US1633384A - Internal-combustion engine - Google Patents

Description

c. E. LUCKE INTERNAL COMBUSTION ENGINE Filed July 25, 1921 m A l 0 June 21, 1927.

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Patented June 21, 1927.

UNITED STATES PATENT OFFICE.

CHARLES LUCKE, OF NEW YORK, N. Y., ASSIGNOR TO WORTHING'ION PUMP AND MACHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA.

INTERN AL- COMBUSTION ENGINE.

,This invention relates to improvements in internal combustion engines, and particularly to means for controlling combustion in engines of the Diesel type.

The object of the invention is to provide simple and durable means which will afford a more effective mixing of the fuel and air than has been attained heretofore with a consequent more efficient combustion.

With these general objects in view, an internal combustion engine embodying the invention comprises in addition to the cylinder and piston, a precombustion space in communication with the cylinder and comprising the largest part or substantially all of the clearance space behind the piston, this precombustion space being divided into two chambers, connected with each other by a passage or passages of relatively restricted area, the chamber most remote from the cylinder forming what may be termed a fuel injection chamber, while the chamber nearest the cylinder forms what may be termed a mixing chamber) The fuel injection chamber receives the fuel first, and owing to the partial ignition which occurs therein the mixed gases and unconsumedfuel are driven into and well mixed in the mixing chamber, where some further combustion takes place,

cylinder.

The invention will now be more specifically described in connection with the accompanying drawings and then particularly pointed out hereinafter.

In the drawings,

Fig. 1 is a diagrammatic sectional view of so much of an internal combustion engine as is necessary to explain the invention;.and

Fig. 2 shows a modified form of nozzle device.

Referring to the drawings, A indicates the cylinder of the engine and B the piston. In the best embodiment of the engine, the piston approaches so close to the inner end of thecylinder on the inner dead center that there is substantially no clearance behind the piston within the cylinder proper.

At C and D are indicated two chambers having a throttled or restricted communication with each other. In the present example the chambers are shown as separated from each other by a wall E having a circular opening in which may be secured a nozzle device such as shown, for example,.at

and finally the mixture is expelled to the F, Fig. 1, which may be a shouldered bushing arranged to fit tightly into the opening in the wall E, this bushing having a central circular passage whose intermediate portion is a short cylinder, while its end portions enlarge in each direction from such Intermediate portion, as will be clear from the drawmgs.

The chamber D communicates with the cylinder through a passage d, provided with 05 a nozzle device F. which may be similar to the one shown at F but having a discharge opening of somewhat larger area.

Any suitable means may be provided for injecting fuel into the chamber C, but in 7 the best embodiment of the invention the fuel injecting device G is arranged to discharge the fuel in the general direction of the axis of the chambers C and D.

In the best embodiment of the invention means for introducing air to the cylinder and for exhausting the burnt products of combustion. This means may consist of the usual inlet and outlet valves or ports controlled by the iston (not shown).

In that em odiment of the invention where the fuel is ignited .immediately upon its entrance into the fuel injection chamber C, by the heat of compression of the air in said chamber 0, the total clearance behind the piston must have such a ratio tothe volume swept by the piston, that the final compression will cause the ignition. .As the total clearance is made up principally of the clearances in the two chambers, the respective volumes of these chambers must be properly related to the stroke and diameter of the piston to produce the desired result. Furthermore, an additional important feature of the invention consists in makin the two chambers so that their diameters w1ll be less than the diameter of the cylinder, and in the best embodiment of the invention the volume of the fuel injection chamber is less than that of the mixing chamber D. More-- over, a great advantage results in having the no length of the chamber in the direction of its axis so short that the fuel, when injected into the compressed air in the chamber C, can passfully across and reach, under its velocity of in ection, substantially to or even through the nozzle device F.

The'operation of the best embodiment of the invention is as follows:

the chamber 0 takes place.

The cylinder receives a charge of air and this charge is compressed by the piston into the clearance space constituted principally by the two chambers. The communication between the cylinder and the chamber D, although somewhat restricted, is still sufficient' to allow the passage of the air from the cylinder to the chamber D without much throttling, so that there is but a slight difference in pressure between the cylinder and said chamber D during and at the end of the compression stroke. But the passage through the nozzle device F is more restricted than that through F, so that there will be more difference in pressure between the compressed air in the cylinder and that in the chamber C during and at the end of the compression stroke. At the proper instant, which may be in advance of or at the moment of the arrival of the piston at its inner dead center, the injection of fuel into Owing to the somewhat lesser pressure of the compressed air in C and the relatively short distance the fuel has to travel, the fuel will not require a high injection pressure to deliver it. As soon as the fuel enters the vchamber C, ignition occurs due to the heat of compression of the air. But-owing to the size of the chamber 0 relative to the amount of fuel supplied, there is not sufiicient air for a com plete combustion of the fuel. However, some of its burns and creates sufiicient heat and pressure to assist in va orizing some of the remaining fuel and to rive the mixture consisting of products of combustion, vapor and particles of unburned fuel, into the chamber D through the nozzle device F, whlch, on account of its construction, tends to send the mixture in such directions and wlth such a pressure-in excess of that in chamber D that, owing to the relatively restricted diameter of said chamber D, it can readily reach all parts of said chamber and thus be mixed well with the air therein. Hence further combustion-takes place in this chamber D, the heat and pressure thereby generated being suflicient to assist in ejectmg the mixture into the cylinder through the nozzle device F which thoroughly distributes the burning mixture in the space behind the piston as the latter moves forward under the pressure. I

The injection of 'fuel into chamber 0 may terminate at or before the instant the piston reaches the inner dead center, or at some point'during the working stroke, as may be desired. During the time of fuel injection an (wer-pressure in said chamber during the period of fuel injection, whereby the mixture will be driven from the chamber C through the chamber D and into the cylinder A. I

During the exhaust there will be a rush of gases from the chambers C and D into the cylinder and. out through the exhaust openings until the pressure in said chambers drops to the atmospheric pressure, the outward discharge from chamber (rthrough chamber D tendingto clear the latter chamber' of carbon particles, if any have been deposited therein.

On the next compression stroke any remaining products of combustion in the two chambers and their passage ways will be compressed back into chamber C only, leaving chamber D filled with substantially pure air. Any products of combustion which may remain in chamber C are not disadvantageous but rather a benefit as such products tend to dilute the air and make a mixture in which the fuel, when injected, burns incompletely and relatively slowly, thereby assisting in preventing the complete combustion of fuel in the chamber C, which, of course, is not wanted.

The invention described is particularly suitable for Diesel oil engines, as it avoids many of the disadvantages heretofore existing in such engines. It has been recognized heretofore thatgreat pressures were necessary to pump the oil into the highly com pressed air, and obtaining such pressures consumed a considerable portion of the energy of the engine, as well as increased the complexity and weight of the machinery.

Where attempts have been made heretofore to force the oil into the cylinder by the combustionof some of the oil in a precombustionchamber which generated. a pressure to force the remainder of the oil into the cylinder there has existed the great difiiculty that the oil would not reach all the air in the cylinder clearance but only the central portion, and hence an incomplete combustion occurred in the cylinder, thus causing a loss of unconsumed fuel in the exreaches every part of the cylinder space.

The nozzle device F,'shown in Fig. 1 is particularly satisfactory as a means for distrlbutmg the mixture from the chamber C to all parts of the chamber D, but other '180 forms of nozzle devices may be employed. For example, instead of having the nozzle device provided with only one opening, it may have a plurality of openings, the total area of all of which will be such as to give the desired restricted communication between the two chambers. One suitable form of such a nozzle device with a plurality of openings is illustrated at M in Fig. 2. In this construction a cup-like structure is employed, having holes whose axes are approximately radial to the cup. The same nozzle may be substituted for the nozzle F between the chamber D and the cylinder.

What is claimed is: An internal combustion engine of the Diesel type in which the volume swept by the piston is so related to the clearance that an ignition temperature is produced by c0mpression in all parts of the clearance, said engine having a cylinder, a piston, and a liquid fuel supplying means, and also having a pre-combustion space constituting sub stantially all the clearance behind the piston, said space being divided into two pre-combustion chambers having only a restricted communication with each other, one chamber constituting a primary pre-combustion chamber arranged to receive fuel directly from the fuel supplying means and by partial combustion to drive fuel to the other chamber, the latter chamber constituting a secondary pre-combustion chamber and being in continuous restricted communication directly with the cylinder, said secondary precombustion chamber being arranged to receive fuel from. the primary precombustion' CHARLES E. LUCKE.

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