US1499145A - Starting of high-compression oil engines - Google Patents

Description

June`24, 1924. 1,499,145 l T.A. BELL STARTING oF mea coMPR/Essrou OIL NGINES i Filed sept.y 4.' 1923 :4f 5922 :a y 6/ @e L 1ra/712562@ Patented June 24, 1924.

UNITED ASTMES 1,499,145 IPATENT OFFICE.

THOMAS A. BELL, OF PARKVILLE, NEAR MELBOURNE, VICTORIA, AUSTRALIA.

STARTING O'F HIGH-COMPRESSION OIL ENGINES.

Application filed September 4, 1923. Serial No. 660,882.

lowing is a specification.

This invention relates to internal combustion oil engines of the relatively high compression type such as those working on the Diesel or semi-Diesel principle in which during normal working combustion is effected whollyor partially by the heat of compression. More particularly the invention refers to the starting of such engines to initiate the necessary heat of compression for normal working. y

Apart from low powered engines which may be started by hand, it is the general practice to start oil engines of the kind indicated by means of compressed air and to change over to the normal Working cycle when the necessary compression is obtained in the engine cylinder. This requires a special air compressor or Istarting reservoir which considerably increases the cost and complexity of the apparatus.

In starting, relatively low compression oil engines such for instance as the type commonly known as kerosene engines, carburetted air fuel is frequently employed the heavier' oil fuel being subsequently intro duced and vaporized by contact with 'a heated surface, in the combustion chamber.

Such engines do not however rely upon the heat of compression to effect ,wimbustion and owing to the relatively low compression no danger is involved in firing the carburetted starting charge at full compression as would be the case with relatively high compression engines.

The present invention aims at starting oil engines of the relatively high compression type with carburetted fuel and spark ignition and to this end it is necessary that the compression in the engine cylinder should be reduced to a suiicient degree during starting voperations to permit of the safe firing of the compressed charge from the carburettor. f

The chief characteristic of the resent invention'consequently resides in discharging portion of the carburetted starting charge of mixture during the compression stroke of the piston during starting operations so that the degree of compression is thus reduced and the carburetted charge may be fired without danger.

This release of part of the starting charge is preferably effected by automatically opening the exhaust valve during the compression stroke as Well as during the exhaust stroke, and such additional opening of the exhaust valve'is conveniently effected by the provision of an auxiliary cam which c is employed only during starting operations and is moved out of operative position when it is desired to change over from the starting cycle to the normal working cycle wherein the cylinder must be closed during the compression stroke.

A further important feature of the invention resides in the provision of a safety device whereby the shifting of the aforesaid cam to discontinue the opening of the exhaust valve during compression cannot be' effected until the carburettor, which supplies the starting charge, has been cutoff from the cylinder and the latter has been opened to the atmosphere to draw in the usual fresh air charge for normal working. It is thus impossible to manipulate the parts to obtain full compression while the engine is operating on the carburettor, such full compression being obtained only when the Carburettor is cut 0H and the parts are in position. to admit fresh air during the suction stroke.

Consequently no danger of firing the carburetted starting charge at excessive pressure is incurred.

Further features of the invention w1ll be evident from the following description and appended claims.

Referring to the drawings which form part of this specification:-

Figure 1 is a part sectional -side elevation of apparatus in accordance w1th the. invention the parts being shown in position for starting.

I lor lu s 23 on the valve casing 3, and

. necte to a tappet rod 24 actuated by a cam to the engine cylinder during starting and atmospheric air during normal running.

Figure 5V is a part sectional plan of Figure 4, and also shows certain of the operative connections whereby manipulation of the fuel control Valve to cut out .the carburettor simultaneously releases a hand lever by movement of which full compression is obtained.

Figure 6 is a plan view of said hand lever and a slotted locking plate carried thereby.

Referring to the drawings the numeral 2 indicates the engine cylinder into the combustion chamber of which carbiiretted fuel or atmospheric air is admitted .by manipulan tion of a fuel control valve illustrated 1n Figures 1 .to 5. This valve preferably includes a hollow casing 3 which may be secured in suitable position on the cylinder head as shown, the valve casing being provided with a gas inlet branch 7 adapted to receive an induction pipe 8 leading from a Carburettor 9. The valve casing 3 also has an air inlet port 11 lopen to the atmosphere.

Rotatably accommodated within the valve casing 3 is a rotary sleeve valve 12, closed at its upper end and opening at its bottom into the engine cylinder. In the wall of this valve are ports 13 and 14 adapted to coincide with the aforesaid gas inlet branch 7 and the air inlet port 11 respectively. When starting the engine this fuel control valve is in the position shown in Figures 4 and 5 so that port 13 registers with the gas inlet branch 7 communicating with the carburettor, while the air inlet port 11 of the valve easing is closed by the vertical wall of the rotary sleeve. When the engine is ruiming on its normal cycle the gas inlet branch 7 is cut 0H" from the interior of the valve casing and the port 14 in sleeve registers with the air inletport 11. Atmospheric air instead oftgasfrom the Carburettor is thus drawn into the cylinder 2 on the suction stroke of the piston.

Seating within a port 15 at the bottom of the valve casing 3 is the usual inlet valve 16 of the poppet type which controls the admission of the carburetted lgas or the atmospheric air as the case may be from the interior of the valve casing 3 to the engine cylinder 2. The stem 17 of this inlet valve 16 may pass through a guide bearing 18 and protrudes upwardly beyond the closed end of the rotary sleeve 12 Where the usual spring 19 is provided to normally retain the head of the valve 16 tightly against its. seating. Said inlet valve 16 may be 'actuated to open during the suction stroke of ,the piston by means of the usual rocker arm 22 .which is intermediately pivoted to a lug con- 26 on the cam shaft 27 thelatter being d'rlven-in the usual manner from the main crank shaft 28 by gears 29 or other suitable means.

Attached to a projection 32 on the rotary valve 12 is a link 31 which is-lexibly connected as by a ball and socket joint 33 to one end of a connecting rod 34 the other end of which may be provided with a similar flexible connection 35 to one arm of a bell crank lever 36. This lever is pivoted as at 37 to a stationary bracket 38 or other convenient part.

Pivoted to the other arm of the bell crank lever 36 is a locking pin 39 which passes through an arcuate slot 4l formed in a locking plate 42. This locking plate is carried by a hand lever 40 pivoted at. 45 to the bracket 38 or other convenient part.. 'The locking pin 39. is capable of vertical n1ovement upon operation of the bell crank lever 36. Formed on the locking pin is a reduced portion or neck 43 which when the pin is in its lowest position, is accommodated by the arcuate slot 41 in the locking plate 42 so that the hand lever 40 may be then moved horizontally about its pivot 45 as hereinafter described. The slot 4l is provided with an enlarged or widened portion 44 (FigureG) to receive the larger diameter of the locking pin 39 in which position the locking pin prevents movement of the locking plate and hand lever 40 for the purposes hereinafter mentioned.

Associated with the abovementioned locking gear is exhaust valve controlling mechanism which may include a sliding member or sleeve 49 Amounted on the cam shaft 27 so as to be capable of axial movement relative thereto, this movement being effected synchronously with the movement of the locking plate 42 and hand lever 40 by means of a projection 51 on said plate orI lever, engaging flanged portions or collars 52 on the sliding sleeve 49. This sliding member also carries two cams 53 and 54 the former cam constituting the usual means of opening the exhaust valve 55 at the beginning of the exhaust stroke while the second cam -54 Constitutes an vauxiliary means to open the exhaust valve during the compression stroke when running on the starting mixture from the Carburettor as before mentioned.

The cams 53 and 54 are mounted close together and are adapted to engage a roller 56 ona rocker arm 57 which operates the exhaust valve. Thus when the enginev is being run on carburetted fuel in starting both cams intermittently actuate the rocker arm 57 so as to open the exhaust valve 55 during the compression as well as the exhaust .stroke of the piston.

By movingthe sleeve 49 axially along the cam shaft 27 the auxiliary leam'54 -is de aligned from the roller 56 and rotates idly withthe cam shaft. This sliding movement of the cams may only be eifected when the reduced portion of the locking pin 39 is in engagement with the arcuate slot 41 and the rotary fuel control valve 12 is Consequently moved to Cut off the Carburettor from the Cylinder. The exhaust cam 53 however still contacts with the roller 56 and causes the exhaust valve to open in the usual manner during the exhaust stroke only.

The usual injection valve controlling the supply of the heavier oil fuel to the Combustion chamber is indicated generally at 61 and the usual 'oil fuel and compressed air supply pipes leading respectively from the oil tank and injection air compressor, to the valve 61 are indicated at 62 and63 respectively. The injection valve is operated in the usual manner by a tappet rod 64 actuated by a cam on the cam shaft.

To start an engine in accordance withthe invention the air injection valve 61'may be rendered inoperative or the supply of oil fuel and compressed air to said valve cut off or other suitable means adopted to prevent admission of the normal working charge into the combustion chamber. The rotary fuel control valve 12 is then moved by hand operation of the connecting rod 34 or lever 36 into the position more clearly shown in Figures 4 and 5. This rotary movement of the valve in relation to the lever 36 being permitted by the flexible connections 33 and 35. In this position ofthe fuel control valve the gaseous starting mixture from the Carburettor is admitted through the inlet branch 7 and port 13 into the interior of the valve casing 3 communication between the latter and the atmosphere being Cut oif by the valve 12 closing the air inlet port 11.

During the suction stroke of the engine Carburetted air is now drawn past the inlet valve 16 into the combustion chamber wherein .it ispartially compressed as hereinafter described and eventually exploded byv the spark plug 66 which may be connected to a magneto (not shown) operated from the cam shaft 27.

It should be particularly noted that when the fuel control valve 12 isin the abovementioned position seen in Figures 4 and 5 the exhaust valve operating Cams 53 and 54 carried by the sliding member 49 are both in position to intermittently actuate the exhaust valve rocker arm 57 and thereby open the exhaust valve 55 during both the Compression and exhaust strokes of the piston. Thus a portion of the carburetted starting charge is discharged from the engine cylinder during the compression stroke and before firing takes place so that the compression is reduced to a sufficient extent to permit of safe combustion of the carburetted Charge. It will also be noted that during.

such starting operations the exhaust operating Cams 53 and 54 are locked against sliding movement on thel cam shaft owing to the compression until the fuel control valve 12 has been moved to cut ofi' the Carburettor and admit atmospheric air to the cylinder,

this movement of-the valve 12 causing theI locking pin 39 to descend and release the c'am shifting hand lever 40 as hereinafter described.

When the enginehas gathered sufficient impetus the fuel control valve 12 isy moved to the right in Figures 3 and15by manipulation of the connecting rod 34 or the bell crank lever 36 so that communication between the Carburettor 9 and the interior of the valve casing 3 is thus Cut olf and the latter is opened to the atmosphere by port 14 of the valve registering with air inlet port 11 of the valve casing so that air only is drawn into the Cylinder durin the suction stroke. This movement o the bell crank lever and fuel control valve has the efl'ect of forcing down the locking pin 39 so that the major diameter thereof 1s disengaged from the widened part 44 of the arcuate slot 41 and the reduced portion or neck 43 of the locking pin is engaged with said slot. The locking plate 42 may now be moved about its pivotal point 45 by 'the operating handle 40 to thereby cause the sliding member 49 to move along the cam shaft 27 to the right in Figures l and 2 so .that the auxiliary or low Compression cam 54 is removed from Contact with the roller 56 of rocker arm 57 and the exhaust valve 55 is consequently opened during the exhaust stroke only by means of the exhaust cam 53.

The parts are now in position for normal working aironly being drawn into the cylinder on the suction stroke and this air being fullycompressed to afford the necessary heat for Combustion of the heavier oil fuel.. This fuel for normal Working may now be supplied to and injected into the engine Cylinder by the injection valve 61 in the usual manner so that the engine may operate on its normal cycle.

The ignition device or spark plug 66 which is provided only to ignite the starting charges, is renderedl inoperatlve 1n anysuitval le manner on Cutting off the supply of carburetted fuel and changing over to full Compression as aforesaid.

It will be evident that various alterations, modifications and/or additions may be' introduced into the particular Construction of the apparatus herein described and illustrated without departing from the spirit and scope of the invention, which it will be seen, may be readily applied toexisting engines and eliminates the necessity of the usual comdiscontinue such reduction of compression after the engine has been started, a manually operated fuel control valve adapted to control the admission. to the cylinder of said carburetted fuel for starting purposes and 'admit atmospheric air for normal WorkiIg, and a safety lockingdevice operably connecting said fuel control valve with said manipulating means to thereby prevent operation of the latter to effect full compression until said fuel control valvehas been moved to cutoff the carburetted fuel supply and admit atmospheric air to the engine cylinder on the suction stroke of the piston for the purpose specified. v

2. Improvements in high compression oil engines consisting-in the combination of means forl supplying a starting charge of carburetted air fuell to the engine cylinder on the suction stroke of the piston, an exhaust valve, an exhaust cam and an auxiliary cam adapted to open said valve during the exhaust stroke and compression stroke respectively, hand operated means to move said auxiliary cam out of action When the engine has been started, a manually operated fuel control' valve adapted to simultaneously cut olf said carburetted fuel sup ly and admit atmospheric air to the cylinlder on the suction stroke of the piston, and a safety locking device interconnecting said fuel control valve with said hand operatedl means to thereby prevent said movement of i the auxiliary cam until the fuel control valve has been operated-as purpose specified. Y

3. Improvements in high compression oil engines consisting in the combination of means for supplying a starting charge of carburetted air fuel to the engine cylinder on the suction stroke of the piston, anl exhaust valve, an auxiliary cam slidably mounted on a cam shaft and adapted to n/pen aforesaid, for the said valve during the compressionss/ okel of the piston, a hand lever adapted to slide the auxiliary cam into an inoperative position when the engine Ahas been started, a manually operated fue'. control valve adapted to simultaneously cut olf the carburetted fuel supply and .admit atmospheric air to the cylinder on the suction stroke of the engine, and a locking member operatively connected AWith said fuel control valve and adapted to prevent movement of said hand lever to render the auxiliary cam inoperative until the fuel control valve has been operated as aforesaid, for the purpose set forth.

fl.' Improvements in highy compress-ion oil engines consisting in the combination of means for supplying a starting charge of carburetted air fuel to the engine cylinder on thesuction stroke of the piston, an exhaust valve, an auxiliary cam slidably mounted on a cam shaft and adapted to open said valve during the compression stroke of the piston, a hand lever adapted to slide the aux1liary cam into an inoperative position When the engine has been started, a locking plate carried by said hand lever and having an arcuate slot therein, a manually operated fuel control valve adapted to simultaneously cut off the carburetted fuel supply and admit atmospheric air tothe cylinder `on' the suction stroke of the engine, and a locking pin operatively connected With said fuel control valve and adapted to engage said arcuate slot of the locking plate Where:

by the hand lever is locked against movement to render the auxiliary cam inoperative until the fuel control valve has been operated as aforesaid for the purpose specified.y

5. Improvementsin high compression oil engines consisting in the combination of means for supplying a starting charge of carburetted air fuel to the engine cylinderv on the suction stroke of the piston, an exhaust valve, an auxiliary cam slidably mounted on a cam shaft and adapted to open said` valve during the compression stroke of the piston, a hand lever adapted to slide the auxiliary cam into an inoperative position when the engine has been started, a locking plate carried by said hand lever and having an arcuate slot therein, a manually operated fuel control valve adapted to simultaneously cut off' the carburetted fuel supply and admit atmospheric air to the cylinder on the suction stroke of the engine, and a locking pin operatively connectcd1-With said fuel control valve, said locking pin having a educed portion adapted to engage said slot df the locklng plate to permit movement of the hand lever to render the auxiliary cam inoperative, the major diameter of said locking pin being adapted to engage an enlarged portion of said slot to thereby prevent such movement of the hand lever until the fuel control valve has been operated as aforesaid and the reduced portion of the locking pin is consequently enaged with said slot for the purpose speci- 6. Improvements in high compression oil engines consisting in the combination of means for supplying a starting charge of carburetted air fuel to the engine cylinder on the suction stroke of the piston, an exhaust valve, an auxiliary cam slidably mounted on a cam shaft and adapted to open said valve during the compression stroke of the piston, a hand lever adapted to slide the auxiliary cam into an inoperative position when the engine has been started, a manually operated rotary fuel control valve adapted to .simultaneously cut olf the carburetted fuel supply and admit atmospheric air to the cylinder onv the suction stroke of the engine, a connecting rod attached at one end to said fuel control valve, a bell crank lever attached to the other end of said rod, aloclring pin depending from said lever, said locking pin having a reduced portion adapted to engage said slot of the locking plate to permit movement of the ,hand lever to render the auxiliary cam inoperative, the major diameter of said locking pin being adapted to engage an enlarged -portion of said slot to thereby prevent such movement of the hand lever until the rotary fuel control valvc has been operated as aforesaid and the reduced portion of the locking pin is consequently engaged With said slot for the purpose specied.

7 Improvements in high compression oil engines consisting in the combination of a carburettor, a cylindrical valve casing in communication with said Carburettor and the engine cylinder, a manually operable rotary fuel control valve mounted Within said casing and adapted to simultaneously cut off communication with the Carburettor and open the cylinder to the atmosphere during the suction stroke of the piston an exhaust valve operating mechanism adapted to open said exhaust valve ,during both the compression and exhaust strokes of the engine during starting operations, a hand lever hand lever until the fuel control valve has been moved to cut off the carburetted fuel supply and open the cylinder to the atmosphere on the suction stroke of the piston for the purpose set forth.

8. Improvements in high compression oil engines consisting in the combination of means for supplying a starting charge of carburetted air fuel to the engine cylinder,

of inlet and exhaust valves operated from a cam shaft, a manually operated fuel con trol valve adapted to control the admlssion to the engine cylinder of carburetted fuel for v starting and atmospheric air for normal Working by Way of said inlet-valve during the suction stroke of the piston, a pair o f alternately operating cams slidably mounted on said cam shaft and adapted to open the exhaust valve on both the exhaust and compression strokes of the piston during starting operations, a hand lever adapted to slide said cams along the cam shaft to thereby render one of the cams inoperative and discontinue the opening of the exhaust valve on the compression stroke after 'the engme has been started and a safety locking device operatively associated with said fuel control valve and the hand lever to prevent said movement of the latter until the fuel. control valve has been moved to va pre-determined position for the purpose specified.

In testimony whereof I ax my slgnature.

T. A; BELL.

-Witness VICTOR J. Kansai'.4

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