US1938275A

US1938275A - Internal combustion engine

Info

Publication number: US1938275A
Application number: US486215A
Authority: US
Inventors: Emma F Woolson
Original assignee: Packard Motor Car Co
Current assignee: Packard Motor Car Co
Priority date: 1930-10-03
Filing date: 1930-10-03
Publication date: 1933-12-05
Anticipated expiration: 1950-12-05

Description

Dec. 5, 1933.

L. M. WOOLSON 1,938,275

INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 1 Filed Oct. 3, 1930 Zia-fl .L/ONEL M MoLso/v, 0565/7550 5) H/s sxecune/x Dec, 5, 1933. M. WOOLSON INTERNAL COMBUSTION ENGINE Filed Oct. 3, 1930 2 Sheets-Sheet 2 An mu Patented Dec. 5, 1933 INTERNAL COIMBUSTION ENGINE Lionel l-vi. Wcolson, deceased, late of Detroit,

Micln,

by Emma F. Woolson,

executrix,

Bloomfield Village, Mich, assignor to Packard Motor Car Company, Detroit, Mich, a. corporation of Michigan Application October 3, 1930. Serial No. 486,215

13 Claims.

This invention relates to internal combustion engines and more particularly to engines of the oil injection, compression-ignition type.

One manner of forming fuel charges in engines, oi the type specified, is to project atomized oil under pressure into compressed air charges, rotating in the combustion chambers, by devices which are actuated in accordance with the engine speed. When the atomization of the oil charges and their penetration of the air charges depend upon the engine speed, it will be seen that while starting and idling there will be less pressure and atomization of the oil charges than when the engine is running under load. I have found that when the injection devices are set to inject the necessary fuel charge for slow engine operation, then the pressure developed for injection is inadequate to produce atomization and air penetration necessary to form a mixture with the air which will ignite in low temperature conditions and which will ignite in starting regardless of temperature conditions except after continued efiort.

An object of this invention is to provide a corn pression-ignition engine with mechanism, driven from a moving part thereof, which will inject oil charges into compressed air in the cylinders under a pressure requsite to produce a mixture which will ignite under compression in the cylinders at any engine R.P.M.

Another object of the invention is to provide a compression-ignition engine with a pair of fuel injection pump actuating mechanisms, operated from the engine at two different speeds, one of which is automatically made effective to produce pressure on the injected oil which is greater rel ative to the engine R.P.M. when the engine is in its low speed range.

. A further object of the invention is to provide automatically controlled mechanism for actuating fuel pumps of 2. Diesel engine to produce a higher pressure upon the injected oil charges relative to the engine R.P.M. when turning in the slower speed range than when turning in the higher speed range.

Still another object of the invention is to provide a new and novel mechanism for driving a fuel pump actuating camfrom the crank shaft of a Diesel type of engine which automatically varies the cam position angularly with respect to the crank shaft.

These and other objects of the invention will appear from the following description taken in connection with drawings, which form a part of this specification, and in which:

Fig. 1 is a rear elevational view of an engine, artly broken away and partly in section to show fuel injection device and the actuating mechaism therefor.

Fig. 2 is a similar fragmentary view showing the cam with the drive mechanism ina position for slow engine operation.

Fig. 3 is a fragmentary sectional view taken on 3-3 of Fig. 1.

Fig. 4 is a sectional view of one of the fuel 5 injection nozzles applied to a fragment of a cylinder.

Fig. 5 is a sectional view taken on a line 55 of Fig. 6 with the governorweights removed.

Fig. 6 is a sectional view taken on line 66 of Fi 3.

Referring now to the drawings by characters of reference, 10 represents the crank case of a four-cycle internal combustion engine, of the compression-ignition type, from which a plurality of cylinders 11 extend radially. Flanges, as indicated at 12, extend diametrically from the cylinders and bear against the exterior casing wall, a pair of compression bands 13 extending around such flanges and being arranged to place the crank case under compression as well as securing the cylinders in position.

Each cylinder head is provided, preferably, with a single Venturi passage 14 which is arranged to extend angularly of the cylinder axis and tangen- 35 tially of the inner wall thereof. Such passages each provide an inlet through which air is drawn into the cylinders by the pistons 15 and through which the exhaust passes during the exhaust stroke of the pistons. In order to close the passages during the compression and working strokes of the pistons, I provide a valve 15 which is actuated by mechanism extending through the

housings

16 and 17 and into the compartment 17 and in the crank case. Such mechanism includes an articulated rod 18 and a valve engaging lever as indicated at 19. Coiled springs 20 are associated with the valves to normally maintain them closed during the suction and compression strokes of the piston.

The diaphragm wall 21 is arranged internally of the crank case in the same vertical plane with the rear compression ring and is provided with a bearing 22 for the reception of one end of the crank shaft 23. The rear cover member 24 is secured to the rear end of the crank case by bolts 25, and intermediate the diaphragm and the rear cover is formed the compartment 1'7 for the reception of crank shaft driven mechanisms for actuating the air valve operating devices and the fuel injection devices. A conventional form of connecting rod structure is associated with the crank shaft 23 and with the pistons 15..

An individual fuel injection device is associated preferably with each cylinder and each consists generally of a nozzle portion 26 and a pump section 27. The nozzle section includes the casing 28 having an axially extending passage therein and a removable end portion 29 which projects into an aperture in the wall of the cylinder, the end of the section 29 being flared at its inner end, as indicated at 30, for association with the head 31 of the valve which lies within the axial passage in the casing. A stop member 32 is associated with the nozzle casing and limits the closing movement of the valve so that the head will not contact with the flared outlet wall 30 of the casing end section, and a coiled spring 33 is associated with the valve, within the passage in the casing,

so that it normally urges the valve in the direction tending to substantially close the nozzle outlet passage.

The pump section of the injection device includes a tubular casing 34, one end which is screwed upon a depending neck portion of the nozzle casing and a plunger barrel 35 which is carried within the pump casing by a shoulder at one end which is clamped in position by a spacer 36 when the nozzle and pump casings are screwed together. The barrel, spacer and nozzle neck are provided with a passage which communicates with the axially extending passage in the nozzle casing, and a pair of check valves 37 are arranged in such passageways to prevent the return of oil from the nozzle to the pump barrel. A ring member 38 is wedged into leak proof relation with shoulders projecting from the pump casing by the nut 39, and the space intermediate the ring member and the pump casing flanges provide a circular chamber into which fuel oil is introduced, such spaces being connected by conduit sections 40 and forming therewith a fuel feeding manifold. The pump casing and the barrel are provided with a plurality of aligned ports 41 which establish communication between the feeding chambers and the interior of the plunger barrels 35. Oil in the manifold is circulated by means of a low pressure pump (not shown) of any conventional form.

The pump plungers 42 terminate in heads 42' which are guided by the interior wall of the pump are pivotallysecured to links 46 which in turn are pivotaly secured to an adjustment ring 47, such ring being held against the diaphragm 21 by a plurality of bolts 48. The ring 4'7 is provided with circularly extending slots to permit limited rotation thereof so that the angular position of the rods 45 can be varied. The inner ends of the rods 45 are associated with a curved surface formed in the free end of slippers 49 which are pivotally mounted on shaft 50 carried by the dia- 5 phragm 21 and the end cover 24. Slippers 51 are also pivotally carried by the'shafts 50, adjacent to slippers 49, and their free end is arranged to receive the inner end of the valve mechanism operating rods 18.

Mechanism is associated with the crank shaft for actuating the injection devices and the valve opening devices. A single lobe cam 52 is mounted upon the rear end of the crank shaft adjacent the bearing 22 and is provided with elongated hub 53 keyed to the crank shaft and upon which a dual cam 54 is rotatably mounted. This dual cam is provided with two sets of parallel lobes and each set preferably includes four equally spaced lobes, the pump actuating lobes being indicated at 54 and the valve actuating lobes being indicated at 55. The cam 52 will rotate with the crank shaft, and I provide mechanism driven from the crank shaft for rotating the dual cam at a greatly reduced speed. The rear end of the crank shaft is reduced and the control member 55 telescopes such end of the crank shaft and is keyed thereto. This control member is provided with an elongated hub over which the gear 57 telescopes and is held in position axially by the starter jaw 58 which is secured to the crank shaft by the stud 59 and the nut 69. A gear 61 meshes with the gear 5''! and is carried upon one end of a shaft 62 suitably supported within the crank case, whil a gear 63 is fixed to the other end of the shaft 62 and is arranged in a plane to mesh with the internal gear 64 of the dual cam. The train of gears just described are formed to rotate the dual cam preferably at the crank shaft speed and in a reverse direction relative to the rotation thereof, thus it will be seen that the two came 52 and 54 are driven at different speeds and in opposite directions.

' With the drive mechanism for the dual cam describedl associate automatic control mechanisni'by means of which the angular relation of the dual cam 54 can be varied with respect to the crank shaft. To this end the gear 57 is provided with elongated slots 65 through which a plurality of pairs of legs 66 of the control member extend, and a weight member 6'7 is pivotally mounted upon a shaft 68 extending across and secured to each of such pair of legs. The inner end of such pivoted weight members are each formed to provide a gear segment 69 which mesh with the gear 57. Coil springs 70 are secured at one end to each of the weight members and at their other end to the base of one of the legs to which the adjacent weight member is pivoted.

It will be seen that the gear 57 is rotated through its association with the control member 56 which is keyed to the crank shaftand that centrifugal force will cause the weight members to move outwardly so that the gear sections thereof will rotate the gear 57 independently of the crank shaft rotation, within a limit defined by theends of the slots 65; The springs '70 normally maintain the weight members in such a position that the gear 57 will be angularly related to the crank shaft to cause the cam 52 to be rotated in effective relation.-

Looking at the rear end of the engine, the cam 54 rotates in a counter clockwise direction while the cam 52 rotates in a clockwise direction. The cam 52, being fixed to the crank shaft, will rotate eight times as' fast as the cam 54, and the single lobe on the cam 52 and the four cam lobes 54' are arranged so that they will cause lifting of the slippers 49 when they pass thereunder, depending on which is effective, and this raising of the slippers will cause the rods 45 and 43 to transmit movement to the pump plungers to cause injection strokes thereof. A coil spring '71 is provided within each of the pump casings to normally move the pump plunger actuating rods and slippers towards the base circle of the actuating cams. The plungers 42 cause injections of fuel oil directly into the compressed air in the cylinders commencing immediately after they are moved to a position where they close the ports ll, and the stroke beyond the port closure posi- ,1

tion determines the quantity of fuel displaced from the nozzle, so that by'regulating the :an'gular position of the rods 45, through rotation of the ring 47, the effective lengthof the plunger strokes can be regulated. A shaft 72 extends through the :crank case and is provided with a gear sector '73 upon .its inner end, such sector meshing with a rack 74 fixed to the regulating ring 47. Suitable means can be associated with the shaft arm for rotating the same and thereby regulating the position of the ring It is through such regulating mechanism that the fuel charge is determined, and "it will be understood that when the plunger stroke is such that it does not close the ponts 41 then the engine will cease to operate.

The

cams

52 and 54 are associated with the crank shaft and with each -other so that their lobes will shield one another from engagement with the fuel slippers depending upon which is in effective position. As shown-in Fig. 2, the faster :cam 52 is in effective position so that it actuates the slippers 49 in advance of the lobes 54' on the cam 54, while in 'Fig. -l the slow cam '54 is in effective position to actuate the slippers in advance of the lobe on the 52. The lobes are 'of such length and aretimed so that the effective cam will hold the slipper-s in a raised position until the other cam passes the actuating relation therewith.

Normally, the springs 10 maintain the weigh-t members in their inward position which places the control member in a position such that the fast cam is eifective, but when the crank shaft speed is such that centrifugal force moves the weight members outwardly, then the control member is moved to a position placing the slower cam in effective position. The spring tension can be regulated as desired, but in the present instance I prefer that it be regulated so that the fast cam is effective below the R. P. M. required to sustain an airship in flight. The rotation of the control member relative to the crank shaft is limited by the length of the slots 65 through which the pairs of legs extend, thus determining the degree to which the cam 54 can be shifted relative to the fixed cam 52.

It will be seen that I have provided mechanism for automatically changing the angular relation of the slow moving actuating cam relative to the crank shaft so that it will be effective above a predetermined crank shaft speed and the faster moving cam will be effective below the predetermined speed, and in this manner irrespective of the crank shaft speed the fuel charges will be injected into the rotating compressed air in the combustion chambers under a pressure and an atomization to form a mixture which will be readily ignited by compression. While I illustrated the slow moving cam as being controlled by centrifugal force, various other mechanisms can be associated therewith for performing the same duty.

Although the invention has been described in connection with a certain specific embodiment,

' the principles involved are susceptible of numerous other applications, as will readily occur to persons skilled in the art and the invention is therefore to be limited only as indicated by the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patout is:

l. In an engine, a liquid fuel injection device includ ng a plunger, mechanism connected to cause reciprocation of the plunger, a pair of mutated cams arranged to actuate the mechanism to cause injection strokes of the plunger and disposed angularly so that the leading one masks the other, engine driven means for rotating the cams "in opposite directions and at difierent speeds relatively, and automatic means associat- -ed with the mechanism for driving the slower cam, said means being actuated below a predetermined engine speed to angularly shift the slow speedcarn to make it ineffective.

2. In an engine, a liquid fuel injection device including 'a plunger, mechanism associated to reciprocate the plunger, a pair of independen means driven at relatively different speeds by the engine for actuating the mechanism, said means being-disposed so that the one in advance shields the plunger actuating mechanism from the othe speed controlled means for automatically placing the slower driven means in leading 'or fol-lowing relation, said slower driving -means being ineffective in the slow speed range of the engine and effective in the high speed rangeof the engine. a

8. ln an engine, a liquid fuel injection device including a plunger, mechanism associated to reciprocate the plunger, a pair of independent means driven at relatively different speeds by the engine for actuating the mechanism and related so that the leading means shields the plunger actuating mechanism from the other actuating means, and means responsive to centrifugal force for shifting the slower driven means into the effective and ineffective relation.

4. In an engine, a liquid fuel injection device including a plunger, mechanism connectedto actuate the plunger, a single lobe cam rotated with the engine crank shaft for actuating the chanism to cause plunger injection strokes, multiple lobe cam rotated by the engine for -actuating the mechanism to cause plunger injection strokes, said single lobe cam operating at a multiples-peed relative to that at which' the other cam is rotated, the leading cam shielding the other from the plunger actuating mechanism, and speed responsive means for shifting the said multiple lobe earn so that it rotates in a leading position above a predetermined engine speed and in a following position below such predetermined engine speed.

5. In an engine, a liquid fuel injection device including a plunger, mechanism connected to actuate the plunger, a pair of separate cams engageable with the mechanism to cause plunger injection strokes, means driven from the engine rotating the cams so that the speed of one is a multiple of the other, said cams being timed so that the leading one engages the mechanism ahead of the other and holds it lifted until the actuating portion of the other cam passes thereunder, and means responsive to the speed of the engine crank shaft for changing the relation of the cam rotating means to place such cam either in a leading or following relation relative to the other cam.

6. In an engine, a liquid injection device including a pump plunger the stroke of which determines the quantity and pressure at which the fuel charges are delivered, mechanism associated to reciprocate the plunger including separate cams, the leading cam shielding the plunger from the other cam, a crank shaft to which one of the cams is fixed, reduction gearing between the shaft and the other cam, and means responsive to centrifugal force for shifting the angular relation of the reduction gearing whereby the slow cam is placed in a leading or following relation to the faster cam.

7. In a Diesel engine, a fuel injection device including a pump plunger, mechanism associated to reciprocate the plunger including a pair of cams, a crank shaft having one of the cams fixed thereto, a control device fixed to the crank shaft, and reduction gearing driven by the control memher and arranged to rotate the other cam, said control device including pivoted weighted extensions having gear segments connected with the reduction gearing and responsive to centrifugal force.

8. In an internal combustion engine, a liquid fuel injection device including a pump plunger, mechanism associated to reciprocate the plunger including a pair of cams relatively associated so that the leading one shields the mechanism from the other one, a crank sha t to which one of said cams is fixed, acontrol device fixed upon the crank shaft, reduction gearing driving the other cam, said control device including a plurality of pivoted members having gear segments at their inner ends meshing with a gear of the reduction gearing, and springs urging the pivoted members in a direction in which the cam driven thereby will be placed in ineffective position, said members being moved above a predetermined speed by centrifugal force to cause the associated cam to be driven effectively.

9. In an engine, a liquid fuel injection device including a pressure producing plunger; and mechanism for actuating the pressure producing plunger including a pair of cams driven at relatively different speeds from a rotating part of the engine, the leading cam masking the other cam, and speed responsive means for automatically shifting the slower cam into ineffective position below a predetermined speed of the rotating engine part and into effective position above such speed.

10. In an engine, a liquid fuel injection device including a pressure producing means, mechanism for actuating the pressure producing means including a pair of cams driven at relatively different speeds by the engine, the angular relation of said cams'being such that either one is adapted to mask the other, and speed controlled means associated with the mechanism to automatically adjust the angular relation of the cams so that either one will lead.

11. In an engine, a liquid fuel injection device including pressure producing means, engine driven mechanism foractuating the pressure producing means including a pair of cams adapted to rotate at two different speeds one of which is a multiple of the other and disposed in an angular relation relatively so that the leading cam masks the following cam, and adjustable mechanism for rotating the slower cam including speed con-- trolled means for changing the angular position of the slower cam in accordance with engine speed whereby it leads the faster cam above a predetermined engine speed and follows the faster cam below a predetermined engine speed.

12. In an engine, a liquid fuel injection device including a plunger, mechanism associated to operate the plunger, a pair ofengine driven cams having lobe means associated to actuate the mechanism and cause'injection strokes of the plunger, one of said cams being shiftable into an advanced or retarded position relative to the other cam whereby its lobe means will shield or be shielded by the lobe means of the other cam member with respect to the plunger operating mechanism,,and automatic speed controlled means for shifting said shiftable cam to control its advanced or retarded position relative to the other cam.

13. In an engine, a liquid fuel injection device including a plunger, mechanism for reciprocating the plunger including arock lever, a pair of parallel engine rotated cams associated to actuate the rock lever, said cams being angularly disposed so that the lobe portion of the leading cam masks the lobe portion of the other cam, and speed responsive means associated to shift one of the cams angularly into a leading or following position with respect to the other cam.

EMMAF. WOOLSON, Executrir of the Estate of Lionel M. Woolson, de-

ceased.