US2448131A

US2448131A - Carbureting apparatus

Info

Publication number: US2448131A
Application number: US572766A
Authority: US
Inventors: Jr Lynn A Williams; Jr William A Marshall; Jr William F Gradolph
Original assignee: Stewart Warner Corp
Current assignee: Stewart Warner Corp
Priority date: 1945-01-15
Filing date: 1945-01-15
Publication date: 1948-08-31
Anticipated expiration: 1965-08-31

Description

Aug. 31, 1948. A. WILLIAMS, JR, Erm. 2,448,131

CARBURET ING APPARATUS 5 Sheets-Sheet 1 Filed Jan. 15. 1945 Aug. 31, 194s.

| A. WILLIAMS, Jn, ErAL 2,448,131

cAnBUnE'rING APPARATUS 3 ShoetsSheet Filed Jan. 15. 1945l Aug- 31 1943- L. A. WILLIAMS, JR., ETAL v2,448,131

t CARBURETING vAPPARATUS med Jah. 15. 1945 y s sheets-sheet s Patented Aug. 3l, 1948 Lynn A. Williams, Jr., Northfield, William A.

Marshall, Jr., Chicago, and William F. Gradolph, Jr., Oak Park, Ill., asslgnors to Stewart- .Warner Corporation, Chicago, Ill., Aa corpora- TIzlon of Virginia Application January 15, Y1945, Serial No. 572,766

l i Our invention relates to carbureting apparatus for use particularly in connection with internal combustion engines for controlling the feed of fuel thereto, and has for its principal object the provision of a new and improved form and ar-l rangement of parts whereby the richness` of the air and fuel mixture fed to the engine shall'be substantially increased momentarily while the throttle is being opened for rapid acceleration. The invention is an improvement on the arrangement shown and described in the prior Williams application, Serial No. 552,651, filed September 4, 1944.

Our arrangementis similar to that shown by.

' ifold brought about thereby is communicated immediately to one of the intake manifold -pressure chambers, but the application of such increased pressure effect to the other chamber is retarded during a period of several seconds. The arrangement is such that this differential'application of the pressure to the two chambers opens the fuel -valve by a small amount additionally yfor obtain- -ing a richer mixture and maintains such excess 'opening until the pressure onthe opposite faces of the intervening diaphragm has been equaliz'ed.

It is one of the objects of our invention to prolvide an improved arrangement of connecting' means between said two chambers for insuring that they will have cooperative action for a limited period for effecting the desired increased Vopening of the valve.

It is another object of our invention to improve apparatus of this type in sundry details hereinafter pointed out.

The preferred means lby which the several objects have been attained are illustrated in the accompanying drawings, in which: Y

Fig. 1 is a perspective view of a portion of an internalcombustion engine provided with a preferred form of our improvements;

Fig. 2 is a central vertical sectional view through the improved valve structure, by which measured amounts of fuel are fed to the engine;

z claims. (ci. zei-69) Fig. 3 is a diagrammatic'viewA of the upper portion of the engine as seen from the left in Fig. l; and

Fig. 4 is a vertical sectional view on a considerably enlarged scale, through the oat bowl.

an intake manifold I2 provided with ducts I3 leading downwardly to the several cylinders of the engine. At its forward end, the manifold I2 assumes the formof a Venturi tube, indicated by the numeral I4, a throttle valve I5 being movably mounted in position to close the passageway a short distance to the rear of the throat portion of the Venturi tube, and a choke valve I6 being movably mounted in position a short distance ahead of the throat portion. Links I1 and I8 are connected with the valves I5 and I6, respectively, for controlling their position in a Well known manner. y

In the arrangement shown (see Fig. 2), the fuel regulating valve I3 is formed of six casing sections 29, 30, 3I, 3Ia, 32, and 33, connected together by any suitable means, with

exlble diayphragms

34, 35, 36, 36a and 3l interposed between the several casing parts to provide a plurality of chambers. By the use of the flexible diaphragms between the several chambers, each of the chambers is given one `or more yieldingv -wall portions adapted to be moved inwardly or outwardly in accordance with pressure conditions in the chambers. By the-arrangement shown, we have provided a fuel pressure chamber 42 at the bottom of the device, connected by a duct 43 with a second fuel pressure' chamber 38 at the top, such duct 43 being formed by connected bores in the casing sections.

Immediately below the fuel pressure chamber 38, there is an air chamber 39, and immediately below that an atmospheric pressure chamberl. Between the atmosphericpressure chamber 40 and the bottom fuel pressure chamber 42, we have provided, by the construction specied, an intake manifold pressure chamber 4I and an auxiliary intake manifold pressure chamber 4Ia. The several chambers are operatively connected with the engine Ill, in the arrangement shown, by a series of pipes, fittings, and other parts as hereinafter specified for establishing the required communication between the' engine and the several chambers whereby the pressure conditions in the en- 3 gine at different points and under varying circumstances may control the feed of the fuel to the engine.

In the construction illustrated, gasoline or other liquid fuel is supplied to the fuel pressure chamber 42 under constant pressure through a pipe 20 from any suitable source. Measured amounts of the fuel are carried to the lower portion of a closed float bowl 20a from the fuel regulating valve I9 by a pipe 2l, and branch pipes`-22 lead from the bowl 26a to spray nozzles 23 of any approved type, mounted in the walls of the air ducts I3 in close proximity to the intake valves of the engine cylinders. Communication is established between the air chamber 39 and the throat portion of the Venturi tube I4 by means of a line of piping 24. A pipe 25, communicating with the atmospheric pressure chamber 40, opens to the atmosphere at any desired point, being shown in the drawings as opening to the atmosphere at a point immediately ahead of the choke valve 1,6. In many embodiments of the invention, it would be immaterial at what point the opening to the atmosphere was provided, but in some instances where an air filter or a turbo supercharger might be employed, it might be highly desirable to have the parts arranged as shown in the drawings so that the pres.- sure in the chamber reflects any differences from true atmospheric pressure caused by the presence of such a lter or supercharger.

In the arrangement shown in the drawings, communication is established by pipes 21 and 28 between the intake pressure chamber 4I and the intake manifold I2 at a point a short distance to the rear of the vthrottle valve I2, and by

pipes

26 and 28 between the casing member 65, as hereinafter described, and the intake manifold at said point to the rear of the throttle valve. It will be understood that xthe form of the connections may be varied as desired without departing from the invention, so long as the desired lines of communication are established.

As is clearly shown in Fig. 2, the walls of the casing members 3Ia and 32 are provided with

openings

86 and 81 therein for providing communication` between chambers 4I and 4Ia. In the opening 81, we have provided a check valve 88 in the form of a disk having a small opening 89 therethrough, such valve being movable downwardly against the action of a light coiled spring 90 for permitting free movement of the fluid from the chamber 41a to the chamber-.4I through the comparatively large opening in which the valve is mounted. Movement of fluid upwardly from the chamber 4I to the auxiliary chamber 4Ia, however, is very substantially restricted, since the fluid moving in that direction must pass through the small opening 89. A removable plug SI is preferably provided-for affording access to the spring 90 and the valve disc 88 if it should prove desirable to substitute a valve disc with an opening of a different size therethrough.

f For controlling the passage of liquid fuel from the pipe 20 or other source into the fuel pressure ,chamber42 for movement -to the spray nozzles 23, a needle valve 44 is provided, tapering to a sharp point at its lower end and movably mounted in position to close an opening 45 through a plug 46 mounted in the bottom wall of the casing part 33. A coiled spring 44a normally raises the valve 44 from its closure' position. vAt its upper end, the needle valve 44 engages a pressure plate 41 carried by the diaphragm 31, the diaphragmbeing gripped between the plate 41- below and a plate 48 above. The diaphragmu36a is gripped between plates 41a and 48a and the diaphragm 38 between two plates 49 and 50.

In the arrangement shown, the diaphragms 36a and 31 are connected together by means of a pin 48h which is riveted to the plates 41 and 4l and a pin 5IY riveted to the plates 41a and 48a. The diaphragms 36 and 36am turn are connected together by means of the pin 5I, a pin 52 riveted to the plates 49 and 58, and a turnbuckle sleeve 5 la having a notched plate SIb mounted thereon.

The diaphragm 35 is provided with reinforcing plates 53 and E5 which are held in gripping relationship to the diaphragm by a cup-shaped rivet 55 winch is connected .to the plate be by a screw threaded pin 56. The diaphragm M also is provided with reinforcing plates 51 and 58 which are held in gripping relationship to the diaphragm by a pin 59 having a riveted connection with said plates, the pin 59 being in axial alignment with the pin 56 and being adjustably connected with said pin by means of a turnbuckle arrangement comprising a sleeve 60 provided with a notched plate 6I rigidly mounted thereon.

Access to the plates 5 I b and 6I may be provided in any suitable manner for turning the plates, as by normally plugged openings through the walls of the casing parts, so as to enable an operator to adjust the distance between either the Adiaphragms 36 and 35 or the diaphragms 38 and, 33a.

Above the plate 51 we have mounted a coiled spring 62 bearing at its upper end on the top wall of the casing member 28, such spring being adapted to apply downward pressure on the needle valve 44 through the train of parts as above described. An upwardadjustment of the pin 5l by means of either of the turnbuckle arrangements serves, of course, to compress the spring 62 so as to cause it normally to have increased resilient pressure downwardly on the needle valve With the chambers 38 and 42 filled with gasoline or other liquid fuel supplied under pressure through the pipe 20, such fuel presses upwardly on the diaphragm 31 and acts through the duct L43 to press downwardly on the diaphragm 34, serving to apply a differential pressure downwardly on the needle valve 44 by reason of the fact that the diaphragm 34 is of greater effective size than that of the diaphragm 31. Such differential downward pressure of the fuel4 and the downward pressure of the spring 62 serve normally tohold the needle valve 44 seated so las to prevent the movement of fuel past the valve.

When the choke valve I6 is moved into'more or less completely closed position in thel air inlet means and the engine is cranked so as to exertv asuction effect on the intake manifold I2such suction'eect applied through the pipes 2l and 21 pulls downwardly on the diaphragm' 36 and upwardly on the diaphragm 31 within the chamber 4I. .Under these conditions` they diaphragm vof the fact that the diaphragm 36 is of larger effective size than that of the diaphragm 31. At the same time under these conditionawith the choke valve closed and with the crankshaft being rotated for starting the engine, the low pressure condition in the intake manifold exerts a strong suction effect through the pipe 24 upon the diaphragms and 36 of the valve chamber 39, serving to apply a strong differential pull upwardly on the diaphragm ss by reason of the fact that the diaphragm 36 is of very much larger effective size than that of the diaphragm 34.

This upward pull on the diaphragm 35 and the other diaphragms connected therewith leaves the needle valve 44 free to be moved upwardly by the spring 44a so as to permit the passage of a substantial stream of fuel past the valve Aand so as to produce a rich mixture in the duetsv I3 leading to the cylinders for starting theengine. Under the conditions specified, the upward pull on the diaphragm 36 for opening the valve 44 is substantially in excess of .the several forces tending v to close the valve, resulting in a rich fuel mixture and easy starting of the engine.

As soon'as the .choke valve is opened andthe engine operates at normal idling speed, the suction effect on the pipe 24 drops, since the Venturi tube suction effect on the pipe 24 is very small so long as the volume of air passing through the tube is also by the movement of air through the opening kept low.. The needle valve 44 thereupon closes and an auxiliary fuel feeding valve 63 serves, as hereinafter described, to keep the engine running during any idling period.

With the engine idling lafter starting, the choke valve i6 being open and the throttle valve l5 being substantially closed, the needle valve 44 remains in its fully rclosed position. When thereafter thethrottle valve I6 is opened for operation of the engine under load conditions with a substantial amount of air being drawn in through the Venturi tube, the suction effect through the pipe 24 is. increased so as to cause the diaphragm conditions named in complete control of the de- 1 livery of fuel to thecylinders.

When the engine'is running under load conditions with the pressure in chambers 4I and 41a fully equalized, the operation of the engine is sub'- stantially the same as it would have been ifthe "auxiliary intake manifold pressure chamber had movement, however, for causing acceleration of the engine, the auxiliary chamber 4Ia is instrumental in bringing about a, highly desired increase in the richness of the fuel mixture. When the throttle valve is openedso as to permit the air to move more freely through the air induction tube, the suction effect in the intake manifold falls off substantially and the pressure in the valve chamber 4I which is connected with the intake manifold by the pipes 28 and 21 is correspondingly increased. There is immediately a tendency for the pressure in the auxiliary chamber 41a to rise -the valve opening 13.

89 from the chamber 4l to the chamber 4Ia for equalizing the pressure, but such equalization requires a period of several seconds for completion. With the pressure temporarily higher in fthe chamber 4| than in the chamber 4Ia,.a substantial differential upward pressure is established Aon the diaphragm 36a so as to bring about an upward opening movement of the valve 44 for causing an increased ow of the liquid fuel past the valve and thus increasing the richness ofthe mixture delivered to the engine. The yopening 89 is designed to be of such size that it shall take only a few seconds for the pressure in thechambers 4l and 4 la to become equalized therethrough. When after a few seconds the pressure in the chamber 4Ia is brought into balance with that in the chamber 4l, the differential upward pressure on the diaphragm 36a is brought to an end.

The increased richness of the mixture fed to the engine during the few seconds immediately following the opening of the throttle valve is sufilcient for bringing about the highly desired quick pick-up of the motor. For a truck or other heavy car, the opening 89 may be of smaller size than for a light car so as to provide the increased richness-of the mixture for a longer period, but in any case the size of the opening 89 may be chosen to nt the conditions expected to be met.

The auxiliary valve means comprising the valve 63 which goes into action for idling operation of the engine, comprises the auxiliary casing member 65 above referred to and a second auxiliary casing member secured by screw threads in the wall of the casing member'v33, such casing members 64 and 65 being secured together by screws 66 with a flexible diaphragm 61 secured between the casing members and dividing the enclosed space into

chambers

68 and 68. The chamber 68 is connected with the fuel pipe 20 by means comprising an opening 18 in the wall of the casing member 33. The chamber 68 is also connected to the chamber 42 by means of a bored opening 1I, a restricted plug 12, and a port 13 in the end wall 14 of the auxiliary casing member 64.'

- A dome-shaped partition 15-having .an opening therethrough at one side is provi-ded across 1the chamber 88, serving to support a screen 16 in said chamber 68 between the opening 10 and The auxiliary valve 83 is connected with the cen-trail portion of the diaphragm 61 in position to close the valve por-t 13, pla-tes 11 and 18 being secured on opposite faces of the diaphragm vfor reinforcing it. a coiled spring A19 being provided between 'the plate 18- and a suitable portion of the auxiliary casing member 65 adaptednormallyto hold the auxiliary .valve 63 seated so as to close the valve opening 13.

The arrangement is suc-h that when the engine shaft is -tu-rned over for starting fthe'engine,

with the cho-ke valve I6 closed and the throttle l valve I5 opened, a strong vsuction effe-ot is exerted on the chamber 69 through the

pipes

28 and 26, servingto open the auxiliary valve 63 .against the action of the spring 19, permitting 'fuel to iiow through the opening 18, the valve pont 13, the bore 1I, andthe plug 12` into 'the chamber 42 so as -to :pass into the pipe 2l with any fuel entering the chamber 42; at the same time through the valve opening 45. After the eng-ine has started andthe choke valve hasbeen opened and 'the throttle valve substantially closed dor causing the engine -to idle, the needle valve 44l promptly closes as above described, and the auxiliary valve serves by itself to provide the necessary fuel for'idling purposes. The auxiliary valve 63 is rthen held open against the action of the spring 19 by the continued suction effect transmitted through the pipes 28` and 26, .the suction effect through said

pipes

28 and 28 being main-tained under these conditions by reason of the fact that the rth-rottle valve is practically closed. As soon as rthe throttle is opened wider for power operation of the engine, the suction .effect through the

pipes

28 and 26 falls and the spring 19 moves the auxiliary valve 83 to ists closed position. Under normal circumstances, the auxiliary valve 63v does not open to permit 'fuel to pass except when` one of the valves lo or I6 is closed so as to prevent any substantial flow of air to the cylinders.

In the arrangement shown, comprising rthe spray nozzles 23 for directing fuel tothe air ducts I3 immediately adjacent rto fthe cylinders, it is important that the fuel be maintained in liquid form at all parts of rthe fuel delivery pipes 2i and 22. In order to protect against the eiiects of vaporization of the fuel in the low pressure feed pipes, an arrangement is provided for promptly removing from the pipe any fuel vapor formed therein. This arrangement comprises a iiosutl 80 in the -bowl 20a, provided with a. pin or stem 8l on its upper face slidably mounted in an opening 82 through a bracket 83 depending from the top wal'l of the bowl. This lbracket -is provided with a chamber 84 therein communieating with the opening 82 in which the pin 8l is mounted, such chamber 84 being connected by a, pipe 85 with fthe intake manifold l2. The arrangement is such that the fuel entering through the pipe 2| is free at all times to iiow through the pipes 22 to the spray nozzles 23. Any 'fuel vapor formed in the fuel feeding pipes will, of course, rise into fthe bowl 20a so as to dis-place a part of the liquid fuel from the bowl and thus lower the level of lthe fuel. When the level of the liquid is lowered suiiiciently yfor causing the stem or pin 8l on the float to clear the upper portion of fthe opening 82 above the chamber 84, the vapor escapes from the -bowl through the chamber 84 land the pipe 85 into the intake manifold. The reduced pressure in the bowl by reason of the escape of the vapor permits the entrance of additional fuel by reason of the pressure thereon in the pipe 20, such additional fuel serving to raise the float for again closing the upper end 8 that changes might well be made in the form and arrangement of the parts without departing from the spirit of the invention.

We claim: i. In an apparatus for feeding fuel and air to an internal combustion engine intake, the comportion of fthe opening 82, whereupon the flow of additional fuel ceases.

By our improved construction, we have provided an operative arrangement adapted to coopcrate effectively with the apparatus with which it is associated without induriously affecting the operation of such apparatus and adapted by automatic actionvto bring about temporarily increased richness of the fuel mixture fed to the engine at every opening movement of the throttle valve during the operation of the car. The arrangement is such that the temporary changes in the richness of the mixture are brought about only upon the opening of the throttle valve and rthatrthere is no corresponding change for cutting down the richness of the mixture when the throttle valve is given a movement toward its closed position.

While we prefer to employ the form and arrangement of the parts as shown in the drawings` and as above described, the invention is not to be restricted thereto except so far as the claims may be so limited. it being understood bination comprising: means forming an air induction passage connected at one end with the intake of the engine, said passage being shaped to form a Venturi portion, means for supplying fuel to said air induction passage, the last said means including a fuel pressure regulating valve, operating means for said valve including diaphragm means connected to be sensitive to the fuel pressure downstream of said valve for tending to close said valve when said downstream pressure rises, second diaphragm means connected to be sensitive to the pressure differential created by ilow of air through said venturi for tending to open said valve as said pressure differential rises, third diaphragm means connected to be sensitive on one side to the pressure at said engine intake, means forming a passage leading between the two sides of the last said diaphragm, a check valve in said passage, means forming a leak port between the two sides of said check valve, said check valve Ibeing so oriented as to close when the pressure on said one side of the last said diaphragm rises and to open when the last said pressure drops, and means connecting the last said diaphragm to said pressure regulating valve so that the existence of a higher pressure on said one side than on the other side thereof will tend to open said pressure regulating valve, whereby a sudden increase in the pressure at said engine intake will produce a pressure differential across the last said diaphragm tending to open said regulating valve, the last said pressure differential being dissipated over a period of time by leakage through said leak port, whereas a sudden decrease in the pressure at said engine intake will open said check valve and reduce the pressure on both sides of the last said diaphragm substantially equally.

2. In an apparatus for feeding fuel and air to an internal combustion engine intake, the combination comprising: means forming an air induction passage connected at one end with the intake of the engine, said passage being shaped to form a Venturi portion, means for supplying fuel to said air induction passage, the last said means including a fuel pressure regulating valve, operating means for said valve including diaphragm means connected to be sensitive to the fuel pressure downstream of saidvalve for tending to close said valve when said downstream pressure rises, second diaphragm means connected to be sensitive to the pressure differential created by flow of air through said venturi for tending to open said valve as said pressure differential rises, third diaphragm means connected to be sensitive on one 'side to the pressure at said engine intake, means forming a passage leading between the two sides of the last said diaphragm, said passage having means therein adapted to permit a. substantially unrestrictedl flow of air from the other side of the last said diaphragm to the said one side thereof and to oder substantial restriction to the flow of air in the opposite direction whereby a sudden increase in the pressure at said engine intake will produce a pressure differential across the last said diaphragm tending to open said regulating valve, the last said pressure differential being dissipated over a period of time by way of the restriction, whereas a sudden decrease in the pressure at said engine intake will reduce the pres- '2,448,181 9 sure on both sides of the last nld diaphragm 2,138,591` Brllcke Nov. 29, 1938 Name Date Schlmanek Oct. 1, 1940 Mock et al. Mar. 31. 1942 Udale Apr. 13, 1943 'Ifwyman Dec. 25, 1945 FOREIGN PATENTS Country Date Great Britain L-- June 16, 1938 France Feb. 25, 1928 OTHER REFERENCES Ber. No. 391.968. Mennesson (A. P. CJ, published May 25, 1943.