US2373302A - Internal-combustion engine - Google Patents

Description

April s. R. ERICSON 2,373,302

I INTERNAL-COMBUSTION ENGINE I Filed Dec. 10, 1942 2 Sheets-Sheet 1 7 INVENT I i GERGE R. REGSQ .aa,

April ,1 e. R. ERlCSON 9 9 INTERikAL-COMBUSTION ENGINE Filed Dec. 10, 1942 2 sheets-sheet 2 ATTORNEY -?atented W, 1945 STATES INTERNAL-COMBUSTION ENGINE George R. Ericson, Kirkwood, Mo., assignor to" Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application December 10, 1942, Serial No. 468,564

l3 Claims.

This invention relates to internal combustion engines and particularly to automotive engine's of the multi-cylinder type The invention is, in some respects, an improvement of the invention shown-in my earlier filed application, Serial No. 453,116, filed July 31, 1942. Indevices of the character shown in the previous application, the

fuel is cut off from some or all of the cylinders in accordance with the power requirements of the engine as indicated by the vacuum in the intake manifold. The fuel cutoff is accomplished by a vacuum control valve in the fuel passage. Where the carburetor is of the plain tube type having a fuel system comprising a plurality of outlets receiving fuel from a single inlet, the most con venient place for the cut-off valve is at the fuel inlet. This is particularly true in' cases where the invention is to be applied in the field to an engine which is already equipped with a carburetor, and where the only changes which can conveniently be made are those which involve nothing more than the addition or substitution of parts without the necessit for doing any drill ing or other machine work on the carburetor or engine. Where thefuel is cut off at the inlet of the branched fuel passage, there necessarily remains a small quantity of fuel in the passage posterior to the valve. After the valve is shut off, the application of suction to. the idle passage in the normal operation of the engine drains the fuel systems posterior to the cut-off valve, thus -reference to the following description and accompanying drawings, referring to which:

-, ,Figure 1. is a diagrammatic view of a multi- I cylinder internal combustion engine having my' invention applied thereto.

Figure 2 is a sectional elevation showing a carburetor equipped for the'performance of my invention.

Figure 3 is a diagrammatic sectional view I taken alongthe' line 3-3 of Figure 2.

pring.

wastin a small quantity of gasoline. Of course,

the quantity in the fuel passages may be very small, but the operation is repeated so often as f to involve noticeable waste of fuel over a period of time.

While the loss of fuel in the manner above described might be disregarded, a slight lag in ac- 'celeration may occur, due to-the fact that when the throttle is open, it is necessary to refill the fuel system before any discharge can, be had into the mixing conduit. The cut-off valve is instantly opened on account of the loss of vacuum as soon as the'throttle is opened, but it takes a noticeable amount of timefor the suction of the car-. buretor to refill the fuel passages. acceleration may be substantially eliminated by withdrawing the fuel from the passages when the valve is cut off and returning it to refill the passages when the engine is again accelerated.

It is an object of my invention to prevent the 'waste of the fuel contained in the fuel system posterior tothe' cut-oil valve. It is a further object of my invention to prevent the lag in acceleration caused by the neces- This lag in Figure 4 is an elevation of the device shown in Figures 2 and 3'with parts broken away and others shown in section along the line ldof.

Figure 2. I

Figure 5 is a detail assembly viewshowing one of the metering rods or control valves'together with its operating means and connections.

Figure 6 is a detail view showing the coasting- Figurel shows a multi-cylinde r internal cornbustion engine having eight cylinders numbered I to 8. The engine block is indicated generally by the reference character 9, and this is connected to intake manifolds l0 and II which are served with fuel mixture by a carburetor l2 having two barrels l3 and I4; Each barrel of the carburetor is supplied with fuel from the float-chamber i5 by-means of separate fuel passages l6 and I1, and the fuel supply to each passage is controlled by metering rods or valves 18 and I9, respectively.

Main jets 20 and 2| are provided with restricted orifices forming valve seats to receive the cooperating valve portions of the metering rods under certain conditions hereafter described.

It will be understood that the barrels of the canburetor maybe substantially the same in construction, and each comprises an air inlet.22, one

or more venturis 23, a main fuel, nozzle 2%, an

idle fuel nozzle25, and a throttle valve 26, which ismounted on shaft 21 controlling the fuel dis-- charge outlet. 28. The carburetor is bolted onto the intake manifolds by means of the flange 29.

-' orries either open or. closed and not regulated.

controlling thejdischarge outlet of one of the with fuel from the jets'lll and 21. through passages 3|, which are connected to the passages l8 and II, respectively, at a point between the main jet and the discharge outlet of the main jet. It will beunderstood thattheidlefuel may be supplied independently from the main jets, if desired, as shown in my prior Patent No. 1,967,708, issued June 5, 1934. Since'the present construction is intended for application in the field, as well as for original equipment, I have shown an existing type of .ca'rburetor which is provided with idle passages, discharge ports, and adjusting screws for both barrels of the carburetor. .In order to,

apply the invention, one of the idling screws 30 is removed and replaced by the pipe fitting -30l An idling adjustment screw 3'. is provided fer "with a valve portion 4: similar to the valve u,

' idling passages.- -The idle passages are supplied which maybe seatedto shut off the fuel from the main jet 2| by furtheFdownwax-d movement of the piston 34 after the valve 39 has seated. The spring 38 is calibrated to permit the seating of the valve .43 when the suction exceeds the normal idling suction, for instance, when coasting at speeds higher than the normal idling speed of the engine. I

One of the important features of this device is the provision ofmeans for preventing the valves 39 and 43 iromoccupying a position in which they substantially restrict but do not completely close the jet, and I have provided special means for this purpose, as follows:

A magnet 54 is mounted on the rod in such a position that its lower end approaches contact with the top of the jet just at the time when the and'the-connectin'g passage ili2'between the low' sity ofdrilling holes in the caiiburetor or manifold.

The above construction is fairly well known (except as indicated), and is frequently referred to as the plain tube type of carburetor. The construction is such that when the throttle valve is in nearly closed position, only fuel from the idle ports 25 is delivered to the engine, and when the throttle is opened, the fuel discharge is transthe main nozzle prevents the discharge of fuel at the outlet 25, it being understood that the venturis 23 cause a higher suction to be established at theoutlet of the main nozzle than that which exists at 25 during open throttle operation.

The metering rods i8 and I! are connected to a pin 32 which is mounted. on piston rod 33.

This rod is connected to the piston 34 mounted in cylinder 35 for operation by suction through the passage 36. This suction passage is connected to the discharge outlet of the carburetor posterior to the throttle, as at 81. A spring 38 is mounted under the piston in a position to be compressed when the suction is high, so as to draw the members l8 and i9 down into the main Jets. The

I metering rod 18' is provided with a valve portion 39, which seats in the main jet 20, to cut oil all ma supply to the carburetor barrel l3 and the inside manifold l when the suction is high. The point at which this main jet is cut off may be at a suction correspondingto to of mercury, depending on the particular installation, and at low suction-s the fuel is permitted to flow normally; subject to regulation by the graduated metering portion 40 carried at the lower end of the rod 18. In some installations, I replace the main jet with one slightly smaller and omit the graduated portion 40, so that the member 39 merely acts as a valve to control the lot which is The rod [8 isIconne-cted withthe pin by means of a limited, lost motion-flexible connection 4| which may be provided with a light spring 42 to insure the firm seating of the valve 39 without preventing further downward movement of the rods 33 and". The rod I9 is provided valve reaches closing position. The jet is made of magnetic material, so that the magnet holds the jet firmly to the seat although with a very light .pressure. The spring 42' is a very light spring, just suihcient to hold the weight of the rod and valve against the slight suction normally present which draws the metering rod portion 4|! of thevalve downwardly, but as soon as the magnet approaches the jet, the additional force or the magnet causes the valve to close with a snap action, which is only overcome when some substantial force is applied by the spring 38 or by the manually operated member 49. However, as

. ferred to the main nozzle 24, and the suction from of the suction itself. During normal operation, with the valve open, the normal suction of the.

soon as the valve is broken away from its seat,

the magnetic action is weakened, and the valve opens with a snap action. This arrangement prevents the valve occupying a position in which it would allow' a highly restricted flow of fuel through the jet but still not sufllcient to permit v operation of the cylinders. If the valve remained in such nearly closed position, it would simply resultin the wastage of fuel.

Another means for preventingthe valve from occupying a nearly'closed position is the action carburetor can act on the metering rod portion only, but the diameter and area of this portion are small compared to the diameter and area of the valve member 39. Thus, when the valve member begins to restrict the'fiow, the

downward force exerted on it is increased in the 4 measure of the difference in area between the rod portion 40 and the valve member 39, and this In many installations, the action of the spring 38 maybe used alone to oppose thev suction action and position the metering rods and the valves 39 and 43. However, in some installations, the positive'opening and closing of the valves will be improved by the use of the precompressed spring 55, which is held in a capsule composed of top and bottom washers 56 held together by the rivet 51 which limits the expansion of the precompressed spring 55, but does not prevent compression. The use of the spring 55 permits comparatively rapid downward movement of the metering rod after-the establishment of a predetermined suction.- Also, the action of this capsule is to present a fairly solid'bottom for the piston 34 during the normal idling period.

-. a'svasoa The valve 39 is designed to shut ofi its jet at approximately winches of mercury of vacuum alone, while the valve 43 is not intended to shut ofi its jet until a vacuum of at least 18 inches of mercury is developed. With this wide differe'nce required in the action of the valves, it would be necessary to provide for substantial travel of the piston 34 and corresponding extra length of 1 the metering rod portions 40, if the spring 38 alone were depended on to control the actuation of the valves. The provision of the spring capsule E6 permits the piston 34 to reach a definite limit of travel responsive to any vacuum between 10 inches and 18 inches of mercury. This position is retained until the 18 inches isexceeded, at

which point the spring 55 yields and permits closing of the valve t3.

By this construction, the action of the parts may be more accurately controlled, and the size and length of theparts may be reduced. It will be understood that the figures of 10 inches and 18 inches of mercury are only illustrative and may be varied substantially according to the re-' quirements ,of the particular engine and the use.

to which the device is applied. Without making any attempt to list the factors on which the closing pressures of the valves will depend, it may be noted that the compression ratio of the engine is an important factor in determining the normal idling manifold vacuum.

It will be understood that the usual accelerating pump is provided, and that the pump discharge to the inside carburetor I3 is made a little heavier thanto the outside carburetor, because thmanifold It will most frequently become dry and will require more fuel to wet it upon acceleratlon. The outside manifold is longer and has more surface to wet, but the wetting action is initiated sooner after coasting, and is kept wet during normal idling.

- It will also be understood that the fuel may be first shut ofi in the outside manifold ll while permitting the engine to idle on the inside manifold it, but, in most'constructions, the shut ofi of the fuel to the inside manifold would be preferred on the ground that the manifold is shorter, has less well surface and capacity and, therefore, requires less time and fuel to set it in operation after idling. h

The throttle shaft 2? is normally biased to close the throttle by the conventional spring starter switch is operated. It may. also be noted throttle.

' It will be understood that the usual accelerating pump actuated by opening movement of the throttle is provided. An example of this pump may be found in my previous patent above mentioned, butit is not believed necessary to describe it in detail. A conventional automatic choke mechanism is also provided, but this is not essential to the present invention and need not be described.

While the-automatic choke mechanism is not described in detail, reference may be had to cosey Patent No. 2,085,351, issued June 29,

1937, or Blattner Patent. No. 2,166,899, issued July 18, 1939, which shows means for preventing the closing of the throttle to its full idle position by the throttle spring, which is provided. to normally'maintain it in that position. This means operates during warmingup period, so that the starting and warming up is accomplished by joint action of all th cylinders of the engine, and it should be noted that the adjustment of the arm 60 with respect to the member as is such as to prevent the closing of the valve 39 when the fast idle is in'operation; that is to say, when the -throttle is held in the fast idle position, as by means corresponding to the members til-t i--% of the Coffey patent, or 32, etc., of'Blattner, the i throttle is opened far enough to insure the lifting generally that the link I26 shown in Figure 2 of this application corresponds generally to the link 26 0f Coffey 2,085,351, and t0 link32 Of Blattner,

and the housing M2 and thermostatic control mechanism may be said to correspond generally to the housing as and thermo-control mechaiiim of the Cofiey patent.

From the foregoing, it will be observed that the present invention may be adopted in carburetors of various types, particularly where the fuel oils tributing system includes a manifold so constructed and arranged as to feed the explosive mixture to separate banks of cylinders from a which is not shown. The shaft 21 is connected by means r the lever st, link as, and lever as to therockshait M.- This rock shaft carries a lever so having a projecting arm #9 which is constructed and arranged to contact thunderside of the horizontal projection 5B which is preferably integral with the upper end of the piston rod 33. The member .has upturned lugs 5! (Figure 3) on which the pin. 32 is mounted, so as to make a direct operating connection between the piston 3t and the metering rods is and It. This connection, however, is flexible by reason of the fact that the spring 42 is bent at its ends to pass through the openings 52 which are controlled through the metering rod above and below the slot or lost motion connection tl. The

connection between the throttle valve and projecting arm eels such that the projection is and the meteringrods are forced upwardly upon -an opening movement oi the throttle, and, in the preferred construction,'the rod 19 is firstlifted.

of! its seat to initiate the supply of fuel to the outside manifold M, and the-rod i8 is forced on" carburetor mechanism. In such assemblies, it will be practical with the present invention to permit the idling of a motor only with an ex tremely small amount of power such as may be derived from an idling mixture supplied to only a part of th total number of cylinders of the engine. This development is elastic, at least to theextent that one or more jets can be totally closed where only a limited amount of power may be necessary to drive along a' substantially level road at'a relatively limited speed. The closing of a jet, or of more than one jet, is essentially synchronized with the mechanism controlling the normal operation of the engine, and it is preferable that the closing of the jet or jets be brought about with a snap action such as will tend to eliminate undesirable and irregular explosions tending to bring about a possible surging condition in the motor.

. The greater part of the above subject matter is disclosedin my copending application, Serial 'No.

453,116, flied July 31; 1942. I have found that the construction can be further improved by the provision ormeans for withdrawingthe iuel from.

his seat later in the opening movement of the the fuel passages of the carburetor between the cut-off valve and the discharge outlet. This fuel withdrawing means is preferably constructed and arranged to operate by suction, so as to withdraw the fuel at the time the fuel supply is cut off and to return it as soon as the fuel supply valve is again opened.

A convenient means for applying this invention to a carburetor in the field is embodied in the structure shown in Figure 3. The idling screw of the barrel of the carburetor, to which the fuel supply is controlled by the valve 39, is removed and replaced by the pipe fitting 3M, and a plug is placed in the passage 302, so that the full manifold suction is applied to the pipe fitting. From this fitting, the suction is conveyed through a pipe 303 to a connecting member 304 at the end of cylinder 305,,which contains a double piston 306-normally held in the position shown by the spring 301. l The travel of the piston is adjustable by means of the screw 308 which is held in adjustable position by lock nut 309. The cylinder 305 is threaded, as at 3l0, to screw into the opening flitt'hebase of the main nozzle 24 at the bottom of t ie'r ei well 3| I. i The piston 306 is constructed and arranged to closes, so that simultaneously with the closing of the valve, the piston is withdrawn against the pring 301. Since the connection 3H1 is at the the fuel from these passages through the port 25,

" which would otherwise occur as soon as the valve 39 is closed, it'being noted that the upper part of the well 3| l is provided with the air passage 3l2,

aslo other air bleeds above the fuel level l ZDllld permit the discharge of the fuel contained 4 the passages, even after the valve 39 is closed.

pen acceleration of the engine, the fuel which has been withdrawn into the cylinder 305 is immediately replaced, due tothe return of the piston 306.

In order to obtain the greatest possible speed in the resumption of normal functioning by the nozzle 24 whenfuel feeding is resumed after being cut off I provide a restricted passage 320 in the connection 3l0 between the nozzle base or well l'|--3|l and the upper end of the cylinder 385. This passage is axially aligned with the passageway through the nozzle 24 in such a manher as to direct a jet of fuel up through the nozzle base so as to produce an injector action to assist in refilling the nozzle and restarting the fuel flow therethrough. The action of this jet may continue from one to five seconds so that there is a continuous tendency to produce flow through the a nozzle whenever the suction drops sufliciently to permit the spring 301 to shift the piston 30 6 to the position shown in- Fig. 3.

It might be supposed that leaving-the outlet of the: snatcher pump wide open and unrestricted would. result in a quicker refilling of the nozzle, but tests show that the cylinders supplied by the nozzle 24 resume operation more quickly and smoothly when the restricted passageway 320,

{respond to the same vacuumat which the valve,

Details of structure in which the valve 39 or its equivalent is interconnected with the piston 308 are shown in copending application Serial No. 453,116, filed July 31, 1942.

Iclaim:

1. In an internal combustion engine, passage means for liquid fuel supply, valve means controlled in accordance with the power demand on the engine for cutting off said passage means, means for withdrawing fuel from the passage means when said valve means is closed, and

. means for restoring said fuel to the passage means when said valve means is again opened. 2. In an internal combustion engine having an intake manifold, a carburetor for supplying fuel to said manifold, said carburetor having a fuel passage, a valve for controlling said fuel passage, means responsive to manifold vacuum for. controlling said valve, and means connected to said passage at a point posterior to said valve for withdrawing fuel when said valve is cut off.

3. In an internal combustion engine having an intake manifold, a carburetor for supplying fuel to said manifold, said carburetor having a, fuel passage, a valve for controlling said fuel passage, means responsive to manifold vacuum for controlling said valve, means connected to said together with its injector action. are used instead of an unrestricted passage at 320. This may be due in part to better synchronization between the I ll action of the valve 39 andthe action of the piston 306; but it has been. found that the restriction and injector action are still desirable even when the valves-39 and piston 306 are interconnectedso as to positively insure simultaneous operation.

opened.

passage at a point posterior to said valve for withdrawing fuel when said valve is cut off, and means for restoring said fuel to. said passage when the valve is again opened. I

4. In an internal combustion engine having an intake manifold, acarburetor for supplying fuel to said manifold, said carburetor havin a fuel passage, a valve for controlling said fuel passage, means responsive to manifold vacuum for controlling said valve, means connected to said passage at a point posterior to said valve for withdrawing fuel when said valve is cut off, and means for delivering said fuel to the fuel supply system of the engine when said valve is again 5. In an internal combustion engine having an intake passage, .a carburetor, a throttle for cona trolling the flow of mixture from said carburetor to said engine, said carburetor having a fuel passageway, valve means for controlling said fuel passageway, means connected to said fuel passageway posterior to the valve for withdrawing fuel therefrom, and means operated by the manifold vacuum for controlling said valve and said fuel withdrawing means.

6. In an internal combustion engine having an intake passage, a carburetor, a throttle for controlling the flow of mixture from said carburetor to said engine, said carburetor having a fuel passageway, valve means for controlling said fuel passageway, means connected to said fuel passageway posterior to the valve for withdrawin fuel therefrom,- means operated by the manifold vacuum for controllingsaid valve and said fuel withdrawing means and 'means controlled by said throttle for overruling said vacuum controlled means. 7. In a multi-cylinder internal combustion engine, separate intake conduits leading to separate cylinders of the engine, fuel supply means for said intake'conduits, valve means for cutting off the supply of fuel from'one of said'fuel supply means, means connected to said fuel supply means at a point posterior to said valve for withdrawing fuel therefrom when the valve is cut off,

. said means being constructed and arranged to return the fuel thereto when said valve is again" opened.

8. In a mu1ti-cylinder internal combustion engine, separate intake conduits leading to separate cylinders of the engine, fuel supply means for said intake conduits, valve means forcutting off the supply of fuel from one of said fuel supply means, means connected to said fuel supply means at a point posterior to said valve for withdrawing fuel therefrom when the valve is cut off, said means being constructed and arranged to return the fuel thereto when said valve is again opened, and means controlled by the vacuum in one of said intake conduits for controlling said valve.

9. In a multi-cylinder internal combustion engine, separate intake conduits leading to separate cylinders of the engine, fuel supply means for said intake conduits, valvemeans for cutting ofi the supply of fuel from one of said fuel supply means, means connected to said fuel supply means at a point posterior to said valve for withdrawing fuel therefrom when the valve is cut off, said means being constructed and arranged to return the fuel thereto when said valve is again opened, means controlled by the vacuum in one of said intake conduits for controlling said valve, and manual means for overruling said vacuum means.

10. In a fuel supply device for internal combustion engines, means forming a mixing conduit, means forming a fuel supply chamber, a passage leading from said fuel supply chamber to said mixing conduit, an expansible chamber connected to said passage, means forming amovable wall for said expansible chamber, said movable wall having positions corresponding to complete expansion and complete contraction 11. In a fuel supply device for internal combustion engines, -means forming a mixing conduit, means forming a fuel supply chamber, a passage for conveying fuel from said fuel supply chamber to said mixing conduit, snap action valve means for opening and closing saidpassage to cut off or reestablish flow of fuel'therethrough, and auxiliary means synchronized with said valve action for assisting the reestablishment of fuel flow through'said passage when said valve is opened.

12. In a fuel supply device tion engines, means forminga mixing conduit,

,means forming a fuel supply chamber, a passage for conveying fuel from said fuel supply chamber to said mixing conduit, snap action valve means for opening and closing said passage to cut off or reestablish flow of fuel therethrough,

auxiliary means synchronized with said valve action for assisting the reestablishment of fuel flow through said, passage when said valve is opened and for assisting the abrupt termination of fuel flow through said passage when said valve is closed.

13. In an internal combustion engine, a mix- Y at an angle from the lower part of said reserof said chamber, valve means for controlling the position.

voir into said conduit, a metering orifice element in said passage, Ia cylinder projecting from the bottom ofsaid reservoir in line with said passage and communicating with said passage posterior to said orifice element, a piston in said cylinder,

spring means normally holding said piston at the upper end of said cylinder, and a vacuum connection from the lower end of said cylinder to said conduit, said cylinder and piston being constructed and arranged to withdraw fuel from said fuel passage when high suction exists in said con duit and to return said fuel when the suction drops in said conduit.

GEORGE R. ERICSON.

for internal combus-

Images