US1899431A - Internal combustion engine - Google Patents

Description

Feb. 28,1933. L. M.- wooLsoN I Y 1,399,431

INTERNAL COMBUSTION ENGINE Filed July 21, 195o i 2 sums-sheet 2 IUMA 'ENaaLsaN f'E-Ef gam-MW il WIllllllllllllllllllllHIIU Patented Feb; 1.933

UNITED STATES PATENT `oFFlcE LIONEL M. WOOLSON, DECEASED, LATE 0F DETROIT, MICHIGAN, BY EMMA F. WOOLSON, EXECUTRIX, 0F BLOOMFIELD VILLAGE, MICHIGAN, ASSIGNOR TO PACKARD l'MOTOR CAR COMPANY, 0F DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN i INTERNAL COMBUSTION ENGINE appncauo filedv July 21, 1930. serial No. 469,325.

This invention relates to internal combustion engines and more particularly Vto en! the combustionchambers varies in accord-f.

ance with the engine speed.` One of the prime requisites for the continued operation of a compression-ignition engine requires that the liquid fuel be properly atomized and sufficiently projected far enough into the compressed air charges such that there will be a uniform mixture of the fuel with the oxygen, and with high .speed engines theltime in which such results must be attained is a very small fraction of a second. With the type of fuel device above mentioned, it is diilicult to maintain combustion when the engine is idling, and it is more diflicult to start the engine because the pressure developed behind the liquid fuel under such circumstances is not sufiicient'to give either the desired penetration of the air charges by the fuel or the desired atomization thereof.

An object of the invention is to provideV i anism for the fuel injection devices which will cause substantially as high a pressure to be developed behind the injected liquid fuel charges during idling or starting as when the engine is running under load.

Another object of the invention is to assure the proper atomization and pressure behind liquid fuel charges which are injected into compressed air charges in the combustion spaces of an internal combustion engine by the use of a cam, running in accordance with the engine speed, which is effective during the higher speed range and by an auxiliary mechanism which 's effective during the lower speed range to cause a faster pump plunger actuation than would result if thecam were effective.

A further object of the invention is to provide mechanism for actuating the plungers of fuel injection devices for compressionignition engines whichffare effective to maintain a suiiicient plunger injection i'mpulse or movement to insure a pressure behind the fuel charges sufficient to penetrate compressed aircharges and form a mixture therewith of a 'character which willbe ignited by compression at any speed under which the crank shaft of the engine is turning.

Still another object of the invention is to provide a fuel injecting mechanismforcompresslon-ignition engines in which a cam causes effective injection strokes during the' high speed range of the engine and in which radially movable abutments associated with the cam cause a fast injection stroke of the devices when the engine yis running in its slower speed range.

These and other objects of the invention. will appear from the following description taken in connection with the drawings. which form a part of this specification, and in which:

Fig. l is a rear elevational view of a radial type of compression-ignition engine, partly broken vaway and partly in section to show `the elements essential to an understanding of-this invention;

FigpQ is a vertical sectional view of the engine taken on line 2-2of Fig. 1; i

Fig. 3 is a vertical sectional view of the mechanism foiactuating the fuel injection devices taken on line 3-3 of Fig. 2;

Fig. 4 is a sectional view of the nozzle portion of one ofthe injection devices associated with a fragment of a cylinder;

Fig. 5 isa fragmentary plan view of the mechanism for actuating the plunger operating devices. e I,

Referring to the drawings by characters of reference, 10 indicates the crank case of ,an internal combustion engine of the Diesel The cylinders are each preferably formed as a steel forging which includes a barrel and an integral dome 14 upon each of which domes is secured a head 15. In order tol pro-l vide for air being drawn into and exhaust being expelled from the combustion chamber 16, which is between the pistons 17 and the domes 14, there is provided a Venturi passage 18 extending through each of the associated heads and domes. Such passages are arranged to extend at an angle to the axis of /the cylinders and tangentially of the interior walls thereof so that air being drawn into the cylinders by the pistons will be given a rotary movement which will continue during the compression strokes of the pistons. In order to control flow through each of the Venturi passages, there is provided a valve 19 opened by suitable mechanism driven from the crank shaft and including a push rod 20 extending into the crank case; a plurality of springs 21 serve to normally maintain the valves in closed relation with` the passage. Y

Liquid fuel oil, in atomized form and under a relatively high pressure, is injected `into each of the cylinders during the air compression strokes by an individual injection device consisting of a nozzle'portion and a pump portion. The nozzle portions ofthe several units are connected by a manifold which consists of conduits 22 which arefcon- -nected at their ends with unions 23 secured upon each of the pump sections by the nuts 24. A reservoir and low pressure pump (not shown) are connected with the manifold for maintaining the same completely filled with fuel oil and an overiow return conduit 25 leads back to the reservoir from the upper` most of the unions 23.A

Each nozzle includes a barrel 26 having the forward end 27 thereof extending through an aperture in the cylinder wall, and the 4pump and nozzle units are securedr rigidly to the cylinders by bolts 28 which extend through flanges forming a part of the nozkzle. A chamber extends axially through the maj or portion of the nozzle and arranged therein is a reciprocable valve element 29 which is provided with a conicalhead Within the fiared end of the nozzle chamber. Associated with the other end of each of the valve members is a stop member 30 which is adjustable to limit the movement of the associ ated valve so that `the head thereof will never quite engage the nozzle b'arrel. Al coil spring 31 is arranged to normally urge each valve into its position of nearest closure.

A pump casing 32 is screwed upon a depending neck-portion of the nozzle barrel, and arranged within the pump casing isa barrel 33 within which the plunger 34 is reciprocated. fIhere is a passage 35 establishing communication between the bore of the barrel and the chamber in the nozzle, such passage having therein a one-Way valve 36 which prevents leakage of fuel oil and air from the nozzle into the pump barrel. rlFhe pump barrel and casing are provided with a r,plurality of registering ports 37 which are arranged to open into the unions 23 so that when the plunger 34 uncovers such ports, oil\ guided section 38 and asection 39 pivotally associated with the inner end of the guided section. A spring 40 is arranged intermediate the pump easing and the pump barrel and serves to normally move the associated plunger into a position uncovering the ports 37 Each of the push rod sections 39 engages with the free end of a pivoted slipper, as indi" cated at 41, and such slippers are carried by shafts 42 which are supported by the partition 12 and the end cover 13. The free ends of the slippers are formed with an arcuate groove extending longitudinally thereof, and v^`the inner end of the push rod sections 39 can be moved along such grooved surfaces in order to vary the stroke of the plungers beyond the ports 37. In order to simultaneously adjust all of the push rods, there is provided a ring 43 which is carried by the partition wall 12 and upon which are pivoted the links 44 which. in turn are each pivoted to one of the push rod sections 39. Rotation of the ring 43 will move the push rods longitudinally .of the slippers in a similar manner, and the ring is provided with a rack 45 having a lgear segment 46 associated therewith and rotated by a shaft 47 through means of a lever 48. Suitable link mechanism can be associated with the lever 48 for rotating the shaft to cause rotation of the ring 43 and a consequent ad'- justment of the plunger-strokes beyond the ports 37. When the plungers close the ports 37, the injection of the fuel charges will commence and the length of such'stroke after closing the ports 37 will determine the quantity Aof the fuel charges displaced from the nozzles into the compressed air charges in the mounted. Fixed to the rear end of the crank shaft is a gear 53 which meshes with a gear 54 carried upon a shaft 55, and upon such shaft is fixed another gear 56 which meshes with a gear 57 formed on the inner wall of the periphery 58 of the cam 52. Such gearing is of a reduction type and preferably of a char- Cil acter such that the cam 52 is driven at oneeighth the crank shaft speed and in an opposite direction` therefrom. Looking at the rear end of the engine, the crank shaft and cam 51 will rotate in a clockwise direction while the cam 52 will rotate inlan anti-clockwise direction. The periphery of the cam 52 is forliied'with four lobes 59 which are similar in form and equally spaced, such lobesbeing arranged in the same vertical plane with the slippers 41. The ,cam 52 is also provided on its periphery with a plurality of lobes which are arranged in a vertical plane to actuate slippers 61 which are pivotally mounted on the shafts 52 and with which the valve push rods 20 are associated, such lobes being `arranged to cause the slippers 61 to move in,

a direction to cause an opening movement of the valves during the suction and exhaust strokes of the pistons. The lobes 59 are preferably arranged so that there will berone fuel injection stroke from each device, caused by their contact with the slippers 41, upon every two revolutions of the crank shaft.

When the engine is running in its higher speed range, the rotation of the cam 52 is fast enough to cause an injection movement of the fuel plungers 34 to deliver suicient pressure behind the fuel charges injected into the cylinders-to insure that they will pene-- trate substantially to the axis of the compressed air rotatingin the cylinders, and thus one revolution of the compressed air will cause a uniform distribution therein of the atomized liquid fuel charge being injected so that a homogeneous mixture results and, consequently, will readily'ignite through heat of compression. lfVhen the engine is running or being cranked in its lower range of speed, the cam is rotating at one-eighth such speed and will not impart a suiicient speed of movement to the pump plungers when the lobes 59 contact with the slippers 41 to -exert a pressure suilicient to cause a pressure behind the fuel resulting in any substantial penetration thereby of the compressed rotating air. This lack of penetration caused by decreased pressure will not produce the proper distribution of the fuel in the air to result in a mixture which will sustain'combustion through the heat of compression, and as a result, starting of an engine of this character is extremely diiiicult and stalling of the engine through lack of ignition of the charges is a common occurrence when idling.

' In order to maintain pressure behind the fuel injected intok the combustion chambers when the engine is running or being cranked in its 'lower range of speed, there is provided auxiliary actuating mechanisms which are associated with the cam 52 and actuated by the cam 50 fixed to the crank shaft. A movable radially extending abutement 62 is piloted in the periphery of the cam 52 and -includes a flange portion 63 fwhich acts as a stop with the inner face of the cam periphery to limit the movement of the abutment beyond the outer face of the cam periphery. The radial abutments extend through apertures in flanges 64 projecting laterally from the cam 52 and a coil spring 'inner end of each of the radial abutments and is also pivoted by means of pins 67 to the web portion of the cam adjacent the cam 50. The periphery of the cam 50 is provided with an abrupt face 68 and the free end of each of the rock levers 66 is provided with a toe portion 69 which is arranged to ride upon the periphery of the cam 50. When the abrupt face of the ca-m periphery passes beneath the toe of the rock levers, the spring which has been compressed will be suddenlyreleased and will cause the abutments 62 to be projected 'outwardly beyond theperiphery of the cam 52. It is to be observed that each of the actuating faces of in the innermost position of their movement.

When the engine is operated in its higher speed range, the lobes 59 of the cam 52 will be effective to cause actuation of the slippers andthe fuel injection plungers, but when the engine is running in its 'lower speed range, the abutments 62 will be effective to actuate the slippers 41 and the fuel plungers. When the engine is running in its higher speed range, the abutments are ineffective because of the lag of the springs 65, the movement of the abutments after the abrupt face of the cam passes under the rock levers 66 and the consequent release of the springs 65 will not cause the abutments to move fast enough to come into effect prior to the time at,which the actuating face lobes 59 will have rocked and passed under the slippers 41. When the engine is running in its slower range of speed, the rotation of the cam 52 is so slow that the abutments will move into effective position to actuate the slippers 41 This fast movement ofthe pump plungers during the engine slow speed range will cause a higher pressure to be developed behind'the This effective position of the radial fuel charges injected into the cylinders and, consequently, when the engine is idling or being cranked, this higher pressure is suflicient to cause the fuel charges to be atomized and to penetrate the rotating compressed air charges to an extent Which will cause a fuel mixture of a character which will readily ignite through compression by the pistons. It will be seen that the cam 50 `is rotating at crank shaft speed and is associated with the lobes of the ca1n52 so that the abutments Will be actuated in a timed relation to be effective as the cam lobes approach the slippers 41.

l/Vith the mechanism described for actuating the fuel injection devices, it is possible to maintain a minimum pressure upon the fuel charges injected into the compressed air in the cylinders which is sufficient to cause a distribution of the fuel in an atomized condition such that the resulting mixture will readily ignite upon compression by the pistons, irrespective of the speed at which the engine is running or'being cranked, and the danger of the engine stalling when using fuel injection mechanism of the engine driven plunger type is eliminated and starting conditions are materially improved.

While there is herein described in some detail a specific embodiment of the invention, which is deemed to be'new and advantageous and may be specifically claimed, it is not desired that it be understood that the invention is limited to the exact details of the construc- .\tion as it will be apparent that changes may be made therein Without departing from the spirit or scope of the invention.

What is claimed is:

l. In an internal combustion engine, a pressure device including a plunger for injecting atomized liquid fuel into compressed air charges in a combustion space, an engine driven cam for causing injection strokes of the plunger above a predetermined engine speed, and radially reciprocable abutments carried by the cam for effecting plunger injection strokes below the predetermined engine speed.

2. In an internal combustion engine, a pressure device including a plunger for injecting atomized liquid fuel into compressed air charges in a combustion space,.an engine rotated cam for causing injection strokes of the plunger while the engine is running above a predetermined speed, radially reciprocable abutments carried by the cam for effecting plunger injection strokes below the predetermined engine speed, and spring means for actuating the abutments toplace ,them in effective position.

3. In an interna combustion engine, a pressure device including a plunger for injecting atomized liquid fuel into compressed air charges in a combustion space, an engine driven cam having a plurality of lobes extending from a base circle, said lobes effecting vfuel intocompressed air charges in a con1- bustion space including a plunger, an engine driven cam having a plurality of lobes eX- tending from a base circle, said lobes effecting actuation of the plunger in injection strokes while the engine is running above a predetermined speed, and axially reciprocated means extending radially through the faces of the cams for effecting actuation of the plungerl while the engine is running below the predetermined speed.

5. In an internal combustion engine, a crank shaft, a cam rotated at reduced speed from the crank shaft, a liquid fuel injection device including a plunger, a rockl lever pivoted in relation to be actuated by' the cam, a rod structure intermediate the plunger and the forward end of the rock lever, spring means urging the plunger and rod structure toward the rock lever, and radially movable abutments reciprocable through the periphery of the cam, said abutments being arranged to engage the rock lever and cause injection strokes of the plunger in the slow l speed range of the cam rotation and ineffective during the high speed range of the cam.

6. In an internal combustion engine, a4

pressure device for injecting atomized liquid fuel into compressed air charges in a combustion space including a plunger, an engine driven cam for causing injection strokes lof the plunger above a predetermined engine speed, radially reciprocable abutments carried by the cam for effecting plunger/injection strokes below the predetermined engine speed, and means imparting a fast movement to the abutments in their movement causing plunger injection strokes.

7. In an internal combustion engine, a pressure device for injecting atomized liquid fuel into compressed air charges in a combustion space including a plunger, an engine driven kcaml for causingv injection strokes of the determined engine speed, radially reciprocable abutments carried by the cam for effecting plunger injection strokes below the said predetermined engine speed, and a cam cooperating with the abutments to effect their actuation. v

9. In an internal combustion engine, a pressure device for injecting atomized liquid fuel into compressed air charges in a combustion space including a plunger, a plural lobe cam rotated at a reduced speed from a moving engine part, abutments carried by the cam and adapted to be reciprocated through the face of the lobes,'a rock lever pivoted adjacent the cam, spring pressed connecting means intermediate the plunger and the rock lever, and springs normally urging the abutments beyond the cam lobes, said cam being effective to act'uate the rock lever to cause plunger injection strokes above a predeterminedengine speed, said abutments being effective to actuate the rock lever to cause plunger injection strokes below the predetermined engine speed.

10. In an internal combustion engine, a pressure device for injecting atomized liquid fuel into compressed air charges in a combustion space including a plunger, a multi-lobe cam rotated at a reduced speed from a. moving part of the engine, abutments carried by the cam and piloted in the periphery thereof, said abutments being reciprocably associated with the cam through the face of the lobes, a' rock lever pivoted adjacent'the cam in a relation to be actuated by the lobes and the .,ab'utments, spring means pressing the abutments beyond the cam lobe faces, a connection between the rock lever and the plunger, and means for compressing and releasing the spring to give impulsive movements to the abutments.

11. In an internal combustion engine, a -pressure device for injecting atomized liquid fuel into compressed air charges in a combustion space including a plunger, a multi-lobe cam rotated at a reduced speed from a moving part of the engine, fianged abutments carried by the cam and piloted in the periphery thereof, brackets extending from the cam through which the abutments extend, coil springs surrounding the ahutments and seated against fianges thereof and the brackets, a

rock lever pivoted adjacent the periphery of the cam, connections between the free end of the rock lever and the plunger, and cam means for moving the abutments inwardly of the multi-lobe cam and compressing the spring, said spring imparting a fast outward movement to the abutments for actuating the rock lever after the cam means passes there- V,under with the engine in the slow speed range,

the spring return being too late for the abuts ments to actuate the rock levers when the predetermined speed.

projecting from the base circle thereof for causing injection strokes of the plunger above a, predetermined speed, a crankshaft, a driving connection between the crank shaft and the cam adapted to rotate the cam in a reverse direction to that of the crank shaft and at one-eighth its speed, a reciprocable abutment carried by the cam and extending radially thereof through each lobe adapted to project through the eective'I face thereof, a cam fixed to the crank shaft having a single lobe thereon, a rock lever associated with each abutment and adapted to be actuated by the single lobe cam for moving the abutment inwardly of the cam, and a spring associated with each abutment adapted to be compressed by the inward movement of the abutment and to be suddenly released prior to the lobe of the fixed cam passing beneath the lever to project the abutments beyond the cam lobes to engage with the plunger actuating mechanism when the engine is running in a -slow speed range, the lobes on the cambeing effective to operate the plunger actuating mechanism when the engine is in its higher speed range.

18. In an internal comb'ustion engine, a

pressure device for injecting atomized liquid plunger, said cam having a plurality of lobes 1,

extending from the base circle, a reciprocable abutmentextending through the effective face of each lobe, saidabutments having a face conforming in o'utline to the surrounding abutment faces when in their innermost position, and means for proj-ecting the abutments beyond the lobes to cause Lplungerinjection strokes when the engine is running below a '14, In an internal combustion engine', a pressure device for injecting atomized liquid fuel into compressed air charges in a combustion space including a plunger, a rotatably mounted multi-lobe cam for causing inj ection strokes of the plunger, a crank shaft,

reduction gearing for rotating the cam from the crank shaft and in a reverse direction relative thereto, an abutment piloted through -each cam lobe, spring means normally projecting each abutment beyond the associated cam lobe, and a single lobe cam fixed to the crank shaft causing compression and sudden release of the springs.

15. In an internal combustion engine, a pressure device for injecting atomized liquid fuel intocompressed air charges in a combustion space including a,l plunger, a rock lever, connections between a free end ofthe rock lever and the plunger, a spring pressing ed to .be projected therefrom to actuate the rock lever and cause plunger injection strokes while the engine is running below a predetermined speed, said cam actuating the rock lever while the engine is running above the predetermined speed, a pivoted lever connected to the inner end of each abutment, a.1 spring associatedr with each' abutment and exerting pressure to project the same beyond the cam lobes, and a single lobe cam fixed to the crank shaft and coacting with the pivoted `levers to move the abutments inwardly-of the lobes during the major portion of its rota# tion and to suddenly release the same in la timed manner to cause effective actuation of the rock levers below the predetermined engine speed. i

16. In an internal combustion engine'having cylinders extending radially from the crank case, pressure devices including a plunger for injecting atomized liquid fuel into compressed air charges in the cylinders, one of said devices being ixedto each cylinder, a plurality of rock levers circularly arranged and pivotally mounted within the crank case,` a connecting rod structure between each plunger and rock lever, a four lobe cam positioned to rotate in a. relation to actuate the rock levers, said lobes actuating the rock levers to impart injection strokes to the-plungers whenl the engine is running above a predetermined speed, radial abutments carried by the cam and adapted to be reciprocated through the effective faces of the lobes, and means for imparting sudden s movement to the abutments to project them beyond the lobe faces to actuate the rock levers when the engine is running below the predetermined speed.

17. In an internal combustion engine,l a

' pressure device including a plunger for inby the lobes of the cam, connecting means between the free end ofthe rock lever and the plunger, a crank shaft, reduction gearing driving the cam from the crank shaft at a reduc'ed speed, abutments extending radially of and carried by the cam, one of said abutments extendingxthrough the operative face of each cam lobe, leverspivoted to the cam and associated to cause axial movement of the abutments, a spring associated with each 'abutment normally urging projection there4` of beyond the lobes, and a cam driven by the crank shaft and coacting with the/pivoted levers for moving the abutments inwardly of the cam lobes against the tension of the associated springs and suddenly releasing the same, said cambeing arranged to actuate and release the abutments in a timed relation such that they will be effective to. actuate the rock levers upon the approach of the actuating faces of the cam lobes when the engine is running below a redetermined speed, the speed of the cam a ove the predetermined engine speed being adequate to cause actuation of the rock levers by the lobes prior to the pro- .jection of the abutments into effective position.

18. In an internal' combustion engine, a pressure device including a plunger for injecting atomized liquid fuel into compressed air charges in a combustion space, an engine rotated cam for causing injection strokes of the plunger, said cam having a plurality of lobes extending from the base circle thereof, radially reciprocable abutments extending one through the face of each lobe, means for reciprocating said abutments in a timed relation to effect fuel injections, and means on the abutments for limiting the outward projection thereof.

In testimony whereof, I have hereunto subscribed my name this 17th day of July,

EMMA F. WOOLSON, Eeeutrz'w of the Estate of Lionel M. Woolsrm, Deceased.

jecting atomized liquid fuel into compressed v

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