US1938273A - Internal combustion engine - Google Patents

Description

Dec. 5, 1933. L. M. WOOLSON 1,938,273

INTERNAL COMBUSTION ENGINE Filed July 21, 1930 r 2 Sheets-Sheet l .LIDNEL MNJULEUN. DEEEAEEC :Y H15 EXEEUZEJX EMMA F. NDULEUN Dec. 5, 1933.

INTERNAL COMBUSTION ENGINE Filed July 21, 1950 lmNEL Mia/00L 5am DECEASED BY H15 EXECL/Z'RIX 5 a fNNA i. Nam 501v 1.. M. WOOLSON 1,938,273

Patented Dec. 5, 1933 UNITED STATES PATENT OFFICE INTERNAL COMBUSTION ENGINE Michigan I Application July 21, 1930. Serial No. 469,324

Claims.

This invention relates to internal combustion engines and more particularly to engines of the compression-ignition type in which fuel is injected into the combustion chambers through mechanism actuated by an engine part.

The invention has to do more particularly with the starting of engines in which liquid fuel is injected into compressed air charges at pressures developed in accordance with the engine speed. With this type of injection mechanism, the degree of fuel atomization and the pressure at which the fuel is injected becomes less as the speed of the engine decreases, and consequently when the crank shaft is being slowly turned in starting, the fuel is not injected into the compressed air in the combustion chambers at a pressure or in an atomized condition conducive to the formation of a readily combustible mixture.

An object of the invention is to create a pressure upon, and atomization of, liquid fuel charges being injected into compressed air in the cylinders of a compression ignition engine by injection mechanism, of the type above set forth, in a manner to insure a homogeneous mixture which will become quickly ignited by compression when the engine is being slowly turned over in starting.

Another object of my invention is to provide a compression-ignition type of internal combustion engine in which the normal pressure produced against the fuel being injected in the compressed air charges, when starting, is materially increased beyond that developed by the mechanism which is eifective when the engine is running under its own power at the same engine speed.

A further object of the invention is to provide a pressure fuel injection system for compressionignition engines which is actuated, when running under its own power, by a slow moving mechanism and which is actuated, when starting, by a mechanism operating several times faster than the mechanism effective when running under its own power so that fuel will be injected at a pr ssure when starting to cause a material penetration of the air charges in the cylinders.

Still another object of the invention is to provide a compression-ignition engine with liquid fuel injection devices which can be driven by a fast or a slow cam through mechanism associated with the crank shaft, such mechanism being automatically retained in a position to cause the slower moving cam to-be effective when the engine is running under its own power and being adjusted through the relation of a starter therewith to maintain the faster moving cam in an advanced eifective position while the engine crank shaft is being turned over by the starter.

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. 1 is a rear elevational view of a radial engine, partially broken away and partially in section to show a fuel injecting device and the actuating mechanism with the cams in position for starting;

Fig. 2 is a sectional view of the same, taken on line 22 of Fig. 1;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a fragmentary sectional view of one of the fuel nozzles associated with an engine cylinder;

Fig. 5 is an elevational View showing the fuel injection mechanism actuating cams with the slower moving cam in effective position for running operation.

. Referring now to the drawings by characters of reference, 10 represents generally the crank case of a compression-ignition type of internal combustion engine from which nine air-cooled cylinders 11 extend radially, the cylinders being secured under compression around the wall of the crank case by a pair of rings, one of which is indicated at 12. The cylinders are formed with an integral dome 13, and secured upon each of the domes is a head 14. Each of the associated heads-and domes is formed with a single Venturi passage 15 leading into the interior of the associated cylinders, such passages serving as both the air inlet and the exhaust outlet for the combustion chambers which are between the cylinder domes and the pistons 16. -In order to control the passages 15, there is associated with each a valve 17 which is normally closed by a plurality of springs 18 and opened by conventional engine actuated mechanism including a push rod 19 which extends into the crank case thr ugh a housing 19.

A diaphragm, or internal wall 20 is secured within the crank case and is formed with a central opening in which is arranged a bearing 21 for supporting one end of the crank shaft 22, the crank shaft projecting axially through the crank case. Arranged in a relation substantially parallel to the diaphragm is a detachable rear wall 23 which closes the open end of the crank case, and detachably secured to the rear wall is a starting device, indicated generally at 24, which is preferably of the inertia type as illustrated in Patent No. 1,739,469, issued December 10, 1929, to R. P. Lansing. Such starting device is arranged with an axially reciprocable jaw 25 projecting into the crank case in alignment with the rear end of the crank shaft, so that it can be moved into a driving relation.

The engine illustrated is of the compressionignition, or Diesel type, operating on a fourstroke cycle, air charges being drawn into the cylinders through the passages 15 upon the suction strokes of the pistons, during which time the valves 17 are mechanically held open. The compression strokes next occur, during which time the valves are closed, and charges of fuel oil are injected under a high pressure at any engine speed and in an atomized condition into the air charges being compressed, in a manner such that the mixture thereof with the compressed air will form a charge of a character producing quick combustion. There is associated with each cylinder an airless pressure fuel injection device which consists generally of a nozzle portion 26 and a pump portion 2'7, the nozzle portions being secured rigidly to the cylinders and arranged to project through the walls thereof so that the fuel charges can be injected directly into air charges in the interior of the cylinders.

Each nozzle consists of a barrel 28 having a detachable end 29 extending through the associated cylinder wall and formed with a conical outlet opening in which the valve head 30 is arranged. The valve stem 31 is arranged to be moved into engagement with the stop member 32 by a spring 33 and such stop member is adjusted to prevent the valve from entirely closing. The barrel 28 is formed with a downwardly extending neck portion which is provided with a passage 34 leading to the hollow chamber in the barrel through which the valve rod extends. Such nozzle neck is screwed into the casing 35 of the associated pump unit and bears against a spacer 36 which maintains the pump barrel 37 in position within the casing 35, there being a pair of spring-pressed valves 38 associated with the spacer and the barrel to prevent liquid fuel and air from the cylinder returning to the pump structure from the nozzle structure. A plunger 39 is arranged to reciprocate within the pump barrel and a fuel inlet manifold 40 communicates with all of the pumps, there being unions 41 in the manifold structure associated one with each of the barrels, and ports 42 extend through the casing and the barrel to establish communication between the fuel feeding manifold and the interior of the barrel. Such ports are controlled by the position of the plunger so that when a plunger uncovers the ports 42, liquid fuel is moved into the pump barrel and nozzle, underlow pressure from a source of supply, completely filling the chambered portions therein. The pump plungers are moved in their injection strokes by adjustable mechanism, which will be hereinafter described, and during such movement they close the ports 42, their stroke after closing such ports determining the quantity of fuel which is displaced from the nozzle into the cylinders.

It will be seen that the speed of the pump plunger movement determines the degree of pressure under which the fuel charge is forced past the nozzle valve. The effective stroke of the plungers will force fuel past the valve heads 30 and from the nozzles in a manner such that the fuel charges are directed into the cylinders in a conical spray. The air inlet passages are formed and arranged so that they cause rotation of the air in the cylinders and such rotation continues during the following compression stroke of the piston the fuel charges being sprayed into such compressed rotating air charges.

Ihe degree of fuel atomization and the extent of the pressure at which it is injected determine the degree of the intermingling of the oil with the air and, therefore, it is necessary that there be sufficient atomized fuel penetration of the air to cause a uniform distribution if efficient engine operation is to result. It is also necessary that the atomization and penetration of the air by the fuel oil be of a certain character if combustion is to be attained when the cylinders are cold, as they are when starting. With the type of injection mechanism described, in which the pressure behind the fuel varies in accordance with the crank shaft speed, difilculty is experienced, when turning the crank shaft at a slow speed in starting the engine, to produce a sufficient pressure behind the fuel charges as the consequent slow movement of the fuel pumps will not cause the atomization and penetration of the compressed air charges required to produce a mixture which will support combustion.

This invention has to do particularly with mechanism for injecting fuel oil in an atomized condition, and at a sunicient pressure, to cause an intermingling with the compressed air in the cylinders such that ignition thereof will readily result from compression, when the crank shaft is being slowly turned through the application of a starting device. To this end, the regular fuel injecting mechanism for the normal running operation of the engine is utilized, and an auxiliary actuating mechanism therefor is provided which is effective only during the application of the starting mechanism to the crank shaft. This auxiliary actuating mechanism is automatically made effective through the application and operation of the starting device and is automatically placed in ineffective relation when the starting device is released from the crank shaft. In carrying out such invention, it

is proposed that the liquid fuel charges will be injected, during the turning of the crank shaft by the startingdevice, at a pressure which will causethe fuel to penetrate substantially to the center of the cylinder and in a finely atomized condition so that one rotation of the compressed air in the cylinder will cause a uniform distribution therein of the atomized liquid fuel.

Under normal running operation, crank shaft actuated mechanism is provided for causing the pump plungers to move in their injection strokes, and such mechanism is returned to a position uncovering the ports 42 by means of the coil spring 43. A fuel plunger push rod 44 extends through the'crank case and has associated therewith a rod 45 which is pivotally connected with a link 46 carried by a regulating ring 47 which is rotatably mounted within the crank case. The ring 47 can be actuated through the association of a tooth segment 48 with a rack 49 which is fixed to the ring, the segment being rotated by means of the shaft 50 which is in turn actuated through suitable mechanism connected with the lever 51. Associated with each of the levers 45 is a slipper or rock lever, as shown at 52, 53 and 54, each being carried by a shaft 55 supported by the diaphragm and the rear casing cover 23. The free ends of the rock levers are formed with a longitudinally extending curved groove in which the associated lever 45 is adjustably positioned by means of the ring 47 and the connecting links 1 ably mounted uponsuch hub.

46, so that upon movement of the levers 45, lengthwise of the slippers, the effective stroke of the pump plungers can be simultaneously varied, A cam member 56 is rotatably arranged between the, diaphragm 20 and the end wall 23 and the rear end of the crank shaft extends axially therethrough. Formed on the forward peripheral end of the cam are a plurality of equally spaced lobes 5'7, 58, 59 and 60 which are arranged to rotate, within the space defined by the pivoted slippers associated with the fuel device of each cylinder, in a relation to actuate the same when the cam is rotated. The cam 56 is also provided with four peripheral lobes, one of which is indicated at 61, arranged to rotate within the space defined by the pivoted slippers 62 which are also mounted upon the shafts 55 at the rear of and adjacent the slippers for actuating the fuel injection devices. The push rods 19 are associated with the slippers 62 and are actuated to open the valves 17 through rotation of the cam 56. Splined to the rear end of the crank shaft is a gear 63, and meshing therewith is another gear 64 carried on the shaft 65. Mounted on the front end of such shaft is another gear 66 which meshes with an internal ring gear 67 formed on the inner wall of the periphery of the cam 56. By means of such train ofgearing the cam 56 is driven from the crank shaft at one-eighth the speed thereof and in an opposite direction to that in which the crank shaft is rotating.

A cam 68, provided with a lobe 69, is formed with a hub '70 through which the rear end of the crank shaft extends, and the cam 56 is rotat- Arranged adjacent the rear end of the hub of the cam 56 and telescoping the hub and the cam 68 is a sleeve '71 which secures the cam 56 axially in position, there being av nut '72 screwed upon the rear end of the crank shaft for retaining the sleeve in desired axial position.

A starter jaw member '73 partially telesooped into the hollow rear end of the crank shaft and a pin 74 extends through the sleeve '71, the cam hub 70, the crank shaft and the starter jaw which projects into the crank shaft. This pin provides a driving connection between the crank shaft, the cam 68 and the starter jaw. The sleeve 71, the cam hub '70 and the starter jaw are provided r with apertures of a character such that the pin can extend therethrough and have a snug fit therewith. The hollow crank shaft end is provided with diametric slots '75 extending transversely of the axis so that the pin is permitted to have a limited rotation without effecting rotation of the crank shaft or of the cam 68, as the case may be, depending upon whether the crank shaft is to be turned by the starter 24 or under its own power. The gear 63 is'provided with a forward flange '76 while the sleeve '71 is provided with a. flange '77 extending parallel to the flange 76, and a tension coil spring '78 is attached at one end to the flange '76 and atthe other end to the flange '77, extending through slots as indicated at '79 for fastening purposes.

When the engine is running under its own power and the starter 24 is disconnected from the starter jaw '73, the spring '78 exerts sufficient force upon the sleeve '71 to maintain the pin '74 in the position shown in Fig. 5, and in this position the cam 68 is in a position where the lobe 69 thereon will pass under the slippers 52 for actuating the fuel injection devices while they are raised and riding upon the lobes of the cam 56 so that the cam 68 is thus ineffective. In other words, when the engine is running under its own power, the spring '78 will cause the sleeve '71 and the pin 74 to maintain the cam 68 in an angular position relative to the crank shaft wherein it will be ineffective to cause actuation of the slippers for operating the fuel injection devices, even though it is being rotated with the crank shaft and at a speed eight times that of the cam 56.

In starting the'engine, the jaw 25 of the starter 24 is moved into engagement'with the starter jaw '73 and during the first rotation caused thereby the starter jaw carrying the pin '74 will be moved in the slots '75 without causing rotation of the crankshaft until the pin reaches the opposite ends of the slots, as shown in Fig. 3, whereupon the crank shaft will be driven. In the meantime, the cam 56 is being rotated by the pin '74 and its angular position relative to the crank shaft is changed so that the lobe 69 will engage the slippers for actuating the fuel injection devices in advance of the lobes on the cam 56, and under such circumstances, the cam 68 will be effective to cause injection strokes of the fuel injecting devices while the cam 56 will be ineffective. With the cam 68 in effective angular position upon the crank shaft the timing is such that the slippers will be riding upon the top of the lobe 69 when the lobes on'the cam 56 reach a point where they would cause an actuation of the slippers; It will, therefore, be seen that the lobes'of the cams 56 and .68 mask each other depending upon which cam is in effective position.

- When the starter 24 has expended its energy and the engine is operating under its own power, the starter jaw '73 will overrun the jaw 25'and upon the release of such jaws the spring78 will cause the pin 74 through its connection with the sleeve '71 to move back into the position shown in Fig. 5 whereupon the cam 56 will again be effective, as the cam 68 will have been rotated to an angular position on the crank shaft such that the lobe 69 will pass under the slippers while they are riding upon the lobes on the cam 56. 'It will thus be seen that in starting, the cam 68 is automatically made effective through the association of the starter with the driving connection between the crank shaft and the cam,

and. that the cam 68 will be moved into ineffecltive position automatically when the engine is operating under its own power, or when the jaw 25 of the starting devicehas been released from the starter jaw '73.

When the cam 68 is effective, the crank shaft is being turned slowly by the starting device and the rotation of the cam is the same as that of the crank shaft, whereas the cam 56 is being rotated at one-eighth the speed of the crank shaft. If

the fuel pump actuating slippers were actuated ofrotation being eight times that of the cam 56, a much faster impact is given to the slippers and consequently a much faster stroke of the fuel plungers results so that the pressure at which the fuel charges are injected into the compressed air charges is materially increased over that which would be present if the cam 56 were effective. By the provision of the starter cam 68 for actuating the fuel injection devices it is possible to maintain, even at the slow starting speed at which the crank shaft is turned, sufficient pressure behind the fuel charges to cause a penetration of the air charges such that the fuel and air will quickly form a homogeneous mixture which will readily ignite under the compression developed in the combustion chambers.

While there has been herein described in some detail a specific embodiment of the invention, which is deemed to be new and advantageous and maybe specifically claimed, it is not desired to be understood that the invention is limited to. the exact details of the construction, 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:

1. In an engine, the combination of a liquid fuel injection device, a'pair of mechanisms for actuating said device, said mechanisms operating at different speeds with the slower one in normally effective relation with the device, a starter device adapted to be associated to actuate the engine, and shifter means associated with the faster mechanism, the operation of the starter device after application to the engine actuating the shifter means to place the faster mechanism into effective position to actuate the device.

2. In a compression-ignition engine, a liquid fuel injection device, a pair of cams arranged to cause injection strokes of said device and effective only one at a time, a crank shaft, mechanisms for rotating the cams at different speeds connected with the crank shaft, the faster driving mechanism being shiftable to move the cam driven thereby into effective or ineffective position, a starter device forengaging the shiftable mechanism to rotate the same and the crank shaft, the starter application to the mechanism shifting the faster cam into effective position in advance of the slower cam prior to rotation of the crank shaft thereby, and means automatically moving the faster driving mechanism to place the faster cam in ineffective position when the starting device is disengaged from the mechanism.

3. In an internal combustion engine, a pressure device for injecting liquid fuel into air charges in the combustion space, a crank shaft, mechanism driven ata reduced speed from thecrank shaft for actuating the injection device, astarter jaw associated with the crank shaft, a mechanism driven by the starter jaw. for actuating the injection device at crank shaft speed, and a connection between said starter jaw, crank shaft and the starter jaw driver mechanism, said connection having a limited angular movement relative to the crank shaft to shift said starter jaw driven mechanism into effective actuating position with the injection device during cranking of the en gine in starting.

4. In an internal combustion engine, a pressure device for injecting liquid fuel into air charges in the combustion space, mechanism driven from the crank shaft to actuate the injection device, a hollow crank shaft having diametric slots extending transversely of the axis, a starter jaw projecting into the hollow crank shaft, a cam member for actuating the fuel injection device, and a pin extending through the starter jaw, the slots inthe crank shaft and the cam member, the initial rotation of said starter jaw when cranking moving the pin in the crank shaft slots and shifting the cam into effective position prior to rotation of the crank shaft, and spring means for normally maintaining the pin in a position causing the cam member to be in an ineffective position.

5. In an internal combustion engine, apressure device for injecting solid liquid fuel into air charges in the combustion space, a hollow crank shaft having diametric slots extending transversely of the axis, a slow speed cam, mechanism driven from the crank shaft for rotating the cam at a reduced speed relative thereto, a starter cam having a hub telescoping the slotted portion of the crank shaft, a sleeve member telescoping the cam hub and the slotted portion of the crank shaft, a starter jaw extending into the hollow crank shaft, a pin extending through the sleeve, cam hub, the slots inthe crank shaft and the starter jaw, and a coil spring fixed at one end relative to the crank shaft and at the other end to the sleeve, said spring normally causing said pin to be maintained in a position retaining the starter cam in ineffective position, the cranking of the starter jaw initially moving the starter cam into effective position against the tension of the spring prior to rotation of the crank shaft.

6. In an engine, in combination, a liquid fuel injection device, a crank shaft,'a pair of cams for actuating the fuel device, mechanisms driven from the crank shaft for rotating said cams at relatively different speeds, the slow cam being normally effective, shifter means associated with the fast'cam mechanism, and a starter device engageable with the shifter means to crank the engine, the application of the starter device to the shifter means moving the fast cam into effective position before rotating the crank shaft.

7. In an engine, in combination, a plurality of liquid fuel injection devices, a pair of cams for actuating the fuel devices, said cams being relatively adjustable angularly so that either one leads and when leading shields the other from actuating the devices, a crank shaft, driving mechanisms associated with the crank shaft for rotating the cams therefrom at different speeds, the slow cam being normally in leading position with respect to the fast cam, the fast cam driving mechanism being movable a limited extent relative to the crank shaft, a starter jaw fixed to the fast cam driving mechanism, and a starter device adapted to be applied to the starter jaw, the'initial rotation of said jaw by the starter device shifting the fast cam driving mechanism and moving said fast cam into leading position prior to rotationof the crank shaft.

8. In a compression-ignition engine, a liquid fuel injection device, a pair of relatively angularly adjustable cams arranged to cause injection strokes of said device when rotated, the leading cam shielding the other from actuating the device during operation, a crank shaft, mechanisms driven from the crank shaft for rotating the cams at different speeds, the fast cam mechanism being rotatable a limited extent with respect to the crank shaft, ajaw fixed to the fast cam driving mechanism, and a starter device adapted to be applied to said jaw to rotate the crank shaft, the application of the starter to the jaw shifting the fast cam driving mechanism and placing the fast cam in a position in advance of the slow cam while rotating the crank shaft.

9. In an engine, the combination of a pressure device for injecting liquid fuel into air charges in-a combustion space, two mechanisms operated at relatively different speeds for causing injection strokes of the device and relatively angularly adjustable so that the lobes of the leader shield the lobes of the follower from actuating the device, the slower mechanism being in advance when the engine is operated under its own power, and means associated to shift the faster operated mechanism into leading relation with the injection device while the engine is being cranked for starting.

10. In an engine, in combination, a plurality of liquid fuel injection devices, a pair of cams for actuating the fuel devices, said cams being relatively adjustable angularly so that either one leads and when leading shields the other from actuating the devices, a crank shaft, driving mechanisms associated with the crank shaft for rotating the cams therefrom at different speeds, the fast cam driving mechanism being movable a limited extent relative to the crank shaft, resilient means normally maintaining the driving mechanism for the fast cam in a relation such that it follows the slow cam, a starter jaw fixed to the fast cam driving mechanism, and a starter device adapted to engage the starter jaw for cranking the engine, the initial rotation of said jaw by the starter device shifting the fast cam driving mechanism and moving said fast cam into leading position prior to rotation of the crank shaft,

EMMA F. WOOLSON, Ewecutrim of the Estate of Lionel M. Woolson, De-

ceased.

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