US2737939A - Method and apparatus for starting internal combustion engines - Google Patents

Description

March 13, 1956 JOECK 2,737,939

METHOD AND APPARATUS FOR STARTING INTERNAL COMBUSTION ENGINES Filed Jan. 5, 1954 INVENTOR.

l9 THOMAS D, JOECK ATTORNEY United States Patent METHOD AND APPARATUS FOR STARTING INTERNAL COMBUSTION ENGINES Thomas D. Joeck, Eatontown, N. J., assignor to the United States of America as represented by the Secrotary of the Army Application January 5, 1954, Serial No. 492,419

6 Claims. (Cl. 123-420 (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for govern, rental purposes without the payment of any royalty thereon.

This invention relates to a method and apparatus for starting internal combustion engines and particularly to the starting of engines under adverse conditions such as extremely low ambient temperatures.

It is well known that one of the major difiiculties in starting engines in the low temperature range has been to properly condition the liquid fuel and supply it to the engine in combustible form during the starting and warming up cycle. This difficulty is greatest the lower the ambient temperature. The fuel at low temperature resists both dispersions and vaporization.

The fuel could be conditioned by the application of heat to the engine and the fuel supplying elements thereof. As a practical matter, however, the quantity of heat and time required to transfer suflici'ent heat to the engine are, under certain circumstances, not available. The present invention supplies the necessary conditioning of the fuel Without the application "of heat. The practice of the invention actually causes intense mechanical vibration or agitation of the fuel. Such vibration takes place preferably at a rate higher than that of the highest audible sound. "The effect upon the fuel is to subdivide it intoextremely minute divisions or droplets. In this manner an extremely high degree of dispersion is accomplished. The fuel thus minutely divided becomes vaporized at a greatly accelerated rate and this finely divided state of the fuel reduces its tendency to coagulate before it is burned. Thus the fuel conditioned in the manner suggested is readily burned when it enters the engine.

in support of the above premise it may be well to point out at this point that the increase in the rate and eificiency of chemical union between the air and the fuel depends upon the opportunity of the reacting elements to effect reciprocal contact. In the present case where a union between a gas and a finely divided liquid is to be accomplished, the rate at which such union increases is dependent upon the fineness of the particles of the liquid and the rate increases tremendously as the size of the particles approach molecular proportions. To illustrate graphically a cube 1 cm. in size when divided into cubes 1 micron in size shows an increase of surface area in the proportions of -6 to 60,000- It is apparent, therefore, that fine dispersion of the fuel has great utility in increasing its rate of vaporization. Moreover, it has been estimated in the case-ofadsorbed gas that the iattrac- 2,737,939 Patented Mar. 13, 1956 the engine and fuel are at very low temperature. The invention is used in connection with internal combustion engines'having conventional fuel supply systems and includes means which function in an auxiliary capacity during the starting cycle of the engine.

Briefly stated, the invention provides an auxiliary fuel conditioning unit in which liquid fuel is dispersed under supersonic vibrations and fed to the intake port or manifold of the engine while the main throttle leading to the conventional fuel supply is closed or substantially closed. Preferably, the conditioning unit is energized by the lowering of the pressure in the engine manifold during cranking of the engine with the main throttle closed. Other means for energizing the conditioning unit may e used and will be indicated hereinafter.

The conditioning unit or nozzle elfectively and elliciently conditions the fuel for combustion in the engine even at temperatures as low as 65 to 70 F. below zero. The engine is operated from conditioned fuel supplied by the conditioning nozzle until its temperature is raised to a degree where the conventional fuel supplying system is capable of operating the engine at which time the main throttle valve is slowly opened and the engine assumes itsnormal power output.

It is a primary object of the invention to provide means for starting an internal combustion engine under adverse conditions such as low subzero ambient temperatures. I A further object of the invention is to provide a source of priming fuel for internal combustion engines which consists of liquid fuel which has been minutely dispersed and vaporized by subjecting it to supersonic vibrations.

A further object of the invention is to provide a method of preparing and utilizing minutely dispersed and vaporized liquid fuel for starting internal combustion engines in conjunction with conventional fuel supplying systems.

Other objects and features of the invention will more fully appear from the following description and will be particularly pointed out in the claims.

To present a better understanding of the invention particular embodiments thereof will be described .and illustrated in the accompanying drawings wherein Fig. 1 is a general view partly in cross-section illustrating a preferred embodiment of the invention.

Fig. 2 is an enlarged cross-sectional view of the fuel conditioning unit used in the apparatus.

Fig. 3 is across-sectional view on line 3-3 of Fig. 2.

The present design of internal combustion engines and the combustion of fuel used therein permits starting and operation at normal temperate zone temperatures, but starting the engine at Subzero temperatures presents difficulties which impose great inconvenience and loss of time. This is particularly true when operating such engines in the Arctic regions where the conventional method is to soak the engine for relatively long periods in a high temperature atmosphere.

The practice of the present invention will start engines having temperatures as low as -65 to 70 E. Stat:- ing of engines at these low temperatures without the application of heat is accomplished by processingthe fuel in a specific manner to render it readily combustible and supplying the engine with the conditioned fuel during the starting period.

The apparatus involved is readily adaptable to existing engines having conventional fuel supply systems since the fuel conditioning apparatus may be applied directly to the intake system or intake port of the engine and suitable means are provided for supplying air and :fuel to the conditioning unit.

Referring to Fig. l of the drawings the invention is shown as applied to a fuel system of an internal combustion engine of conventional construction. The main fuel supply system of the engine may, however, be designed specifically for use in connection with the invention. The engine 5 is provided with one or more cylinders 6 containing a reciprocating piston 7 and a cylinder head 8 containing an intake port 9 and an intake valve 10 for admitting fuel to the cylinder.

An intake manifold 11 is connected to the intake port 9 and receives fuel from a conventional carburetor 12. The main operating fuel supply to the engine is controlled by throttle valve 13. Liquid fuel is fed to the float chamber 14 thru a supply line 15 connected to a source of fuel or to a fuel pump not shown. The level of fuel in the chamber 14 is maintained by the usual float valve and float.

The invention provides a specially constructed fuel conditioning jet 16 having its outlet extending into the intake manifold 10. Desirably, the jet is so located that its output enters the intake port directly. While the principles of the invention apply equally well when the jet 16 is located anywhere in the manifold, by locating the jet to feed fuel directly to the intake port, condensation of fuel caused by contact with cold surfaces is reduced to a minimum.

The jet shown in detail in Fig. 2 is composed of a main outlet nozzle member 17 provided with a male pipe thread received in a complementary threaded aperture in the engine manifold 11.

The member 17 is provided with a hollow cylindrical portion 18 presenting a cylindrical chamber within which a nozzle receiving sleeve 19 is located. The nozzle itself is indicated generally at 20 and extends into the sleeve 19. For convenience in assembling and installing, the nozzle 20 is provided with a hexagonal wrench receiving collar 21 by means of which its threaded outer end may be assembled to a conventional tube receiving fitting 22 which in turn is connected to an air supply. The air supply may be opened to the atmosphere directly or may be connected to the air input duct from the engines air cleaning system.

The sleeve member 19 is provided with a flange 23 which abuts the end face of the portion 18 of the member 17. To secure the member 19 in its proper position a retaining nut 24 engages the outer face of the collar 21 of the nozzle member 20 causing the inner face of the collar to engage the flange 23 of the member 19. Internal threads formed upon the nut 24 engage the outer threads of a sleeve nut 25. The nut 24 thus secures the members 19 and 20 in proper relationship to the member 17. In assembling these parts the nut 24 is desirably tightened only as tight as it can be turned by hand. Desirably, the nut 24 is split at one point in its periphery and a screw is provided which acts to contract the nut upon the member 25 to lock the parts in adjusting posi tion.

The sleeve nut 25 is internally threaded and engages external threads on the portion 18 of the member 17. Before the sleeve nut is installed, however, an annular fuel supply ring is slipped into place upon the unthreaded portion of the sleeve 18 of the member 17 and against the inner face of the wrench receiving collar thereon. The fuel supply ring desirably fits snugly over the member 17 and is held in place by tightening the nut 25 into contact therewith.

The fuel supply ring 26 has a groove extending around its inner peripheral face which forms an annular chamber 28, the outer surface of the unthreaded portion of the member 17 becoming the inner wall of the chamber.

An aperture is provided in the ring communicating with the chamber 28 by which a fuel supply line may be connected thereto to feed fuel to the chamber. A plurality of radial apertures 29 are formed in the portion 18 of the member 19. These apertures conduct fuel from the chamber 28 into an inner chamber of the member 17 from where it flows to the jet in a manner to be set forth.

The active portions of the fuel conditioning means which minutely disperse and vaporize the liquid fuel will now be described. The sleeve 19 has formed in its inner end a recess which together with the end face of the cylindrical chamber in the member 17 forms a resonating chamber 30. The nozzle receiving recess at the other end of the sleeve 19 extends to a plane a short distance from the chamber 30 to present a wall 31 within which an aperture 32 is formed leading into the chamber 30.

The nozzle 20 has a portion adjacent to its wrench receiving flange 21 which fits the inner wall of the chamber in the member 17 quite snugly while its extreme inner portion is of less diameter and is provided with a conical end 33 which extends into the aperture 32 to form a concentric opening thru which an atomizing air stream is forced. The air stream enters thru an aperture 34 extending axially thru the nozzle member and opening at its outer end into the air supply system or directly to the atmosphere and terminates at its inner end in a transverse aperture 35 opening into the space surrounding the conical end of the nozzle. To provide an adequate sup ply of air the nozzle is desirably cut away adjacent the ends of its transverse aperture, avoiding mutilation of the tip of its conical section which enters the aperture 32 to form an annular orifice.

To complete the channel thru which the fluids travel an aperture 36 is formed in the member 17 in axial alignment with the aperture 32. Desirably, this aperture is slightly larger than the aperture 32 and is slightly divergent outwardly. The slight divergence of this aperture provides ready access of the conditioned fuel from the nozzle to the engine manifold. The outer end of the member 17 where it enters the engine manifold is bored out to a relatively large diameter to permit a free flow of conditioned fuel to the engine.

The supply of liquid fuel is desirably controlled by a valve of any suitable type such as the valve 37 located in the fuel supply line leading to the fuel reservoir or other source. The fuel enters the chamber 28, passes thru the radial apertures in the member 17 and enters a narrowspace surrounding the inner end of the sleeve member 19 from where it flows to another narrow space 38 between the end of the member 19 and the end wall of the chamber in which the sleeve is received. Thus, the liquid fuel is fed to the stream of air passing from the nozzle thru the circular orifice formed at the aperture 32.

The movement of the air may be accomplished in any desired manner such as by creating a positive pressure above that of atmospheric pressure at the air supply line. However, it has been found very effective to rely upon the partial vacuum created within the intake system of the engine during the cranking thereof and to maintain atmospheric pressure at the intake tube.

The rapid flow of air thru the jet creates a supersonic vibration in the air stream at the point where it issues from the circular orifice. This vibrating air current enters the chamber 30 which is designed and proportioned to cause the vibrating air to resonate at its initial rate within the chamber and thus by prolonging the vibrating period a violent high frequency agitation is created in the chamber 30 which imparts its energy to the liquid fuel as it enters the air stream thru the narrow space 38. Thus, when the fuel is subjected to this violent vibration it is dispersed into such a finely divided state it becomes combustible and is readily ignited by the spark plug within the engines cylinder.

An increase in the efficiency of the fuel conditioning device may be realized by feeding the liquid fuel to the air stream at a predetermined point related to the zones of pressure within the air stream. The vibrating character of the air stream produces zones of diflerent pressure. For each vibration a zone of high pressure and a zone of low pressure is created thus a region of relatively high pressure appears at a specific point in the air stream depending upon the frequency of vibration and a corresponding zone of relatively low rarified gas is produced adjacent thereto. It has been found that the efficiency of the device is enhanced by feeding the liquid fuel at a zone of low pressure within the resonating chamber 30. In the structure illustrated in Fig. 2 the narrow chamber 38 is situated at a zone of low pressure in the air stream.

Referring to Fig. l of the drawings a specific arrangement of the various elements constituting the invention is shown. Other suitable arrangements may be made without departing from the spirit and scope of the invention. Such variations may be dictated by the existing structure of the engine to which the invention is applied. As shown the intake of the fuel conditioning member 16 shown more or less diagrammatically in this figure is taken from the air cleaning system 39. The liquid fuel supply may be obtained in any desired manner. The supply may be taken from the float chamber 14 or may be obtained directly from the main fuel line 15 as shown in dotted lines. A metering valve 40 may also be provided to limit the total flow of fuel.

A conventional butterfly valve 13 is provided to control the flow of fuel from the carburetor 12 to the engine after the engine has been started. To start the engine the valve 13 is closed or substantially closed, the valve 37 controlling the liquid fuel is opened and the engine is cranked in any suitable manner as by means of the starting motor 41. By so doing a partial vacuum is created in the intake manifold and a flow of air is set up within the fuel conditioning jet 16 and, as above pointed out, the liquid fuel is highly dispersed therein and flows directly to the intake port or ports of the engines cylinders where it is readily ignited even through ambient temperature is extremely low. The engine is operated in this manner until it assumes a normal running temperature or at least a temperature at which it will continue to function on fuel from the conventional fuel supplying system. The valve 13 is then gradually opened and the valve 37 is closed at which time the power of the engine may be increased to normal and its load may be assumed.

Under certain conditions it may be desirable to apply air under pressure to the fuel conditioning jet 16 during the starting cycle. This may be accomplished in any desired manner such as by a hand air pump 42 shown diagrammatically in Fig. 2. The pump may be connected to the air supply line of the jet and maybe operated while the engine is being cranked thus to provide the necessary conditioned fuel to start the engine. When the engine to be started is the power plant of a vehicle a supply of compressed air is sometimes available which is used in the operation of the vehicles brakes. In such a case the compressed air supply may be applied to the conditioning jet.

What is claimed is:

l. A method of operating internal combustion engines having at least one intake port and a main fuel supply system comprising excluding the flow of fuel from said main fuel supply, cranking the engine, introducing a jet of air to said intake port, causing the air to vibrate at supersonic frequency, supplying liquid fuel to the vibrating air stream, whereby the fuel becomes highly dispersed in the air stream, introducing the prepared priming mixture of air and fuel to the engine cylinder, igniting the fuel in timed relation to the power cycle of the engine and subsequently when the engine has warmed up introducing fuel from the main fuel supply system.

2. A method of operating internal combustion engines having at least one intake port and a main fuel supply system comprising excluding the flow of fuel from said main fuel supply, cranking the engine, introducing a jet of air to said port, causing the air stream to vibrate at supersonic frequency, supplying liquid fuel to said vibrating air stream, intensifying the dispersing effect of the vibrating air stream upon the fuel by causing the mixture of air and fuel to resonate at the vibrating frequency, introducing the prepared priming mixture of air and fuel to the engine cylinder, igniting the fuel in timed sequence to the power cycle of the engine and subsequently when the engine has warmed up introducing fuel thereto from said main fuel supply system.

3. A method of operating internal combustion engines having at least one intake port leading directly to the cylinder and a main fuel supply system comprising excluding the flow of fuel from the main fuel supply system, forcing air thru a small orifice to produce supersonic vibrations in the air stream, feeding liquid fuel to the vibrating air stream, intensifying the dispersing effect of the air upon the fuel by resonating the mixture of air and fuel after it has issued from said nozzle, directing the stream of conditioned fuel directly to said input port during the starting and warming up period and subsequently feeding fuel to the engine from the main fuel supply.

4. A method of operating internal combustion engines comprising the steps defined in claim 3 and in which the liquid fuel is fed to a zone of low pressure in the vibrating fluid stream.

5. A method of operating internal combustion engines having at least one intake port and a main fuel supply system comprising temporarily excluding the flow of fuel from the main fuel supply, cranking the engine, forcing a stream of air under pressure greater than atmospheric thru a small orifice to create supersonic vibrations, therein, feeding liquid fuel to the air stream, intensifying the dispersion of the liquid fuel by resonating the mixture of fluids in a resonance chamber, feeding the conditioned priming fuel to the engine during starting and warming up and subsequently feeding fuel to the engine from the main fuel supply system. a

6. In an internal combustion'engine having an intake port, a main fuel supply system, a valve for controlling the fiow of fuel from said main fuel supply; a priming device for starting the engine comprising a jet type nozzle having its output directed into the said intake port, means for causing air to flow thru an orifice in said nozzle, a chamber adjacent to the orifice having the correct dimensions to cause the stream of air issuing from said orifice to resonate therein at a supersonic frequency, means to feed liquid fuel into said chamber and means to feed the mixture of treated priming fuel to the engine thru said port.

References Cited in the file of this patent UNITED STATES PATENTS 1,069,502 Wadsworth Aug. 5, 1913 1,375,172 Phillips Apr. 19, 1921 2,043,514 Mennesson June 9, 1936 2,532,554 I Joeck Dec. 5, 1950

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