US1981551A - High pressure injection fuel pump - Google Patents

Description

J. F. HERMANN HIGH PRESSURE INJECTION FUEL PUMP Filed Nov. 11, 1932 Nv. 2o, 1934.

Patented Nov. 20, 1934 UNITED STATES PATENT OFFICE: .l

HIGH PRESSURE INJECTION. FUELPUMP John F. 4Hermann, Havana, lll. u Appuuation November 11, 1932, serial No. 642,185 v 4 claims.- (ci. 29e-107.2)v

My invention relates to fuel pumps for supplying fuel to internal combustion engines under high pressure; an object being in. my device to provide an individual high pressure gasoline pump for. each cylinder of a gasoline engine whereby the emciency derived from the use of my pump with its mechanical operating connections may result in a substantial saving'of gasoline and a consequent increase in the mileage per gallon obtained therefrom'.

Heretofore it has been the common practice' Aof internal combustion engineers to mix with the gasoline fuel, for instance, a small percentage of high viscosity lubricating oil in order to attempt to lubricate the pump mechanism, particularly the plunger. `In the common practice operating with these conditions, it has been found that it was impractical and in manycases impossible to exceed a speed of 900 reciprocations per minute without causing the moving parts to freeze, and in addition to that limitation ofl speed in operation of such pumpsfthere was an attendantloss of fuel back through the pump l which was excessive.

With my invention, I propose not, only to suc-Y viscosity lubricating cil forced into the punip under variable pressures, especially throughout the pump cylinder Wall as a successful lubrication for the pump' parts, but with this arrangement I also provide a very effective means of preventing losses of fuel which have commonly occurred under previous methods. Operating with my invention under these conditions, I have secured under tests a reciprocating speed in the pump of 1500 per minute, with results which indicate some modifications which will permit a substantially greater speed than I permitted in my tests with the testing equipment at my-disposal.

A purpose of my invention is to provide a mechanically operated fuel pump adapted to project gasoline into the combustion chamber of a gasoline engine at the instant of high compresf sion therein with a forcethat is a comparatively higher pressure, breaking the fuel thus projected up into a relatively fine delicate spray as it enters the combustion chamber without loss of gasoline in the pumping.

.A further purpose of my invention is to provide a high pressure fuel pump of the injection type which is mechanically actuated by a mecha'- nism which is adjustable in a manner providing for the handling of variable quantities of gas oline in a simple and positive operation with a uniform stroke of the plunger.

A further purpose of my invention is to provide a relatively simple, economical, and prac-v tical high pressure injection fuel pump provided with a positive means of advancing and retarding the delivery of fuel to the point from which it is injected into the combustion-.chamber ofthe motor.

A further purpose of my invention is to provide a high .pressure injection fuel pump which is adjustable vfor varying the quantities of fuel to 'bepumped at each stroke of the plunger and which lis provided with'a simple, novel, and practical means for lubricating the vpump plunger and pump cylinder walls under optionally variable pressures in a manner adapted to permit the plunger in its reciprocal movements toconstantly operate in a bath of oil under pressure and to constantly swipe the cylinder walls with an effective -molecular seal of oil rings about the pump plunger that will prevent losses of fuel back lthrough the pump.

A particular purpose, therefore, of my invention is to yprovide a fluid fuel pump which will not only deliver the fuel therefrom under high pressure, but a pump which has all its parts .thoroughly lubricated by oil of a high viscosity administered under a variable pressure and a pump which in its construction provides for a pluraltiy of spaced annular oil pockets about the pump plunger permitting through the high viscosity of the oil in such rings a very effective and practical molecular seal between the gas chamber and the lubricating chamber. This molecular seal when the pump is in operation with the oil under ,high'pressure eiectively makes of each of these cited in the claims, and illustrated in the accompanying drawing in which like reference numerals v indicate like 'parts in the several'gures.

Referring to the figures: i

Figure 1 is a vertical half Section of my-inven. 4

tion disclosing to view the details of construction thereof and also showing its operative connection with a high pressure fuel injection feature thereof.

-The salient features of my'invention are the I result of extensive research and experimentation in the fuel pumping art and comprises in its mechanical organization anew `article of manufacture which has under a series of tests proved to be highly emcient. 1-

With the mechanical perfection of my option- `ally variable pressure lubricating system for the pump a successful high speed operation thereof may be assured while with the spiral cut-olf feature of the plunger head operating in conjunction with the fuel intake orifice of the pump cylinder an optional adjustment of the rotatable position of the plunger makes it possible and convenient to vary the quantities of fuel handled by the pump at each stroke, permitting a suitable control thereof to successfully conform to the fuel eiiiciency demands of the internal combustion engine to which it may be attached.

My invention comprises in cooperative organization a housing 1 into which is detachably se cured a .sleeve 2 encasing a pump cylinder 3 adapted to receive the fuel and discharge the same at a predetermined highpressure, sufficient to break up the fuel into a delicate-spray as it is forcefully injected thereby into the combustionA chamber 6 of a gasoline engine 7, for instance, through a high pressure injection nozzle 8.

My pump is preferably provided with a plunger member 9 having at one end a head 10 having a portion of itscylindrical wall recessed in spiral form l1. Below head 10 of plunger 9 there is provided a series of spaced annular oil carrying recesses l2 for carrying lubricating oil to the inner walls of the pump cylinder and to define by these rings of oil a series of molecular oil seals between the oil chamber and the fuel chamber of the pump; while at the end opposite the head ofl plunger 9 a non-circular shape 13 is provided for holding the plunger 9 in selective positions of rotatable adjustment.

It will be observed that the plunger 9 normally reciprocating in cylinder 3 is forced to the forward or top end of cylinder 3 by the rotation of cam 14 on a shaft l5 supported in a bearing 16 in housing l. rThis cam transmits its force which moves plunger 9 through a push rod 17 which detachably engages'non-circular end 13 of plunger 9. After plunger 9 is actuated by cam 14 iri its forward movement then it is automatically retracted by a compression spring 18 operating Within a cylindrical chamber 19 lof sleeve 2. This spring 18 presses against a spring head 20 on l plunger 9.

In my invention I provide for a thoroughly eilicient means of lubricating my pump.

In order to effectively lubricate my fuel pump` I provide an annular recess 21 in the inner wall of pump cylinder 3 and an annular channel about the outer wall of sleeve 2 and this channelis designated by reference numeral 22. I also provide' a plurality of transverse passages 23 establishing communicative connection as an oil passage between recess 21 and channel 22.

.Oil from the source of supply enters housing 1 under optionally variable pressure through feed connection 24 and passage 25 from which it enters the annular spaces 2l and 22 and 23 from which the oil is supplied to annular oil recesses 12 in plunger 9 as these recesses reciprocate in their movement with the plunger and thus tend to successively pass the oil along the inner wall of cylinder 3; where this lubricating oil has a high viscosity these rings of oil provide an eilicient molecular seal between the oil and fuel.

In order to explain how a maximum of efllciency' may be secured through the use of my pump operated under high pressure so far as handling the fuel under'high pressure is concerned the gasoline, for instance, is taken in through an intake connection 26 from a source of supply thereof from which it is conducted through a passage 27 and an annular channel 28 in a plunger casing 29 from which the fuel is then conducted through a passage 30 in neck 31 and thence through a passage 32 and into an annular fuel pocket 33 defined by adjacent recesses in sleeve 2 and cylinder 3.

From -annular pocket 33 the fuel is drawn through an orifice 34 into the head of cylinder 3 as plunger 9 is retracted by spring 18 which is of a high compression spring type.

In order to vary the amount of gasoline for instance to be discharged from cylinder 3, I provide a head 10 whose front surface is disposed at some angle other than a right angle to the axis of the plunger so that by a slight manual rotation of plunger 9 the amount of reciprocal movement passing orifice 34 will be changed.

That is, by changing the rotary position of plunger 9 the amplitude of the intake passage for fuel will be varied, for example, (see reference numeral 11, Fig. 19 by the spiral edge 11 of head 10 of plunger 9, thus resulting in varying the amount of gasoline discharged by the plunger out through fuel passage 35.

As the fuel is thus discharged through passage 35 on its way to combustion chamber 6 it passes through a channel 36, thence into an annular space 37 communicating with channel 36 (see Fig. 3), in high pressure injection nozzle 8 from which space there is provided a series of parallel communicating fuel channels 38 to carry the gasoline down to the annular terminal space 39.

When the gasoline reaches this point due to the high pressure thereon exerted by plunger 9, then the force of this pressure in the end opening 39 reacts against shoulder 40 of needle valve 41 causing the same to retract against a plunger spring 42 in casing 29 resulting in pulling needle point 43 away from its registry with relatively small orifice 44 at the tip of nozzle 8. With needle point 43 retracted from its normal position over orifice 44 this will permit the discharge of a fine spray of gasoline out into combustion chamber 6 of internal combustion motor 7 under high pressure.

In fact, my high pressure fuel pump injects a spray of gasoline 'into the cylinder 6 when the piston thereof is at the bottom of the stroke, thus entering the fuel into free entering air in the cylinder prior to compression.

Plunger rod 45 has a feeler tip 46 used for the purpose of holding the nger thereon to ascertain the amount of movement taking place in the re` ciprocal action of needle valve 41 and the dust v cap 47 is adapted to protect tip 46 from dirt.

In order to optionally adjust the rotatable position of plunger 9 to the desired position for measuring and ejecting predetermined quantities of gasoline from the pump cylinder there is provided an adjustment pinion 48-provided with a segment 49 of gear teeth adapted to be controlled by an adjustment ring gear 50, only a part of which is shown in the drawing. Where such an adjustment feature as this is used on a radial engine, for instance, the ring gear 50 may be operatively connected with the pump furnishing fuel to each cylinder of the engine so that the adjustment in all pumps may be simultaneously made. When lifting rod 17 in normal operation lifts plunger 9, then the non-circular terminal 13 of plunger 9 slidably moves through an opening 5l of a corresponding shape in pinion 48.

It will be'noted in Figure 1, that cylinder 6 of municating therewith; said sleeve provided with' engine 7 is provided with a free air intake 52 which is adapted to receive the air for the mixture under a low mechanical pressure. This free air enters cylinder 6 when piston 53 is at the bottom of the stroke and just at this point the gasoline spray 54 is projected directly into the incoming air stream; thus to more effectively break up the gasoline or complete atomization thereof before the piston 53 starts on its compression stroke.

Having described my invention, what I claim 1. In a high pressure injection type fuel pump having a fuel spray nozzle for admitting fluid fuel to an internal combustion engine, a fuel pump cylinder provided with a pump chamber defined by its'inner walls and provided with an outlet opening 4communicating with said injection nozzle, a plunger slidably movable within the cylinder and control means for actuating the same, said plunger provided with a spirally recessed head and a plurality of spaced annular grooves disposed along the length of the body thereof, a cylindrical sleeve encompassing said pump cylinder and provided with an annular channel encompassing the outer wall of the cylinder defining a fuel pocket; said pump cylinder provided with a transverse fuel orifice establishing communication between said pump cylinder chamber and said fuel supply pocket defined by said channel about thel cylinder; said cylinder provided with an internal annular channel operatively communicating with said annular grooves of the plunger during the reciprocating movement of the plunger, an annular channel in the outer annular wall of the cylinder and a corresponding annular channel in the inner wall of said sleeve registering with said outer channel of th cylinder to define an intermediate annular oil pocket about the cylinder and within the sleeve said cylinder provided with a plurality of spaced holes in the cylinder establishing oil supply communication for the annular oil channel within the cylinder from a source of oil supply through said intermediate `oil pocket and through said sleeve wall; said sleeve provided with an outer oil pocket also defining a portion of saidor communicating means for the pump; thus to provide an oil seal foi' the plunger of the pump and lubrication for the plunger adapted to be applied under high pressures and to provide in a pump and injection nozzle organization a means of forcing a spray of fluid fuel into a combustion chamber of fluid fuel engines under variable pressure.

2. In a high pressure injection type fuel pump having co-operative means for forcefully injecting fluid fuel into a cylinder of an internal com-- bustion engine, the combination comprising a cylinder, a fuel intake opening and outlet opening therein, a plunger slidably movable in the cylinder and whose head reciprocates in motion between said intake and said outletopening for the high pressure discharge of fuel therefrom; said cylinder provided with an outer annular channel and a sleeve encompassing the cylinder in a manner defining an annular fuel receiving chamber communicating with said intake opening of said cylinder, and a fuel intake connection communicating with said defined annular fuel receiving chamber; said plunger provided with a plurality of spaced annular grooves below said plunger head thereon; said cylinder provided with an inner annular channel about said plunger, and an outer annular channel coman inner annular channel co-registering with said outer channel of the cylinder and together defining an annular oil feed chamber; said chamber communicatively connected with a source of lubricating oil supply; a plurality of transverse passages in said cylinder and said sleeve for establishing oil communication from an' outer recess of said sleeve to said inner channel of the cylinder through said oil feed chamber; whereby said annular channels and plunger may carry oil to the inner walls of said cylinder under high pressure from said source of oil supply by reciprocating motion ofthe plunger.

3. A high pressure injection type fuel pump having means for spraying fluid fuel into an internal combustion engine cylinder, the combination comprising a cylinder, a fuel intake and outlet therein, a plunger slidably movable in the cylinder and whose head reciprocates in motion between said intake and said outlet opening for the high pressure discharge of fuel therefrom into said fuel spraying means; said cylinder provided with an outer annular fuel receiving channel, a sleeve having an inner annular channel encompassing the cylinder in a manner. defining an annular fuel receiving chamber by said channels and communicating with said intake opening of said cylinder, a fuel receiving connection communicating with said annular fuel receiving chamber; said plunger provided with a plunger head whose end surface is not at right angles with the cylindrical walls thereof to permit rotatable adjustment to be made in the plunger head for varying the quantity of fuel measured off and forced from the cylinder thereby during each reciprocal motion of the plunger; said plunger provided with a plurality of spaced annular grooves along its wall below said plunger head'thereof; said cylinder provided with an inner annular oil channel about said plunger, an outer oil channel about the cylinder and a plurality of transverse oil passages connecting said inner and outer channels of the cylinder; said sleeve provided with an annular channel registering over said outer oil channel of the inner cylinder defining an intermediate oil feed chamber and communicatively connected with a source of lubricating oil supply.

4. A high pressure fuel injection. pump comprising in co-operative combination a fuel pump cylinder, a plunger therein provided with a spiral edged head and having a plurality of spaced annular grooves in the body Wall thereof, a sleeve encompassing said cylinder; said cylinder and sleeve provided with co-registering annular' channels defining an annular fuel pocket adjacent one end of the cylinder and connected by a fuel passage with the cylinder interior adjacent the operating position of the spiral edged head of the plunger, a fuel outlet channel communicating with the end of the cylinder and a fuel intake channel communicating with said annular fuel pocket about the cylinder with a source of fluid fuel supply, an annular oil pocket around the inner wall of said sleeve and spaced from said fuel pocket, and an annular oil channel in the inner and outer wall of said cylinder and communicatively connected together and with. said annular oil pocket of said sleeve by a plurality of transverse oil passages; said plunger provided with an adjustment terminal at the end opposite its spiral edged head, said plunger adapted to be actuated through a second plunger lifted by a cam on a ros sleeve for automatically retracting said plunger from the end of the cylinder after said cam forces the same forward for ejecting fuel under high pressure from the end of the cylinder, a fuel dispensing head communicatively and operatively connected with said cylinder and provided with a pressure actuated needle valve slidably movable therein, said distributing head provided witha shallow fuel pocket at each end communicating with said cylinder and a plurality of longitudinal fuel channels establishing communication between said pockets in said head, said distributing head provided with a relatively small oricecommunicating with the explosion chamberof a gas engine and a spring aetuatedplunger operativelyconnected with said needle valve for automatically closing said orifice in said distributing heid after fuel under high pressure coming from said cylinder has forcibly retracted said needle valve from its closed position over said orice; said annular oil pocket about said sleeve and said annular recess in said cylinder communicatively connected with a source of o il supply under relatively high pressure; said plunger adapted to be manually adjusted rotatably so as to permit said spiral edged head thereon to effectively and selectively measure the quantity of fuel to be ejected from said pump cylinder head when the plunger is normally operating in a reciprocating movement; said spaced annular recessesinsaidplunger adapted to carry the oil under said high pressure to the inner wall surfaces of said pump cylinder so as to permit lubricating oil of high viscosity under high pressure in said annular recesses when the pump is in operation to block and prevent said fluid fuel from ltering back into the pump cylinder proper.

JOHN F. HERMANN.

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