US2091987A - Internal combustion engine - Google Patents

Description

sept. 7, 1937. H, v HONN 2,091,987

INTERNAL COMBUSTION ENGINE Filed Sept. 26, 1954. v 2 Sheets-Sheet 1 IN VEN TOR. HHPlA/V VEP/YE O/V/V 'Hfs ATT RNEY.

Sept. 7, 1937. H. v. HoNN INTERNAL COMBUSTION ENGINE Filed Sept. 26, 1934 2 Sheets-Sheet 2 E@ R ww. fm lm M@ .w w

lPatented Sept. 7, 1937 UNITE-o `sTArEs-PATENT Torr-ics j mrnnmnczg'ron ENGINE'.l I v L `Harlan Verne 11mm,vl San Francisco, Galli'. App ca on'emms. 2( 19mg 3) o.'lv Y My invention relates .to internal combustion engines. and particularly to enginesv adapted for .burning the heavier grades of liquid fuel.

charges for heavy oil engines; to provide variablemeans for metering fuel charges for heavy oil engines; to provide means for pre-igniting a heavy oil charge; to providea means of .controlling the speed of a heavy oil engine; to provide a heavy oil injector system for internal combustion engines in which the fuel lines are at relatively low pressure; and to provide a means and method, flexible as to adjustment and control, for operating an internal combustion engine on the heavier ygrades of fuel.

Other objects of my invention willbe apparent or will be specifically pointed out in the descrip- -tion forming apart of this specification, butI do bustion engine by injecting a pre-ignited charge .of frothed fuel into the combustion chamber of the engine. The instant application, while concerned with a pre-ignited charge, deals withl a lconstruction and method differing in many respects therefromVas will be seen from the following disclosure.

In the drawings: y Figure 1 is a sectional view through a portion ,of an internal combustion engine cylinder and `through a preferred fuel charging structure attached thereto. l

Figure 2is a diagram, reduced to lowest terms, showing the interrelation of parts in a complete single cylinder engine.

Figure 3 is a longitudinal section of a preferred type of fuel metering pump. y V

For purposes of simplicity I have chosen to Ndescribe my invention as applied toa singlecylinder, as it will be obvious from thedescription' `that by multiplication of parts the invention may be applied to multicylinder engines. Actually, the parts shown in Figures 1 and 3 are component parts of an airplane radial cylinder power plant. to which my invention is ideally adapted.

The following description of parts which, when j assembled formthe preferred illustrative embodiment of my invention, will be made without reference to operational function, this being dealt with ater. Y v

Referring to the drawings, particularly to Figure 1 thereof, an engine cylinder I0 is provided with cooling fins .I I and a finned cylinder head I2 preferably attached by head threads I4. The head is supplied with the usual valve portsy I5 shown more distinctly in Figure 2.

The head is provided with a fuel port I6 forming the opening of a fuelchannel I1 of conical shape and which continues into a channel plug I9 screwed to the cylinder head.

Below, this plug supports a preheating cylinder 20, preferably finned in which an igniter piston 2i reciprocates, this piston being well supplied with igniter piston rings 22. An igniter piston rod 24 passes through a guide block 25 at the lower end of the preheating cylinder, and is preferably maintained at its lower limit of stroke by igniter piston springs 26. l 1

Above, the channel plug supports an injector valve assembly comprising an injector valve cage 21 having an internal bore 29 in which is mounted an injector valve 30.

The injector valve lcomprises a stem. 3l adapted to fit and slide in the 'internal bore 29, and a conical face 32 provided with a relief 34 giving upper 35 and lower 36 face rings, the latter bearing on a conical seat 31, part of the internal bore 29 of the cage 21. The apex of the seat is broken through to form an ignitor cylinder outlet port 39, preferably of relatively small dimensions.

'I'he internal'bore 29 communicates with the small end of the fuel channel i1 through a pe,` ripherai igniter port 40, which also communicates with an `opposing air channel 4i in the channel plug I9.

v 'I'he cage 21 is held in the plug I9 by a cage retaining nut 42, and the injector valve is seated by an injecter valve vspring 44 positioned by an injector valve spring nut 45 screwed to the cage 21. For'ease of assembly I' prefer to split the cage 21 vat the peripheral igniter port and fuel charging' fitting 46, `fastened at one end to the channel plug I9 and at theot-her to the preheating cylinder 20. T'he air channel 4| connects the peripheral igniter port 40 with the auxiliary combustion chamber 41 through a fuel port 49, but is normally closed by a fuel valve 50 opening toward the fuel port and seated against a fuel face 5| on the fuel charging fitting 46.

This valve is held against the seat by a fuel valve spring 52 contained in a spring extension 53 projecting from the fitting 46. The usual spring retainer 54 is attached to the valve stem,

and a stem guide cap 54' provided.

The fuel face 5| on the seat of the fuel valve is provided with an annular fuel chamber 55 which at some poin't on its circumference conl5 nects with a liquid fuel inlet 56 which in turn is supplied by a metering fuel pump assembly shown in detail in Figure 3, through an inlet check valve 56'.

Here a pump frame cylinder 51 is fitted at one end with a pump block 59 held in place by a lock nut 60. A single inserted pump sleeve 6| passes through the block if for use with a single cylinder engine, or a plurality of sleeves may be used if several cylinders are supplied.

A tubular fuel piston 62 slides in the sleeve 6|, and is extended by a fuel piston spring 64 bearing against the lower end of the tube and against a check valve fitting 65 screwed in the top of the block. This check valve fitting 'is supplied with the usual outlet ports 66, ball valve 61 and ball spring 68.

The lower end of the tubular piston is provided with a ball bearing 69 rolling on the face of a. rotating plate 10 which is provided with a peripheral cam 1| positioned and adapted to raise the piston 62 when rotated.

The rotating plate 10 has an extended stem 12 which, by means of an internal spline 14v slides freely on a fuel pump drive shaft 15. The rotating plate and extended stem are set in a screw threaded bearing 16 which is raised or lowered by rotating a bearing drive sleeve 11 by means of a rack 19 and pinion 80. Thrust is taken up by an apertured thrust plate 6| fastened to the pump frame cylinder 51 and bearing on the top of the drive sleeve 11.

Referring to Figure 2, the connection of the various moving parts is shown diagrammatically.

A piston 82 is mounted in the usual manner in the cylinder |0, thus providing a main combustion chamber 84. A connecting rod 85 drives the usual crank shaft 86 and cam shafts 81-81 through the customary gears 69-89 and the valves are lifted through any convenient operating mechanism 90.

The inlet valve 9| is connected to a source of air 92, and the exhaust valve 94 provided with an exhaust pipe 95.

One of the cam shafts, in this case the exhaust cam shaft, carries an igniter piston cam 96 and a bevel gear assembly 91 for driving; the fuel pump drive shaft 15. In this diagram, for the sake of simplicity, I have shown a bell crank and sleeve assembly 99 for lifting the rotating plate 1.

Fuel, of the relatively heavy oil type may be supplied to the fuel pump chamber |00 under slight pressure from any convenient storage device, and as is clearly seen in both Figures 2 and 3, a fuel pump inlet |02 is provided slightly below the top of the pump chamber, and is not provided with lany check valve.

I prefer to operate my engine` on the four stroke cycle system, and as one complete up and down stroke of the piston is a scavenging movement, I prefer to start my operational description at the vbeginning of the charging stroke, after all scavenging has been completed.

At some time after the firing stroke, the time being at any portion of the complete cycle when the fuel valve 50 is closed and therefore not critical, a metered charge of fuel is deposited in the annular fuel chamber 55.

The metering is accomplished by regulating the distance the tubular fuel piston 62 travels past the fuel pump inlet |02. I'his regulation is acv complished by raising or lowering the rotating plate 10, and the raising mechanism may be said to constitute the throttle of the engine.

As there is no check valve in the fuel pump inlet, and as I adjust the pressure in the fuel supply pipe to be less than the pressure offered by the ball valve 61, all oil or fuel in the fuel pump chamber on the upstroke of the fuel pump piston will pass back into the fuel supply line up to the time that the piston covers the fuel pump inlet |02, but after the piston crosses the inlet the additional travel of the piston forces oil through liquid fuel inlet 56 into the annular fuel chamber 55, the amount depending on the extent of travel of the piston edge past the fuel pump inlet. The charge of liquid fuel in the annular chamber may thus be accurately regulated and metered, the ball valve 61 keeping it there until used.

As the piston 82 drops and starts to rise, air is admitted under relatively low pressure to the main combustion chamber, and on the upstroke is compressed, the pressure being communicated through the fuel channel |1, the peripheral igniter port 40, and the opposing air channel 4| to the back of the fuel valve 50 which will not open while the top of the igniter piston 2| is above the port 49.

Just as the piston 82 approaches top center, creating a head pressure of from 100-105 pounds per square inch, the igniter piston cam 96 allows the igniter piston to descend, creating a negative pressure in the auxiliary combustion chamber 41. As the fuel valve 50 then has the full head pressure on one side thereof and a negative pressure on the other, it snaps open and air rushes through the opening, carrying with it into the auxiliary combustion chamber, the fuel resting in the annular fuel chamber.

'Ihe igniter piston at once rises due to the cam contour, rising fastery than the main piston and compresses the fuel charge in the auxiliary combustion chamber, the pressure rising until the charge ignites at about 3,500 pounds per square inch pressure according to the type of oil used. As soon as the igniter piston passes the fuel port 49 the fuel valve, having equal pressure on both faces, reseats under the action of the fuel valve spring 52, and the annular fuel chamber 55 is ready to receive the next charge of fuel.

With the fuel ignited in the auxiliary combustion chamber at 3,500 pounds per square inch pressure, the injector valve is subject to two gas pressures; one, on the lower or smaller face of 3,500 pounds per square inch, and the other of 350 pounds per square inch on the upper or larger face. I prefer to make the face relations such that the combined pressures, plus the minute action of the injector valve spring 44 will hold the injector valve closed until the pressure of the ignited charge reaches approximately 5,000 pounds per square inch whereupon the valve will open and the ignited charge at high pressure will rush into the main combustion chamber having air therein at approximately 350 pounds per square inch pressure. The ignitedfuel combines with .the air in the main combustion chamber, finishes itsv combustion and drives the piston down. It is obvious that the ignition in the auxy5 iliary chamber and the subsequent injector valve opening can be timedjto place theignited fuel into the main combustion chamber at exactly the proper time for maximum effect on the piston I2, usually arrivingthree or four'degrees before l the piston starts down on the power stroke.

At the proper time in the powerstroke theexhaust valve opens and the main combustion chamber is scavenged on the next two strokes as is usual in this type of engine, and the power l stroke is repeated.

No special means are used to scavenge the fuel channel Il, the space above the igniter valve 30 or the opposing air channel Il as the gases4 remaining therein do not affect the ignition of 20 the fuel charge.

' It should be noted that the ignited charge is extremely rich, and not until it reaches the main combustion chamber does it receive sufilcient air toV explode with proper air mixture. In the aux- 25 iliary chamber the fuel is merely ignited, only in the main combustion chamber is full power exerted.

lMy invention has numerous advantages. Pre-` ignition of the fuel reduces ignitionlag in they 0 power cylinder practically to zero, and a predetermined cycle can be followed. vThe maximum speed available in the engine is much greater than that obtainable inthe Diesel type of engine, and the whole cycle of the igniter assembly can 35 be timed to any advance or retard in respect to the cycle taking place in the power cylinder.

Another important feature lis that since the fuel` enters the power cylinder above ignition i temperatures, any compression ratio may be used 440 in the power cylinder.v

-Other factors aid the efficient operation of the engine, as for example. in the case of idling. As

' the stroke of the igniter piston` is constant, the fuel mixture in the auxiliary combustion chamber 45 will be leanest when the engine is throttled and idling. This however leads to better ignition, I

the firing of the charges is still more certain, and the engine idles perfectly with minimum fuel v consumption. 50 It will be at once apparent that the proper operation of the igniter valve can be controlled, for any relative pressure ratios, by regulating the size of the 'areas exposed to the head pressure and the pressure of the ignited gases, and this I bei' 55 lieve to be well within the knowledge of those skilled in engine design. 'I'he igniter valve spring is substantially only a returnspring, the relative pressures being the major forces controlling the action of the valve. 60 f Incidentally, this valve is not, as might be supv posed, subject to excessive temperatures. The gases are ignited, but the temperature has not had time to rise to the point where excessive i pitting, erosion or wire drawing might occur. 65 I have found that ordinary valve steels are perfectly satisfactory for use in valve and seat, and that the life of this valve is at least no less than other valves in the same engine.

W'hile I have described my invention as applied 70 to a four stroke cycle engine, its advantages will be equally apparent when applied to internal combustion engines operating with any of the known cycle relationships. I claim: 75 1. In combination with an internal combustion f ignited lfuel into said combustion chamber.

2. In combinationv with an internal combustion engine having a combustion chamberv and a compression therein insuiiicient to cause automatic ignition of heavy oils, a receptacle for liquid fuel, y means for depositing a metered amount of fuel therein, means for'char'ging said engine with air, means for mixing said fuel with 'a portion of said charge when compressedby the piston of -said engine, means separate from said combus-y tion chamber for compressing said fuel and air mixture to cause ignitionthereof by heat of compression, and automatic means for releasing the ignited fuel into said combustion chamber when the pressure of the burning fuel reaches a pr'e-` determined figure.

3. In an internal combustion engine having a main combustion chamber containing a piston operating at a compression therein insuilicient to cause automatic ignition of heavy oilsymeans for charging said chamberv with air, an auxiliary combustion chamber, means for utilizing a portion 'of said air charge when compressed by said piston to blow liquid fuel into said auxiliary chamber, means timed with said pistonrfor compressing said fuel and air mixture in the auxiliary combustionchamber to cause ignition thereof by heat of compression, and a valve between said auxiliary chamber and said main combustion chamber,V 40 said valve having a face exposed to each of said combustion chambers, each face differing rin area in accordance with the working pressures directed thereagainst to control the opening thereof when the pressure of the ignited fuel reaches a i predetermined figure.

4. In combination with an engine having a main combustion chamber and an auxiliary com bustion chamber containing an inlet port, a poppet valve closing said port, an annular fuelrecess i in the seat of said'valve and covered by said valve when closed, means for depositing liquid fuel in said fuel recess, and means for supplying air under pressure to said port from said main combustion chamber, said air carrying fuel from said fuel chamber into said auxiliary combustion chamber when said valve is opened.

5. In combination with an engine having a main combustion .chamber and an auxiliary combustion chamber containing an inlet port, a poppet valve closing said port, an annular fuel recess in the seat of said valve and covered by said valve when closed, means for depositing liquid fuel in said fuel recess, resilient means for maintaining said valve in closed position, and conduit bustion chamber containing an inlet port, a popy pet valve closing said port, an annular fuel recess in the seat of said valve and covered by said valve when closed, means for depositing liquid fuel in said fuel recess, resilient means for maintaining said valve in closed position, conduit in the seat of said valve and covered by said valve when closed, means for depositing liquid fuel in said fuel recess, resilient means for maintaining said valve in closed position, means for supplying air from said main combustion chamber under pressure sumcient to open said valve and sweep said fuel in said fuel recess into said auxiliary combustion chamber, means for igniting said fuel in said auxiliary combustion chamber,

and means for releasing said ignited charge into 10 said main combustion chamber atapredetermined combustion pressure.

HABLAN VERNE HoNN.

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