US1119386A - Internal-combustion engine. - Google Patents

Description

A. W. AUGUR.

INTERNAL COMBUSTION ENGINE.

APPLICATION IILED JULY 29. 1912.

1,1 19,386, Patented Dec. 1,1914.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 29. 1012 1,1 19,386. Patented Dec.1,1914.

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APPLICATION FILED JULYZE). 1912. 1,1 19,386 Patented Dec. 1, 1914.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 29, 1912.

1,119,386. Patented Dec. 1, 19m

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Specification of Letters Patent.

Patented Dec. it, are.

Application filed Jufy 29, 191. Serial No. 711,992.

To all whom it may concern Be it known that l, AnLrsoN W. AUGUIQ a citizen of the United States, residing at Chicago, in the county of Cook and cltate of Illinois, have invented certain new and useful improvements in intern-al-Comlmstion Engines, of which the following is a specification.

My invention relates to improvements in internal combustion engines and has for its general object to provide a two-cycle engine in which the cylinders are positively scavenged and in which the fuel charges are introduced under pressure following the introduction of a noncombustible scavenging blast, so thatthe fresh fuel charge may not encounter the hot gases of the previous spent charge, and that thereby danger of back-firing may be obviated.

My inventionhas among its objects to provide a structure of this general character which is simple in construction, positive in its scavenging and charging operations, and efhcient in power production.

in the drawings wherein l have illus trated the embodiment of my invention Figure l is a longitudinal vertical section through a two-cylinder engine embodying my invention, with parts broken away; Fig. 2 is a vertical section on line 2-2 of Fig. 1 Fig. 3 is a plan view of the engine; Fig. at is a horizontal section on line tl of Fig. 1; Fig. 5 is a fragmentary section on line 5+5 of Fig. 3; Fig.6 is a section on line 6--6 of Fig. 5; Fig. 7 is a section on line 7-7 of Fig. 6; and Figs. 8 and 9 are 'side and end elevations respectively or a valve-timing cam.

The engine units-- 5. 2., cylinders, pistons and associated parts-are arranged in pairs, each unit having two cylinders and a compound piston for the provision of a power element and a pump element in the same physical structure, the pump element o'i each unit being connected with the power element of the companion unit through suitably controlled passage ways to act as an air pump for the supply of scavenging air to the companion unit.

In the construction shown 10 and 10' indicate in general the two engine units the frames of which are preferably cast en bloc to afford for the respective, appropriatelyseparated, units the combustion cylinders 11-41 and pump cylinders 12-42. The cylinder structures of the respective units receive the respective piston structures 13 and 13 each having portions of two diam cters, as shown respectively l t, 15, and 14; 15 to cooperate with the correspomling cyl inder portions, thus obviously providing For each unit a. power member and a pump member in tandem. The piston structures lEZ IZB are of course connected by respective piston rods 16--l(5' with the cranks l'T-----'li of a crank shaft 18 mounted in suit able hearings in a base structure or crank casing 11 secured to the cylinder casting, the cranks ot the pair being preferably di rectly opposed so that the piston structure of one unit makes its instroke as the other ma kcs its out-strolm.

llach oi the combustion. cylinders '11., 11', is water jacketed, for cooling in the con- \cntional fashion, the walls 21 and 2t forming the water jacket space tor the up" per combustion cylinders merging into the cylinder walls ii, .113 of the pump members. .lictwcen the exterior walls oi the two cylinder units lv provide vertical walls 122- 92 and 23.3, top wall 21 and bottom wall 25 to rovidc two vertical air Cllilll'llJQlS 26 and 26, rcs 'urctivelv, conununieating through ports ill and 27 with the upper ends of? the pump elements of units 10 and 10', and also respectively communicating by ports 28---28 with ducts 29 and 29 leading through the heads of the respective units to the power cylinders 1l-'l1 thoreo'l, thus providing from the pump cylinder of each unit to the power cylinder of the other unit, an air passage enlarged, 1n part, to form an air compression chamber. For the introduction of air into the respective compression ehan'ibers Ht--26 I provide ports in the bot tom all 25 of the chamber structure controlled by inwardly opening check valves 30-30 and I also preferably provide in cylinders 19, 12', intake ports 31-31 positioned to he passed by the respective pistons at the ends oi their out-strokes. The intake duct 2) has communication with the cylinder 11 controlled by a valve llll inwardly opening against the resistance of a light spring 3t acting against an adjustable head 35 or the valve stem 36, the spring being iucased in a housing 37 threaded into the head of the engine. The spring is suitably tcnsioned merely to hold the valve normally closed and to respond to a pre determined dill'ereuce in pressure as between the sides of the valve. By adjustmerit of the head 35, which acts as the limitation stop to llmit the throw of the valve,

the valve opening may be regulated to suit the duration of opening of the exhaust ports. Similar provision is of course made for the cylinder 11, the parts being indicated by similar numerals distinguished by the exponent prime ('ji. The cylinders 11-11 have their open exhaust ports 3838 positioned to be uncovered at the end of the out-stroke of the power piston, as is common in two-cycle construction.

From the foregoing it will be apparent that the pump member 12-15 of unit 10, on its out-stroke from the position shown in Fig. 1, will cause air to be drawn through the valve80-into chamber 26 such air introduction being supplemented by the air entering through port 31 at the end of the piston out-stroke) and that on its instroke, which terminates with the parts in position shown in Fig. 1, it will force the air through the path 2o 2s 29 and valve 33 of the companion unit into the cylinder 11 whence said air finds escape through the exhaust ports 38. ment of the opposing unit may act in the same way with respect to cylinder 1].. By this arrangement ll provide in a two-cyclc engine appropriate means automatically to scavenge the engine during the period of time that the exhaust ports are open, by positively forcing through the power cylinder fresh air impelled by the pump element of a companion engine unit.

The air pump cylinder capacity for each unit is materially greater than the capacity of the power cylinder, and the in-take valve is so set that there is a flow of air (or mix ture, as hereafter described) through the power cylinder as long as the exhaust ports are open.

The fuel,-z'. 0., the gasolene or other hydrocarbcn,is forced under pressure into pcsiticn for admixture with an air body which is also under pressure, and the mixture, controlled by suitable valve means, is

introduced into main air body flowing into the cylinder to be charged at an appropriate time in the engine cycle. Specifically 4'0 indi ates a fuel-holding pressure tank into which fuel is forced through a pipe 4-1 from a pump l2 operated by connection43 with an eccentric it on crank shaft 18, said pump receiving fuel from the pipe l5 leading to a reservoir not shown. A return pipe 47 leads from near the bottom of the tank 40 through a pressure controlling check valve 48 and a connecting pipe l9 back to the res- ;f ervoir, the valve 4-8 being of any suitable character to oppose a definite resistance to the return of the fuel to the reservoir. top of the tank 4-0 is closed (though it may have a valved connection 50 to a source of constant air pressure supply to enable the @bviously too, the pump ele-- The i lance functions of the device to be pertormed in starting the engine, or if the pump 4-2 for any reason fails, or its connection become disturbed) and the imprisoned air tends constantly to expel the fuel. The construction described is such that the pump, working constantly while the engine is in opera tion forces fuel into tank l0 raising its level and imprisoning air in the upper portion of the tank until such time as the air pressure on-the fuel may unseat the valve 4-8 and return fuel to the reservoir by the return pipe 4:7, 49, after which the air pressure is kept nearly constant by the relief of valve 48, thus insuring that all times during the workingof the apparatus the fuel will be maintained under a definite pressure limited by the adjustment of valve 48. From the bottom of the tank l0 run the two fuel pipes 52-52 for connection with appliances of the two respective units to control the admission of fuel to their combu tion chamhere. These appliances being uplicates i will describe only those connected with the unit 10, it being understood that like parts provided in the duplicate apparatusare designated by like referencenumerals distinguished by the exponent prime Pipe 52, as best shown in Figs. 6 and 7, leads to a port 5% controlled by a needle valve 55, said port opening through the seat 56 for a valve 57 which controls the fuel flow and also the communication between two chambers 58 and, 59 in a suitable fitting 60. Chamber 58 has communication through a pipe 61 with an air chamber 62 suitably mounted on the engine frame and having valved controlled communication through a tube 63 and ports-6d with the compressed air chamber 26 such passage being normally closed by a valve tainwardly opening into chamber 62 and normally retained on its seat by a spring 66. In this specific construction ll prefer to make the tubular member 63 in the form of a. connecting thimble supporting chamber 62 on the top of the engine frame and constituting also a valve-cage in cooperation with 'the spring 66 surroundingthe stem and bearing on the bottom of the cage.

The mixing chamber 59 below valve 57 has pipe connection ('37 with a nozzle (3? opening into the air passage 29 in the direction of air flow through said passage. The

valve 57 which controls the mixing and charging operations is preferably mechanically operated from the engine shaft and to this end receive from above the pressure of a stiff spring 69 located in a housing 70 screwed into fitting 60, said valve having a stem 71 extending downward through suitable bearing into the crank casing of the engine and there provided with a roller 72 to bear (n a cam structure mounted on the engine shaft. A single cam sleeve 73 may be provided for operating both valve rods 71 and 71, and for timing adjustment the cam sleeve 73 is made slidable on the shaft upon a key 74, sliding movement being imparted thereto by a shipper lever 75 pivcted as at 75 and having its motion receiving end extending into the space between the top of the crank case and the bottom wall of the compressed air chambers The sleeve 73 is preferably cylindrical except where on diametrical sides it is provided with two cam projections 7676' each of which has its rear edge, with reference to the direction of rotation of the shaft, on a straight line for uniform timing of the closure of the valve and its forward edge run ning at an angle to the rear edge so that farther the sleeve is shifted to the right (Fig. 1 or Fig. i) the earlier the valve will open and the longer it will be held open, so that, as will be apparent, the fuel content of the charge may be varied to suit changes of running conditions.

It will be understood that my engine will be providedwith ordinary means for ignition of fuel charges, oiling, and like operations, but 1 have not illustrated such matters as the present invention is not concerned therewith and the same are well understood by all persons versed in this art.

The running of my engine causes the operation of pump 42 which forces fuel as hereinbefore described into the pressure tank until it is under such pressure that the resistance of valve 48 may be overcome and surplus fuel returned to the reservoir. The pressure thus engendered is higher than any air pressure which will exist in the auxiliary air chamber 62 and therefore when valve 57 is open fuel is forced through pipe 52 past the needlevalve 55, and sprayed into the mouth of eduction chamber 59, the same ope a tion of course taking place for each cylinder Assuming that the engine is running with the parts in the position as shown in Fig. 1 explosion of the compressed charge in cylinder 11 drives the working piston on its out-stroke, the working pressure within the cylinder holding valve 33 closed. The pump element 1215' of unit 10 therefore forces air under pressure through port 27 into the air chamber 26. and when the pressure becomeshigh enough it forces open valve and fills the supplemental air chamber 62 with compressed air. When the power pis ton of unit 10 reaches the end of its outstrolre it opens the exhaust ports 38, instantly reducing the pressure iii the cylinder whereupon valve 33 is opened by preponderance of pressure in the air chamber 26 and compressed air sweeps through the cylinder driving out the spent gases. This positive scavenging, which commences automatically instantly upon the opening of the exhaust port, insures that a body of fresh air, substantially free from combustible material, is introduced into the combustion chamber between the time that the exhaust ports open and the time that a fresh fuel charge is introduced into the chamber. As soon as the air from the main compression chamber 26 be ins its flow through the combustion chamber 11, valve 65 between the main compression chamber and the supplemental air chamber will close, maintaining supplemental air chamber 62-under relatively high pressure until such time as its pressure is utilized in conveyance of the fuel into the moving air body in intake passage 29. While the exhaust ports of the combustion chamber are open, but at a time depend ing on the adjustment of the cam member 78, valve 5'? is opened by the operation of cam 76 on valve rod 71, thus opening; the fuel supply port 5i and the outlet; from the supplemental air chamber (52 so that fuel is expelled in a. more or less atomized state into the mixing chamber 59, and is carried by the air flowing from supplemental chamber 62 through the pipe (37 and nozzle 67 into the main air body with which it flows through passage 29 and into the combustion chamber 11 through the open valve 33. At a moment predetermined by the construction of the cam 'Tb',--and which I prefer should be substantially coincident with the moment of closure of the exhaust port for the combustion chamber,the controlling valve 57 is again seated. shutting off the fuel supply and closing the outlet of supplemental air chamber 62. The valve 33 is then seated as soon as the pressure within the cylinder substantially equals the pressure in air chamber 23 and as the piston continues on its instroke it compresses the new charge. It will be observed that any tendency to stratification of the mixture results in the location of the richest mixture at the highest elevation in the cylinders so that rapid response to ignition is insured. Furthermore the interposition of an appreciable body of air substantially free from combustible material between the fresh fuel charge and the previously spent charge insures that the fresh charge will not be ignited from the previous charge and so back firing is obviated. The shape of the walls of the clearance space in the head of the combustion chamber is designed to promote efliciency in scavenging and the tendency to stratification of the mix ture, the interior surface of the head throughout a portion 100 centering at the alve preferably following substantially a parabolic curve larger in its extreme circumference than the circumference of the c lindrical surface in which the piston travels, and connected with the cylindrical portion by a curved deflecting shoulder 101 which meets the truly cylindrical wall at nearly right angles, so that the gases spread end of its working stroke, and means for injecting fuel, associated with compressed air into the path of the scavengin air before entry into the cylinder and be ore the closure of said check valve on the instroke of the piston.

In testimony whereof I hereunto set my hand in the presence of two witnesses.

ALLISON W. AUGUR. In the presence of- MARY F .,ALLEN, W. LINN ALLEN.

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