US2321211A - Auxiliary fuel feeding device for internal combustion engines - Google Patents

Description

June 8, 1943.

A. v. JOHNSON 2,321,211

AUXILIARY FUEL FEEDING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed July 27, 1940 aM 4 ATT RNEY:

Patented June 8, 1943 AUXILIARY FUEL FEEDING DEVICE FOR INTERNAL COLIBUSTION ENGINES Albin V. Johnson, Cedar Grove, N. J., assignor to Automotive Economy Corporation, Jersey City,

. J., a corporation of Delaware Application July 27, 1940, Serial No. 347,998

1 Claim.

This invention relates to auxiliary or supplementary fuel feeding devices, such devices for example as are intended for feeding liquid antiknock agents or detonation suppressers in conjunction with and separately from base or primary fuel. These so-called auxiliary fuels may contribute added B. t. u. value to the primary fuel in addition to acting as anti-knock agents or may be devoid of any B. t. u. value and merely act as anti-knock agents.

Separate feeding of such liquids is well understood to those skilled in the art and numerous devices have been proposed for such separate feeding. Some of the devices heretofore proposed have been too complicated, both from the standpoint of manufacturing and installing, as well as servicing. Others are unitary with the carburetor for the primary fuel, and require material alteration in the engine structure. Still others are uneconomical in the use of the auxiliary fuel. In this connection it is pointed out that in the use of certain auxiliary fuels which have a combined anti-knock and B. t. u. value (such as alcohol or a mixture of alcohol and water), the fuel cost is not justified when reckoned solely on the B. t. u. basis but only when its additional anti-knock property is required for optimum engine operation-and this last operative condition occurs at only relatively narrow ranges and time intervals.

An object of the invention is to provide a device of the character described which is a unitary structure separate from the primary fuel carburetor but adapted for conjoint use therewith and capable of ready installation.

Another object is to provide a simple and dependable device which is adapted to be easily adjusted or adapted to engines of varying characteristics.

The invention consists in the novel features, arrangements, and combination of parts embodied by way of example in the apparatus hereinafter described as illustrating the present preferred form of the invention, and the invention will be more particularly pointed out in the appended claim.

Further objects and advantages of the invention will more fully appear from the following description taken in connection with the accompanying drawing, which shows by way of example,'the preferred embodiment of the invention.

In the drawing:

Fig. 1 is a plan view of the device with the cover removed;

Fig. 2 is a development section taken substan- Fig. 2.

Before giving a detailed description of the invention as embodied in the drawing, a general description will first be given.

Different makes of cars and trucks have different knock characteristics. That is, the detonation usually increases with the engine speed up to a certain point, and then diminishes and disappears. This peak knock varies with different engines; and accordingly in using a supplementary or auxiliary fuel to suppress detonation it is economical to use-only the amount required for this purpose at the various engine speeds and throttleopenings peculiar to the characteristics of the particular engine.

The vacuum or suction in the engine intake,

on the engine side of the throttle, varies inversely as the engine speed and throttle opening, i. e., at higher engine speed and opening, the vacuum is greater than at a lower engine speed and wider throttle opening. Accordingly, it is useful to utilize the intake suction of the engine as a means of controlling the feed of the auxiliary fuel. The prior art has utilized the intake suction of an engine as a means of shutting off or turning on a flow of auxiliary fuel, but the balance of control necessary in regulating the auxiliary fuel consumed by the engine was not maintained in a manner to pro-'- duce economy. I have solved this problem by utilizing the suction of the respectively opposite sides of the engine-throttle and by a special arrangement of feed jets and atmospheric vent. In general, I effect the desired balance of control as follows: A' float chamber, or other suitable constant level fuel chamber, supplies the fuel to a primary jet which is opened or closed in accordance with the intake suction from the engine side of the throttle. The size of the primary jet when fully opened is adjustable so as to provide for a maximum flow capacity through said jet. From the primary jet the fuel passes to a secondary jet through which it is drawn by suction imposed on the auxiliary fuel discharge nozzle which is positioned in the carburetor mixing chamber, and the size of this jet is predeterreduced throttle mined in accordance with the motor characteristics so that the amount of fuel which can be sucked therethrough is in proportion to the engine needs. Since the suction at this point in the carburetor increases with the engine speed, and since the peak knock occurs at an engine speed well below the maximum speed, the rate of feed of the auxiliary fuel would be uneconomical above the peak knock engine speed. I have prevented this uneconomical use of auxiliary fuel by placing a vent intermediate the two jets so as to prevent the suction from being imposed upon the primary jet, which is accordingly subjected only to gravity feed from the chamber; and by adjusting the maximum opening of the primary jet this flow may be limited to a maximum corresponding to any peak knock speed of the engine. By this means I am able to feed auxiliary fuel in increasing amounts in accordance with the suction in the carburetor mixing chamber up to the desired engine speed and then maintain a substantially constant maximum feed along a substantially straight line throughout the remaining range of engine speed; and the feed is commenced and stopped under control of the suction on the engine side of the throttle. In the embodiment of the device illustrated in the drawing, I designates a body member and 2 a cover therefor. A fluid chamber 3 is provided therein and the fluid level in the body member, designated as 4, is maintained substantially constant as by means of a float 5 pivotally supported at 6 by a float lever I engageable with the valve stem of a feed valve designated in general as 8 and which may be of any suitable well-known form; the valve 8 being disposed in the cover 2 and being in connection with a suitable source of fluid supply through-pipe 9. A fluid level plug I is preferably provided in the wall of chamber 3 to facilitate the correct setting of the float 5.

The fluid chamber 3 is adapted to supply, on demand, fluid (such as auxiliary fuel) to a discharge nozzle 1 I through an interconnecting passage comprising a horizontal bore l2, 2. vertical bore l3, a horizontal bore H, a vertical bore l and a horizontal bore I6 which is in communication with the bore of the externally extending nozzle The flow of fluid through said passage is controlled in the manner now to be described.

A vertical bore I1 is disposed in axial alignment with the vertical portion l3 of the fluid passage and accommodates a needle valve member |8 vertically movable therein. The lower end of the needle I8 is provided with the usual point operatively disposed relative to a cooperating seat I8 provided at the upper end of the bore I3; the lower end of the needle being reduced in cross section at the junction of the bores l2 and 13 to pro ide an annular passage portion between the bores -|2 and I3. The upper end of the needle I8 is connected by a link 20 with the upper end of a pneumatic piston 2| positioned in a cylindrical bore 22 formed in the body and whose axis is substantially parallel to and spaced laterally from the axis of needle IS. The piston 2| is urged upwardly by means of a helical spring 23 disposed within a bore provided in said piston and seated on the lower cylindrical end. The cylinder is supplied with suction through a tube 24 in communication with the intake of an internal combustion engine on the engine side of the intake throttle valve 25, as by being in communication with the intake manifold of said engine designated as 26. The throttle valve 25 may be the throttle of the usual engine fuel carburetor designated a 21,

and the mixing throat of which is designated as 21', within which is positioned the auxiliary fluid.

discharge nozzle II. From the foregoing it will be seen that the valve stem I8 is normally urged upwardly to open position by the spring 23, the open position being flxed by an adjustable stop provided by a screw 28 passing through the cover 2 and held in adjusted position by a helical spring 29. When the suction imposed on the piston 2| overcomes the force of the spring 23, the valve stem or needle I8 is moved downwardly and is seated on the valve seat l9 to close the control jet provided by this valve structure and herein termed the primary jet or high speed flow control jet.

A secondary or low speed control jet may be a fixed jet such as 30, which is disposed in the vertical portion l5 of the fluid passage. This jet is of such size as to control the flow of fluid in accordance with suction imposed on the nozzle H even when the high speed flow control jet is open, i. e., when the valve stem I8 is raised by the spring 23. The jet 30 is selected in accordanc with the characteristics of the engine for which the feeder is intended, and in the present embodiment when the jet was selected for a Ford 1937 engine, the jet opening is .040 inch. A jet plug 3| closes the threaded bore into which the jet 30 is positioned and the plug 3| i provided with suitable axial and radial fluid passages in register with the passage |5 and I4. As is well understood by those skilled in the art, an adjustable jet of the screw needle valve type may be used so as to provide a universal device which may be adjusted for the desired engine. For example, the plug 3| may be replaced by a needle valve stem assembly illustrated in Fig. 5,where 33 designates a modified plug through which passes a needle 34 threadably engaged in the plug '33 for axial adjustment relative to the jet 30, against which the needle point is adapted to cooperatively seat, and the bore of the jet 30 will be increased (say to .055 inch diameter) to provide for the largest capacity desired. A suitable packing gland is provided in the usual manner and is adjusted by mean of the nut 35.

A vertical bore 36 is positioned intermediate the high speed flow control jet |8-|9 and the low speed suction controlled jet 30 and is in communication at its-lower end with the horizontal passage portion l4; while its upper end is in communication with a recess 31 provided in the cover 2 and which communicateswith the float chamber 3 by means of a passage 38. The float chamber, and thereby the passage 38, reces 31 and bore 35 are vented to atmosphere by means of a vent plug 39 provided with passages for this purpose. The fluid level in bore 36 varies in accordance with flow through nozzle 30.

From the foregoing it will be understood that by selecting a spring 23 which will overcome the opposite force exerted on the piston 2| by a suction of the order of magnitude indicated, the valve stem |8 will be caused to move away from its seat H3. The spring is such as to open the valve at the desired degree of suction (which is usually 4"5" Hg or less) such as at relatively low speed and open throttle positions; and to close the valve at increased suction, such as at partly closed throttle and increased speed. The maximum opening of the valve is set to provide a maximum gravity flow capacity equal to the capacity of the suction jet 30 at the engine speed desired (preferably corresponding to the peak knock engine speed). This arrangement not only supplies auxiliary fuel when needed but prevents an excess of auxiliary fuel being fed to the engine at such times as the engine requires a limited supply thereof.

In the use of certain auxiliary fuels, such as a mixture of alcohol and water, it is not only wasteful to use excessive amounts of such auxiliary fuel but it is important that auxiliary fuel in excess of that which may be taken into'the intake of the engine and consumed be not fed to the intake, since this will cause harmful crank case dilution. I have found that the present invention has very satisfactorily met all of these requirements and its arrangement is such as to prevent leakage of the auxiliary fuel into the system when the auxiliary fuel is not required. Furthermore, by the use of this invention the .I aim in the appended claim to cover such changes and modifications as are within the scope of the invention.

What I claim is:

In a device of the character described. the combination of a body portion and a cover therefor, a fluid chamber in said body, a horizontally disposed discharge nozzle extending externally of said body adjacent the top of said body and adapted to be inserted within the zone of suction of an internal combustion engine carburetor, a fluid passage within said body and interconnecting said chamber and nozzle, said passage comprising horizontally and vertically disposed portions, a first metering jet in said .vertically disposed fluid passage portion intermediate said discharge nozzle and said horizontally disposed passage portion constructed and arranged so as to vary the flow capacity in accordance with suction imposed through said nozzle, a second jet between said first Jet and said chamber constructed and arranged so that'the flow of fluid therethrough is under the pressure influence of gravity only, said first and second 'jets being substantially below the liquid level of said fluid chamber and being so constructed and arranged that the entire fluid flowing through said nozzle passes in series through said jets, an air vent passage formed jointly in said cover and said body and in communication with said fluid passage intermedlate said jets, a vertically movable valve member positioned in a bore in said body for varying said jet opening, a pneumatically operable piston substantially parallel to said valve member positioned in a cylinder formed in said body and connected to said valve member for movement thereof, means for urging said piston upwardly against pneumatic operation and adjustable stop means carried 'by said cover for limiting the upward movement of saidvalve member and piston.

ALBIN V. JOHNSON.

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