US2139170A - Engine - Google Patents

Description

Dec; 6, 1938. M M RPHY 2,139,170

ENGINE Filed Dec. 15, 19:55 5 Sheets-Sheet 1 I INVENTOR. Nos e51 Murphy wfw ATTORNEY.

Dec. 6, 1938.

M. J. MURPHY- 2,139,170

' ENGINE Filed Dec. 13, 1935 5 Sheets-Sheet 2 INVENTOR: Mag/e5 J Warp/7g ATTORNEY.

M. J. MURPHY Dec. 6', 1938.

ENGINE Filed Dec. 15, 1935 5 Sheets-Sheet s n u muH h INVENTOR. Noyes J. Murphy d/mm g g g NQ ATTORNEY} Dec. 6,1938. M RP Y I 2,139,170

ENGINE Filed Dec. 15, 1935. 5 Sheets-Sheet 5 m m; a

CF H3 Mimi" |l|||||||H||||||m 75 74 72 I m INVENTOR. Wages J Murphy ATTORNEY.

Patented Dec. 6, 1938 PATENT OFFICE ENGINE Moyes J. Murphy, Milwaukee, Wis., assignor to Murphy Diesel Company Ltd., Milwaukee, Wis., a corporation of Nevada Application December 13, 1935, Serial No. 54,270

8 Claims.

My invention relates to engines intended to operate usually on the Diesel cycle but convertible by a simple manipulation of the controlling mechanism to operate in accordance with the Otto cycle. A typical engine of this character is disclosed h in my copending application entitled Engine, filed October 20, 1931, with Serial No. 569,907.

In my copending application there is shown an engine in which the relatively small combustion chamber for use during operation on the Diesel cycle is augmented by an additional, auxiliary combustion chamber when the engine operates on the Otto cycle. Suitable poppet valves are utilized to control the events of the operating cycle, and additional valves are utilized to convert the auxiliary combustion chamber to an operative or an inoperative state. In many installations, the operation of the engine according to the Otto cycle is useful primarily for starting the engine from cold, and where an engine must be started .often from a cold condition it is advantageous to have such Otto cycle mechanism incorporated with the Diesel engine. On the other hand, in certain circumstances the engine is started but seldom and sometimes is permanently connected to a suitable starter, such as an electric generator. In the latter case it may not be desirable to have the Otto cycle starting 30 mechanism incorporated in the engine.

It is therefore an object of my invention to provide an engine in which the Otto cycle mechanism is almost entirely contained in a separate, detachable unit.

5 Another object of my invention is in general to improve Diesel engines which are capable of operating accordingito the Otto cycle when desired.

A further object of my invention is to provide 40 an improved internal combustion engine.

An additional object of my invention is to provide an engine which can be operated either on gasoline or on fuel oil, and in which there is an abrupt change-over from one fuel to the other with no intermediate operation on a mixture of two fuels.

A still further object of my invention is to provide a simple control means for an engine as de- 50 scribed.

The foregoing and other objects are attained in the embodiment of the invention shown in the drawings, in which- Fig. 1 is an exhaust side elevation of an engine 55 constructed in accordance with my invention.

Fig. 2 is an intake side elevation of the engine of Fig. 1.

Fig. 3 is a cross-section, the plane of section being indicated by the line 3-3 of Fig. 2.

Fig. 4 is for the most part a cross-section the 5 plane of which is indicated by the line 4-4 of Fig.

3 but which in part is broken away to show the interior arrangement of the cam shaft and injector mechanism.

Fig. 5 is an end elevation of the upper portion 10 of the engine of my invention.

Fig. 6 is a fragmentary cross-section, the plane of section being indicated by the line 6-45 of Fig. 4.

Fig. '7 is a cross-section through the carburel5 tor, the plane of section being indicated by the line 1-1 of Fig. 2.

Fig. 8 is a schematic diagram showing the operative relationship of the engine parts, particularly the controlling devices. 20

In its preferred form, the engine of my invention incorporates a cylinder assembly having a main combustion chamber and an auxiliary combustion chamber, the latter of which is partly contained in a detachable body. The mechanism includes an inlet valve between the auxiliary combustion chamber and the main combustion chamber, and a valve between an air manifold and the auxiliary combustion chamber. Means are provided for operating the inlet valve in time with the operation of the engine and for disabling the inlet valve and the valve under the control of a single control means which likewise is effective to control the supply of fuel to the combustion chamber.

While an engine in accordance with my invention can be embodied in a large number of variant forms, it has been constructed successfully as shown in the drawings herein. In this exemplary modification the engine includes a block casting B, in the present instance designed for the accommodation 'of six cylinders in line. The casting 6 at one end merges with a fiy-wheel housing 1 having supporting feet 8 thereon, and at the other end is carried on a pedestal support 9. The bottom portion of the casting 6 is closed by an oil pan H secured to the casting by suitable fastenings l2 and forming therewith a crank-case. Disposed within the crank-case so formed is a crank-shaft l3, heldin place by main bearings l4. Journaled on the crank-shaft are connecting rods I6, each including a removable cap l'l held on by studs l8 and nuts l9. Access to the interior of the crank-case is attained 55 through handholes 2|, normally closed by covers 22.

The working cylinders are formed by suitable liners 23 introduced into the block casting 6 and receiving reciprocable pistons 24 to which the connecting rods I6 are articulated by wrist pins 26. The piston24 is provided with a depressed head within which a heat insulator 21 is disposed, to provide a partially insulated main combustion chamber 28. The combustion chamber'is likewise bounded by the lower planar face 29 of a cylinder head 3| which is held in place on the cylinder block 6. Operating in each cylinder, and disposed in the cylinder head 3|, is a pair of inlet valves 32 and a pair of exhaust valves 33. The exhaust valves control communication between the combustion chamber 28 and a pair of exhaust manifolds 34 and 36 to which exhaust stacks 31 are connected. The inlet valves 32 control communication between the combustion chamber 28 and an inlet passage 4I formed in the cylinder head 3|.

The passage 4I communicates with an air duct 42 merging with an intake manifold 43 formed as a separate body 44 secured to the side of the head 3| opposite to the manifolds 34 and 36. Clean air is admitted to the air manifold 43 from air cleaners 46 and 41, each of which contains baffling material 48 for filtering dirt and oil entrained by air entering from the atmosphere through an entrance tube 49 and passing in contact with a pool of oil 5| in the removable bottom of each air cleaner. The inlet valves 32 are operated by an intake cam shaft 56 journaled in a cam shaft block 51 disposed on the cylinder head 3|.

Rocker arms 58 are interposed between each cain and its respective valve stem of the intake valves 32, and, similarly, rocker arms 59 are interposed between the stems of the exhaust valves 33 and the cams on an exhaust cam shaft 62 likewise journaled in the cam shaft block 51. The two cam shafts 56 and 62 are preferably driven in synchronism but in opposite directions of rotation, by a suitable drive mechanism (not shown) connected to the crank-shaft adjacent the flywheel. The valves are operated in time with the operation of the engine, so that the engine performs in accordance with the customary fourstroke cycle.

In order to provide the cylinders with fuel for operation on the Diesel cycle, each cylinder is provided with a solid injector II generally disposed in the cylinder head 3|, including, in addition to the customary casing, a reciprocable plunger connected to a crosshead I2. The crosshead at opposite extremities carries roller followers I3 and 14 bearing respectively on the intake cam shaft 56 and the exhaust cam shaft 62. Identical cams on each of these shafts produce a rectilinear translation of the crosshead I2 in time with the operation of the engine, in order to inject fuel at the correct time.

The amount of fuel injected by each injector and, correspondingly, the speed and load-carrying capabilities of the engine are controlled by a regulating crank 15 (Fig. 4) which is rotatable on a stud I6. The crank I6 is provided with an arm II which is connected by a manually releasable pin 18 to a cross-link 19. This link is mounted for approximately parallel motion transversely of the engine by being pivoted at opposite ends to levers 8| and 82 surrounding longitudinal shafts 83 and 84. The lever 8| is freely rotatable on the shaft 83, but the lever 82 is fast on the shaft 84. Thus, rotation of the shaft 84 produces a translation of the link I9 and, through the arm 11, controls the operation of the injector. Since each injector is so connected to the shaft 84, rotation of the shaft 84 governs all of the cylinders simultaneously.

In order that the shaft 84 may be appropriately controlled to vary the speed of the engine, it

.extends to a governor 9|, preferably located at one end of the cam-shaft block 51 and driven by the exhaust cam-shaft 62. The governor is of any convenient kind, but preferably is of the hydraulic type interconnected with the lubricating oil system of the engine so that in the event of failure of the lubricating oil supply the engine will be shut down. The governor is capable of rotating the shaft 84 in order to maintain the speed of the engine at any set value.

In order to vary the speed of the engine by varying the set speed of the governor, the gov ernor is provided with a control shaft 92 (Fig. 5) to which a lever 93 is secured. This lever projects forwardly and at its extremity is provided with an adjustable tappet 94 adapted to bear against one arm 96 of a lever pivoted at 91 to the cam shaft block 51. The other arm 98 of the lever is bifurcated to receive a pivot pin 99 connecting the lever to a link |0I extending to a cam disc I02. A pin I03 secures the link IM to the disc I02. 'The cam disc is fast on one extremity of a gear shaft I04 suitably journaled in a gear housing I06 secured to the manifold body 44. Within the housing I06 the shaft I04 carries a worm wheel I01 with which meshes a worm I08. This worm is on a main control shaft I09 likewise journaled in the housing I06 and at its end carrying a control wheel IIO equipped with an axially movable handle III. A peripherally perforated plate II2, secured to the housing I06, provides a backing for the wheel 0 and provides locking stops for the axially movable handle I II which is normally pressed by a spring II3 into engagement with one of the apertures to hold the control wheel H0 in any selected position.

When the handle III is retracted against the urgency of the spring I I3 to release the wheel I I0 from the plate II2, the wheel IIO can be rotated, thereby rotating the shaft I09 and the worm I08. Rotation of the worm I08 produces a corresponding rotation of the worm wheel I01 and of the shaft I 02. This causes the link IOI to rock the lever 98, thus, through the tappet 94, moving the lever 93 and the shaft 92. Such movement either opposes the action of the governor tending to shut down the engine, or permits such slowingdown action of the governor to be effective in order to reduce the engine speed. The governor manipulates the shaft 84 and directly governs the injectors. Thus, by setting the wheel III) in any selected position the operator can predetermine any desired governed speed for the engine or, by suitably manipulating the wheel, can at random accelerate the engine or permit it to slow down.

In accordance with my invention, means are provided for preventnig operation of the engine on the Diesel cycle and for alternatively operating the engine on the Otto cycle. This last type of operation is especially desirable for starting the engine from cold and for warming up the engine, at the conclusion of which operation a rapid 1 change-over to functioningon the Diesel cycle can be effected.

The combustion chamber volume requisite for Diesel cycle operation is that provided by the depressed head of the piston; namely, the combus- 7 tion chamber 28. Operation in accordance with the Otto cycle requires a considerably augmented volume of combustion chamber, and I consequently provide means for utilizing a portion of the intake passage 4| forthis purpose. Furthermore, in accordance with my present invention I dispose most of the mechanism for effecting operation on the Otto cycle in the manifold body 44, so

that when such body is removed from the engine the engine is virtually a standard Diesel cycle engine without possibility of operating in accordance with the Otto cycle, and so that in those installations where gasoline starting and operation is not requisite the engine can be utilized as a straight Diesel engine and its construction is in no wise, or at least very little, affected by its adaptability.

To this end I provide means for segregating or isolating, when desired, part of the air intake passage 4I and air duct 42 so that they can be combined with the combustion chamber 28 to provide an augmented combustion chamber. The body is provided, atthe junction of the air intake manifold 43 with the air duct 42, with a seat II6 for a poppet valve II1 the stem of which is carried in a boss I I8 in the manifold body 44 and which valve is normally urged to seat by a coil spring I I9 held in place by a flanged cip I2I. To supply the auxiliary combustion chamber M with a combustible gasoline-air mixture, I provide a mixture manifold I22 which is preferably cast integrally with the manifold body 44 and communicates with the auxiliary combustion chamber under the control of an automatic poppet valve I24 normally urged onto its seat by a light coil spring I26 surrounding its stem. Ignition of mixture within the auxiliary combustion chamber is afforded by an ignition device such as a spark plug I21 which is seated in the body 44 and is re.- movable when a closure cap I 28 is removed.

In order that the mixture manifold I22 may be suitably supplied with fuel there is located in the manifold body 44 a carburetor such as shown in Fig. 7. Air flows into the carburetor body from the manifold 43 through passages I3I leading to a down draft passage I32. Situated in this passage is a venturi I33 through which the air flows on its way to discharge into the mixture manifold I22. Some of the air entering the carburetor flows from the passage I3I, through passages I34,

into a float chamber I36. From the float chamber air passes through a metering nozzle I31 into a mixing chamber I38 from whence it discharges as mixture through a passage I39 and through oriflces MI in the venturi I33 to join the main and from thence passes into the float chamber.

I36. Flow into this chamber is controlled by a needle valve I54 actuated by a pair of floats I56, one of which is disposed on each side of the center of the carburetor. The floats are joined to pivot on a pin I51 and rise and fall with the level of gasoline in the float chamber. I36. A

constant level is thus maintained in the float chamber.

From the chamber I36 gasoline flows through a suitable orifice I58 into a needle valve chamber Within this chamber is locateda needle valve I6I which is manually adjustable to govern the size of passage through an orifice I62 leading to the mixing chamber I38. Sincethe quantity of air is fixed by the size of the orifice in the metering nozzle I31, and the quantity of gasoline can be regulated by the needle valve I6I, a suitably rich mixture is maintained in the passage I39. This mixture, when mixed with the air flowing through the passage I32, provides a combustible mixture in the manifold I22.

The spark plugs I21 are supplied with ignition current through leads I66 passing through the air manifold 43 which thereby serves also as a suitable high tension duct and protector. The high tension leads are preferably carried along the bottom of the intake manifold and pass under the carburetor body through a jumper I61, finally being carried through a tube I68 at the rear of the manifold body to a magneto I69 situated at the rear of the intake cam shaft 56 and disposed to abut a pad I (Fig. 5).

In accordance with my invention I preferably provide that'all of the described instrumentalities are under the control of the'single control wheel IIO. There has already been described the mode of operation of such wheel in governing the speed of the engine when operating on the Diesel cycle. Since, when the engine is converted from opera tion on the Diesel cycle to operation on the Otto cycle, the combustion chamber must be augmented, I preferably effect this by lifting all of the inlet valves 32 and holding them in lifted or inoperative position. To this end each of the rockers 8| for the inlet valves is provided with an upstanding lug I1I ending in a cam face I12. The cam face abuts a flat I 13 provided at a suitable location onthe shaft 83. This shaft projects from the rearward end of the cam shaft block 51 and at its extremity is provided with a lever I14 carrying a roller follower I16. A coil spring I11 engages the pivot pin I18 of the rollerI16 and likewise is hooked into a bracket I18 fastened to the cylinder block 6. tends to hold the lever I14 in its lower position, as seen in Fig. 5, against a stop pin I80. This holds the shaft 83 in such a position that the cam faces I12 do not contact the flats I13. I

When the engine is conditioned for gasoline operation the hand wheel H0 is rotated in such a way that the link IOI permits the governor to cut off the supply of fuel to the injectors. Such rotation of the wheel IIII entails a corresponding rotation of the cam disc I02. A shoulder I8I on the disc I02 contacts the roller follower I16 and lifts the lever I14 from the stop pin I80 against which it has been held by the spring I11. The lever I14, in lifting, correspondingly rotates the shaft 83, so that the flat portions I13 of the shaft act against the cam faces I12, thereby moving the rockers 83 about their pivots and forcing the stems of the inlet valves 32 downwardly into open position wherein they are held as long as the shoulder I8I of the disc I02 rides underneath the roller I16. I

Also in contact with the disc I 02 is a roller follower I82 at the extremity of a lever I83 secured on a through-shaft I84 passing through the manifold body 44. The shaft I84 where it passes through the carburetor is provided with notches I86 with which pins. I81 engage. These pins fit loosely in the passages I34 and extend to projections I88 on the lever I89 of the float mecha- The spring I11 normally nism. During operation of the engine on the Diesel cycle the shaft I84 is in such a position that the pins I8'I are forced against the projections I88 to lift the floats I56 and simultaneously to seat the float valve I54 so that no gasoline can flow into the fioat chamber. When the shaft I84 is rotated from Diesel cycle position to Otto cycle position, the notches I85 free the pins I 87 which then no longer bear against the projections I88, and the floats I56 seek their normal level. Since the fioat valves I54 are thus freed to operate to admit gasoline, the carburetor, which is normally held out of action during operation of the engine on the Diesel cycle, is released for operation of the engine on the Otto cycle.

The shaft I84, in addition to controlling the carburetor as described, is at suitable intervals provided with drop arms I 94 and I96 which straddle the cap I2I surrounding each of the springs I I 8. When the engine is operating on the Diesel cycle, the springs II9 are held compressed, since the arms I94 and I96 press against the encompassing caps and-are held in such location by the position of the shaft I84. This shaft is prevented from rotating since the follower I82 bears against the enlarged portion of the disc I02. When the engine is changed over to operation on the Otto cycle, however, the follower I82 is free to drop into the smaller diameter I91 of the disc I02, and the springs II9 are thereupon effective to rotate the shaft I84 so that the valves III can seat. This precludes communication between the air manifold 43 and the auxiliary combustion chamber 4| thereby ensuring a suction within the auxiliary combustion chamber of sufiicient value or effect to operate the automatic valves I24 in suitable. time with the operation of the engine. These valves normally are inoperative, since when the valves II'I are held open during operation of the engine on the Diesel cycle there is not suflicient suction upon the auxiliary valve heads to cause them to open automatically against the urgency of their springs I261 The magneto I69 is not in the present instance directly under the control of the operating wheel I I but is preferably connected to its driving cam shaft 56 through a clutch L98 which is completely ineffective above a predetermined number of revolutions per minute but which cuts the magneto into operation automatically as soon as the engine speed drops to a predetermined value. This automatically governs the speed of the engine when operating on the Otto cycle, since above the predetermined speed the magneto is thrown out of operation and there is no spark ignition.

I claim:

1. An engine comprising a structural assembly defining a combustion chamber and an inlet passage leading to said combustion chamber, an inlet valve for said chamber operating in time with the operation of said engine, means in a-body detachable from said structural assembly for augmenting saldcombustion chamber, spark ignition means on said body and communicating with said augmenting means and means for preventing the operation of said inlet valve in time with the operation of said engine.

2. An engine comprising a structural assembly defining a combustion chamber and an inlet passage leadingto said combustion chamber, an inlet valve between said passage and said chamber, an air duct communicating with said passage, a valve in said air duct, a mixture manifold opening into said duct between said valves, means w an auxiliary combustion chamber in communication with said combustion chamber, an inlet valve for controlling communication between said combustion chamber and said auxiliary combustion chamber, means for conducting air to said auxiliary combustion chamber, a valve for controlling communication between said air conducting means and. said auxiliary combustion chamber, means for conducting a combustible mixture to said auxiliary combustion chamber, a valve for controlling communication between said combustible mixture conducting means and said auxiliary combustion chamber, and ignition means in said auxiliary combustion chamber.

4. An engine comprising a structural assembly defining a combustion chamber, means forming an auxiliary combustion chamber in communication with said combustion chamber, an inlet valve for controlling communication between said combustion chamber and said auxiliary combustion chamber, means for operating said inlet valve in time with the operation of said engine, means for conducting air to said auxiliary combustion chamber, a valve for controlling communication between said air conducting means and said auxiliary combustion chamber, means for holding said valve open, means for conducting a combustible mixture to said auxiliary combustion chamber, an'automatic, suction-responsive valve for controlling communication between said combustible mixture conducting means and said auxiliary combustion chamber, and ignition means in said auxiliary combustion chamber.

5. An engine comprising a structural assembly defining a combustion chamber, means forming an auxiliary combustion chamber in communication with said combustion chamber, an inlet valve for controlling communication between said combustion chamber and said auxiliary combustion chamber, means for operating said valve in time with the operationof said engine, means for supplying said combustion chamber with fuel, means for controlling said fuel supplying means, means for conducting air to said auxiliary combustion chamber, a valve for controlling communication between said air conducting means and said auxiliary combustion chamber, means for holding said valve open, means for holding said inlet valve open, and a single control means for alternatively actuating either said inlet valve holding means or said other valve holding means and said fuel controlling means to supply fuel.

6. An engine comprising a structural assembly defining a combustion chamber and also an inlet passage leading to said combustion chamber, an inlet valve between said passage and said chamber, a manifold body detachably secured to said structural assembly, said body defining an air duct communicating with said passage, a valve for isolating a portion of said duct which together with said passage forms an auxiliary combustion chamber, a mixture manifold communicating with said auxiliary combustion chamber, and means on said body for alternativelypreventing the cyclic operation of said inlet valve or of said valve.

7. An engine comprising a structural assembly defining a combustion chamber for operation by compression ignition, an inlet valve for said chamber, means in a bodydetachable from said structural assembly for augmenting said combustion chamber for operation by spark ignition, spark ignition means in said body, means for holding said valve open, and means on said body for operating said valve-holding means.

8. An engine comprising a structural assembly defining a combustion chamber, means forming an auxiliary combustion chamber in communication with said combustion chamber, an inlet valve for controlling communication between said combustion chamber and said auxiliary combustion chamber, means for operating said valve in time with the operation of said engine, means for conducting air to said auxiliary combustion chamber,v a valve for controlling communication between said air conducting means and said auxiliary combustion chamber, means for holding said valve open, means for holding said inlet valve open, and a single control means for alternatively actuating either of said holding means.

MoYEs J. MURPHY.

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