US 2347363 A
Description (OCR text may contain errors)
Y Apnl 25, 1944. v. PALUMBO y FUEL INJECTION MEANS FOR INTERNAL COMBUSTION ENGINES Filed March 20, '1941 Patented Apr. 25, 1944 FUEL' INJECTION MEANS FOR INTERNAL COMBUSTION ENGINES Vincent Palumbo, Cleveland, Ohio y Application March 20,1941, Serial No. 384,271
6 Claims. (Cl. 299-1072) This invention relates to improved fuel injection means for internal combustion engines.
Among the .objects of the invention are to provide a fuel injector that is relatively simple yet highly efficient and wherein the valve that governs the fuel injection is actuated and controlled by fuel pressure; to provide an injector of'the aforesaid character in which the valve is biased toward closed position and is operated by a pres-` sure fluid actuator means that may consist of a piston, a diaphragm, or the equivalent, and
whose opposite sides are exposed, respectively,
to a valve opening working space and to a valve closing working space, the rst mentioned of which spaces, along with the fuel passage, is constantly in free communication with a high pressure part of the fuel system, while the second mentioned space is in constant but restrained communication through a restricted passageway or bleeder port with the same high pressure part of the system thereby to permit attainment of a balancedpressure on both sides of the actuator means so as to ,allow the valve to close, the pres-v sure in the valve closing working space being subject to intermittent relief; and to provide a fuel injector of the foregoing nature that-is intended to be individual to an engine cylinder and which includes an adjustment whereby the action of its valve may be regulated according to the peculiarities of the cylinder whose fuel supply it con'' trols to the end that, in a multiple cylinder engine, maximum smoothness of`operation and efciency may be realized.
Objects Yadditional to the foregoing will appear as I proceed to descrim the invention in detail by reference to the accompanying drawing wherein like reference characters designate cor-y responding parts throughout the severalviews. The detailed description, however, is not to be taken as limiting the invention to the structural features disclosed further` than required by the terms of the claims appended hereto. n
In the drawing, Fig. 1 represents aside elevation of a multiple cylinder internal combustion engine, each cylinder of which is equipped with my `improved fuelinjector; Fig. 2 is a diagrammatic representation of a systemwherein the injector, a pump and a selector-relief valve are shown in section; and Fig. 3 shows a modied form of the injector in central section.
For illustrative purposes I have shown my fuel injection .means in association with a multiple cylinder engine, the same being of the four-cyclev type. It willbe understood that in, other respects the engine may be of standard character having the usual ignition system, valve controlledl a selector-relief valve, a throttle, and a pump.
inlet and exhaust ports,l and, means forsvupplyfw'l-y ing an' in lieu of the ordinary gaseous mixture to the cylinders,` such being omitted from the drawing. Communicating with each cylinder of the engine A is an injector designated generally by .the reference numeral I and later to be described in detail. Mounted on apart of the engine is a unit 2 which, incidentally, incorporates The `mechanism of this unit is driven from a moving part ofthe engine, forexample, the crank shaft, through a chain a or other' means. The
high pressureiside ofthe pump communicates through a conduit 3 and its several branches with the supply sides Vor inlet passageways, and, as will later appear, with both valve working spaces, of
thai-,is adapted to vcommunicate through a relatively small outlet orifice or passage l2 with the interior'of a cylinder of the engine A, the body IU being shown as counterbored aboveand below said orice. The orifice is vshown as axial of an externally threadedboss l3fthat'is'adapted to be screwed into'a threaded aperture vin the wall of the engine cylinder in' much the manner-of a y spark plug, the joint'between the body and wall being sealed by agasket "I4 that is compressed betweena shoulder on the body and the adjar cent part of the engine. Threaded onto the upper end of the body" l0 is a cap I5 having an inlet passageway I6 anda relief' passageway ll. rOpferating within a centralraxial bore or cylindrical .y
chamber ofthe body l0 is an'actuator means 20. Iny certainones of the appended claims this ac tuator means is termed tegral withthe actuator means., yThe actuator means is biased in a direction toIengage the valve with aseat surrounding the inner end of the ori-- flce I2 by a relatively light spring 22 that is.
confined between a part of the cap l5 andthe bottom wall of the cavity of the actuator means 20'. The extent to which the valveZl may open is determined by a stop 25 formed by a pin-like extension of a screw 26 that extends through and yfrieten in Fig. v2; comf pressure-responsive, means and, vin the embodiment at present un-vk der consideration,` the same is'in the form ofl an open t'op hollow piston that carriesat its lower closed end a needle-point; valve 2| shown as inis threaded in the cap- I and is adapted to be secured in any adjusted position by a lock nut 21.A Applied to the screw above said nut is a sealing cap 28. The previously mentioned valve opening working space or chamber I| communicates through holes 38 with an annular recess 3| in the top of the body I8, and a port 32 establishes free communication between the recess 3| and the inlet passageway I5 of the cap. Rssirained communication (as distinguished from free communication above) between sai-d passageway I8 and the space within the actuator means 20, which space I term the valve closing working space of the injector, is maintained through e. restricted passage or bleeder port 33. Also communicating freely with said valve clcsing working space through a port 35 is the relief passageway I1 of the cap.
It will be apparent from the foregoing description that the injector valve 2|, biased toward closed position by the spring 22, will remain closed as long as the pressure of the fuel in the valve opening and closing working spaces remains balanced, and that said valve'will open the instant the pressure in the valve closing working space is relieved, this condition being brought about by permitting the pressure fluid (liquid fuel under pressure) to escape from the valve closing working space more freely than it can enter said space through the restricted passage or bleeder port 33.
I shall next describe the unit 2 which, as previously brought out, includes the pump, throttle and selector-relief valve. The casing 48 of said unit shown in section intwo diiferent planes in the diagram of Fig. 2 encloses a pump chamber 4|, afid` a valve chamber 42. A pump rotor 45 has a working fit in the pump chamber 4I, and extending diametrically through the rotor is a s mounted on its outer end a gear 54, shown in It is the gear 54 Fig. 1 in dot-and-dash lines. wherewith the previously mentioned chain a engages to drive the pump and the selector-relief valve.
As appears from the transverse sectional view of the pump, which view constitutes a part of Fig. 2, the cylindrical portion of the pump chamber 4| wherein the rotor 45 operates opens into two compartments 80 and SI, the one designated 60 being the high pressure compartment, and the other, 8|. being the lower pressure compartment. The former compartment communicates with the inlet passageway I8 of each of the injectors I through the branched conduit 3, while the latter compartment communicates through a conduit 63 with a source of liquid fuel supply. shown as a fuel tank B. To effect the result just described, the pump rotor 45 rotates in the direction indicated by the arrow associated with the rotor in Fig. 2.
The. compartments 60 and 8| are adapted to communicate through a by-pass passageway 65 adjacent the bottom of the casing. Screwed into an extension of said passageway that opens through one side of the casing is the end of an internally threaded sleeve-like fitting 86; and shown as clamped between the inner end of said fitting and a shoulder 61 that surrounds the remote end of the by-pass passageway is a thimble 68 within which a plunger valve 89 is adapted to reciprocate and control oneor more ports 10 i'n the wall of the thimble which open into the low pressure compartment 6I. As a means of providing free communication between the ports 10 and said chamber, regardless of the angular position of the thimble within the passageway, the thimble is turned down between its ends to a diameter less than that of the passageway, as indicated at 1I in Fig. 2. The plunger valve 69 is urged toclosed position, in which it is stopped by the engagement of an extension 13 thereof with an opposed wall portion of the compartment 60, by a spring 'I4 that is compressed between the plunger valve and an adjusting screw 15 that operates within the threaded bore of the fitting 66,'the outer end of which bore is closed by a screw plug 16.
It is apparent from the foregoing description that, as the pump rotor 45 is turned in the direction indicated by the arrow in Fig. 2, the pump piston 48 will be reciprocated within the bore 41 by reason of the eccentricity of the crank shaft 5| with respect to the axis of rotation of the pump rotor. In further explanation of this action it may be pointed out that as the rotor turns it will propel the crank pin 50 about an orbit concentric to the axis of the crankshaft, and since the shaft is offset with respect to the axis of the pump rotor, the pump piston will be caused to reciprocate within the pump bore.
As the pressure builds up within the compartment 80 above the resistance of the spring A14, it will force the plunger valve 69 along the bore of the thimble 68 until the adjacent port 'III is ope'ned thereby to cause the fluid to circulate within the pump at the pressure determined by the strength of the spring 14, and as this factor may be varied by the adjustment of the screw 15, so may the maximum pressure of the fluid within the high pressure part of the system.
I shall now briefly describe the selector-relief valve. As shown in Fig. 2, a plurality of distributor ports 80 (four in the present case) open through the peripheral wall of the valve chamber 42. Said ports are shown as spaced apart about said wall and each communicates through one of the conduits 4 with the relief passageway I1 of one of the injectors.
A suitable throttle is provided which involves segmental elements 83 that are disposed in spaced relation to one another about the peripheral wall of the valve chamber 42 and alternate ones thereof are stationary, One edge of each of the stationary elements 83 is disposed in substantially radial alignment with one side of one of the dis tributor ports 80, The other elements 83 are movable in unison, by suitable means (not shown, and constituting no part of the present invention) toward and from the stationary elements so as to alter the width of the gates constituted of the spaces between adjacent elements that register with the distributor ports 80.
The cylindrical body 88 of the selector-relief valve has a working fit within the segmental elements 83 of the throttle. The body 88 has a hub 89 mounted on the shaft 5| and held against turning with respect thereto by suitable means, as a key 90. In the peripheral wall ofthe valve body is a port 9| that sweeps past the gates of asaases the throttle that control the distributor ports as the valve member is rotated by the shaft The valve chamber 42- or, more accurately, the
space within the valve body 80-communicates4 through a passageway |02 with the low pressure compartment 6| of the pump by way of the bypass passageway 65.
The manner in which the pump functions to has already been described. It is obvious from the previous description that the fuelfis constantly maintained at high pressure within the valve opening working space or chamber of each of the injectors, where it has access to the adjacent side of the actuator means of the valve 2|, and such high pressure is also permitted to build up on the opposite side of the actuator means, i. e. in the valve closing working space, through the relatively small bleeder port 33. Under these conditions the valve is held closed by the spring 20. As the valve body 00 of the selector-relief valve rotates it will intermittently establish communication between the valve closing working space of each of the injectors l and the low pressure side of the system, it being remembered that the space within the valve body 88 communicates through the port |02 with the low pressure compartment 6| of the pump. The extent to which the valve 2| of each injector is allowed to open is determined -by the adjustment of the stop 25, as previously explained; and the time the valve remains open is determined by the duration of the period of relief of the valve closing working space of the injector, ,4
the latter depending upon the adjustment of the throttle elements 83.
In the modified form of the injector, shown in Fig. 3, a diaphragm |20 constitutes the actuator means of the valve 2|a corresponding to the valve 2| of the previously described form. The remaining corresponding parts of the two forms are designated by like reference numerals, those associated with the modification shown in Fig. 3 being augmented by the exponent a. In the case of the modification, the resiliency of the diaphragm |20 is relied upon to close the valve 2|, although, if desired, a spring may be used to urge the diaphragm in a direction to close the valve.
Having thus described my invention, what I claim is:
, 1. A fuel injector for internal combustion engines comprising a casing made up of two parts engaged in face-to-face relation, a recess in each of the mating faces of said parts, that of one part constituting a valve opening working space and that of the other a valve closing working space, a diaphragm disposed between the mating faces of said parts and separating said spaces, a fuel passage in the part having the valve opening working space that leads from said space and through which passage fuel is adapted to be delivered to the engine, a valve carried by the diaphragm for controlling the flow of fuel through said passage, means for connecting the two parts of the casing together, a'. fuel receiving passageway in the casing, the same having two branches, one of said branches communicating with the valve opening working space and the other branch, which is of much smaller now capacity than the first mentioned branch, communicating with the valve closing working space, and a relief passageway in the casing, the same being of much larger flow capacity than the second mentioned branch and communicating with the valve closing working Space.
2. A fuel inJector for internal combustion engines comprising av casing provided with an inlet passageway anda relief passagewaylanda valvecontrolled outletorifice, a valve controlling said outlet orifice, pressure-responsive means addil` tional to said valve for yoperating the latter, there being ports leading from the inlet and relief passageways to one side ofthe pressure-responsive means, the port leading from the relief passageway being relatively much larger in cross sectional area than the port leading from the inlet passageway, there being a working space within said casing on the opposite side of said pressure-re-A sponsive means, anda portleading from said inlet passageway to said working space and having a greater cross sectional area than that of the port leading from the inlet passageway to the first mentioned side of said pressure-responsive means. 3. In a fuel injector for internal combustion engines, the combination defined by claim 2 plus: means forsupplying fuel under constant pressure to the fuel inlet passageway, and means for periodically relieving the pressure in the relief passageway, the pressure-responsive' means being so arranged with respect to the outlet orifice that when the pressure on the side of said pressureresponsive means opposite said working space is relieved by said periodically operated pressure relief means, the valve is opened, and when the pressure is reestablished on said side of the pressure-responsive means, the valve is closed. 4. A fuel injector for internal combustion engines, the same comprising a casing, av fuel" passage in the casing for the delivery of fuel to the engine, a valve opening working space enclosed by the casing and from which said passage leads, pressure-responsive means movable within the casing and having one of its sides exposed to said space, a valve flxedly attached to and movable with said pressure-responsive means for controlling the aforesaid fuel passage, a valve closing working space within the casing to which the opposite side of said pressure-responsive means is exposed, an inlet passageway in the casing that freely and constantly communicates Vwith tlie valve opening working space, a'bleeder port that is relatively much more restricted than said passageway through which said passageway constantly communicates with the valve closing working space, a relief passageway in the casing that is relatively much larger in cross sectional area than said bleeder port andY that communicates freely and constantly with the valve closing working space, means for supplying fuel under constant pressure to the inlet passageway, and means for periodically relieving the pressure in the relief passageway, the pressure-responsive means being so arranged with respect to the fuel passage that when the pressure in the valve closing working space is relieved by said periodically operatedpressure-relief means the valve is opened, and when the pressure is re-established in the valve closing working space, the valve is closed. i,
5. In a fuel injector for internal combustion engines', the combination defined by claim 4, plus: a spring serving to urge said valve toward closed position.
6. A fuel injector for internal combustion engines comprising a casing made up of two parts engaged in face-to-iace relation, a cylindrical -and the other branch communicating with the cylindrical chamber on the side of the piston remote from said space, the first mentioned branch being relatively much larger in cross sectional area than the second mentioned branch, a relief passageway V `in the casing, the same being relatively much larger in cross sectional area than the said second mentioned branch of the inlet passageway and communicating with the same part of the cylindrical chamber as said second mentioned branch, means for supplying fuel under constant pressure to the fuel inlet passageway, and means for periodically relieving the pressure in the relief passageway, the piston being so arranged with respect to said fuel passage that when the pressure in the cylindrical chamber is relieved by said periodically operated pressure relief means, the valve is opened, and when the pressure is reestablished in said chamber, the valve is closed.