US2002668A - Internal combustion engine - Google Patents

Description

May 28, 1935. A. s. LACK I INTERNAL COMBUSTION ENGINE Filed Nov. 16, 1929 2 Sheets-Sheet 1k FIGJ FIQZ

INVENTOR ERA/01.0 3. L/YCK 8% ATTORNEY May 28, 1935. A. s. LACK 2,002,658

INTERNAL COMBUSTION ENGINE Filed Nov. 16, 1929 2 Sheets-Sheet 2 IIIIIIIIIIIIIIIII/ v III/I14 IIIIIIII INVENTOR fiR/VOLD 5. L HCK ATTORN EY PM May 2a, 1935 INTERNAL COMBUSTION ENGINE Arnold 8. Lack, Beloit, Wis., assignor to Fairbanks, Morse I; 00., Chi

tlon of Illinois cage, 11].. a corpora- Application November 10, 1929, Serial No. 407.134 7 volume.

This invention relates to improvements in internal combustion engines, and particularly to improved cylinder scavenging means.

An object of the present invention is to provide an improved arrangement of inlet ports, in

which the walls of the ports serve to direct the flow of scavenging air within the cylinder, in such a manner as to insure complete and emcient removal of the exhaust gases therefrom.

A further object is to provide simple and effective means for directing a plurality of inflowing air streams into the interior of the cylinder, so as to form resultant air streams whose inherent path of travel is progressively away and removed from, the outgoing flow through the cylinder exhaust ports.

An additional object is an improved provision for scavenging engine cylinders, whereby a plurality of inlet fluid streams are directed to unite into a single resultant stream having directional flow differing from the individual inlet fluid streams. I

A still further object is to provide an improved arrangement of inlet and outlet cylinder ports, particularly in those types of internal combustion engines, in which the ports are controlled by the working piston, so that the inlet ports may be situated in close proximity to the exhaust ports, and to provide improved'means for directing the branch scavenging streams, so as to unite them into a single closely confined current, directioned away and removed from the cylinder exhaust ports, in order to minimize interference, admixture and diffusion between the inand outgoing fluid streams.

Further objects and advantages will appear from the following detailed description of parts and the accompanying drawings, in which Fig. 1 is a fragmentary longitudinal section through a working cylinder of an internal combustion engine, to which certain of the present improvements are applied; Fig. 2 is a section taken along the line 22 in Fig. 1; Figs. 3 and 4 are longitudinal sections, of modified forms of the port arrangement; and Fig. 5'is a section taken along the line 5-5 in Fig. 4. It will be understood that in each of Figs. 1, 3, and 4, the piston appears at substantially its inner, or bottom dead center position, with the inlet ports fully open.

It will, of course, be understood that the present detailed description of parts and the accompanying drawings relate only to certain preferred embodiments of the invention, and that substantial changes may be made in the described arrangement andconstruction of parts without departing from the spirit and full intended scope of the disclosure as defined by the appended claims.

Referring by numerals to Figs. 1 and 2 of the 5 drawings, l0 designates a working cylinder of a two-stroke cycle internal combustion engine, in which operates a piston ll of any suitable type. Inlet ports I! and exhaust ports 13 are. grouped about the cylinder, and in substantially 10 the same plane, transverse of the cylinder. These ports are controlled, by preference, by the working piston, although it, will be understood that any other suitable form of control may be used without appreciably aflecting the underly- 15 ing principles of the invention. Conduits l4 serve to cooperate with the ports l2 to supply the inlet air or fuel laden mixture into the cylinder. These conduits may be connected to any suitable source of supply (not shown) which 20 maintains, by preference, a uniform pressure in the supply conduits. Likewise, the exhaust ports l3 cooperate with conduits l5 to direct the burnt gases away from the cylinder lb. The edges of the ports l4 and I3 are normally related to each 25 other, in respect to time and distance of piston travel. A difierence in height N between the edges of the inlet and exhaust ports, is provided to permit effectively lowering the combustion pressure in the cylinder, in advance of the first 30 introduction of scavenging air, and thereby to insure maximum time available for complete cylinder scavenging.

In Figs 1 and 2, the inlet ports I! are, by preference, arranged in oppositely disposed 35 groups in the cylinder wall, the exhaust or outlet ports l3 being arranged in the cylinder wall substantially midway between the groups of inlet ports and in substantially the same plane, transverse of the cylinder. In Fig. 2 the inlet'40 ports l2 are arranged in diametrically opposite groups, although it will be quite evident that they may, just as well, be arranged oifset from a diameter as shown in Fig. 5. As best seen in dotted lines in Fig. 2, the walls or conduits ll 45 serve to direct the inflowing air currents, inwardly, in such a manner, that the individual streams from each port I! unite into a single closely confined air current. With this arrangement the resultant stream is directioned pro- 50 gressively away and removed from, the outlet ports l3, thereby insuring eflicient scavenging of the cylinder. In certain of the older, prevailing port arrangements, the inflowing streams usually cooperated with the cylinder wall or piston, in order to effect the desired directioning of the scavenging fluids. In the present arrangement, the ports are so disposed that the which are, in turn, directioned by the meeting impact of the individual streams. It will be quite apparent that the resultant stream is given a directional effect which is progressively away a from the outgoing flow of exhaust gases. This directional eil'ect may be seen by reference to the dotted lines and arrows appearing not only in Figs 1 and 2, but also employed in like manner in the subsequent figures, hereinafter described.

In constructing the cylinder I6 as shown in Fig. 3, the ports I! are, by preference, inclined with respect to a plane transverse of the cylinder, and likewise the piston I8 may be provided with a conical top IS, the slope of which may correspond to the inclination of the ports, as well as to the slope of the air conduits 20. According to this arrangement, the piston cooperates with the inclined ports in aiding the flow of the inlet streams. It will, however, be seen that the scavenging principle herein described does not necessitate the use of the piston and other engine member, apart from the ports and cylinder itself, as means for directing the several individual or component streams. It will be understood that the component streams issuing from the inlet ports, do not travel in directions such that the distance between their component particles and the exhaust ports 2| progressively increase, but that this path of travel is, however, inherent in the combined streams produced by the impact, or other form of coaction between the oppositely directioned component streams.

In Figs. 4 and 5 are shown a cylinder 22 providing a modified form of the port arrangement. In this arrangement, the piston 23 and means integral therewith, cooperate with the ports 24 and passages 25 to produce and aid the directional effect of the component inlet fluid streams. The inlet streams are directed away and partitioned off, from the outlet ports 26 and conduits 21, by means of a bafiie or projection 28 formed on the piston top. By this provision, the pair of inflowing streams impinge, collide, or otherwise cooperate, while in contact with the guiding surface of the projection, to form a single, unidirectioned flow stream within the cylinder. Further, the inlet ports 24 are inclined oppositely to the inclination of the ports I! as shown in Fig. 3, in order to force the inflowing air into intimate cooling contact with the face of the piston. A further advantage may be obtained in this arrangement, in that dual and specially separate fuel introducing means,

such as injectors 29 and 30 may be used, due to the fact that by using the piston projection 28, a combustion clearance 3| is formed, in which these injection nozzles may be disposed. Such a combustion space is, generally, of greater diameter than depth, and is therefore particularly suitable for the application of two or more injection nozzles. These nozzles may be disposed with their axes either parallel or arranged obliquely with respect to each other.

The foregoing description relating to the course of the individual or component streams of inlet air, has dealt principally with the manner of introducing the several separate air streams,

and thereafter directing them in a manner to cause their union into one or more resultant streams. These resultant streams are, in each case, directed upwardly or outwardly, toward the cylinder head. After traversing the cylinder, the resultant stream engages the cylinder head, which serves as a transverse bame serving radially to divert the air stream, and thereafter to cause a reverse or counterflow,.toward the piston, and exhaust ports, as well understood in the art. The arrangement of inlet ports described in the several figures produces a mean path of scavenging fluid flow, the length of which is a minimum, consistent with its making a complete circuit of the combustion space.

By the described directional flow of the scavenging air, the commixtlne of the incoming charge with the gases left in the cylinder from the previous working cycle, is minimized. Further, by uniting the individual or component inlet streams, the larger cross-section of the combined stream, as well as the homogeneous front, presented thereby to the exhaust gases, render the entire stream more effective in displacing the old charge from the cylinder, than would be the case if the same quantity of scavenging air, or air-fuel mixture were caused to traverse the cylinder as a plurality of smaller, individual streams. By causing the several individual or component streams to coalesce soon after entering the combustion space, and thereafter presenting a substantial front to the exhaust gases remaining from the previous working cycle, contamination and admixture of the fresh charge, is minimized, and expulsion of burnt gases rendered more complete. The changed direction of the resultant stream caused by the impact of the individual streams, is produced with least possible abruptness. Hence, the kinetic energy of the entire stream is substantially preserved, to obtain greater penetration of the more remote recesses of the cylinder. It is, therefore, possible to use lower admission pressures, which minimize the possibility of undesired turbulence and intermixture between the inand outflowing streams. It will be apparent that by the use of lower pressures employed for introducing the scavenging fluid, less engine power is consumed for this purpose, and therefore greater engine economy is obtained.

With the presently described port arrangement, the cylinder is filled almost entirely with pure scavenging air, and a relatively complete evacuation of the exhaust gases is attained. Also, the directioning of the inflowing streams is such as to avoid what may be designated as a short circuiting of the inflowing stream through the exhaust ports, and vice versa, thereby minimizing the contamination of the fuel charge by the exhaust gases. It will be further apparent, that the described, natural flow of the inlet air through the cylinder, drives the exhaust gases out through the exhaust ports, in such a manner as effectively to eliminate dead gas pockets within the cylinder.

I claim as my invention:

1. A cylinder for an internal combustion engine, a piston adapted to operate therein, ports formed in a cylinder wall for the intake of scavenging fluid, exhaust ports at right angles to the intake ports, the intake ports each being disposed in aligmnent on opposite sides of the cylinder, and directed at substantially a right angle to a plane of symmetry. extending along the axis of the cylinder, said intake ports being formed to direct the opposed streams o' intake scavenging fluid to a zone of stream-convergence substantially within said plane of symmetry, and a baflle structure on said piston having a portion extending along said plane of symmetry.

2. In an internal combustion engine, a cylinder, a piston adapted to operate therein, inlet ports disposed in line, substantially on opposite sides of the cylinder, and arranged to be controlled by said piston,.exhaust ports at right angles to the inlet ports, said inlet ports all being formed to deliver streams of scavenging fluid at substantially a right angle to a plane of symmetry extended axially through the power cylinder, and at substantially a right angle to said exhaust ports, and a baflile projecting at substantially a right angle to the working face of said piston, and formed to'maintain substantially the initial trends of said streams, between said ports and said plane of symmetry.

3. In an internal combustion engine, a cylinder, inlet and exhaust ports, the exhaust ports being at right angles to the inlet ports, said inlet ports all being arranged in opposed alignment, and directioned tocause a flow, along a common plane, of individual streams of scavenging fluid, causing said streams to converge in a plane parallel to and extending along said exhaust ports, at a right angle to the first named plane, a piston operable in the cylinder, and a baflle structure thereon, having angularly disposed stream-directing portions.

4. An internal combustion engine, a cylinder, and a piston adapted to operate therein, inlet and exhaust ports in the cylinder wall, the exhaust ports being arranged at a right angle to the inlet ports and the ports all being symmetrically arranged with respect to a plane including the axis of the cylinder, said ports adapted to be controlled by said piston, said inlet ports being disposed in opposed spaced relation and directed to efiect a movement of each of the inlet streams along a common plane at a right angle to the plane of symmetry, whereby to efiect a union of fluid streams from the several inlet ports at substantially a common point, and whereby the fluid streams from said inlet ports are caused, after proceeding beyond said point, to traverse the combustion space within the cylinder, and a deflecting structure on the piston having a portion substantially coincident with the said plane of symmetry.

5. In an internal combustion engine, a cylinder including inlet ports adapted to be controlled by a piston, and disposed in opposite wall portions of the cylinder, the ports being arranged symmetrically with respect to a plane directed along the axis of the cylinder, and each being of a trend to cause the individual streams therefrom to follow a common plane, and to unite at a common point, within the plane of symmetry, the impingement of such streams adapted to produce a resultant unidirectional flow of scavenging fluid, in a direction along the plane of symmetry, and substantially over the length of the combustion portion of said cylinder, exhaust ports at right angles to the inlet ports, a piston operable in the cylinder, and a baffle on the piston, characterized by portions extended, respectively, across the produced axes of the inlet and exhaust ports.

6. In an internal combustion engine, a cylinder, a piston adapted to reciprocate therein, a pair of inlet ports and an exhaust port at right angles to the inlet ports, the ports being symmetrically disposed about a plane extended along the cylinder axis, the inlet ports being disposed on opposite sides of the cylinder in a plane normal to the plane of symmetry and thereby arranged for efiecting convergence of the inlet streams, and for directing a flow of intake fluid after convergence of said streams, in substantially a straight line to the head portion of the cylinder, and a baiile on the piston having portions extending, respectively, along and across the said plane of symmetry.

7. In an internal combustion engine, a cylinder, a piston adapted to operate therein, a plurality of intake fluid ports and exhaust ports at right angles to the intake ports, the ports being also symmetrically disposed with respect to a plane including the axis of the cylinder, said intake ports each being disposed substantially in a plane at a right angle to said plane of symmetry, and of a trend adapted to conduct the intake fluid in opposite directions across and in close adjacence to the piston face, said intake ports being formed to project all of said intake fluid toward a common point adjacent the piston and in the plane of symmetry, to eifect a resultant fluid stream proceeding from the piston along the axis of the cylinder to the head end thereof, and baflles on the piston, one being of a trend along said result-ant stream, and a second baiile at a right angle to the flrst.

ARNOLD S. LACK.

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