US2170477A - High speed motor operating with heavy liquid fuel - Google Patents

Description

Aug. 22, 1939.

R. P. F. LEMASSON HIGH SPEED MOTOR OPERATING WITH HEAVY LIQUID FUEL Filed March 10, 1958 2 Sheets-Sheet 1 Aug. 22, 1939- R. P. F. LEMASSON HIGH SPEED MOTOR OPERATING WITH HEAVY LIQUID FUEL Filed March 10, 1958 2 Sheets-Sheet 2 Patented Aug. 22, 1 939 UNIT-ED s'rATEs PA ENT OFFICE HIGH SPEED MOTOR OPERATING HEAVY LIQUID FUEL WITH Roger Pierre Felix Lemasson, Montrouge, France Application 8 Claims.

. .countered when it is desired to obtain high speeds in heavy fuel or Diesel engines the. speeds of which are below those of gasoline or carburetter engines.

The usual heavy fuel engines which operate with an injection of fuel under very high pressure at the end of the compression stroke, are allowed only .a very short and insumcient time (V of a second for 2400 R. P. M. with an injection. at 24 before top' dead centre) for effecting the four fundamental operations (a) injection and distribution of the fuel in the body of air, (2)) vaporisation and formation of a mixture for ignition, (c) ignition and (d) combustion which, whatever care is taken, continues.

through part of the expansion.

'Another drawback of the heavy fuel or Diesel engines in use, which engines were originally in-. tended to operate in accordance with the constant pressure cycle, resides in that they operate, at the moment of the injection which is performed before top dead centre in accordance with the constant volume cycle. Consequently by reason of the higher compression in such engines, there arises a high peak pressure which requires an oversizing of the different parts of the engine which is thus rendered uselessly heavy, as this high peak pressure produces but little useful work by reason of the extremely short time during which it persists.

Other drawbacks inherent to this type of engine, are due to the use of feed pumps which are necessary for forcing the liquid into the strongly compressed air, these pumps requiring enormous pressures of 500 or 600 atmospheres, Such pumps are of .delicate construction and of difficult upkeep both as concerns fi'iidtightness and adjustment. The same may be said of the injecting means which are moreover subject to wellknown and detrimental irregular vibratory motions.

The method according to my invention removes the above drawbacks by injecting pure fuel (ie. without anyadmixture of air) into a portion of the combustion chamber momentarily shut. off or,

isolated to this end. The fuel is completely vaporised under the action of the vacuum produced by .the prior expansion acting up to the moment of March 10, 1938, Serial No. 195,163

France March 25, 1937 injection on the portion of chamber considered. At the end of the compression stroke following the injection and during which this vaporization occurs, said portion of the combustion chamber is set again in communication with the remaind- 5 er of the chamber. At this moment the air which has entered the cylinder has been sufliciently compressed (a little more than in the usual Diesel motors so as to compensate for the increase of volume produced by the communication between 10 the two portions of the combustion chamber) to pass beyond the temperature of ignition of the fuel. This temperature is substantially constant by reason of the prior vaporisation of the fuel inside a space substantially devoid of oxygen 15 whereas the temperatureof self-ignition of a mixture containing a somewhat considerable proportion of oxygen is exceedingly variable.

.The ignition is thus obtained in the case of my invention inside a space in open and wide com- 20 munication with the cylinder, said space forming integrally part of the combustion chamber without being separated therefrom through any valve or throttled part. The immediate, accurate and uniform ignition at constant temperature thus 5 obtained ensures a very regular and progressive combustion. It will be noted that the fuel vapour in the fuel chamber never saturates the combustible charge as it only forms one thirtieth part or thereabouts of the volume of the air of the 30 charge; as the ratio of compression is about fifteen, the total compression chamber including the. vaporizing chamber allows the. fuel vapour to expand in a volume equal to one fifteenth (instead of only one thirtieth) of the cylinder charge.

,The engine provided for the application of my invention comprises a combustion chamber part of which. is adapted to be isolated for approximately the duration of the compression stroke and into which fuel is injected just before the 40 beginning of the compression stroke, the isolation being preferably performed through a tubular sleeve sliding between the cylinder and the piston under the control of the camshaft. This sleeve which is totally or partly balanced or in 5 equilibrium with reference to the pressure of the gases acting on both sidesthereof as it opens and closes, is provided with two seats which cooperate with the cylinder proper and, with the cylinder head, the admission of air into the cylinder being 50 effected through ports provided to this'end in the lower part of the tubular sleeve, when the piston has uncovered said ports. The arrangements provided remove the usual high peak pressures set up in prior heavy fuel engines. The-combus- 55 Fig. 2 is a part sectional transverse view of a modified form of the cylinder of an engine constructed in accordance with the invention, at the end of the air intake period.

Fig. 3 is a partly sectional detail view of the tubular sleeve modified so as to carry an independent seat screwed on to it, said sleeve being partly balanced or in equilibrium during its movement under the action of the pressure of the gases on its sides, so that the small resulting pressure efiiciently seats the valve in closed position.

Fig. 4 is a cross-section of the cylinder-shown in Fig. 2, perpendicular to the axis of the cylin der and showing the vaporisation chamber and the injecting means in operation, together with the working chamber of the cylinder and the lower two-part seat formed on the latter.

Fig. 5 shows a modification of the head of the slide.

Figs. 6 and 7 are .diagrammatic views showing the different positions of the bottom and of the connecting rod respectively for the first two strokes in a cycle and the two last strokes of the cycle for an engine of the type shown operating in accordance with the four-stroke cycle.

As explained hereinabove, it is apparent from the accompanying drawings that the combustion chamber comprises a compression chamber l and a vaporisation or auxiliary chamber 2, communication between which is controlled by a tubular slide or sleeve 3 moving parallel to the cylinder axis and arranged round the periphery of the piston. This slide is provided with two seats 4 and 5 adapted to co-operate respectively with a seat on the cylinder proper at 6 and with a seat on the cylinder head at I (which latter seat is preferably fiat so as not to require an accurate centering of the head with reference to the cylinder proper), I thus open or close communication between the compression and vaporisation chambers forming the two portions of the combustion chamber. When the crank on the chankshaft has passed beyond its upper dead point M (Fig. 6), the piston 8 moves downwards and produces a vacuum inside the cylinder and consequently in the chambers l and 2 which have been set in communication through the sleeve 3 actu-f ated by the cam 9 controlled by the shaft I rotating at half the speed of the engine crankshaft, the cam acting on the adjustable tappet ll screwed on to the two-part collar l2 rigid with the slide 3. When the engine crank arrives at the position 0a of Fig. 6, the cam 9 ceases to act on the tappet H and provides the rising motion of the slide by acting on a plate l3 secured to a yielding device M (of which the tension may be adjusted by the nut 14), which device is secured to the sleeve through the projection l2 on the collar l2; the tubular sleeve rests then with its upper seat against the seat IS on the cylinder head whereby the communication between the chambers i and 2 is interrupted; the rising surface of the cam is greater than the stroke of the sleeve so as to provide a suficient tensioning of the spring to hold the seat 5 against the seat IS in an efficient manner.

The crank then occupies the position 0b; at

this moment, a pump l6 forces under very small pressure, through the injecting means ll, the amount of liquid fuel required into the vaporisation chamber 2 where the liquid fuel is entirely vaporised by the vacuum in the chamber 2, the Y vaporisation being accelerated by the heat of the air which is subsequently compressed on the other side of the sleeve wall whichtransmits to the chamber the heat thus produced.

When the crank continuing its movement, arrives in the position 0c the piston 8 uncovers the ports l8 allowing the admission of air. By reason of the high depression produced in the cylinder, the air enters said cylinder very quickly until the crank arrives into the position 011 in which the piston, as it rises, closes ports I8. It is possible to increase the charge coefficient and thereby the power of the engine by forcing the air in under pressure by a fan 19, for instance, by a mechanically driven compressor or by a compressor making use of the kinetic energy of the exhaust gases or by any pump which .may be formed by the piston reciprocating inside the crankcase for instance.

The piston, as it rises, compresses theair in the cylinder to the required pressure so as to bring its temperature to a value sufficient (about 800 C.) for producing ignition as soon as the communication between the chambers I and 2 is restored when the crankarrives in the position 0e. Ignition occurs in spite of the increase in volume of the combustion chamber and the consequent fall in temperature. This is possible, due to the fact that as soon as combustion has begun, it produces an increase in temperature and pressure. The communication is obtained through rotation of the cam 9 which engages the gle unitary part; in this latter case the upper seat of the sleeve is formed independently (Fig. 3) and screwed for instance into the sleeve with the interpostion of a fluid-tight packing 2| the tongues 22 and 23 of which are afterwards turned-down inside corresponding grooves provided in the sleeve and in the double .seat element so as to prevent unscrewing.

The sleeve 3 is brought to bear against either of its seats by the pressure of the gases (Fig. 2) or else it is partly balanced or in equilibrium during operation under the opposed action of the gases on its sides (Fig. 3). In this latter case the bore 11 of the cylinder defined by the inner diameter of'the sleeve is slightly greater than the inner diameter (dE) of the seat 5 and slightly smaller than the inner diameter (d+E) of the seat 4. It is also possible to give the sleeve the shape shown in Fig. 5 where the seats 4--5 are formed on an outer flange on the upper end of the sleeve.

During the extremely short time required for the changing of seats by the sleeve, the fluid tightness of the working'chamber in the cylinder is ensured by a fluid-tight packing or rings 24. The downward movement of the sleeve is then progressively arrested by the pressure of the gether with the expension pressure as the cam 9 rotates. The pressure of the gases on the-upper part of the sleeve (which is reduced to the minimum required in the case of Fig. 3) ensures a proper application'betweenthe co-operating seats with a minimum of shocks and noise.

At the moment the chambers I and 2 are set in communication, the highly compressed air has been given a rotary turbulent motion, due to the fact that the piston 8 carries a head 25 provided with helical grooves 25' which, a little before the upper dead point, enter a restricted portion 26' of the sleeve 26. The air enters with a hight speed of rotation the vaporisation chamber 2 of compact annular shape inside which it becomes intimately mixed with the combustible vapours which are thus very speedily ignited.

The combustion is then produced at substantially constant pressure, under the conditions previously disclosed, in a regular end progressive manner and after the crank has passed its upper dead point M, expansion is produced and the piston is urged downwards in its working stroke until the crank arrives into the position M (Fig. '7) At this moment the exhaust begins through the opening of the valve 21 arranged on the cylinder head along the axis of the cylinder. As the heat distribution is thus uniform along the different radii of the cylinder, the upper portion'of the slide may expand uniformly, which is necessary for its proper working.

For the position 057 of the crank, the residuary gases begin being scavenged for instance by air under pressure entering through the ports 18 in the sleeve 3, the air pressure being sufficiently high for said air to enter the :cylinder while the slide is in its'lower position and -the side wall of the piston prevents the air from passing into the crankcase. I may also give the ports 18 a height which is smaller than the rise of the slide, which slide may moreover receive a complementary rotary motion to close the air inlet port [8 as usual in the art of valveless motors. with or without compressed air ceases for the position on of the crank and the exhaust continues as usual up to the position 01' a little after passing the upper dead point.

My invention is not limited to the constructional form described and illustrated. modifications may be brought thereto, without widening the scope of my invention which is applicable to all types of internal combustion engines intended for the mostvaried applications, working in accordance with any cycle and using any kind of liquid fuel.

In particular it is applicable as well for two stroke and for four-stroke cycles.

What I claim is: V

1. In an internal combustion engine, the combination of a cylinder, a cylinder head, a piston adapted to reciprocate in said cylinder and to form a main combustion chamber between the piston head and said cylinder head at the top dead center position thereof, an annular fuel chamber forming a peripheral extension of said main combustion chamber, an annular peripheral passage providing an unrestricted communication between-said. chambers, a fuel injection device for delivering fuel directly into saidfuel chamber, means operative to actuate said device to inject a fuel charge during a portion only of the The scavenging Many mined point in the compression stroke to cause ignition of the fuel in said fuel chamber.

2. In an internal combustion engine, the combination of a cylinder, a cylinder head, a piston adapted to reciprocate in said cylinder and to form a main combustion chamber between the piston head and said cylinder head at the top dead center position thereof, an annular fuel chamber forming a peripheral extension of said main combustion chamber, an annular peripheral passage providing an unrestricted communication between said chambers, a fuel injection device for 'delivering fuel directly into said fuel chamber, means operative to actuate said device to inject a fuel charge during a portion only of the suction stroke of the piston, a piston controlled air intake port, an exhaust valve in the cylinder head, a sleeve surrounding the piston inside the cylinder and adapted to control said peripheral passage and means'for longitudinally actuating said sleeve to hold said peripheral passage open during a portion of the'suction stroke to reduce the pressure in said fuel chamber, to close said peripheral passage at the end. of the suction stroke dead center position thereof, an annular fuel chamber forming a peripheral extension 'of said main combustion, chamber, an annular peripheral passage between the cylinder and the cylinder head providing an unrestricted communication between said chambers, a fuel injection device for delivering fuel directly into said fuel chamber, means operative to actuate said device to inject a fuel charge during a portion only of the suction stroke of the piston, a piston controlled air intake port, an exhaust valve in the cylinder head, a sleeve surrounding the piston inside the cylinder and adapted to control said peripheral passage, said sleeve being provided at one end with two annular seats adapted to cooperate respectively with the cylinder head and the edge of the cylinder limiting the peripheral passage and means for longitudinally actuating ,said sleeve to apply the second seat against the 'cylinder edge to hold the peripheral passage open during a=portion of the suction stroke to reduce the pressure in said fuel chamber, to bring the first seat against the cylinder head to close said peripheral passage at the end of the suction stroke-prior to the opening of the intake port and then to apply the second seat against the cylinder at a predetermined point in the compression stroke to cause ignition in said fuel 'chamber.

4. In an internal combustion engine the combination of a cylinder, a cylinder head, a piston adapted to reciprocate in said cylinder and to form a main combustion chamber between the piston head and said cylinder head at the top dead center position thereof, an annular fuel vof the intake port and then to apply the second cylinder head, a sleeve surrounding the piston inside the cylinder and adapted to control said peripheral passage, said sleeve being provided at one end with two annular seats adapted to cooperate respectively with the cylinder head and the edge of the cylinder limiting the peripheral passage the inner diameters of said seats being for one smaller and for the other larger than the inner diameter of the sleeve and means for longitudinally actuating said sleeve to apply the sec-- ond seat against the cylinder edge to hold the peripheral passage open during a portion of the section stroke. to reduce the pressure insaid fuel chamber, to bring the first seat against the cylinder head to close said peripheral passage at the end of the suction stroke prior to the opening seat against the cylinder at a predetermined point in the compression stroke to cause ignition in said fuel chamber.

5. In an internal combustion engine, the combination of a cylinder, a cylinder head, a piston adapted to reciprocate in said cylinder and to form a main combustion chamber between the piston head and said cylinder head at the top dead center position thereof, 'an annular fuel chamber forming a peripheral extension of said main combustion chamber, an annular peripheral passage providing an unrestricted communication between said chambers, a fuel injection device for delivering fuel directly into said fuel chamber, means operative to actuate said device to inject a fuel charge during a portion only of the suction stroke of the piston, a piston controlled air intake port, an exhaust valve in the cylinder head, a sleeve surrounding the piston inside the cylinder and adapted to control said peripheral passage, said sleeve being provided at one end with two annular seats adapted to cooperate respectively with the cylinder head and the edge of the cylinder limiting the peripheral passage, the inner diameter of the seats being substantially equal to the inner diameter of the sleeve throughout the major part of its length, and means for longitudinally actuating said sleeve to apply the second seat against the cylinder edge to hold the peripheral passage open during a portion of the suction stroke to reduce the pressure in said fuel chamber, to bring the first seat against the cylinder head to close said peripheral passage at the end of the suction stroke prior to the opening of the intake port and then to apply the second seat against the cylinder at a predetermined point in the compression stroke to cause ignition in said fuel chamber.

6. In an internal combustion engine the combination of a cylinder, a cylinder head, a piston adapted to reciprocate in said cylinder and to form a main combustion chamber between the piston head and said cylinder head at the top dead center position thereof,- an annular fuel chamber forming a'peripheral extension of said main combustion chamber, an annular peripheral passage providing an unrestricted communication between said chambers, a fuel injection device for delivering fuel directly into said fuel chamber, means operative to actuate said device to inject a fuel charge during a portion only of the suction stroke of the piston, a piston controlled air intake port, an exhaust valve centrally located in the cylinder head, a sleeve surrounding the piston inside the cylinder and adapted to control said peripheral passage, said sleeve being provided at one .end with two annular seats adapted to cooperate respectively with the cylinder head and the edge of the cylinder limiting the peripheral passage, and means for longitudinally actuating said sleeve to apply the second seat against the cylinder edge to hold the peripheral passage open during a portion of the suction stroke to reduce the pressure in said fuel chamber, to bring the first seat against the cylinder head to close said peripheral passage at the end of the suction stroke prior to the opening of the intake port and then to apply the second seat against the cylinder at a predetermined point in the compression stroke to cause ignition in said fuel chamber.

7. In an internal combustion engine, the combination of a cylinder, a cylinder head, a piston adapted to reciprocate in said cylinder and to form a main combustion chamber between the piston head and said cylinder head at the top dead center position thereof, an annular fuel chamber forming a peripheral extension of said main combustion chamber, an annular peripheral passage providing an unrestricted communication between said chambers, a fuel injection device for delivering fuel directly into said fuel chamber, means operative to actuate said device to inject a fuel charge during a portion only of the suction stroke of the piston, a piston controlled air intake port, an exhaust valve in the cylinder head, a sleeve surrounding the piston inside the cylinder and adapted to control said peripheral passage, through its edge and provided with a port adapted to cooperate with the air intake port, said sleeve being further provided at one end with two annular seats adapted to cooperate respectively with the cylinder head and the edge of the cylinder limiting the peripheral passage and means for longitudinally actuating said sleeve to apply the second seat against the cylinder edge to hold the peripheral passage open during a portion of the suction stroke to reduce the pressure in said fuel chamber, to bring the first seat against the cylinder head to close said peripheral passage at the end of the suction stroke prior to the opening of the intake port and then to apply the second seat against the cylinder at a predetermined point in the compression between said chambers, a fuel injection device for delivering fuel directly into said fuel chamber, means operative to actuate said device to inject a fuel charge during a portion only of the suction stroke of the piston, a piston controlled air intake port, an exhaust valve in the cylinder head, a sleeve surrounding the piston inside the cylinder and adapted to control said peripheral passage, said sleeve being provided at 7 one end with two annular seats adapted to cooperate respectively with the cylinder head and the edge of the cylinder limiting the peripheral passage, and means for longitudinally actuating said sleeve to apply the second seat against the cylinder edge to hold the peripheral passage open during a portion of thesuction stroke to reduce the pressure in said fuel chamber, to bring the first seat against the cylinder head to close said peripheral passage at the end of the suction stroke prior to the opening of the intake port then to apply the second seat against the cylinder at a predetermined point in the compression stroke to cause ignition in said 'fuel chamber and finally to bring again the first seat against the cylinder head after ignition.

ROGER, PIERRE FELIX LEMASSON.

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