US2462854A

US2462854A - Fuel injection system

Info

Publication number: US2462854A
Application number: US603101A
Authority: US
Inventors: Howard L Gates
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-07-03
Filing date: 1945-07-03
Publication date: 1949-03-01
Anticipated expiration: 1966-03-01

Description

ch 1, 1949. H. L. GATES FUEL INJECTION SYSTEM 2 Sheets-Sheet 1 Filed July 5, 1945 INVENTOR. Howard L 6afe$ D X ATTORNEY H. L. GATES I FUEL INJECTION SYSTEM 2 Sheets-Sheet 2 Filed July 3, 1945 v/ ZIIIIIIIJI I i INVENTOR. Howard L. 68 fes Qui /LL ATTORNEY Patented Mar. 1, 1949 Pram" orrics (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) Claims.

This invention relates to a fuel injection system for internal-combustion engines.

An object of this invention is to provide a fuel injection system in which the injector, fuel supply and pumping mechanism all are mounted internally of the engine cylinder.

Another object is to provide a fuel injection system in which the power-transmitting piston and connecting rod of the engine form part of the fuel injector thereby eliminating auxiliary fuel injecting pumps and connections.

Still another object is to provide a self-timing fuel injection system in which the pressure on the piston created in the engine combustion chamber during the compression stroke provides the necessary pumping force for injection.

A further object is to provldea self-timing fuel injection system in which injection is controlled by the compression pressure in the cylinder combustion chamber, which, in turn, is controlled by adjustable means for varying the combustionchamber volume and hence the compression ratio.

Further objects and advantages of this invention, as well as its construction, arrangement and operation will be apparent from the following description and claims in connection with the accompanying drawings, in which,

Figure 1 is alongitudinal sectional view of a portion of a cylinder of an internal-combustion engine showing the fuel injection system comprising this invention,

Figure 2 is a perspective view of a portion of the engineconnecting rod including the pumping housing of the fuel injector secured thereto, and

Figure 3 is a perspective view of a portion of the piston including the fuel-pumping plunger.

The fuel injection system comprising this invention includes a fuel injecting pump and nozzle mounted in the piston of an internal-combustion engine and a pumping chamber secured to the connecting rod. The piston has limited axial motion with respect to the connecting rod so that sufllcient pressure applied to the face of the piston, as occurs during the compression stroke of the engine, results in fuel-pumping action and consequent injection of the fuel into the cylinder. The compression pressure in the combustion chamber of the cylinder governs the cycle time at which injection occurs and means are provided to vary such time of injection by adjusting the volume of the combustion chamber and hence the compression ratio.

In the drawings, there is shown in Figure 1 an internal-combustion engine of the two cycle type comprising a cylinder I having a bore 2, exhaust ports 3 and air inlet and scavenging ports 4. A finned cylinder head 5 closes the top of the cylinder and a closure plug 6 is mounted in the head 5 by screw threads for example. The plug 6 has a central cavity I which forms a continuation of the combustion chamber forming the upper portion of cylinder I. An adjustable shield or plunger 8 is slidably mounted in the cavity 1 for regulating the volume thereof. The plunger 8 has a threaded shank 9 that engages the plug 6 as shown. The shank 9 extends through the plug 6 and its end projects exteriorly of the cylinder head 5. A pinion 1 is secured to the end of the shank 9 and meshes with an operating rack l0. Rotation of the pinion I by the rack in produces longitudinal adjustment of the plunger 8 within the cavity 1 and thereby varies the volume of the latter as well as the volume of the combustion chamber in the cylinder I.

A piston l I and connecting rod l2 are mounted in the bore 2 of the cylinder l. The connecting rod i2 is connected to the engine crankshaft (not shown) and the piston and connecting rod assembly reciprocates in the cylinder bore 2. The fuel injector comprises a pumping housing I3 having a pair of diametrically opposed trunnions M as shown in Figure 2 which are suitably mounted in corresponding yoke arms 12a and no comprising the forked end of connecting rod l2.'

A lateral extension member l5 forms part of pumping housing l3 and is spaced away from the trunnions l4 approximately 90 circumferentially. The pumping housing I3 is cylindrical in shape and has a central column l6 forming an annular pumping chamber H. The column portion I6 of the housing I3 is traversed by a fuel-oil duct [8 (see Figure. 1) terminating in an enlarged valve chambenIB. A branch l8a of duct I8 leads to the pumping chamber I1, and the duct I8 at its opposite end connects with an opening 20 in extension I5 (see Figure 2). A fuel-oil gland 59 (Figure 1) in the form of a hollow cylindrical body having partly closed ends is seated in the opening 20 of extension l5 and is provided with an orifice aligned with the entrance to duct l8 as shown in Figure 1. A portion of the periphery of the pumping housing I3 is threaded as shown at 2| Figures 1 and 2, and a regulating collar 22, which is internally threaded as at 23, is mounted thereupon. The periphery of the regulating collar 22 is provided with gear teeth' 24 and an annular flange 25 on the regulating collar 22 overlaps the end of the pumping housing I3 as shown in Figures 1 and 2.

The piston II has a piston face I la and a skirt portion 21. A nozzle housing 26 in the form of a hollow boss projects downwardly from the face lid of the piston i I into the interior thereof, the nozzle housing 26 being coaxial with the piston as shown in Figures 1 and 3. The nozzle housing 26 terminates in a flared annular stop shoulder 21 and has an internally threaded bore 28 in whichthere is secure-d a fuel injector pump member 29. Pump member 29 consists of plunger 36 in the 'form of a, hollow cylinder and a hollow threaded shank 3I that engages the threaded bore 28 in nozzle housing 26. The plunger portion 30 of fuel pump 29 is slidably mounted in the annular pumping chamber I! in pumpinghousing I3, and it fits the column I6 exteriorly and the bore of the chamber I'l internally, as shown in Figure 1. The piston I I is therefore fioatingly mounted with respect to connecting rod I2 and pumping housing I3 and has rotatative and axial motion with respect to each of the latter. The annular flange 25 on regulating collar 22 is interposed between the shoulder 21 on fuel plunger 26 and the top of pumping housing I3 to limit the axial motion of the former with respect to the latter. This comprises a translatory motion between the piston II and the connecting rod I2.

An injector nozzle 33 (Figure 1) is mounted in injector housing 26 and projects slightly outwardly fromthe face Ila of piston 'II into the combustion chamber formed between the cylinder head and piston face Na in cylinder I. A plurality of radially disposed fuel orifices 34 are provided in the projecting portion of nozzle 33. The injector nozzle 33 is secured in injector housing 26 by a hollow threaded nipple 35 which is secured at one end by the internal threading 36 of the shank 3I of fuel pump 29, the nozzle 33 being threaded to the nipple 35 at its other end. One end of nipple'35 is partly closed by a conical valve seat 31 which is connected by opening 38 to the hollow interior of the plunger 29.

A spring-loaded fuel injection valve 39 is slidably mounted in the interior of nipple 3I. The injection valve 39 consists of a cylindrical body traversed by a series of longitudinally extending,

peripheral fuel-oil passages 40 and a conical closure member M which seats in the valve seat 31. Valve spring 42, located within the nozzle 33, normally holds valve 39 closed. A check valve 43 having grooves 44 and a conical closure member 45 similar to valve 39 in structure is slidably mounted within the recess I9 of the core I6 of the pump body I3. The check valve 43 is normally held closed by check valve spring 46 as shown in Figure 1.

An annular shoulder 41 extends circumferentlally around the inner surface of the skirt portion 21 of piston II as shown in Figures 1 and 3.

' length adjacent where they are joined so that they are rotatably locked together but capable of longitudinal sliding motion relative to each other to causing combustion to take place.

permit tube 49 to reciprocate with the piston I I and crankshaft I2. Tube 49 is rotatably secured to the extension I5 on pump body I3 for translatory motion therewith, by means of a pair of thrust collars 5I and 52 attached to tube 49. The portion of tube 49 which fits in gland 59 is circular and rotatably mounted therein. A pinion 53 is fixedly mounted on the end of tube 49 and engages the peripheral gear 24 on regulating collar 22. The lower end of tube 50 is provided with a bevel gear 54 which is engaged by a control gear 55 driven by a manual or governer controlled shaft 56. Tube 56 is connected by a fitting 51 and suitable flexible tube means 58 to a fuel supply pump (not shown).

A special gland is provided in chamber 29 of the crank l5 to permit fuel flowing in tube 49 to enter duct I3 in the plunger block I3 for all angular positions of adjustment of the tube 49. Such gland (Figure 1) comprises a bushing 59 having an annular chamber 62 and an outlet Orifice 60 aligned with the entrance of duct I8 (Figure 2). A number of radially disposed openings 6| are provided in the periphery of tube 49 inside chamber 62 (Figure 1) so that there is continuous communication between the interior of tube 49 and duct I8 as the former is rotated relative to the bushing 59.

The operation of the internal-combustion engine and the fuel injection system is as follows:

Fuel oil is continuously supplied from a suitable low-pressure pumping source through the

flexible connection

58 and 51 and thence through

tubes

59 and 49 into the chamber 62 of the gland 59. The fuel oil then enters duct I3 where it fills the annular chamber I'I formed between the end of plunger 29 and pump housing I3. Inasmuch as fuel pump 29 is slidably mounted in the plunger body I3, the pressure of the fuel oil is sufficient to raise fuel pump 29 and piston II with respect to the pump housing I3 by an amount limited by the engagement of shoulder 41 on piston II with extension I5 of the pumping housing I3, when the pressure in the combustion chamber is low, as, for example at the end of the expansion stroke. At the same time, the fuel oil also flows past check valve 45 and fills chamber I9, but does not enter the inside of nozzle 33 because in- .iection valve M is held closed by the relatively strong injection pressure regulating spring 42.

During the compression stroke the pressure in the combustion chamber between the piston face I la and cylinder head 5 rises, until, at a predetermined point, the compression pressure acting over the piston face Ila, forces the piston II together with plunger 30 of fuel pump 29 downwardly axially with respect to the pumping chamber I1 thereby pumping the fuel oil in chamber I9 through the injection valve M and out through the spray orifices 34-into the combustion chamber As the gases expand during the combustion or power stroke piston II is forced downwardly, with shoulder 21 abutting shoulder 25 on regulating collar 22 until the piston II uncovers-exhaustport 3and scavenging air port 4. When the piston has uncovered scavenging air port-4, the nozzle 33 is aligned therewith and the inrushing scavenging air cleanses whatever deposits may have accumulated on the nozzle. At the completion of the combustion stroke the pressure of the incoming fuel in fuel line 49 is sufficient to again raise the piston II together with plunger 36 into cocked position with shoulder 21 on injector housing 26 spaced from regulatin collar 22 as previously-described and the cycle continues.

The amount of fuel injected per stroke is regulated for various load and speed conditions by adjusting the gap between shoulder 21 and regulating collar 22. This is accomplished by adjusting operating shaft 56 which is controlled either by the engine governoror by a hand throttle, thereby rotating

bevel gears

54 and 55,

tubes

49, 50, pinion 53, and regulating collar 22. Collar 22 is thereby raised or lowered with respect to the pump body I 3 on which it is threadingly mounted to rotate in the threaded engagement, thereby regulating the gap between the annular shoulder 25 on collar 22 and the flared shoulder 21 forming part of piston II. The amount of gap is directly proportional to the pumping stroke of the injector mechanism and the amount of fuel injected is thereby proportionally controlled.

The pressure in the combustion chamber of the cylinder multiplied by the ratio of the area of the piston face Ila to that of the pumping end of plunger 29 determines the injection pressure of the fuel 011. Due to the fact that injection nor-' mally begins when the pressure of the air in the combustion chamber is suflicient to overcome the resistance ofl'ered by injection valve 39, the cycle time at which fuel injection begins can be regulated by increasing or decreasing the volume at the top of the cylinder, which regulates the cycle time at which the pressure due to compression is of a magnitude suificient to initiate injection. The adjustable plunger 8 is used to regulate in this way the point of injection. The operating rack I0, which may be coupled to the same governor actuated means as control shaft 56, or which may be manually adjusted, regulates the position of plunger 8 and hence the compression ratio in the engine cylinder, thereby to advance or retard the point of injection in response to various load conditions.

The injection pressure is also controlled by the strength of the discharge-valve spring 42. Since the pressure acting on the fuel oil increases as the piston I I moves upwardly on the compression stroke, a spring of suitable strength must be employed to prevent injection valve 4I opening too early during the compression stroke.

Piston I I is free to rotate relative to the plun er body l3 and connecting rod I2, since it is pivotallymounted with respect to the latter by the engagement of plunger 29 with plunger body I3. Such freely floating piston arrangement is advantageous inasmuch as it distributes wear between the piston II and cylinder wall 2. The piston II i normally held from comin off the connecting rod I2 by the annular shoulder 41 secured to the skirt of piston I I as shown in.Figures 1 and 3 abutting extension I5. The limit lugs 48 at each end of shoulder 41 prevent the piston II rotating to a point where the gap between the ends of shoulder 4'! would align with arm I5. When it is desired to remove piston II for servicing after cylinder head 5 ha been removed, regulating collar 22 is screwed all the way down until flange 25 abuts plunger housing I3. This leaves a wide gap between flange 25 and the flange 21 on the injector housing 26. Piston II can now be rotated until arm I5 clears the limit lugs 48 and is aligned with the gap between the ends of shoulder 4'! previously mentioned, after which piston II can be removed. The external periphery of nozzle 33 has suitable flats or wrench slots to permit easy removal thereof. Each cylinder moreover can be easily isolated by reinoval of plug 6 in the cylinder head 5, thereby venting the cylinder to the atmosphere.

Various modifications and changes may be made in the above described device without departing from the spirit and scope of this invention as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In an internabcombustion engine having a reciprocating piston and connecting rod, the combination of -a fuel injector comprising a spray nozzle mounted in said piston, a floatable mounting between said piston and connecting rod, said floatable mounting including a pumping chamber secured to the connecting rod and a fuel injection pump secured to said piston and movably mounted in said pumping chamber, said piston bein movable relative to said connecting rod in response to pressure exerted on said piston during the compression stroke of said engine.

2. In an internal-combustion engine having a combustion cylinder and a power transmitting reciprocating connecting rod, the combination of a pumping chamber secured to said connecting rod, a piston slidably mounted in said cylinder, a fuel injecting plunger secured to said piston and slidably mounted in said pumping chamber to form a floatable connection between said connecting rod and piston, and a fuel spray nozzle mounted in said piston and having access to the combustion chamber of said engine, said piston and said fuel injecting plunger being movable relative to said pumping chamber in response to pressure exerted on said piston during the compression stroke of said engine.

3. A fuel injection system for internal-combustion engines having a cylinder and power transmitting connecting rod reciprocating therein comprising, a fuel pumping chamber secured to said connecting rod, a piston slidably mounted in said cylinder, a fuel injecting plunger secured to said piston and slidably mounted in said pumping chamber to form a floatable connection between said connecting rod and piston, a fuel spray nozzle mounted in said piston exposed to the combustion chamber of said cylinder, a fuel passage connecting said fuel pumping chamber with said fuel spray nozzle, said piston and said fuel injecting plunger being movable with respect to said pumping chamber in response to pressure exerted on said piston during the compression stroke of said engine.

4. A fuel injection system for internal-combustion engines' having a cylinder and power transmitting connecting rod reciprocating therein comprising, a fuel pumping chamber secured to said connective rod, a piston slidably mounted in said cylinder, a fuel injecting plunger secured to said piston and slidably mounted in said pumping chamber for axial and rotative movement relative thereto, a fuel spray nozzle mounted in said piston and exposed to the combustion chamber of said cylinder; fuel passage means connecting said pumping chamber with said spray nozzle, valve means in said fuel passage regulating the flow of fuel to said nozzle, and elastic means engaging said'valve means to normally hold the latter closed; said piston and said fuel injecting plunger being movable relative to said pumping chamber in response to pressure exerted on said piston during the compression stroke of said engine, whereby fuel in said pumping chamber is forced through said fuel passage and valve into the combustion chamber of said engine.

5. A fuel injection system for internal-combustion engines having a cylinder and power transmitting connecting rod reciprocating therein comprising, a fuel pumping chamber secured to said connecting rod, a piston. slidably mounted in said cylinder, a fuel injecting plunger secured to said piston and slidably mounted in said pumping chamber for axial and rotative movement relative thereto, a fuel spray nozzle mounted in said piston and exposed to said combustion chamber of said cylinder, a fuel passage connecting said fuel pumping chamber with said spray nozzle, said piston and said fuel injecting plunger being movable with respect to said pumping chamber in response to pressure exerted on said housing to permit free flow of fuel therebetwen as the fuel line is rotated relative to said pumping housing.

9. A fuel injection system for internal-combustion engines comprising, a fuel pumping housing secured to a connecting rod of said engine, an annular fuel pumping chamber in said pumping housing, a hollow piston having a face portion piston during the compression stroke of said englue, and regulating means adjustably mounted ,on said pumping chamber, said regulating means said cylinder, a fuel injecting plunger secured to regulating collar axially of said pumping chamber whereby the shoulder on said regulating collar inand skirt portion, an annular fuel plunger pro jecting from the face portion of said piston, said fuel plunger being slidably receivable in said annular fuel pumping chamber for reciprocating and rotative motion therein, shoulder means on said fuel plunger, a fuel spray nozzle mounted in the face portion of said piston coaxially with said fuel plunger, a fuel passage connecting. said annular fuel pumping chamber with said spray nozzle, a regulating collar adjustably mounted on 'said fuel pumping housing for axial movement relative thereto, a shoulder on said regulating collar interposed between said fuel pumping housing and said shoulder means on said fuel plunger, said piston being axially movable relative to said pumping housing upon application of pressure on the face portion of said piston, and means for adjusting the position of said terposed between said fuel plunger shoulder and said pumping housing limits the amount of axial movement between said piston and said pumping said piston'and slidably mounted in said pumping chamber, a fuel spray nozzle mounted in said piston and exposed to said combustion chamber of said cylinder, a fuel passage connecting said fuel pumping chamber with said spray nozzle, said piston and said fuel 'injectingplunger being movable with respect to said pumping chamber in response to pressure exerted on said piston during 7 the compression stroke of said engine, regulating means adjustably mounted on said pumping chamber, stop means on said regulating means interposed between said plunger and said pumptatably mounted with respect to each other and connectable at one end to a fuel supply source.

8. A fuel injection system for internal-combustion engines comprising a fuel pumping housing secured to a connecting rod of said engine, an annular fuel pumping chamber in said pumping housing, a hollow piston having a face portion and skirt portion, an annular fuel plunger projecting from the face portion of said piston, said fuel plunger being slidably receivable in said annular fuel pumping chamber for axial and rotative motion therein, a fuel spray nozzle mounted in the face portion of said piston coaxially with said fuel plunger, a fuel passage connecting said annular fuel pumping chamber with said spray nozzle, a fuel check valve and a spring loaded fuel injection valve mounted in said passage, a fuel supply line rotatably mounted in said pumping housing, said fuel line being secured to said pumping housing for translatory motion therewith, and gland means connecting said fuel supply line with said fuel passage in said pumping housing.

10. In an internal-combustion engine having a cylinder, cylinder head and reciprocating connecting rod, the combination of a cavity in said. cylinder head accessible to said cylinder, a shield adjustably mounted in said cavity for varying the volume thereof, operating means connected to said shield, a fuel pumping chamber mounted on said connecting rod, a piston having a face por: tion and skirt portion slidably mounted in said engine cylinder, a fuel pumping plunger secured to said piston and slidably mounted in said fuel pumping chamber, a fuel spray nozzle mounted in said face portion of said piston accessible to the combustion chamber of said engine cylinder, a fuel passage connecting said fuel pumping chamber to said nozzle, said piston and said fuel pumping plunger being movable relative to said pumping chamber in response to pressure applied on the face portion of said piston, adjustable stop means between said fuel pumping plunger and said fuel pumping chamber for limiting the amount of motion therebetween, and control means for operating said adjustable stop means, said control means and said first mentioned shield operating means being responsive to load variations on said engine.

11. In an internal-combustion engine having a cylinder, cylinder head and power transmitting connecting rod reciprocally mounted in said cylinder, the combination of a fuel injector comprising a power transmitting piston slidably mounted in said cylinder, fuel pumping means secured to said piston, a fuel pumping chamber secured to said connecting rod, said fuel pumping chamber slidably receiving said fuel pumping means on said piston and forming a fioatable connection between said connecting rod and piston, a fuel spray nozzle in said piston and a fuel passage connecting said fuel pumping chamber to said nozzle, said piston being axially movable relative to said fuel pumping chamber in response to pressure applied to said piston.

12. In an internahcombustion engine having a cylinder, cylinder head and power transmitting connecting rod reciprocally mounted in said cylinder, the combination of a fuel injector comprising a power transmitting piston slidably mounted in said cylinder, fuel pumping means secured to said cylinder, a fuel pumping chamber secured to said connecting rod, said fuel pumping chamber slidably receiving said fuel pumping means on said piston for combined axial and rotatable motion relative thereto, a fuel spray nozzle in said piston, a fuel passage connecting said fuel pumping chamber with said fuel spray nozzle, spring loaded injection valve means in said fuel passage, said fuel pumping means being axially movable relative to saidpumping chamber in response to pressure applied to said piston, a cavity in said cylinder head and adjustable means for varying the volume of said cavity and hence the compression ratio in said cylinder, whereby the cyclic time at which the pressure on said piston required to open said injection valve can be varied in response to said volumetric variation.

13. In an internal-combustion engine the combination of a combustion cylinder, a power transmitting piston and connecting rod mounted for reciprocating motion therein, said piston being floatably mounted upon said connecting rod, said floatable mounting including a fuel pumping chamber secured to one of said connecting rod and piston elements and a fuel injecting plunger secured to the other of said elements and slidably mounted within said fuel pumping chamber.

14. In an internal-combustion engine the combination of a combustion cylinder, a power transmitting piston and connecting rod mounted for reciprocating motion therein, said piston being 10 floatably mounted upon said connecting rod, said fioatable mounting including a fuel pumping chamber secured to one of said connecting rod and piston elements and a fuel injecting plunger secured to the other of said elements and slidably mounted within said fuel pumping chamber,

secured one to the connecting rod and the other to the piston, the mounting of the connecting rod for the piston comprising a translatory motion to provide relative movement between the plunger and the pumping chamber to operate the injector pump.

HOWARD L. GATES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,102,019 Dorwald June 30, 1914 1,162,789 Loane, Jr. Dec. '7, 1915 1,349,515 Lombard Aug. 10, 1920 1,622,266 Ake Mar. 29, 192'! 2,067,997 White Jan. 19, 1937 2,132,083 Pescara Oct. 4, 1938 2,203,669 Butler June 11, 1940 Whitfield Feb. 18, 1941 Certificate of Correction Patent N 0. 2,462,854. March 1, 1949.

HOWARD L. GATES 4 It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

, Column 2, line 38, before the word housing insert pumping column 3, line 20, 5" for floatingly read floatabl'y;

lines

27, 28 and 29, strike out This comprises a translatory motion between the piston 11 and the connecting rod 12. and insert the same in line 19, same column, before The pistons; column 5, line 12, strike out threadingly and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 26th day of July, A. D. 1949.

THOMAS F. MURPHY,

Assistant Oomn iuioner of Patents.