US1995579A - Two-stroke sleeve-valve internal combustion engine of the liquid fuel injection compression ignition type - Google Patents

Description

March 26, 1935. R RlCARDo 1,995,57

Two-STROKE SLEEVE VALVE INTERNAL COMBUSTION ENGINE OF THE LIQUID FUEL INJECTION COMPRESSION IGNITION TYPE Filed. April 1, 1955 I-NVENTO'R Patented Mar. 26, i935 i UNiTEl) sTATEs PATELN T OFFICE? .TIOhTTYBE Harry Ralph-Ricardo, London,

Application aim-n .1, weasel-m No. 664,040

In Great Britain April 20, 1932 9 Claims. (cues-s1 This invention relates to internal combustion engines of the liquid fuel injection compression ignition'type operating on the two-stroke cycle wherein inlet ports in the cylinder wall are con- 5 trolled by one or more sleeve valves and the .air

charge enters the cylinder in such a manner as to cause rotation of this charge about the cylinder ams i'or the purpose offacilitating the admixture of fuel and air during the'iuelinjection and combustion process.

-'In engines of the above type as generally made:

the scavenging air entering through ports in the cylinder wall is deflected so as to enter the cylinder tangentially by means of bailies formed in or attached to thiscylinder wall and while the ports in the sleeve are normally shaped so as not to impede this'tangential entry more than-can be avoided, yet owing to the thinness oi the part '.of .the sleeve in which the ports are formed -these ports cannot appreciably assist in guiding the air charge into the cylinder in the desired direction. Further where, as, is generally preferred in sleeve valve engines, the sleeve has. a combined oscillating and reciprocating motion, the bar-likeparts extending betweenthe adjacent ports in the sleeve cause some obstruction to the flow of the scavenging air,.since thesleeve tary movement of the air in an engine of the.

above general type may. be eflected';

. To this end in an internal combustion engine of the liquid-fuel injection compression ignition type operating on the'two-stroke cycle according to the present invention, there is combined with a cylinder, a sleeve valve controlling exhaust ports and having a part or parts formed integral- 1y therewith or attached thereto in which are formed inlet or scavenging passages which are so shaped and of such efl'ective length as to cause tersgthebzcylindeleinsth "an reeti movemith thesleeveival' entitnesleeye the scavenging charge flowing therethrough to enter the cylinder in a direction which will tend to cause the charge to rotate about the cylinder the passages which direct the charge has that part in whichthe of ports B in the sleeve valve which register with "the exhaust ports in thecylinder wall during the wees? leading to the ports are formed in this thickened I part. For example, the sleeve maybe formed with a thickening in the form of a circumferential belt in which the scavenging passages *are formed. Further, in this case, the mechanism for operating the sleeve valve .conveniently acts either on the thickened part thereof or on a portion 01' the sleeve. adjacent to this thickened part. C

- The movement imparted to the sleeve may vary. but'th'e invention is particularly applicable to engines of the kind in question in which the sleeve valve has imparted to it a combined oscillating and reciprocating movement, for example by means of a member rotating about an axis at right angles. to the cylinder axis and connected at a point eccentric with respect to such axisoi,

rotation to the sleeve through a self-aligning joint orlike flexible connection. The invention may be carried into practice in 'various wayszbut one construction according to the invention as applied to a double-acting twostroke engine having a cylinder provided with scavenging ports'or a scave in air belt adjacent to the centre of its length and communicating with scavenging passages in the sleeve which servetoadmitascavensi airchargetoeach working chamber in turn as they are uncovered respectively by the two ends of the piston, is illustrated somewhat diagrammatically by way oi example in the accompanying drawing, in which Figural is aisectional elevation, and Figure 2isasectionintheplane-2-2ot Figure 1.

In the construction illustrated, the engine comprises a' cylinder'A containing a sleeve valve 13 and closed at its ends by plug-like cylinder adjacent to the inner end of. each plug-like cylinder wall adjacent to the inner end of each'pluglikecylinderhieadisaringoiexhaustportsA adapted to cooperate with a corresponding ring scavenging period.- The cylinder A is so formed as to provide approximately midway in its length a scavenging belt A which eral direction of each of which is tangential with respect to a circle having for centre the axis of the cylinder so that the air charge entering through these passages will tend to rotate about the cylinder axis. Air may be deliveredunder pressure to the scavenging belt A'-'.

Formed on or in the thickening or belt 3* is a socket 3* in which is mounted the outer memher E of a self-aligning joint or hearing the inner member E of which is engaged ,by a crank pin F or the like on a small crankshaft F the axis cylindrical form having a diameter less than Lil and, for example, approximately three-fifths of that of the sleeve B, while its depth, measured in a direction parallel to the cylinder axis, is con- ,siderablyJessthan its'diameter and may be, for example, approximately one-third of its diameter. The end of the circumferential wall of each combustion chamber- G remote from the piston is conveniently connected to the end wall by a part G having a curved surface so as to avoid a sharp comer where the circumferential wall meets the end wall. 4

A fuel sprayer H is provided in the wall of. each combustion chamber and so arranged as to inject a single jet of fuel from a point in the circumferentialwall of this chamber approximately midway between the mouth of the chamber and the end of the chamber, the mean direction of the spray being in a plane normal to the cylinder axis and inclined at an angle of between 30 and 60 to a tangent to the circumferential wall of the combustion chamber at the point from which the spray issues; a

Reciprocating within the sleeve B is a piston J -the circumferential portions of the end faces J of which may be somewhat chamfered as shown atJ so as to lie parallel to corresponding chamfered faces C ,.D on the parts of the cylinder heads C and D surrounding the combustion chamber mouths, to which faces the-chamfered faces J on. the piston closely approach at the ends of the piston strokes. The piston J is connected to a piston rod J which passes out through a suitable gland J in the lower cylinder-head D so that the piston rod J fills the centre .part of the combustion chamber G in such cylinder head and gives to this combustion chamber an annular form.

The, operation of the engine is as follows:- Assuming the piston J to be at one end of its stroke so that it has compressed an air charge into the combustion chamber G at the-end of the cylinder remote from the piston rod J3, the sleeve valve B then occupies the position in which the exhaust ports A B at the end of the cylinder adjacent to the piston rod J are open, while the scavenging passages B in the thickenedbelt B are uncovered by the face of the piston J adjacent to the piston rod J scavenging air thus enters through the scavenging ports B in such a manner as to rotate about the cylinder axis and forces the gases burnt during the last working stroke out through the open exhaust ports A B and thus fills the end of the cylinder adjacent the piston rod with a fresh air charge which rotates about the cylinder axis. The piston now isomers.v

moves under the action of the expansion of the B in "the end of the cylinder adjacent to the'piston rod J whereupon continued movement of the piston compresses the fresh rotating air charge into the lower combustion chamber G adjacent to the piston rod J so that substantially the whole of the charge is compressed into this combustion chamber at the end of ,the stroke.

At the end of the piston stroke, when the piston is in its lower dead centre position, the face of the pistonJ remote from the piston rod J uncovers therscavenging ports B and the sleeve valve opens the exhaust ports A B at the upper end of the cylinder remote from the piston rod so that the burnt gases are expelled from the upper end of .the cylinder and such end of the cylinder is refilled with a fresh rotating aircharge. At the same time fuel is injected into the lower combustion chamber G adjacent to the piston rod and the expanding gases force the piston away from such combustion chamber to compress the fresh rotating charge which has been admitted into the upperend' of the cylinder, the cycleof operations described above being repeated.

It is to be understood that the construction more particularly. described above is given by passages so formed in this thickened part as to,

to rotate about the cylinder axis.

- 2; In an internal combustion engine of the liquid fuel injection compression ignition type operating on the two-stroke cycle, the combination with a cylinder having a scavenging belt constituted by a circumferential recess extending completely around the cylinder, of a sleeve valve having an external annular thickening extending-around that part which lies within the scavenging belt with scavenging passages so formed through this annular thickening as to tend to cause a charge on entering the cylinder to rotate aboutthe cylinder axis. 4 g

3. In an internal combustion engine of the liquid fuel injection compression ignition type as claimed in claim 1, the combination with the sleeve valve, 'of operating mechanism for this valve acting on a portion of the sleeve connected with this thickened part.

4. In an internal combustion engine of the liquid fuel injection-compression ignition type as claimed in claim 2, the combinationwith the thickened part of the sleeve, of a part carried by a recess in this thickened part, a; member, rotating about an axis at right angles to the axis of the sleeve, and means for connecting this rotary member at a point eccentric with respect to its axis of rotation to the part carried by the recess in the thickened portion so as to impart to the sleeve 9. combined oscillating and reciprocating motion.

5. In an internal combustion engine of the liquid fuel injection compression ignition type, operating on the two-stroke cycle, the combination with a cylinder, of a sleeve valve having a part in which are formed inlet or scavenging passages so shaped and of such efiective length as to tend to cause a charge on entering the cylinder to rotate about the cylinder axis, said scavenging passages being controlled only by the piston and being uncovered thereby at the end of each working stroke, and exhaust ports situated at the end of the working chamber of the engine remote from the scavenging passages and con trolled by the sleeve valve.

6. In an internal combustion engine of the liquid fuel injection compression ignition type operating on the two-stroke cycle, the combination with a cylinder having a scavenging port, of a sleeve valve having an external thickening provided with passage-ways therethrough, the longitudinal axis of each passageway forming an angle with that diameter of said cylinder which passes through the passageway concerned.

7. In an internal. combustion engine of the liquid fuel injection compression ignition type as claimed in claim 1, the combination with the sleeve valve, of operating mechanism for this valve acting in the thickened part thereof.

8. In an internal combustion engine of the liquid fuel injection compression ignition type operating on the two-stroke cycle, the combination with a cylinder having a scavenging belt constituted by a circumferential recess extending completely around the cylinder, of a sleeve valve having an external annular thickened portion extending around that part which lies within the scavenging belt with scavenging passages so formed through this annular thickened portion as to tend to cause a charge on entering the cylinder to rotate about the cylinder axis, and operating mechanism for said valve acting on the external annular thickened portion.

9. In an internal combustion engine of the liquid fuel injection compression ignition type operating on the two-stroke cycle, the combination with a cylinder, of a piston operable in said cylinder, a sleeve valve having a part in which are formed inlet or scavenging passages so shaped and of such effective length as to tend to cause a charge on entering the cylinder to rotate about the cylinder axis, said cylinder being formed to provide at least one air passage in constant communication with said scavenging passages, whereby said scavenging passages are controlled solely by said piston.

HARRY RALPH RICARDO.

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