scope of'the appended claims is
contemplated.
I claim:
I
.
1. In a carburetor, a mixture conduit, a main
aphragm and extending through and controlling
said metering ori?ce, and guide means closely
being aligned with said passageway and being
65 positioned inward of said metering ori?ce.
The invention is not limited in details to the
structure shown, but may be modi?ed in various ‘
respects as will occur to those skilled in the art
and the exclusive use of all such modi?cations as
sage and said pocket, a metering ori?ce in said
passageway, a metering valve secured to said di
?tting a portion of said valve said guide means
‘tionythan from a nearly closed throttle position.
fuel passage, a constant level fuel chamber hav
one wall of said recess, a passageway
in said thickened wall connecting said
nozzle passage and said recess, a metering ori?ce
in said passageway, a metering valve secured to
said diaphragm and extending through and con-l
trolling said metering ori?ce, and guide means
closely ?tting a portion of said valve, said guide
means being aligned with said passageway.
1-
5. In a carburetor, a mixture conduit, a fuel
bowl forming a constant level ?oat chamber
formed on one wall of said conduit, the common
wall between said conduit and said chamber‘
being thickened, a main fuel nozzle passage ex
tending from the lower part of said bowl through
opening into said mixture
conduit, a fuel nozzle arranged in said nozzle
passage and extending into said mixing conduit,
. said common wall and
75 an opening in an outer wall of said float cham-_
7
2,408,726
her, a suction responsive diaphragm secured over
said opening, a passageway formed in said thick
ened wall and connecting said nozzle passage and
said ?oat chamber, a metering ori?ce in said
passageway, a metering valve secured to said
diaphragm and extending through and control
ling said metering ori?ce, and guide means closely
?tting a portion of said valve, said guide means
being aligned with said passageway and being
positioned inward of said metering ori?ce.
6. In a carburetor, a mixture conduit, a fuel
bowl forming a constant level ?oat chamber
formed on one wall of said conduit, a portion of
the wall of said conduit adjacent said ?oat
chamber being thickened, a main fuel nozzle pas
sage extending from the lower part of said bowl
through said thickened wall portion and opening
into said mixture conduit, a fuel nozzle arranged
in said nozzle passage and extending into said
mixing conduit, an opening in an outerrwall of
said ?oat chamber, a suction responsive dia
phragm secured over said wall opening and
formed with a central opening, a suction cham
ber formed over the outer face of said diaphragm
including a wall formed with an opening in align
ment with the opening in said diaphragm, a tube
secured at one end portion to the Wall de?ning
' the central opening in said diaphragm and mov
able with said diaphragm, the outer end of said
tube extending through and closely ?tting the
wall de?ning the wall opening in said suction
chamber, a passageway formed in said thickened
wall and connecting said nozzle passage with said
?oat chamber, a metering ori?ce in said passage
Way, a metering valve having one end portion
extending into said tube and its other end por
tion extending through said metering ori?ce,
means for adjustably securing said metering valve
in said tube, and means engaging said valve to
maintain its axis in constant predetermined
relationship with the axis of said metering
ori?ce.
'
'
‘GEORGE M. BICKNELL.
Документ
Категория
Без категории
Просмотров
0
Размер файла
754 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа