US2435213A - Preheated fuel injection device for internal-combustion engines - Google Patents

Description

Feb. 3, 1948. R. E-LHANCOCK PREHEATED FUEL INJECTION DEVICE FOR INTERNAL-COMBUSTION ENGINES Filed Sept. 23, 1944 A ////////////////////////M W a w w m f Jwemto n ously ignited in the combustion chamber by being .rization point of the least volatile constituents of equal charge at a remote point, said chamber within and surrounded by a compressed air chameach equal to a single charge, .equal portions atented Feb. 3, 1948 qum'reo STATES PATENT ol-"r ca rnnnna'mn FUEL INJECTION nnvroa'ron' m'rnnmn-conmosrron memes Robert H. Hancock, Miami, Fla.

Application September 23, 1944, SerlalNo. 555,552

6 Claims. (01. 123-32) 2' This inventionrelates to internal combustion piston, the discharge ports of said fuel chamber engines of that type in which fuel is spontanechamber whereby during the entire period of adinjected into a body of highly compressed air. mlssionjof the fuel to the combustion chamber as More particularly; the type of engine in contemplation is one in which the combustion continues through an appreciable extent of the working stroke of the piston. One of the objects of the invention is to providean engine of the class described, in which a confined body of liquid fuel, suflicient for a plurality of charges is maintained under pressure, fuel being admitted under pressure-to one part of said body in the form of successive portions,

expanded air from said compressed air chamber, ensuring thorough and complete mixing and complete combustion of the fuel charge.

the following description of a preferred and practical embodiment thereof proceeds,

This application is a continuation-in-part of February 23, 1943.

In the accompanying drawing: from another part of said body being simultaneously discharged through displacement by the admitted portions, the confined body of liquid fuel being subjected to-heat developed in the en ine by which the part of said body from which charges are released is heated abovethe vapothrough an internal combustion engine cylinder and fuel injecting and preheating apparatus embodying the principles of the invention;

Figure 2 is a cross-section taken along the line 2-2 of Figure 1. v A

Referring now in detail to the drawing, the

the fuel, said body being maintained under pressure sufliciently high to inhibit the vaporization of any part thereof until released to the combustion chamber, into which it issues as a y as.

formed with a casing 3, constituting the .outer wall ofa compressed air chamber which communicates with the clearance space within the cylinder'by a restricted mouth 4. The casing 3 Another object of the invention is to provide m y be n t p n, the outer P rt 5 a fuel injector comprising a fuel chamber filled 3' being bolted h inner P with a body of liquid fuel sufflcient for a plurality 0 An injector tube 6 extends through theiouter of charges, with means for simultaneously admitend wall I of the casing 3,.having its inn r e ting a charge under pressure into said chamber at terminating adj nt he m h 4 of said casin one point, and by displacement forcing out an A cylin r l l r pt c 8 urr nds the major portion of the injector tube 6, having its being subjected to a temperature above the vap.-- orization point of all fractions of the liquid fuel, the time of travel of said fuel through said chamber from its point of admission to its point of discharge being suflicient to raise the temperature of that portion of the fuel body from which charges are released above the vaporization point of all of its constituents and the body of fuelin said chamber being maintained ,at a sufilcient high pressure to inhibit vaporization of any part thereof until released from said chamber, so that when released it instantly expands into a dry gas. a

A further object of the invention is to provide a fuel injector as above described, positioned the upper end of said fuel receptacle abutting the inner face of the end wall '1 of the casing 3 in fluid-tight manner. The nut 9 screwed to the injector tube 6 and bearing against the outer face The fuel receptacle defines with the casing 5 a compressed air chamber 9 surrounding the fuel receptacle. The outside wall of the fuel recepcompressed air chamber, forming an extended surface by which heat is transferred from the compressed air in the compressed air chamber to 0 the liquid fuel within the fuel receptacle.

The compressed air chamber is designed to contain the major portion of the air compressed by the engine p'iston., In the proportionate dimensions shown, of it.

ber communicating with the combustion chamber of the internal combustion engine, charged with highly compressed air at each compression stroke of the engine piston and so sized asto contain' a major portion of the aircompressed by said being adjacent the mouth of said compressed air a-dry gas, it is mixed with'a continuous supply of Other objects of the invention will appear as my abandoned application Ser. No. 476,873; filed Figure 1 is, a longitudinal diametrical section engine cylinder 1 is provided with a head 2,

35 bottom wall secured axially to the injector tube,

of the casing 3, enables the fuel receptacle to be drawn tight against the end wall I of the casing.

tacle is provided with fins 10, extending into the it contains about nine tenths The injector tube has ports ll, communicating with the fuel chamber within the fuel receptacle adjacent its outer end, and other ports l2 communicating with the fuel chamber adjacent its inner end. It also has the divergent nozzles '20 at its inner end, opening into the clearance space adjacent the mouth of the casing 3. A plunger valve l3 reciprocates within the injector tube 6. It is actuated by an engine driven cam 14 bearing upon its outer end I5. A spring I6 and the valve urges the latter to closed position.

The valve I! has a longitudinal inlet bore 22 communicating at one end with a source of liquid fuel under pressure, and at the opposite end it opens into a pe I'l adapted to register with the inlet ports H to the fuel chamber. At its inner end the valve l3 has a passage i8, positioned to register with the outlet ports i2, when the inlet passage ll registers with the inlet ports 'ii. The valve also has a passage 59, adapted to register with the divergent nozzles 28, when the passage i8 is in registrywith the outlet ports l2. A longitudinal bore 2| connects the passages i8 and 19. In the closed position of the valve, passages IT, IS and i9, occupy the respective dotted line positions shown in Figure 1, all communication between the fuel chamber and the source of fuel on the one hand, and the nozzles 29 on the other, being then cut oil. In operation, the heated compressed air within the air compression chamber will be transmitted through the fins iii and the wall of the fuel receptacle to the fuel which fills the fuel chamber. This heat will be augmented by heat of combustion conducted through the contiguous metal parts of the engine to the fuel in the fuel chamber. Theavailable heat is amply suflicient to produce a temperature above the vaporization point of all of the fractions of the liquid fuel.

However, assuming that the engine turns up only 1500 R. P. M, and that the charge of fuel must be injected and burned through a time interval corresponding to an angular displacement of about 35 crankshaft revolution, this allows only .004 second for this complete operation to be performed. This allows: for too short an exposure of a single charge to the available heat to raise the temperature of the chargeabove the that the fuel chamber holds enough fuel for a pinrality of charges, permits the charges after admission to said chamber to travel gradually toward the discharge-zone, acquiring heat all the while, so that the temperature of the liquid fuel in said chamber in said discharge zone will have become raised above the vaporization point of its least volatile constituents.

In the subject invention, it is assumed that pressure in the fuel chamber will be maintained at such high value as to inhibit any vaporization of fuel within said chamber. This assumption is predicated upon the conditions that the fuel chamber is always full, that the source pressure I is at the requisite high value, and that the charge 76 least volatile constituent of said liquid fuel by the leased charge of fuel having a temperature high s enough to vaporize all of its constituents flashes into jets of dry gas across the mouth or the compressed air chamber.

when the valve I3 is moved to bring the peasages and it simultaneously into communica- 10 tion with the fuel chamber, a charge of relatively retained between the end of the injector tube cool liquid fuel under the requisite pressure is forced in and an qual charge under the same pressure heated above the vaporization point of its least volatile constituents, is simultaneously forced out. Since the bulk of the compressed air is back of the zone of emission of the divergent jets of dry fuel gas, and since the valve operation is timed to deliver a charge beginning at the top dead center of the piston and continuing until 90 the crankshaft has rotated through an angle such as to the combustion zone is continuously traversed by the expanding air from the compressed air chamber throughout the period of injection, intimately mimng with the jets of exg5 pending dry fuel gas and progressively supplying so chamber while the piston continues its recessive movement and until the scavenging phase of the cycle commences. Thus no combustion will ever.

occur in the compressed air chamber and substantiaily no products of combustion can enter 35 said chamber, so that pure air with its full quota of oxygen is always presented to the burning gaseous fuel.

Since the degree of heat imparted to the liquid fuel depends upon the time it takes a charge to travel from its point of admission to the fuel chamber to its point of discharge therefrom, and

this in-turn is depended upon the capacity of said chamber, the desi n of the preheated apparatus enables the liquid fuel at the point of discharge to be heated to a temperature well above its autoadmisslon point when ejected as a dry gas. This eliminates any ignition lag, assuring instantane- -ous ignition, and instantaneous combustion in the ample volume of air from the air chamber being forced through the issuing lets. With instantaneous ignition and complete combustion, no detonation or shock explosion can occur because no cumulative charge of fuel is at any time available for detonation.

5 What I claim as my invention is:

I 1. In an internal combustion engine of the type wherein ignition is spontaneously enacted in an atmosphere of highly compressed air, a charge forming device comprising means forming a liquid so fuel chamber having a capacity to hold a sufficient body of liquid fuel for a plurality of charges, and normally full of liquid fuel, having aliquid fuel inlet at the top and a liquid fuel outlet at the bottom, means about said liquid fuel chamber forming an, air compression chamber having a mouth communicating with the compression space within the engine cylinder, said liquid fuel outlet opening at the month, said compressed air chamber being of larger capacity than the clearance space within the engine cylinderwhen the engine piston is at the compression and of its stroke. at least the lower part of said fuelhody.

assume heat of the compressed air in said compressed air chamber and heat of the explosion transmitted through the walls of said liquid fuel chamber, means for maintaining the liquid fuel body in said liquid fuel chamber under sufficiently high pressure to prevent evaporation within said liquid fuel chamber, said means being constructed to simultaneously admit a charge into said liquid fuel inlet against the pressure maintained in said chamber and-release an equal charge from said i.iquid fuel outlet, whereby the charge upon release expands instantly into a dry gas at the mouth of said compressed air chamber.

2. In an internal combustion engine as claimed in claim 1, said fuel outlet comprising downwardly divergent nozzles.

3. Methodof operating an internal combustion engine of the type wherein ignition is spontaneously effected in an atmosphere of highly compressed air, comprising compressing the major portion of the air into a chamber communicating' with the engine clearance space, maintaining a confined body of liquid fuel sumcient for a plurality of charges, in heat exchanging relation to the compressed air in said chamber and to the heat of explosion, so that the heat absorbed by said liquid fuel body issufllcient 'to raise the temperature of the liquid fuel in at least the lower part of said liquid fuel body above the vaporizing point of all the constituents of said liquid fuel, maintaining said liquid fuel body under sumcient pressure to prevent vaporization in said confined liquid fuel body, and, at the top of the compression stroke of said engine, simultaneously admitting a charge of liquid fuel from a supply to the upper part of saidliquid fuel body against the pressure at which said liquid fuel body is maintained and releasing an equal charge from said body in the zone which demarks said chamber from said clearance space whereby the released charge flashes into a dry gas in said zone, traversedby expanding air from said chamber as the engine piston recedes.

4. Method of operating an internal combustion engine of the type wherein ignition is spontaneously effected in an atmosphere of highly, compressed air, comprising compressing the major portion of the air into a chamber communicating with the engine clearance space, maintaining a confined body of liquid fuel suflicient for a plurality of charges, in heat exchanging relation to the compressed, air in said chamber and to the heat of explosion, so that the heat absorbed by said liquid fuel body is sufficient to raise the temperature of the liquid fuel in at least the lower part of said liquid fuel body above the vaporizing Number point of all the constituents of said liquid fuel, I

maintaining said liquid fuel body under suflicient pressure to prevent vaporization in said confined liquid fuel body. and, at the top of the compresslon stroke of said engine, simultaneously admitting a charge of liquid fuel from a supply to the upper part of said liquid fuel body against the at which said liquid fuel body is maintained and releasing an equal charge from said as tion period by expanding air from said chamber v as the engine piston recedes.

5. In an internal combustion engine as claimed in claim 1, the common wall of said compressed air chamber and liquid fuel chamber being formed with-external longitudinal fins extending to the outer wall of said compressed air chamber dividing the latter into a plurality of longitudinal channels.

6. In an internal combustion engine of the type wherein ignition is spontaneously effected in an atmosphere of highly compressed air, a charge forming device comprising a liquid fuel chamber having a capacity to hold a sufiieient body of liquid fuel for a pluralityv of charges, adapted to be maintained full of liquid fuel, means for maintaining at least the lower part of said liquid fuel body in said chamber at a temperature above the vaporizing point of the least volatile constituents of said liquid fuel, means for maintaining the liquid fuel body in said chamber at constant pressure sufliciently high to prevent vaporization of any part of the fuel within said chamber, said means comprising a single positively actuated valve having an inlet port communicating with a source of liquid fuel under requisite pressure and with the upper part of said liquid fuel chamher, and a port communicating with the lower part of said liquid fuel chamber and with the compression space of said internal combustion engine, said ports being so arranged as upon operation of said valve, to simultaneously admit a charge to REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Name Date 1,160,480 Wheeler Nov. 16, 1915 1,804,413 Grofi' May 12, 1931 807,354 Burger Dec. 12,1905 1,752,031 Schaer Mar. 25, 1930 1,915,218 Dotterweich June 20, 1933 2,108,706 "Crillon Feb. 15, 1938 1,492,111 Tartrais Apr. 29, 1924 678,160 Diesel Apr. 30, 1901 1,281,282 harness et al. ........Dec. 10, 1918 2,384,990; Malott Dec. 12, 1945' 2,368,423 Olsen Jan. 30, 1945 FOREIGN PATENTS Number 5 Country 7 Date 1,199 England June 5, 1911 1am an mia July 3, m2

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