US2242231A - Internal combustion engine - Google Patents

Description

May 20, 1941.

H. D. J. CANT ONI INTERNAL COMBUSTION ENGINE Filed Feb. 11. 1938 Fig. 3isa Patented May 20, 1941 Humbert Denis Jean Cantoni, Paris, France Application February 11, 1938, Serial No. 189,924 In France February 12, 1937 6 Claims.

The present invention relates to internal combustion engines and has particular reference to internal combustion engines of the two cycle type. Still more particularly the invention relates to two cycle internal combustion engines of the kind in which one or more banks of cylinders are arranged in, radial or star formation around the crank shaft of the engine and are encircled by an annular ported valve member with respect to which the cylinder bank has relative rotary motion.

In so far as the presentinvention is concerned the engine may operate on the Diesel cycle with compression ignition or may be of the type in which a charge is fired by means of a spark plug or other timed ignition means.

Inengines of the character described, the desired relative motion between the cylinder bank and the encircling valve ring may be obtained in different ways. That is, the valve ring may be stationary or both it and the bank of cylinders may rotate, but at diiferent absolute speeds. The preferred form of ,construction is, however, one in which the outer valve ring is stationary and in which the bank of cylinders rotates in a direction opposite from the direction of rotation of the crank shaft, and the present'invention will accordingly be described in connection with an engine constructed to operate in this manner, although it will be understood that it. is equally applicable to engines in which the desired relative motion between cylinders and valve is attained in other ways.

The general object of the present invention is to provide novel and improved construction whereby engines of the general type under con--' sideration may advantageously be operated in accordance with the two stroke cycle. The manner in which the invention may be carried into eifect'and the more detailed objects and advantages thereof may best be understood from a consideration of the ensuing portion of this specification, taken in conjunction with the accompanying drawing, descriptive of a suitable form of construction which is illustrated byway of example.

In the drawing:

Fig. 1 is a vertical section taken in the central plane of the cylinder bank;

Fig. 2 is a partial section on larger scale taken transversely to Fig. 1.

section taken on the line 33 of Fig. 1} and Fig. 4 is asection taken on the line 4-4 of Fig.1.

Referring now to the drawing, the engine illustrated has a bank of five radially arranged cylinders l0 suitably secured to a crank case l2 mounted for rotation about the axis of crank shaft l4, there being suitable bearings I6 and I8 between the crank case and the crank shaft. These bearings are advantageously of the kind which do not limit axial movement of the crank shaft relative to the crank case and the cylinder bank is encircled by an annular valve member 20 provided with a series of exhaust ports 22 passing therethrough. Ports 22 are equally spaced around the periphery of the valve ring and are spaced from each other by the amount indicated by angle a in Fig. 1. For reasons which will hereinafter appear, the number of exhaust ports is not the same as the number of cylinders and in the present instance is six, for the five cylinders shown.

The inner face of the valve ring is ground to provide a concave spherically curved surface 24 and the open outer ends 26 of cylinders III are sealed by the seating against the inner face of the valve ring of a series of annular sealing members or cuffs 28, one for each cylinder, which cufls have cylindrical barrel portions 30 slidably mounted for movement longitudinally of the cylinder axes and flange portions 32 with convex spherically ground outer faces seating against the spherically ground inner surface of the valve ring. The cufl's 28 are suitably packed by rings or the like (not illustrated) to prevent-leakagebetween themand the cylinders and are advantageously held outwardly in radial direction against the valve ring by means of suitable springs or the like (not illustrated). The details of construction and mounting of the sealing members are not, per se, a part of the present invention and need not be described herein in detail. Such details of construction for sealing elements of this kind are fully disclosed in U. S. Patent No. 1,915,582, granted to Ignacz Sklenar June 27, 1933. If desired, intermediate sealing The valve ring is supported by the rotationally fixed casing 34 which at 36 provides a bearing for one end of crank shaft l4. This bearing, like bearings It and 18, is preferably of the type which will permit relative axial movement between the crank shaft and casing 34.

The'opposite end of the crank shaft has journaled thereon an annular manifold structure 38, the outer wall of which cooperates with the circular 'portion 40 of the stationary casing 34 to form a bearing which is' suitably packed as by means of rings 42.

The central manifold structure I8 is connected by means of radial manifold arms 44 (one of which is shown in Fig. 1) to the several cylinders, and at their outer ends these manifold arms communicate with annular passages 46 encircling the cylinder barrels. Communication between passages 48 and the interiors of the several cylinders is provided by means of inlet ports 48. As will be observed from Fig. 1, the manifold structure is fixed with respect to and rotates with the cylinder assembly.

Each of the cylinders is provided with a piston II and the pistons of the several cylinders are interconnected with each other and with the crank pin 52 of crank shaft H by the usual arrangement of master rod 54, iournaled on the crank pin, and connecting rods 58 which at their lower ends are pivotally connected to the master rod. This connecting rod construction is of conventional and well known form for radial engines and need not be described herein in detail for an understanding ofthe present invention. It will further be understood that other connecting rod arrangements may be employed.

In the embodiment illustrated, the "cylinders and crank shaft are arranged to rotate in opposite directions in suitably timed relation and this opposite rotation is effected through the medium of the gear train comprising gear 58 secured to the crank shaft, gear 60 mounted for rotation about a stationary axis provided; by the support 62 fixed on the stationary casing 34,- and the internal gear 84 formed on flange 66 extending from the cylinder and crank case assembly.

As previously noted, six exhaust ports are employed in the five cylinder embodiment illustrated and in this connection it is to be noted that the number of exhaust ports cannot be the same as the number of cylinders. If the number of cylinders is N, the smallest number of exhaust ports in an operative engine of the kind disclosed, with crankshaft and cylinders rotating in opposite directions, is N+ I. The angle a which separates two successive exhaust openings, is therefore equal to Consequently, when the crank shaft effects one complete revolution (21), one cylinder must tratel in the opposite direction through an angle equivalent to the distance between two successive in absolute value, which makes it readily possible to determine the proper gear ratio for the gear train 58, CI, for any given number of cylinders.

If through the interposition of an additional idler gear in the gear train or through direct meshing of the crank shaft gear with the internal gear on. the cylinder assembly, the cylinders were made to rotate in the same direction as the crank shaft, the number of exhaust openings would be N-l and the speed ratio between cylinders and the crank shaft would be in absolute value. This latter arrangement is, however, to be avoided since it results in absolute speeds of rotation which are higher for a relative speed equal to the relative speed in the example illustrated.

.The portion 4| of the stationary casing surrounding the rotating manifold structure has connected thereto the air intake passage. 8 through which air under pressure is delivered from a suitable pump or supercharger II.

The admission of air to the manifold structure 18 from the intake passage 08 is controlled by valve means comprising in the illustrated embodiment a rotary valve consisting of ported plates 12 and I4; Plate 12 is integral with and forms in eifect an end plate for the manifold structure SI, and of course rotates with this structure at cylinder speed. Plate 14 is fixed to crank shaft l4 and rotates at crank shaft speed. As will be observed from Fig. 3, plate I! is provided with a series of ports ll, these ports being equ lly spaced circumferenti'ally of the plate and the'number of ports being equal to the number of cylinders. Plate I4 on the other hand is provided with a single port ll adapted to successively register with the several ports in plate I! upon rotation of the two plates relative to each other. The central manifold structure 38 is advantageously provided with axially extending radial partitions 18, these partitions being spaced peripherally and located between adjacent port openings 'li'so that individual separate passages are provided from the valve formed by plates 12 and 14, which may for convenience be termed a timing or distributins valve, to the admission ports 48 in the several cylinders.

As previously noted, the manner in which the charges are formed and ignited in the several cylinders may be varied. By way of example the engine illustrated is shown asbeing provided with a series of fuel injecting nozzles or injectors II for injection of fuel and with a. series of spark plugs 82 for its ignition. The number of injectors provided is equal to the number of exhaust ports,

six in the present embodiment, and they are spaced fromeachotherbyadistancerepresented by angle a, the same angle as tint separating the exhaust ports. Obviously, if spark plugs or other ignition devices are employed for timed ignition,

properly spaced relative thereto for the timing of the. cycle of operation of the particular engine in which they are used. Obviously, if the engine charge in the. cylinder.

is intended to operate with compression. ignition, the igniting devices may be omitted entirely.

The method of operation of the above described engine is in accordance with well known and understood principles of operation for a two-cycle engine of the injection or Diesel type with simultaneous scavenging. The cycle'is as follows: As shown in Fig. 1, the piston 50 is at the bottom of itsstroke and in this position the cylinder ports 48 have been fully uncovered by the piston. The gearing which determines the position of the'piston in the cylinder, in

relation to the position of the cylinder with respect to the valve ring, is so adjusted that with the piston at the bottom of its stroke, the passage through the annular cuff or sealing 'member 28 is in registry with an exhaust port 22. Also, port 18 is in registry with one of the ports 16 in the valve plate 12 of the air distributing valve. With the parts in these relative positions, air under pressure from the supercharger is forced in the direction of the arrows b through the manifold structure and ports 48 in the cylinder to scavenge the same by forcing the products of combustion out through the exhaust port. The piston 50 on its ascending stroke covers ports 48 to cut off further admission of air to the cylinder and at the same time air admission is gradually closed off by passage of the distributing valve port 18 out of registry with the port 16 with which it was in registry when the piston was at the bottom of its stroke. Also, as the piston ascends, the rotary movement of the cylinder with respect to the valve ring carries the sealing member out of registry with the exhaust port with which it just registered and air is thus trapped in the cylinder and compressed by the piston during the remaining portion of its upward or compression stroke. By the time the piston is at or near its upward dead center, the rotary movement of the cylinder has carried it to a position such that the opening in the sealing cuff is in registry with an injector and fuel is injected into the air If compression ignition is relied upon, ignition will, of course, immediately take place upon entry of the injected fuel into the cylinder and if such ignition is not relied upon, the charge is ignited by the spark at the proper time. On the power stroke, the cylinder moves toward the next exhaust port and by the time it reaches this port piston 50 has reached a position in the cylinder where'it is about to or is gradually uncovering the admission ports 48 through which scavenging air is again admitted, the distributing valve parts having in the meantime moved to a position such that scavenging air is again admitted to the manifold structure.

It will be seen that in the arrangement illustrated there is complete coincidence of the port opening 18 in the distributing valve with one of the openings '|6 for each revolution of the crank shaft relative to the cylinder bank, which is the same as one complete cycle of a cylinder because of the fact that the cycle is a two-stroke sion ports 48 in that cylinder. Furthermore, the timing control of the air through the distributing valve arrangement makes it possible to decrease the length of the piston 50 since the skirt portion 84 thereof is then not required to provide a seal for the admission ports 48 when thepiston is at its upper dead center. 1

From the foregoing it will be evident that many diflerent modifications of engine structure may be employed without departing from the scope of the present invention and that the invention is applicable to diflerent modes of charge formation and ignition in two cycle operation. The scope of the invention is therefore to be considered :as embracing all forms and types of engines falling within the scope of the appended claims when they ,are construed as broadly as is consistent with the 'state' of the I prior art.

What is claimed:

1. In a two-cycle internal combustion engine of the kind having a bank of cylinders arranged radially around the crankshaft of the engine, a circumscribing valve ring-having a series of exhaust ports therein, and means providing for relative rotary motion between said cylinders and said valve ring, the combination with the aforesaid parts of air admission ports in each of said cylinders located to be covered and uncovered by movement of the pistons and means for supplying scavenging and combustion air tosaid admission ports comprising, a source of air under pressure, manifold structure for conveying air from said source to said air admission ports, and engine driven valve means for distributing the air in proper timed sequence to the respective. admission ports including a first valve member formed with a single port, a second valve member formed with a number of ports equal to the number of cylinders and means for rotating said valve members relative to each other at a speed ratio of unity to a number differing from the number of cylinders by one.

2. In a two-cycle internal combustion engine of the kind having a bank of cylinders arranged radially around the crankshaft of the engine for relative rotary motion therebetween, a circumscribing valve ring having a series of exhaust ports therein and means providing for relative rotary motion between said cylinders and said valve ring, the combination with the aforesaid parts of air admission ports in each of said cylinders located to be covered and uncovered by movement of the pistons, a source of air under pressure, manifold structure for conveying air from said source to said air admission ports, and

engine driven valve means for distributing the air in'proper timed sequence to the respective admission ports including a first valve member formed with a single port, a second valve member formed'with a number of ports equal to the number of cylinders and means for rotating said valve members in opposite directions at a speed ratio of unity to a number exceeding by one the number of cylinders.

3. In a two-cycle internal combustion engine of the kind having a bank of radially arranged cylinders mounted to rotate about a crankshaft and having stationary casing structure supporting a valve ring .circumscribing said cylinders and having a series of peripherally spaced exhaust ports adapted to register with said cylinders, the combination with the aforesaid parts of air admission ports arranged. in said cylinders to be uncovered by the pistons therein, a manifold structure for admitting air to said ports, said manifold structure being fixed to and rotating with said bank of cylinders and having centrally located inlet for air, means for supplying air to said manifold structure and valve means for controlling the admission of air to said manifoldstructure including a valve member having a single port mounted to rotate with said crankshaft, a second valve member havins a'number of ports equal to the number of cylinders mounted to rotate with said cylinders, and gearing between said crankshaft and cylinders having a gear ratio of unity to a number differing by one from the number of cylinders.

4. In a two-cycle internal combustion engine of the kind having a bank of radially arranged rotatably mounted cylinders and a stationary casing structure comprising an annular valve ring having a series of spaced exhaust ports therein adapted to register with said cylinders, the combination with the aforesaid parts of air admission ports located in said cylinders and adapted to be covered and uncovered by the pistons therein, a manfold structure fixed to and rotating with said cylinders, said manifold structure including a central annular portion encircling the crankshaft of the engine and a plurality of radially extending manifold arms for connecting said central portion with said admission ports, valve means for admitting air to said central portion in desired timed relation to the engine cycle comprising a ported end plate rotating with the cylinder bank and having a number of ports equal to the number of cylinders and a cooperating plate having a single port fixed to and rotating with the crankshaft, and gearing between said crankshaft and cylinders having a gear ratio of unity to a number difierin by one from the number of cylinders.

5. In a two-cycle internal combustion engine cause relative rotation therebetween in prede-' termined timed relation, the combination with the aforesaid parts of means for admitting scavenging air to said cylinders including admission ports in the cylinders arranged to be opened and closed by the pistons and distributing valve means for separately controlling the admission of scavenging air to said ports, said valve means including a first valve member formed with a single port, a second valve member formed with a number of ports equal to the number of cylinders and means for rotating said valve members relative to each other at a ratio of unity to a number differing by one from the number of cylinders.

6. In an internal combustion injection engine of the two-cycle type having a bank of radially arranged rotatably mounted cylinders, a crank shaft,'means connecting the crankshaft and the cylinders to provide relative rotation therebetween, and a stationary casing structure providing a valve ring encircling said cylinders and having a plurality of exhaust ports adapted to register with said cylinders, the combination with the aforesaid parts of a series of fuel injectors mounted in said ring intermediate said exhaust ports and located so as to register with successive cylinders when the pistons thereof are at or near their upper dead center position, and means for admitting scavenging and combustion air to said cylinders including airv admission ports in the lower portions of the cylinders located to be covered and uncovered by the pistons and means for controlling the supply of air delivered to said air admission ports comprising manifold structure moving with the cylinder bank and distributingvalve means associated with said bank and said crankshaft, said distributing valve means said valve means including a first ,valve member formed with a single port, a second valve member formed with a number of ports equal to the number of cylinders and means for rotating said valve members relative to each other at a speed ratio of unity to a number differing by one from the number of cylinders, to thereby timethe admission of air to said cylinders independently of the timing eifected by said air admission ports.

HUMBERT DENIS JEAN CANTONI.

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