US2154504A - Internal combustion engine - Google Patents

Description

April 1s, 1939. s, B; GOLD ET AL 2,154,504

INTERNAL GCMBUSTION ENGINE Filed Nov. 4, 1956 4 Sheets-Sheet l 4 Sheets-Sheet 2 5 Galas INVENTOR Samue/ 94?, 'ru

ATToN EY April 18, 1939. s. B, GOLD ET AL INTERNAL CCMBUSTION ENGINE Filed Nov. 4, 195e April 18? 1939., s. B. GOLD ET AL INTERNAL CQMBUSTION ENGINE Filed Nov. 4, 1936 4 Sheets-Sheet 5 ATTORNEY April 18, 1939. s. B. GOLD ET AL 2,154,504

INTERNAL COMBUSTION ENGINE I 4 Sheets-Sheet 4 Filed NOV. 4, 1936 INVENToR/S 500706/ E 6a aj face E a/af IQ I ATTORNEY Patented Apr. 18, 1939 UNITED STATI-:sA

PATENT OFFICE 2,154,504 INTERNAL coMBUs'rIoN ENGINE Application November 4, 1936, Serial No. 109,116

3 Claims.

' this character, now in common use, are of low volumetric efciency for the reason that they operate with excessive clearance volumes in order to keep the compression pressure of the air or mixture at a minimum, otherwise considerable power is lostv because of the internal work required in effecting higher scavenging pressures. Another disadvantage is that in engines using gas as a fuel it requires five to twenty piston displacements per cylinder before the governor is effective in regulating the air and gas ratio responsive to load variations on the engine, consequently the mixtures of gas and air in the power and com-v pression chambers are never uniform with the engine load.

It is, therefore, the principal object of the present invention to provide a two-cycle engine wherein the air or mixture is handled to give high volumetric efficiency with low scavenging pressures and with minimum internal loss of power incidental to compression of the air or mixture admitted to the combustion chamber.

It is also an important object to eliminate the lag between changes in the fuel ratio responsive to variations in the engine loads.

Other important objects of the invention are to provide a simplied engine construction which Ypermits of splash lubrication in the crank case; to provide efficient, economic means of lubricating moving partsof the engine; to provide mechamsm for compression of the combustion supporting medium that will operate equally well inengines using gas or liquid fuels; to provideautomatic pressure means for controling flow of fuel to the engine; to provide for uniform admission of the combustion supporting medium or mixture to each of a number of` cylinders; and to effect admission of the medium in Ja manner to thoroughly scavenge the cylinders of burnt'gases without loss of medium through the exhaust ports.

In accomplishing these and other objects of the invention, as hereinafter described, we have provided improved details of structure, the preferred form of which is illustrated in the accompanying drawings, wherein: y

Fig. 1 is a vertical section through a two cylinder, two-cycle internal combustion engine embodying the features of the present invention and (Cl. 12S-59) showing a piston in one of the cylinders at the end of its power stroke and the piston in the other cylinder at the beginning of its power stroke.

Fig. 2 is a cross-section through the engine on the line 2-2 of Fig. 4. 5 Fig. 3 is an end view of the engine, particularly illustrating the fuel supply mechanism, the gov- A ernor controlling the amount of fuel supplied and the mechanism for supplying lubricant to the respective working parts of the engine. f

Fig. 4, is a horizontal section through the engine on the line 4--4 of Fig. 2.

Fig. 5 is an enlarged detail section through the automatic shut-off valve for controlling flow of fuel medium to the engine. 15

Fig. 6 is a detail section through the air and fuel inlet to the engine.

Fig. v'I is a detail cross-section through the lower portion of the engine particularly illustrat-A ing the method of lubricating the main bearings. 20

Fig. 8 is a horizontal section extending through the intake and exhaust ports ofwone of the engine cylinders, and showing the directional'ow of the fuel mixture or scavenging medium relatively tol the flow of exhaust gases.

Fig. 9 is an enlarged perspective section through one of the cylinders to better illustrate flow of the fuel mixture or scavenging medium.

Fig. 10 is a view of an indicator card showing -the pressures in the reservoir supplyingthe re-30 spective pistons.

Fig. 11 is a view of a similar card showing the -pressures occurring in one of the charging 4cylinders.

Fig. l2 is a section through one vof lthe'inter-` 35 mediate inlet ports of a combustion 'chamber on theline I2-I2 of Fig. 8. v

Fig. 13 is a similar section throughone of the fouter inlet'ports on the line |3-I3 `of Fig". 8.

Referring more in detail to the drawings: y I designates a two-cycle internal combustion 'engine which is constructed in accordance with the" present invention and includes va vcrank case 2 comprising a base portion 3 and an upper or. cover portion 4. The base portion 3 is provided 45 with transverse bearing supports 5,' 6 and "l-to rotatably mount a crank-shaft 8. 'I'he crankshaft 8 includes bearing portions 9, I Il and II rotatably mounted in bearings I2, I3 and- I 4 carried by the respective supports 5, 6 and 'half of 50 each bearing being formed in the respective supports and the other half in caps I5' that are securedto the supports by suitable stud bolts as in conventionalk practice. The Vcrank-Shaft has cranks I6 and I1 positioned between the spaced 55 bearings to connect piston rods |8 and |9 carrying pistons 20 and 2| that are connected therewith by the conventional wrist pins 22 and 23. The upper half 4 of the crank case is secured to the lower portion by stud bolts 24 that are extended through aligning lugs 25 and 26 formed on the respective portions as best shown in Fig. 2. The respective ends of the crank case are closed by end plates 21 and 28 that are provided with sealed openings 29 and 30 through which ends of the crank-shaft extend for respectively mounting a y wheel 3| and a ratchet type starting crank 32 whereby the crank-shaft is rotated to initially start operation of the engine or position the pistons for operation of an air starter where used. Supported by the upper half of the crank case are parallel side walls 33 and 34 and end Walls 35 and 36 connected by horizontally spaced partitions 31 and 38 to support charging cylinders 39 and 40 above each of the cranks |6 yand |1.

The 1- charging chambers include cylindrical walls 4| cooperating with the end Walls 35-36, the side wall 33, a wall 42 inset from the other side wall 34, and webs 43 and 44 to form a closed transfer reservoir 45 having connection with the respective charging chambers through ports. 46 that are formed in the side walls of the cylinders and which are normally closed by valve plates 41 attached to a seating ange 48 circumscribing z the boundary of the respective ports.

` annular fuel distributing chamber 12 that com- The valve plate 41 includes a frame having a plurality of outlet openings 49 that are normally closed by leaf'springs 50 each having one of their ends attached to the frame of the valve plate and their opposite ends free to move to and from valving relation with their respective openings, the springs being mounted on the outlet side of the openings to seat thereagainst when pressure in the transfer reservoir exceeds the pressure within the charging chambers.

Formed in the opposite side of the chambers are inlet ports circumscribed by flanges 52 connecting the walls of the charging cylinders with the inset partition 42. Formed in the partition in alignment with the-inlet ports are openings 53 and 54 that are covered by valve plates 55 having slotted openings 56 therein that are normally closed by leaf springs 51 having their intermediate portions 58 fixed to transverse bars 59 of the valve plates so\ that the ends thereof are free to move to and from covering relation with the slotted openings, and which are adapted to automatically open responsive to suction pressureswithin the charging chambers to permit ow of charging fluid therethrough from a manifold space 60 having an inlet port 6| that is formed in the side wall 34 at afpoint substantially midway of the length of the crank case.

Fixed to the side wall and extending over the inlet opening 6| is an air and fuel mixing device 62 having a flat platey portion 63 that is'seated against the side wall and has a peripheral flange 64 extending laterally therefrom to form an annular seat for a filtering diaphragm 65 that is clampingly Supported thereagainst by a covering cap 66. The cover cap 66 is spaced from the illtering diaphragm to form an air passage 61 into which atmospheric air is drawn through lateral ports 68 formed at the side edges of the cap.

Extending inwardly from the plate portion, in encircling relation with the opening 6|, is a circular flange 69 that cooperates with an inwardly extending flange of a ring 1| to provide an municates with the opening 6| through an annular slot 13. Fuel is admitted to the annular chamber through a. tangential inlet port 14 that is connected by a pipe With an automatically operated valve 16 which controls admission of fuel to the respective charging chambers responsiveI to suction pressures that are created therein.

The valve 16 includes upper and lower diaphragm supporting sections 11 and 18 that are secured together to form pressure chambers 19 and 80 on the respective sides of the diaphragm. Formed as a part of the lower section 18 is a valve housing 8| having inlet and outlet ports 82 and 83 respectively connected between sections of the supply line 15.

The inlet port 92 communicates with the pressure chamber 80 through a passage 84 and the outlet port 83 communicates with the chamber 80 through a port having a valve seat 85 that is adapted to be closed by a valve 86. The valve 86 may be of any approved construction and is operated by the diaphragm responsive to differential pressures on the respective sides thereof. The pressure chamber 19 is open to atmosphere and contains a coil spring 81 that seats against the diaphragm and against a spring seat 88 that is supported by an adiusting screw 89. It is thus apparent that when the pressure in the passage 84 is' greater than the pressure acting on the opposite side of the diaphragm the valve is closed against action of the spring 81. However, when the engine is in operation and Vfuel is being drawn through the pipe 15, the pressure .in the valve chamber 90 drops suciently to allow the spring 81 to move the valve to open position.

The inlet end of the pipe 15, or that section connected with the port 82, is attached to a throttle valve 9| that is operated by a governor 92 in conformance with the load requirements of the engine, as in conventional practice, so that the fuel is admitted in proportion to the load demand acting on the engine, the governor being actuated by a suitable connection with the crankshaft.

Carried by the crank case, in concentric alignment with each of the charging cylinders, are power cylinders 93 and 94 having combustion chambers 95 and 96 in which the pistons 20 and the combustion chambers are smaller than the diameters of the charging chambers so that skirt portions 91 and 98 on the respective pistons cooperate with the charging cylinders to form annular charging chambers 99 and |00.

Formed as a part of each piston, and on the lower end of the respective skirts, are charging pistons |0| and |02 having sliding contact with the walls of the charging chambers so that when the pistons are reciprocated the charging pistons act to draw in an air and gas mixture and to compress the mixture for discharge into the transfer reservoir, as later described.

' I'he cylinders 93 and 94 are preferably waterjacketed, as indicated at |03, and have their lower Cpl heads carry suitable ignition devices, such as spark-plugs |08, to ignite the fuel charges when they are drawn into the combustion chambers. Formed in the lower end of each cylinder are passageways |09 having inlets ||0 communicating with the transfer reservoir and'having connection with the combustion chambers through inner and outer pairs of intake ports I I I-I I2 and ||3||4 respectively.

The inner ports III-I I2 are of greater height than the outer ports and are arranged, as shown in Figs. 8, 9 and 12, to inject the admitted fuel in upwardly directed streams converging at a point offset from the axis of the cylinder midway be-` toward exhaust ports ||5 that are formed in the opposite side walls of the respective cylinders to push the' exhaust gases therethrough. 'I'he mixture drawn in thus scavenges the cylinders of burnt gases and lls themwith a combustible mixture that is compressed for ignition upon the -upstrokes of the respective pistons. The exhaust ports communicate with manifold chambers IIS having outlets I I1 to a common exhaust manifold I|8 that is secured to the sides of the respective cylinders as shown in Fig. 2. In order to lubricate the cylinders, the end of the crank case supporting the governor and throttle mechanisms mounts a lubricator I I9 having lines leading to oil ports I2 I l formed in the walls of the cylinders as best shown in Fig. 1. One of the lead lines of the lubricator extends to the governor to lubricate the governor mechanism. The crank shaft and connecting rod bearings, as well as the walls of the charging cylinders, are lubricated by combination splash and direct feed of lubricating oil from a -power driven pump |22 that is actuated fromfthe crank-shaftand which pumps oil from the bottom of the crank case through a screen |23 and delivers it to an oil reservoir |24 that is formedn the bearing support 'I.

' Extending from the reservoir |24 are oil lines |25 leading to splash pans `|26 that are supportedj bearings flows through ports |30 to sumps |3I carried by the bearing supports 5, 6 and 1. 'Ihe oil level in the sumps is above the bottom of the crank-shaft bearing so that there is a bath of oil in the bearing at all times, regardless of the variation in the amount supplied by the pump. From the bearings the oil returns to the bottom of the crank case where it is again drawn through the filter and recirculated by the pump.

The operation of an .engine constructed and assembled as described is as follows:

A gaseous fuel is delivered to the engine through the throttle valve 9| under control ofthe governor 92.v Upon cranking the engine suction created within the effective charging chambers, that is the one in which the charging piston is moving downwardly, eifects opening of the diaphragm valve 86 to allow admission of the fuel into the circumferential space |2 from where itis drawn through the annular slot I3 under the inducing action of air drawn through the air lter 65. Upon entering the valve chamber the air and gas are mixed incidental to the circumferential movement of the fuel. During the downstroke of the charging piston, the fuel mixture is drawn through the openings in the valve plate r`forfthat cylinder unseating the spring leaf valves'for ow into the charging chamber for the entire stroke of the piston. On the upstroke the spring leaves of the inlet valveseat while the spring leaves on the discharge valve for` that cylinder unseat to allow flow of the fuel mixture into the transfer reservoir. Attention is here directed to the fact that since the valves automatically open by reason of pressure differentials on the respective sides thereof the charge drawn into the charging chamber is expelled during the entire upstroke of the piston, thereby eliminating any back pressure other than that caused by the pressure contained in the transfer reservoir prior to uncovering of the intake ports of. the combustion chamber of the -other cylinder.

When the charging piston has substantially reached the upper limit of its travel the power A piston for the "other cylinder hasuncovered the intake ports so that the fuel mixture passes from the transfer reservoir into the combustion cham.- ber for that cylinder. the respective `charging chambers and transfer reservoir are such that the pressures in the transfer reservoir seldom exceed three `to five pound pressure and when the mixture has passed into the combustion chamber ofthe other cylinder, the pressure in the transfer. reservoir drops to substantially atmospheric pressure. Therefore, a minimum of internal power is required in operating the charging pistons since the fuel mixture is compressed only suiciently to effect scavenging of the exhaust gases from a previousfpower cycle of the cylinder into which the fuel mixture is drawn. i

By observing Figs. 8 and 9, it will be noted that the outer pair of intake ports ||3 and H4 direct separate jets of the fuel mixture into impinging relation at a point substantially midway between the axis of the combustion, chamber and the wall thereof. Simultaneously the inner pair of intake ports III' and-H2 effect discharge of impinging jets at a point slightly above the impinging point of the jets admitted through the outer ports. This is accomplished by different angular relationship of the pairs of ports to the axis of the combustion chamber and also by the diierent angular inclinations of the innerfand outer ports, as clearly illus` trated in Figs. 12 and 13.

The inner portsare slightly higher than the outer ports so that the jets of fuel begin to beadmitted therethrough slightly prior to opening The relative capacities of of the outer ports, thereby assuring that the jets admitted through the one set of ports act in upwardly lifting relation with the jets admitted Vthrough the other set of ports to cause the fuel mixture to move upwardly adjacent that side wall of the combustion chamber and across the igni s shown by the arrows in Fig. 9. We are thereby enabled to provide thorough scavenging of the combustion chamber with the low pressures as above noted.

The admission of the respective jets of fuel mixture at diiferent'elevations also causes defiection of the indrawn mixture without the aid of deflector plates on the piston head as is usually the practice in this type of engine. When the pistons move on their other cycle the charge is compressed and ignited by means of the sparkplug |08 as in conventional practice. During the power stroke another charge is being drawn into the charging chamber ofl that cylinder to be discharged into the corresponding combustion chamber of the other cylinder for continuous operation of the engine. It is thus obvious that the fuel drawn into the charging chamber of one cylinder is utilized in the combustion chamber of the other cylinder and vice versa, thereby eliminating the necessity of storage chambers and at the same time effecting high volumetric efficiency with low scavenging pressures.

What We claim and desire to secure by Letters Patent is:

1. An internal combustion engine including combustion chambers having intake ports in the sides of the chambers and having exhaust ports at theopposite sides thereof, charging chambers having intake and discharge ports, a transfer reservoir providing a common connection between the discharge ports of the charging chambers and all of the intake portsV of the combustion chambers, pistons reciprocable in the combustion chambers and movable over the intake and exhaust ports of said combustion chambers, valves in the discharge ports of the charging chambers automatically operable responsive to differential pressures in the-transfer reservoir and charging chambers, mea'ns in theV charging chambers for drawing a charging medium into said chambers through the intake ports thereof and discharging said medium through said pressure responsive valves for transfer to the combustion chambers when the pistons uncover the intake ports to effect scavenging of exhaust gases through the exhaust ports of said combustion chambers and effecting charging of the combustion chambers, and valves controlling the intake ports of the charging chambers, the intake ports of the combustion chambers being of different capacities and arranged so that certain of said intake ports of the combustion chambers are uncovered by the respective pistons in advance of opening of the other intake ports whereby the portion ofthe charging medium admitted from the transfer reservoir through the first' opened ports is caused to move upwardly along the sides of the combustion chambers and the portion of the charging medium admittedfrom the transfer reservoir through the second opened ports is caused to flow under that admitted through the first opened ports to maintain movement of the medium to the upper end of the combustion chambers dur-c ing the time said exhaust ports are opened by the pistons.

2. )In an engine of the character described, a

combustion chamber having different sized intake ports in a side -of the chamber and having an exhaust port at the opposite side, common transfer means connecting all of said intake ports, a piston operable in said chamber for admitting a charging medium from the transfer means through the intake ports and having an upwardly and inwardly directed deiiecting portion movable across said intake ports, the larger of said intake ports being arranged to be uncovered by the piston in advance of the smaller port whereby the portion of the charging medium admitted through the larger port from the transfer means is caused to move upwardly along the side of the combustion chamber having the intake ports to expel products of combustion from a previous charge down the opposite side and through the exhaust port and the portion of the charging medium admitted through the smaller port is subsequently defiected and caused to flow under that admitted through the larger port.

3. In an internal combustion engine, a combustion chamber having a plurality of intake and exhaust ports arranged in arcuate series on the respective sides of the combustion chamber, a charging chamber located in axial alignment with said combustion chamber and having intake and discharge ports, transfer means connecting the discharge port of the charging chamber with all of the intake ports of the combustion chamber, a power piston reciprocable in the combustion chamber and movable over the intake and exhaust ports of said combustion chamber, valve means controlling the discharge port of the charging chamber automatically operable responsive to differential pressures in the transfer means and the charging chamber, a charging piston connected with the power piston and operable in the charging chamber to draw a charging medium into said chamber through the intake port and discharging said medium through said pressure responsive valve into the transfer means for transfer to the-combustion chamber when the power piston uncovers the intake ports to effect scavenging of the exhaust gases through the exhaust ports of said combustion chamber and to effect charging of the combustion chamber, and valve means controlling the intake port of the charging chamber, one of said intake ports of the combustion chamber being arranged to be uncovered by the power piston in advance of another of said intake, ports whereby the portion of the charging medium admitted from the transfer means through the first opened `4port is caused to move upwardly along the side of the combustion chamber and a'portion of the charging medium Aadmitted from the transfer means through the'second opened port is caused to iiow under that admittedthrough the first opened port to maintain movement of saidme dium to the upper end of the combustion cham'- ber during the time said exhaust ports are opened by the piston.

SAMUEL B. GOLD.

BRUCE E. GOLD.

Images