US2018516A - Internal combustion engine - Google Patents

Description

Oct. 22, 1935. H. c. EDWARDS 2,013,516

INTERNAL COMBUSTION ENGINE Filed March 20, 1931 2 Sheets-Sheet 1 :J-rwemtoc HERBERT C EUNHRUS.

dttowwq Oct. 22, 1935. A s 2,018,516

INTERNAL COMBUSTION ENGINE Filed March 20, 1931 2 Sheets-Sheet 2 a in 4e 46 J4 J1 f.45 E

a i I i 1 50 l J .59 I may J7 a! gnw'ntom 12 5555222" 5517x5525 Patented Oct. 22, 1935 PATENT OFFICE INTERNAL COMBUSTION ENGINE Herbert 0. Edwards, Detroit, Mich., assignor to Packard Motor Car Company, Detroit, Mich a corporation of Michigan Application March 20, 1931, Serial No. 524,205

2 Claims.

This invention relates to internal combustion engines and more particularly to fuel injection mechanism for Diesel engines.

One of the objects of the invention is to pro- '5 vide a novel form of mechanism for regulating the fuel charges injected into a Diesel type of engine.

Another object of the invention is to provide control mechanism for a plurality of fuel injec- 10" tion devices associated with a Diesel type of engine which can be adjusted with very little effort upon the part of the operator.

A further object of the invention is to provide a fuel injection pressure device for Diesel engines 15 in which the pump stroke remains constant throughout the range of quantity adjustment.

Still another object of the invention is to provide a fuel injection device for Diesel engines in which a pair of reciprocating members are arranged side by side and operated through a single member, one of the reciprocating members being in the form of a plunger and the other member being in the form of a valve to control the timing and the quantity of the fuel injected by the plunger member.

Another object of the invention is tojprovide a valve control mechanism for fuel injection devices which is operated through a connection with the pump operating means and which is adjustably associated therewith to regulate the timing and the quantity of the fuel charges injected by the device.

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 type of Diesel engine, partly broken away and partly in section, with which my invention is associated;

Fig. 2 is a sectional view of one of the injection devices, illustrating mainly the pump and valve control mechanisms;

Fig. 3 is a sectional view of the nozzle portion 45 of one of the injection devices shown associated with a fragment of a cylinder.

Referring now to the drawings by characters of reference, in which I have illustrated one embodiment of the invention, l0 designates the 50 crank case of a radial type of Diesel engine which is closed at its rear end by the cover plate I l. A plurality of cylinders 82 extend radially from the crank case and are provided with shoulders l3 which bear against the crank case and are se- 5 cured thereto by a pair of compression ring members M which encircle the shoulders IS on opposite sides of the cylinder.

The cylinders are each provided with an integral head l5 upon which a dome I6 is secured. Extending through the dome and head of each 5 cylinder is a Venturi passage I! which is arranged tangentially of the inner wall of the associated cylinder and at an angle to the axis thereof, and connected with the outer end of each of such passages is an open end conduit 18 which 10 extends transversely thereof and in line with the direction in which the engine travels.

These passages and conduits provide both the air inlet and the exhaust outlet for the cylinders and a valve I9 is associated with the inner end of the passages to control the flow of air and exhaust therethrough. Air is admitted in the forward ends of the conduits and exhaust leaves the conduits through their rear ends. The valves are normally closed by a plurality of springs and 20 suitable mechanisms extend through the housings 2| and 22 to the interior of the crank case where they are actuated for opening the valves Hi. It will ,be understood that the engine illustrated is of a four cycle typeand the arrangement is such that the valves are open during the exhaust and air intake strokes, while they are closed during the compression and power strokes.

Crank shaft 23 extends axially through the drum-like crank case and adjacent its rear end is provided with a fixed gear 24 with which a reduction gear 25 meshes. The gear 25 is fixed to the stub shaft 26 suitably supported by the engine casing and fixed to this same shaft is another gear 21 which meshes with the internal gear 28 formed on the cam 29. Such cam is arranged in the rear compartment of the crank case and is provided with two sets of lobes, one set being indicated at 30 for actuating the valve opening mechanism, while the other set is indicated at 4 31 for actuating the fuel injection devices which are associated preferably one with each cylinder. The power transmitting mechanism intermediate the crank shaft and the cam is of the reduction type and rotates the cam in a counter-clockwise 4!! direction from the shaft which is rotating in a clockwise direction when looking at the rear of the engine. The engine illustrated is designed primarily for use as the lower plant of an aeroplane and it will be understood that a propeller (not shown) is associated to be driven from the front end of the crank shaft.

Each of the fuel injection devices consists generally of a nozzle section 32, a pump section 33 and a fuel control-section 34, all of which are 56 preierably arranged to term an integral structure which can be readily attached to or detached from its cylinder.

The nozzle section in each fuel injection device includes a casing 35 having an extension 88 detachably screwed into one end thereoi and a passage 31 extending axially through the extension and partially through the casing. A valve 88 extends through the passage in the extension and in the casing and has iormed at one end a head portion 38 which cooperates with the iiared inner wall 40 at the outlet end of the e in the extension to atomize iuel passing therethrough. The nozzle extensions are associated in the recess 4i, iormed one in each cylinder wall. and the injection units are secured to the cylinders by means of bolts 42 which extend through flanges 43 formed on the main body of the nozzle casings. A plug 44 is screwed into the end of each casing opposite the extension and a stop member 45 is screwed into the plug and serves to limit movement of the valve in a direction toward the outer end oi the passage 31, and the adjustment of this member is such that the head 38 will never quite touch the wall portion 40 of the nozzle extension. Each valve is normally urged toward closed position and against the stop member by a coil spring 48 which is arranged within the passage 31 in the nozzle casing. The valve stem is provided with grooves 41 while the retainer members 48 on the end oi the valve stem are provided with grooves 48, such grooves permitting the passage 01 liquid iuel through the passageway in the nozzle.

A casing 58 is screwed upon a neck 5| extending irom the nozzle casings and serves to receive the associated pump and valve sections of each device. The flanged portion oi the barrel 52 is seated within such casing and is maintained in such position by a spacer 53 which is held thereagainst when the casing is screwed upon the neck or the nozzle casing, and a passageway 54 extends through the spacer and the nozzle neck establishing communication between the passage 3! in the nozzle casing and the barrel 52. Check valves 55 are arranged in this passage and in the end of the passage in the barrel to prevent return flow from the nozzle section to the pump section of each device. A combined guide and bearing member 55 is arranged to reciprocate within the casing 50 and is provided with a slotted end for receiving the enlarged end 51 of the plunger 58 which is arranged to reciprocate within the barrel.

Coil spring 59 is seated intermediate the barrel and the surrounding casing and exerts pressure against the bearing and guide member 56 to normally move the plunger away from the nozzle sections of the device. 1

The casing 58 is provided with an oil'set portion to form the housing for the valve control mechanism and is provided with a two diameter bore 60 which extends therethrough in a parallel relation with the plunger 58. A rod valve 8| is arranged to reciprocate in the smaller diameter portion oi the bore 60 and is arranged to control the connecting passage 82 which extends between the interior of the barrel and the bore 80, the upper end or the bore 60 being closed by a cap 63. A port 64 extends betweenthe bore 60 and the'exterior oi the casing and suitable conduit means 85 is arranged to establish communication between the ports 64 01' adjacent injection devices, it being understood that the ports 64 extend through the casing'perpendicularly to the bore and that conduit sections extending to adjacent injection devices irom each device are connected with opposite ends of the ports 84. Detachably associated with an end or the valve 6| is a guide head 68 which reciprocates in the larger diameter portion 01 the bore 80. The valve 5 member BI is provided with a reduced axial section 6'! permitting communication to be established between the ports 64 and the passage 82 so that liquid fuel can pass therethrough from the manifold to the interior 0! the barrel and the m nozzle.

Fuel oil is moved from a suitable source of supply by a low pressure pump (not shown) through the conduits and the ports 64 so that when the valves establish communication be- 1 tween the passages 82 and the ports 64 and the reduced diameter portions of the pump plungers 58 are in a position uncovering passages 82, then liquid fuel will fill the space in the barrels above the plungers and the space in the passages in m the nozzles and those connecting the barrels with the nozzles.

The crank case is provided with a pair of parallel radially extending openings 68 adjacent each cylinder through which bearing members 88 ex- 3 tend and bolts 10 secure the flange portions of such bearing'members against the exterior of the crank case. Extending through such bearing members are sections II and 12 of articulated push rods and associated with each push rod sec- .0 tion 12 is another section 13, while pivoted to the inner end of each push rod section II is another section 14. Pivoted between the diaphragm wall I5 extending transversely of the crank case and the end cover II are a plurality of rock levers 16 .5 which are mounted upon stub shafts 11 secured between such walls. There is a rock lever associated with the push rod structures of each injection device and such rock levers are arranged in a circular relation around the interior or the a crank case and engage with the periphery of the cam 29 so that they will be actuated by the lobes 3i when they pass thereunder to cause the push rod structures and the plungers 58 and the valve members 6| to move in a direction toward the a nozzle section. The push rod sections 13 are pivotally associated with the free end of the rock levers, while the push rod sections 14 are adjustably associated with the rock levers between the free end and the pivoted end. The rock levers are so provided with arcuate undercut grooves 18 in which the enlarged ends of the push rod sections 14 engage, and the relation of these enlarged push rod ends in the undercut recesses is established and adjusted longitudinally of the rock le- 88 vers through means of the ring 19 and the links 88 which are pivotally connected to the ring at oneend and to the push rod sections 14 at their other end. The ring 19 is provided with a plurality of arcuate slots 8| through which bolts 82 U extend, these bolts being screwed into the diaphragm wall 15 to retain the ring therewith.

In order to adjust the control ring 18, I secure a rack 83 thereto and provide a pinion 84 for engaging the rack. This pinion is rotated through 85' means of a shaft 85 which extends exteriorly of the crank case and carries an arm 86 which can be actuated through suitablemechanism extending to a point adjacent the pilot. Rotation of the shaft 85 will transmit rotation to the ring 19 70 which through the instrumentality oi the links 80 will adjust and position the large end 01' the push rod sections 14 longitudinally of the undercut groove in the rock levers 18. This curved arrangement or the groove 18 is of a character II such that adjustment of the push rod sections 14 therewith will vary the stroke imparted to the rod valves 6| when the rock levers are moved outwardly through contact of the cam lobes therewith, and in this way the timing of the cut off of the ports 62 can be regulated relative to the stroke of the plungers 58, and thus the timing and the quantity of the liquid fuel charges projecting from the nozzles can be regulated.

The push rod sections I2 are provided with adjustable extensions 88 exteriorly of the crank case which engage the members 56 and are retained by lock nuts 90. The push rod sections II have extensions 92 screwed into their exterior ends which are retained in adjusted position by the lock nuts 9|. The guide bearings 66 are formed with undercut slots to detachably receive the heads 93 of the extensions 92.

As before stated, the engine illustrated is of the four cycle type. Air is drawn into the cylinders during the suction stroke of the pistons 89 after which the valves are closed and there is a compression stroke, and during the later portion'of the compression strokes the liquid fuel charges are injected into the interior of the cylinders and explosion takes place due to the heat of compression. The power stroke follows the ignition of the fuel charge after which the valves open and the exhaust strokes take place. The air drawn into the cylinder during the suction strokes will be rotated due to the relation of the passages with the interior of the cylinder and will continue to rotate during the compression strokes so that fuel charges injected into the cylinders will penetrate substantially to the axis of the rotating mass of air and will be uniformly distributed therein upon one revolution of the compressed air.

When the rock levers are moved outwardly through the contact therewith by the cam, the associated push rod structures are moved simultaneously toward the associated nozzle, and so long as the reduced portions 61 of the valves overlie the ports 64 and the passages 62 the liquid fuel in the barrels will be r'eturne'dto the conduit sections. When the valves 6| reach a point where they close the passages 62, which is prior to the time that the plungers 58 close the passages 62, then pressure will be placed upon the fuel in the nozzles and in the barrels so that fuel charges will be projected from the nozzles into the cylinders under high pressure. The time, therefore, at

which fuel is projected from the nozzles relative to the compression stroke in the associated engine cylinder is determined by the time at'which the valves 6| close the passages 62, and the quantity of fuel injected into the cylinders is determined by the stroke of the plungers 58 after the passages 62 have been closed. Therefore, by

adjusting the stroke of the valves relative to the stroke of the associated plunger, both the timing and the quantity in the charges injected can be regulated. Movement of the push rod sections 14 lengthwise of the undercut groove 18 in the rock levers will adjust the stroke of the valves 6| so that the timing of their closing relation with the passages 62 can be regulated relative to the stroke of the plungers 58, and consequently through adjustment of the ring 19 both the timing and the quantity of the fuel injections can be regulated. It will be seen that the stroke of the plunger is uniform at all times and that the fuel charge regulation is controlled entirely through the valves 6]. The cam 29 is driven at one-eighth crank shaft speed, and as there are nine cylinders and four cam lobes, there will be an injection from each of the fuel devices every two revolutions of the crank shaft. Operation of the ring and movement of the push rod sections 10 14 relative to the rock levers can be accomplished with a very slight amount of efiort on the part of the pilot and, therefore, regulation of the fuel charges requires very little effort and can be readily made. 15

While I have herein described in some detail a specific embodiment of my invention, which I deem to'be new and advantageous and may specifically claim, I do not desire it to be understood that my 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 my invention.

What I claim is:

1. Fuel injection mechanism for internal combustion engines comprising a plurality of pump barrels each having a constant stroke plunger therein, a spring urging each plunger away from the outlet of the associated barrel, a push rod for each plunger, a housing adjacent each barrel having a fuel feeding passage therein, a balanced slidable valve mounted in each housing to control the flow offuel therethrough, said valves being unbiased by springs, a push rod associated with each valve, a rock lever for actuating each set of valve and pump plunger push rods, an engine driven cam for tripping the rock levers, a control means connected to the valve push rods, and means for adjusting the control means, the movement of said control means changing the position of the valve push rods similarly and simultaneously to vary theclosing time of the valves relative to the injection strokes of the plungers.

2. Fuel injection mechanism for internal com- 4 bustion engines comprising a plurality of pump barrels each having a constant stroke plunger therein, a spring urging each plunger away from the outlet of the associated barrel, a push rod for each plunger, a housing adjacent each barrel having a fuel feeding passage therein, a balanced slidable valve mounted in each housing to control the flow of fuel therethrough, said valves being unbiased by springs, an articulated push rod connected with each valve, a rock lever for actuating each set of valve and plunger push rods, an engine driven cam for tripping the rock levers, a control ring, links pivotally connected to the control ring and to the valve push rod sections associated with the rock levers, and re- 9 motely extending means for rotating and positioning the ring, the rotation of said ring changing the position of the valve push rod sections attached thereto similarly and simultaneously to vary the stroke of the valves and their time of 35 closing relative to the injection strokes of the plungers.

. HERBERT C. EDWARDS.

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