US3812829A

US3812829A - Fuel injection system and associated structure

Info

Publication number: US3812829A
Application number: US00281770A
Authority: US
Inventors: A Mccormick
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-08-18
Filing date: 1972-08-18
Publication date: 1974-05-28
Anticipated expiration: 1991-05-28

Abstract

A fuel injection system and structure therefor, wherein a highpressure pump is used to inject fuel through the air intake valve structures of the engine. The valve structures are unique in many particulars, among which is the structural provision for valve displacement to effect air intake, as well as fuel injection through the valve stem at desired times directly into the associated cylinder. While the system lends itself to multiple piston pump operation, still, single piston pump operation is preferred for cost and maintenance considerations. A lost-motion structural provision is incorporated so as to insure the commencement of fuel injection immediately prior to valve opening as to air intake. A low pressure fuel return system is provided in the event of seal-leakage or failure in the valve stem structures. Timing as to fuel injection depends solely upon rocker-arm or other depression of the valves and, hence, is of simplified and yet highly effective form.

Description

rated atent 1 1 on 3,812,829

McCormick 1 May 28, 1974 FUEL INJECTION SYSTEM AND Primary Examiner-Laurence M. Goodridge ASSOCIATED STRUCTURE Assistant Examiner-Ronald B. M. Cox

[76] Inventor: Alan G. McCormick, 645 Aloha,

Salt Lake City, Utah 84103 [57] ABSTRACT [22] Filed: Aug. 18, 1972 A fuel injection system and structure therefor,

21 Appl. No.: 281,770

wherein a-high-pressure pump is used to inject fuel through the air intake valve structures of the engine. The valve structures are unique in many particulars, among which is the structural provision for valve displacement to effect air intake, as well as fuel injection through the valve stem at desired times directly into the associated cylinder. While the system lends itself to multiple piston pump operation, still, single piston pump operation is preferred for cost and maintenance considerations. A lost-motion structural provision is incorporated so as to insure the commencement of fuel injection immediately prior to valve opening as to air intake. A low pressure fuel return system is provided in the event of seal-leakage or failure in the valve stem structures. Timing as to fuel injection depends solely upon rocker-arm or other depression of the valves and, hence, is of simplified and yet highly effective form.

8 Claims, 3 Drawing Figures /"'ro INTAKE MANI FOLD FUEL INJECTION SYSTEM AND ASSOCIATED STRUCTURE The present invention relates to fuel injection systems for internal combustion engines and, more particularly, to a new and improved fuel injection system and accommodating structure.

In the present invention, fuel injection is provided directly through the air intake valving structure of the engine. The valving structures are modified such that these themselves contain valves to permit the selective injection of fuel directly into associated cylinders. Fuel injection is thus directly related to rocker arm or other prime mover movement of the individual valves. Low pressure return means is employed as a safety feature such that in the event any seal-failure, or where leakage past the seals occurs in the individual valve stems structures, such fuel will be returned via its own low pressure system to the low-pressure fuel pump of the engine, for subsequent introduction to the operative side of the high pressure pump utilized.

The system is designed to accommodate desired pressures of from 1,000 to 4,000 psi, this to insure optimum atomization of fuel within the individual cylinder chambers, for combustion purposes. When operating at such pressures. a maximum combustion as well as reduction of contaminants are achieved.

Accordingly, a principal object of the present invention is to provide a new and improved fuel injection system.

A further object is to provide improved structure design to accommodate fuel injection in internal combustion engines.

An additional object is to provide a fuel injection system wherein fuel is injected at high pressure directly into the cylinders of the engine.

An additional object is to provide for the introduction of high pressure fuel through the valving structure of an internal combustion engine.

A further object is to provide air intake valve structure for internal combustion engines incorporating fuel injection, wherein the individual valve structures themselves are provided with valves for permitting the selective introduction of fuel directly into the associated cylinders.

A further object is to provide in a valve structure a lost-motion connection such that air inlet valve opening is time space from but closely follows the commencement of fuel introduction under high pressure into the associated cylinder.

An additional object is to provide a low-pressure return system in a fuel injection system incorporating fuel-travel passageways in valves, wherein seal failure or leakage will not cause any undue hazard as to safety of operation.

An additional object is to provide a fuel injection system for an internal combustion engine, such that modification of the internal combustion engine itself is minimized in the incorporation of such fuel injection system.

A further object is to provide a fuel injection system which by its design precludes the necessity for complex fuel filtering.

The features of the present invention may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a plan view of an internal combustion engine utilizing the system and structure of the present invention.

FIG. 2 is an end view taken along the line 2-2 in FIG. 1.

FIG. 3 is an enlarged fragmentary detail, principally in vertical section, of a representative valve and valve stem, with surrounding structure, illustrating the means by which fuel is injected into a respective cylinder.

FIG. 4 is an enlarged fragmentary detail taken along the arcuate line 4-4 in FIG. 3.

In FIGS. 1 and 2 an internal combustion engine, modified in accordance with the principles of the present invention, is shown. Accordingly, the internal combustion engine 10 has its usual block 11 which for the purposes of nomenclature may include also the valve head, pan l2, and crankshaft 13 provided with pulley l4 keyed thereto. It will be understood that the engine structure will be conventional excepting for the addition of the fuel injection system 15 comprising pump 16 and the pressure and return lines operatively associated therewith as hereinafter described. Specifically, pump 16 preferably comprises the inventors improved bellows pump as disclosed and claimed in a co-pending US. Pat. Application under the same title, executed by the inventor July 25, 1972. There are several reasons for this preference among which are low cost in manufacture, piston-bellows use for obtaining positive displacement, and a pump choice, consistent with the incorporation ofa single piston, for supplying fuel to multiple cylinder cavities, an uncommon approach in fuel injection systems in general. Further, by employment of such a pump, ease of maintenance is facilitated and maintenance operations can be performed in any standard shop. For other types of fuel injection pump systems, such as the Bosch system, highly trained personnel are required to maintain such pumps. Likewise, in the inventors pump design close tolerances are avoided. The foregoing observations do not rule out the possibility of incorporating another type of pump design for pump 16. Thus, a Bosch pump, or indeed, any other type of high pressure pump capable of pumping fuel at high pressure may be used. In the present instance, however, it is most important to note that a single operating piston within the pumps design serves to effect a pumping of fuel to each of the cylinders of the engine. This will be described later in detail.

In any event, the preferred pumps design is that explained in the inventors above-referenced co-pending patent application which is now fully incorporated herein by way of reference.

The high-pressure side 17 of the injection system is provided with a pair of

check valves

18 and 19, constructed and arranged in the usual manner such as to permit a flow as shown by the'direction of arrows A and B. Input drive shaft 20 for the pump 16 is provided with a pulley 21 keyed thereto. Pulley 21 comprises a driven pulley that is connected by belt 22 to pulley 14 associated with the crankshaft I3. Stub shaft 23 is appropriately journaled by suitable structure, not shown, for enabling the securement of pulley 24. Shaft 23 will mount the usual fan 25. Stub conduit 26 leads to tee 27 which joins

conduit

28 and 29. Conduit 28 and conduit 29 serve as pressure lines for fuel pumped to the respective banks of cylinders on opposite sides of the engine. Conduit 29 connects to tee 30 that is simply plugged off by plug 31. Conduit 32,33 and 34 are connected together as shown by

tees

35, 36, 37 and 38. Tee 38 is plugged off at its outer end by plug 39 as indicated. Branch lines 4043 are connected to their respective tees as indicated in FIG. 1.

The opposite or left-hand extremities of conduit 40-43 are connected to their respective valve stem structures 44-47, either directly or via respective flexible conduit 48 as secured to a representative conduit 40 via coupling 49. For convenience of illustration the flexible connection conduit 48 and coupling 49 are shown only in FIG. 2; FIG. 1 illustrates a direct connection of the respective conduit 4043, possibly flexible, to the respective valve stem structures 44-47. The high-pressure and low-pressure line connections are il lustrated both in FIG. 1 and also in FIG. 3. To under stand the structural provisions involved, reference is now made to FIG. 3.

In FIG. 3 it is seen that engine block 11 is provided with respective air intake valve stem bore 50 and guide 51. For convenience of explanation, only one of the valve structures of the engine will be described and explained in detail. It will be understood that the remaining valves and remaining cylinders will likewise be constructed in essentially the same manner. Hence, the representation in FIG. 3 is typical of all valve guide structures.

As seen in FIG. 3, representative high-pressure conduit 40 is operatively connected to fitting 52. The latter is provided with a transverse bore 53 that receives valve stem 54. Valve stem 54 includes, of course,

radial apertures

55 and 56. These latter register with apertures 57 and 58 of valve stem liner 59. O-ring seals at 60 and 61 are provided in O-

ring grooves

62 and 63, as indicated. Low-pressure conduit 64 includes a corresponding fitting 65 having an interior groove 66 cooperatively associated with radial apertures 67 of valve stem 54. The valve stem 54 is interiorly threaded at 68 to receive externally threaded plug 69. The latter includes a relief bore 70 for receiving threaded shaft 71. No threaded engagement exists between threaded shaft 71 and this bore. In any event, threaded shaft 71 is threaded into axial threaded aperture 72 of the valve stem liner 59. A compression spring 73 is operatively disposed between the upper end of threaded plug 69 and inner surface 74 of spring retainer 75.

Valve return spring 76 is a compression spring operatively disposed between engine block 11 and spring retainer 77. Spring retainer 77 is retained in position by conventional, split spring-retainer lock 78.

The lower portion of FIG. 3 and also FIG. 4 disclose the pintle valve structure at the lower portion thereof. Specifically, valve member 79 includes, of course, not only the valve stem 54 but also valve portion 80 integral therewith. The valve portion 80 is threaded at threaded aperture 81 to receive valve plug 82. Valve plug 82 is provided with key slots 83 so that the plug may be threadedly turned in position. Plug 82 includes a pintle seat 84 communicating with fuel passageway 85; the latter may be chamfered at 86 if desired. Pintle 87 is threaded at 88 and is received in threaded aperture 89 of valve stem liner 59. The latter thus is seen to be of tubular construction which is closed at its lower end. Valve stem liner 59 includes plural

radial passageways

90 and 91 which communicate with longitudinal

exterior surface grooves

92 and 93. The construction is such that fuel passageway space 94 is pro vided.

In operation, valve member 79 comprises the air inlet valve of the engine; thus, though there is no carburetor in the engine, since this comprises a fuel injection system: nonetheless, cavity 95 will lead to the conventional intake manifold of the engine. Hence, as valve 80 descends, air is drawn into the associated cylinder. It will be noted, however, with the descent of such valve poppet 80, fuel also comes through the valve via conduit 40. In describing fully this operation it will be seen that the aligned apertures proximate the fitting 52 will admit fuel from'the high pressure conduit 40 such that such fuel enters the interior passageway 96 of valve stem liner 59. This fuel is under pressure and proceeds downwardly to

radial passageways

90 and 91, for example, proceeding therefrom through

slot passageways

92 and 93 into fuel area 94.

In considering FIG. 2 in conjunction with FIG. 3, it is most important to note that conventional rocker arm or other prime mover 97, of standard construction in the engine, not only serves to depress the over-all representative valve member 79 but, in addition, to spacedly lower the pintle 87 relative to the pintle seat 84 of the valve. This is accomplished by virtue of the fact that a depression of cap nut 98, threaded onto shaft 71, will effect, first, a depression of the valve stem liner 59and, associatively, pintle 87, just prior to the time that interior shoulder 99 engages the upper extremity of valve stem 54. Upon such engagement, then the rocker arm, in its further travel, will separate or lower the valve portion 80 from its seat at 100, allowing air to enter cylinder.

It is important that the space 101 between the aforementioned shoulder and valve stem be made adjustable, so that the fuel flow through the pintle valve at 87 can be adjusted. The purpose for the inclusion of spring 73 and cap nut 98 is to close pintle 87 against its seat.

The purpose for the inclusion of the low-pressure system as at 64 will now be explained. It is noted that we are dealing with high pressure fuel injection. In the absence of the inclusion of a low-pressure system, then, should the seals fail as at O-

rings

60 and 61, there would be a chance of leakage out of the upper portion of the valve stem structure, possibly rendering a dangerous condition for the engine. To avoid such a difficulty, the inventor includes at each valve stem structure a fitting 65 and a representative conduit 64, all of which are connected together and lead to conduit 102. The latter in turn connects to tee 103 which joins to the remaining low-pressure side of the engine via conduit 104 and also to the input conduit 105 of conventional low-pressure fuel pump 106, i.e., the same incorporated to draw gasoline from the engine. The output of low-pressure fuel pump 106, at 107, is connected via conduit 108 to the input side 17 of the high pressure fuel injection pump 16 of the present invention. Line 105 simply leads to the fuel supply for the engine. The structure at C in FIG. I is identical to the structure at E and simply accommodates the remaining bank of cylinders of the engine. Accelerator rod 109 leads to the foot accelerator of the vehicle and is connected at its forward extremity to an acceleration control 110 via pivot connection 111. The acceleration control at 110 will simply connect to the volume control of pumped liquid, herein fuel, as is customarily supplied the pump.

See by way of example the displacement volume adjustmerit control of the inventors co-pending application above referenced, herein incorporated fully by way of reference.

Accordingly, the present invention provides a conventional internal combustion engine, having valve displacement rocker arm structure, with new and improved valve structure that facilitates the valve introduction of air flow and also fuel injection upon such air introduction. It is noted that fuel injection is begun just prior to air inlet valve opening, which affords a maximum combustion effect for the particular cylinder in question. Further, no complicated timing problems are presented relative to the fuel injection since the same relies upon the rocker arm movement for effecting the necessary fuel injection at desired times. Timing will be wholly controlled by the settings of the rocker arms.

What is provided hence is a new and improved system and structure for fuel injection wherein the fuel injected comes actually through the air intake valve stems of the engine.

While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art the various changes and modifications which may be made without departing from the essential features of the present invention and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

l claim:

1. In an internal combustion engine having a cylinder block provided with air-intake valve bores and means for cyclically depressing individual valve structures disposed in respective ones of said bores: an improvement comprising fuel injection pump means, having input and output sides, for operatively introducing fuel into said cylinder block; plural air intake valve structures individual ones of which are disposed in respective ones of said air-intake valve bores, each of said air intake valve structures comprising an air valve member having a valve stem and an air intake valve portion integral therewith, and provided with a fuel valve seat said air valve member being provided with fuel passageway means disposed axially through said valve stem and an air intake valve portion; and conduit means interconnecting said fuel injection pump means at said output side with said valve structures, and wherein each of said air intake valve structures includes a hollow valve stem liner, a fuel valve pintle connected to said valve stem liner and seated in said fuel valve seat, and a single mechanical member for cyclically, thrustingly depressing said valve stem liner relative to said valve stem and said valve stem relative to said cylinder block.

2. Structure according to claim 1 wherein each of said valve stems and said valve stem liners are provided with seal means disposed therebetween, plural fittings respective ones of which are disposed about said valve stems above said seal means, said valve stems being provided with respective passageway means for provid' ing communication between the interior of said valve stems above said seal means and said fittings, and conduit means coupling all of said fittings back to said fuel injection pump means at the input side thereof.

3. Structure according to claim 1 wherein said valve stem includes a plug having an axial guide aperture, spring retainer means disposed above said plug, a compression spring disposed between said spring retainer means and said plug. and a shaft fixedly disposed with respect to said valve stem liner and said spring retainer means and passing through said axial guide aperture.

4. The combination of claim 1 wherein said air valve portion has a lower threaded plug seat, a plug threaded into said plug seat and having a downwardly facing valve seat as said fuel valve seat and a central passageway communicating therewith, said fuel valve pintle being seated in said downwardly facing valve seat and being secured to said valve stem liner, said valve stem liner having fuel passageway means providing communication between the exterior of said fuel valve pintle and the hollow interior of said valve stem liner.

5. In an internal combustion engine having a cylinder block provided with air-intake valve bores and means for cyclically depressing individual valve structures disposed in respective ones of said bores; an improvement comprising fuel injection pump means, having input and output sides, for operatively introducing fuel into said cylinder block; plural air intake valve structures individual ones of which are disposed in respective ones of said air-intake valve bores, each of said air intake valve structures comprising an air a valve member having a valve stem and intake valve portion integral therewith, said air valve member being provided with fuel passageway means disposed axially through said valve stem and air intake valve portion; and conduit means interconnecting said fuel injection pump at said output side with said valve structures, said valve stem includes a plug having an axial guide aperture, spring retainer means disposed above said plug, a compression spring disposed between said spring retainer means and said plug, and a shaft fixedly disposed with respect to said valve stem liner and said spring retainer means and passing through said axial guide aperture, and wherein said spring retainer means comprises a cap-configured retainer having a lost-motion interior shoulder, said shoulder being dimensioned to cyclically abut the combination of said plug and said valve stem.

6. In combination, an internal combustion engine having at least one, air-intake valve bore having a valve seat; at least one air intake valve structure disposed in respective one of said bore and having an air intake valve portion; a single mechanical member for structurally depressing said valve structure, said air intake valve structures having interior passageway means for conducting fuel through such air intake valve structure to the interior of said engine; a fuel injection pump; and conduit means for coupling said fuel injection pump to said valve structure, and wherein said air intake valve structure includes a valve stem having an integral air admitting valve poppet portion and is itself interiorly provided with interior fuel admittance valving means disposed proximate to and operative in connection with said interior passageway means, and structural means actuated by said single mechanical member for enabling opening of said interior valving means prior to depression of the valve stem operatively associated therewith.

7. Structure according to claim 6 wherein bypass means is provided for conveying leakage fuel, from the interior of said valve stem, back to said fuel injection pump means.

8. In combination, an internal combustion engine having plural, air-intake valve bores having valve seats; plural air intake valve structures disposed in respective ones of said bores and having air intake valve portions;

mechanical means for sequentially structurally depressing said valve structures, said air intake valve structures having interior passageway means for conducting fuel through such air intake valve structures to the interior valve structures, and wherein said valve structure has lost-motion structural means enabling, upon downward thrusting of said valve structure, first, opening of said valve structure interior and, second, depression of said of said engine; a fuel injection pump; and conduit valve stem and said valve portion from its valve seat.

Claims

2. Structure according to claim 1 wherein each of said valve stems and said valve stem liners are provided with seal means disposed therebetween, plural fittings respective ones of which are disposed about said valve stems above said seal means, said valve stems being provided with respective passageway means for providing communication between the interior of said valve stems above said seal means and said fittings, and conduit means coupling all of said fittings back to said fuel injection pump means at the input side thereof.

3. Structure according to claim 1 wherein said valve stem includes a plug having an axial guide aperture, spring retainer means disposed above said plug, a compression spring disposed between said spring retainer means and said plug, and a shaft fixedly disposed with respect to said valve stem liner and said spring retainer means and passing through said axial guide aperture.

8. In combination, an internal combustion engine having plural, air-intake valve bores having valve seats; plural air intake valve structures disposed in respective ones of said bores and having air intake valve portions; mechanical means for sequentially structurally depressing said valve structures, said air intake valve structures having interior passageway means for conducting fuel through such air intake valve structures to the interior of said engine; a fuel injection pump; and conduit means for coupling said fuel injection pump to said valve structures, and wherein said valve structure has lost-motion structural means enabling, upon downward thrusting of said valve structure, first, opening of said valve structure interior and, second, depression of said valve stem and said valve portion from its valve seat.