US2032755A - High compression engine - Google Patents

Description

March 3, 1936. JOHNSTON 2,032,755

HIGH COMPRESSION ENGINE Filed Aug. 19, 1931 4 Sheets-Sheet l Ira/@2507 [Vim/a J .j Aim, J fl March 3,v 1936. E. A. JOHNSTON HIGH COMPRESSION ENGINE Filed Aug. 19', 1951 4 Sheets-Sheet 2 March 3, 1936. E. A. JOHNSTON HIGH COMPRESSION ENGINE 4 Sheets-Sheet 3 Filed Aug. 19, 1931 IZZY/6261207 March 3, 1936. E. A. JOHNSTON HIGH COMPRESSION ENGINE Filed Aug. 19, 1931 4 Sheets-Sheet 4 Patented. Mar. 3, 1936 UNITED STATES nIGnooMeREssIoN ENGINE Edward A. Johnston, Chicago, 111., assi'gnor to International Harvester Company, a corporation of New Jersey Application August 19, 1931, Serial No. 557,397

9 Claims.

This invention relates to a high compression internal combustion engine.

More specifically it relates to a means for starting an engine of the compression ignition type.

The principalobject of the invention is to provide means for starting a compression ignition engine by first operating the engine for a short time on a volatile mixture cycle and subsequently automatically shifting to high compression with oil injection and compression ignition.

A more specific object is to provide mechanically operated means, actuated by the rotation of the engine to automatically increase the compression of the engine after a predetermined number of revolutions. Other objects will be apparent from the detailed description to follow..

The objects of the invention are accomplished by a construction and arrangement of parts such as illustrated in the drawings. A reducing gear train is operatively connected to the crank shaft of an engine and to a trip device which is automatically released after a predetermined number of revolutions of the engine. The trip device is connected to a valve operating mechanism operable to actuate a valve controlling communication between the main combustion space of an engine and an auxiliary compression space. The auxiliary compression space or chamber is provided with spark ignition means and a carburetor is provided for furnishing volatile mixture to the engine when it is operating on the Otto cycle on comparatively low compression.

In the drawings:

Figure 1 is an elevation of a high compression engine showing, in addition to the usual fuel pump and oil lines, the trip device of the invention and the means by which it is operated;

Figure 2 is a sectional view on an enlarged scale, showing the gearing of the trip actuating mechanism and details of the trip mechanism;

Figure 3 shows a carburetor for the volatile mixture cycle and the valve for shifting from said carburetor to an air intake for operation on a compression ignition cycle;

Figure 4 is a plan view of the latch for the trip mechanism;

Figure 5 is a sectional view through the head of the engine, showing a particular mechanism for operating the valves controlling communication between the main combustion chambers and .the auxiliary compression chambers; and

Figure 6 is an end view of the engine with, certain parts in section to show the connection between the trip mechanism and the valve operating mechanism; also showing the means for shifting from' the volatile mixture inlet to an air inlet. In the drawings Figure 1 shows the exterior parts of a compression ignition oil engine, commonly known as 2. Diesel engine. An oil pump 10 operated by drive connections ll delivers fuel I through oil lines 12 to the individual cylinders of the engine in proper amounts. Said pump is provided with a governor. 13. The drive connections II are operated from the crank shaft of the engine through gears contained in the housing l4. The drive connections include a shaft 15, as shown in Figure 2, which drives a vertical extending shaft 16 arranged at right angles thereto. The shaft 16 is carried in suitable bearings in a housing 11, secured to a housing I8 surrounding the shaft 15 and secured to the housing 14. The shaft I6 carries a worm l6 operatively engaging a worm gear 19 mounted on a shaft 20 extending at right angles to the shaft Hi. The shaft 20 carries a worm 2| operatively engaging a worm gear 22 formed on and integral with a sleeve 23. Said sleeve is freely rotatable on a vertically extending shaft 24. The shaft 24 is rotatably mounted in a bearing formed below the gear 22 in the housing 11. The upper end of the sleeve 23 is formed with a plurality of ratchet teeth 25. Said teeth are shaped to provide for transmitting a small amount of power in one direction and to provide a slip clutch action when the torque exceeds a predetermined amount, to similar teeth 25 formed on a sleeve 21 rigidly mounted on the shaft 24. The shaft 24 extends vertically upwardly. An enclosing housing 28 surrounds said shaft and is provided with a portion 29, extending into the housing I! and providing a bearing for the upper-portion of the sleeve 23. The housing 28 is secured by catch screws 30 to the housing I1. The upper portion of the housing 28 is spaced from the shaft 24, thereby providing a recess 3| annular in cross section, in which a spring 32 is positioned. Said spring is seated against the bottom of the recess and abuts at the top a member 33, which is secured to the top of the shaft 24 against rotation with respect thereto. Said member is formed with a fiat upper face 34, as best shown in Figure 4. A notch 35 extends substantially radially to the member 34 and axially completely through said member. The member is spaced some distance above the top of the housing 23 and a notch 36 is formed in said housing at one position to provide a considerable space below the bottom of the member 34 for a purpose to be hereinafter described.

A bracket 31 is rigidly securedto one portion of the cylinder head 38. A lever 39 is pivoted intermediate its ends on a transverse axis on said bracket. One end of said lever extends over the member 33 with the narrow end portion 49 normally, seated on the surface 34 formed on said member. The end portion 40 is somewhat narrower than the slot 35 whereby said end portion will slide vertically therethrough when the slot comes into vertical alignment therewith. The end portion 49 has a vertical thickness less than the distance between the bottom of the member 33 and the bottom of the slot 36, whereby aftersaid end portion has passed through the slot'it will not thereafter engage the memher.

A rigid, downwardly extending bracket 4| is secured to the lever 39 near the end portion 40. A strong tension spring 42 is secured at one end to the lower end of the bracket 4|. At its other end the spring 42 is secured to a lever arm 43 integral with a member 44. The member 44 is keyed to a rotatable shaft 45. Said member is provided with a handle 46 for manual operation, and a lug 41, which is shaped and positioned to engage a notch 48 formed in an end of the lever 39.

The shaft 45 extends transversely above the cylinder head of the engine, as best shown in Figure 6. Said shaft is suitably supported in bearings. Asmall portion of a worm 49 is cut on the shaft intermediate its ends. Said worm engages a worm 56 non-rotatably mounted on a shaft 56 extending longitudinally of the engine above the cylinder head. As shown in Figure 5, cams 5| are mounted on said shaft. One of these cams is positioned for operating the mechanism of each cylinder which is exactly similar in construction.

The essential parts of a conventional compression ignition oil engine are shown in Figure 5. A

piston 52 is operated in a cylinder 53. A cylinder head 54, cored to provide water circulation passageways, is mounted above the cylinder 53 in the usual manner. Said cylinder head is also provided with bores 55 into which auxiliary combustion chambers 56 are fitted. Said combustion chambers are fitted at their upper ends with oil delivery nozzles 51. An oil feed line 58 connects with each of the fuel nozzles. The cylinder head 54 is also formed with auxiliary compression chambers 59. Said chambers communicate with the main combustion chamber formed by the cylinder of the engine by means of a passageway 66 formed in the' cylinder head. The passageway 60 communicates with the maincombustion chamber through aneck portion 6|, circular in cross section. A conical valve seat 62 is formed on the cylinder side of said neck portion. A pocket valve 63, having a head 64'formed with a conical seat 65 is positioned with said seat in engagement with the seat 62. Said valve has a stem 66 extending vertically through the upper wall forming the passage 60. The cylinder head is so formed as to provide -a vertical bore 61 of a substantial length from the point where the valve passes through the wall of the passage 60 to the top of the cylinder head. A sleeve 68, rigidly secured to the valve stem 69 for movement therewith, slidably fits into a bore 61. At the end of said bore a conical seat 69 is formed. A

similar seat 10, formed on the bottom of the sleeve 68, is engageable with the seat 69 to form a gas tight seal. A recess 1| is formed in the top of the cylinder head concentric with respect to the bore 61. A sleeve 12, fitted in said recess,

at its upper end abuts against a flange 14 formed on a member 15 rigidly secured to the valve stem 66. The upper surface of the member 15 forms a seat for an actuating member 16. The other end of said member engages a member 11 slidably mounted on a stud 18 threaded into the cylinder head. Said stud is spaced from the valve stem 66 and is substantially parallel thereto. A compression spring 19, considerably stronger than the spring 13, is seated in a recess formed around the stud 18 and abuts against the lower side of the member 11. A pin through the stud 18 above the member 16, limits the upward displacement of that end of said member. The cam 5| operatively engages the actuating member 16 intermediate its ends.

The remaining parts shown in Figure 6 are conventional elements found in all internal combustion engines utilizing valve-in-head construction. The rocker arm 8| is actuated by the push rod 82 to operate the valve 83. These elements have not been shown in detail as they are not a part of the present invention.

one end with the manifold and having a cover-,

ing plate at the other end. The shaft 81 extends axially through the cylindrical portion 89. 'A barrel valve 9| is mounted on said shaft. Said 'valve is constructed to close either an air inlet 92 communicating with one side of the cylindrical portion 89, or a mixture inlet 93 communicating with the bottom of said cylindrical portion. In Figure 4 the valve is shown in position with the volatile mixture inlet cut off and the air inlet in communication with the manifold for operating as a Diesel engine. A small carburetor 94, having a fuel inlet 95 and air inlet 96, furnishes the volatile mixture when operating the engine on low compression.

In the operation of the particular embodiment of this invention, above described. the handle 46 is rotated against the tension of spring 42,

thereby rotating, through the shaft 45 and the worm 49, the worm gear 50 and the shaft 58 on which said gear is rigidly mounted. The cam 5| also carried by the shaft 59', is rotated downwardly in the direction indicated by the arrow in Figure 5. Said cam engages the actuating member 16, thereby moving the end over the valve 63 downwardly. This action is due to the fact Said shaft that the spring 19 is stronger than the spring 13. Said movement continues opening the valve 63 until the seat 10 formed on the sleeve 68 engages the seat 69. This forms a positive stop. Further rotation of the cam 5| compresses the spring 19. By this construction a positive seating of the sleeve 68 is always assured and it is held in position by the force necessary to compress the spring 19.. As it would obviously be dif ficult to make any construction for a plurality of valves as used in a multiple cylinder engine, of such accuracy as to positively seat a valve and assure the proper pressure, this construction has been utilized to great advantage.

With all the valves 63 of the engine in open position, the volume of the passage 69 and the individual auxiliary compression chambers 59 is such that compression in the engine will be about the ratio ordinarily used for the volatile mixture cycle. The engine is then turned over by a hand crank or by other suitable means. It will be noted that the linkage connecting the shaft 45 with the valve 9| is such that when the valves 63 are in open position the valve 9| will close off the air inlet 32. Upon rotation of the engine air will be drawn in through the inlet 96, forming a combustionable mixture in the carburetor 95 and pass ing through the intake manifold 88 into the engine. pression chambers 59 are provided with a time source of electricity by an ignition system as commonly employed on internal combustion engines. The engine will start and operate on the volatile mixture cycle.

When the handle 46 is moved to rotate the shaft 45, as previously described, the lug 41 is brought into engagement with the notch 48 formed at the end of the lever 39. The spring 42 then acts to hold said lug in said notch. The end portion 40 at the other end of the lever 39 is lifted byhand and seated on the member 33 as the handle 46 is being turned. Due to the ratchet teeth 25 and 26 the member 33 may be turned by hand to any desired position, that is, it may be turned to lift the end portion 40 through the slot 35 and subsequently turn so that the said end portion will seat on the surface 34. Through the shaft l which is operated by and with the crank shaft of the engine and through .the reducing gearing,

the member 33 is rotated very slowly. It has been found that under ordinary conditions the engine will be warm enough and have attained suflicient momentum to run compression ignition, utilizing oil as fuel, after about 600 revolutions. The gearing has, therefore, been designed so that the member 33 will move approximately 360 degrees during 600 revolutions of the engine crank shaft. As shown in Figure 4, after the member 33 has moved in the direction indicated by the arrow one revolution, the end portion 49 will come into align-- ment with the slot 35 and will drop therethrough. At the same time the tilting movement of the lever 39 releases the notch 48 from the lug 41. The spring 42 then rotates the member 44 and the shaft 45, whereby, through the gear arrangement previously described in detail, the cams 5| are lifted. The valves 63 immediately seat, cutting off the communication between the auxiliary compression chamber and the main combustion chamber. The compression ratio is thereby increased to that necessary for operation as a compression ignition engine. Oil is delivered through the nozzles 51 and the engine is then operated as a so-called Diesel engine.

In the drawings and the description the particular means for cutting dill] the ignition and for beginning the delivery of fuel oil, have not been shown and described. Such'means could be accomplished by a variety of constructions well known in the art. The principal object of this invention is to provide means for automatically shifting from low compression to high compression aftera predetermined number of revolutions.

The volatile mixture supply means cannot obviously be allowed to function after the engine is in operation on compression ignition as the fuel supplied by such a mixture would fire too early in The spark plugs positioned in the com-' the compression stroke. The link 85 automatically operates the valve 9| to open the air inlet 92 and to close the inlet to the carburetor 94 when the shaft 45 rotates to lift the cams 5|.

It is to be understood that applicant has shown and described only a preferred embodiment of his improved means for starting high compression engines and that he claims as his invention all modifications falling within the scope of the appended claims.

What is claimed is:

1. In a high compression internal combustion engine the combination of means operable to lower the compression for starting, and engine actuated means to increase the compression after a predetermined number of revolutions of the engine.

means actuated by the engine to close communication between said chambers after a predetermined number of revolutions of the engine.

4. In an internal combustion engine the combination of a combustion chamber, air inlet and exhaust outlet means, an auxiliary compression chamber in communication with the combustion chamber, a valve operable to close communication between said chambers, means for initially opening the valve thereby reducing the compression in the combustion chamber, means for supplying a volatile fuel to the air inlet and for igniting said fuel whereby the engine may be run on a volatile mixture at low compression, and means actuated by the rotation of the engine to close the auxiliary compression chamber and. to cut off the supply of volatile fuel after a predetermined number of revolutions of the engine.

5. In a high compression oil burning engine having a combustion chamber, an air inlet communicating with said chamber, inlet and exhaust valves, and means for supplying oil to the combustion chamber, means for starting comprising an auxiliary compression chamber in communication with the combustion chamber, a valve operable to open and close said chamber, spark ignition means in said chamber, means for opening the valve thereby reducing the compression in the combustion chamber, means for supplying a volatile fuel to theair inlet whereby the engine may be operated on a volatile mixture cycle at means actuated by the engine to indicate a predetermined number of revolutions of engine op eration after starting, and means actuated by said control means to shift from the lower compression to the high compression upon completion of said indicated number of revolutions.

8. In an internal combustion engine, the combination of means for operating the engine on a volatile mixture with spark ignition and low compression, means for operating the engine on high compression with non-volatile fuel and compression ignition, means for shifting from one form of operation to the other, and control means for the shifting means comprising a delayed action tripping element mechanically actuated by the engine during operation on low compression and moving in timed relation' to the revolutions thereof.

9. In an internal combustion engine, the com- .bination of means for operating the engine on a volatile mixture with spark ignition and low compression, means for operating the engine on high compression with non-volatile fuel and compression ignition, means for shifting from one form of operation to the other, and control means on the shifting means comprising a rotating tripping element mechanically actuated by the engine while operating on low compression and effective to operate the shifting means after op'- eration of the engine for a limited number of revolutions. 4 EDWARD A. JOHNSTON.

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