US2151853A - Internal combustion engine - Google Patents

Description

March 28, 1939.

c. JONVILLE ET AL. INTERNAL COMBUSTION ENGINE -Fi1ed March 17, 1938 Patented Mar. 28, 1939 PATENT OFFICE 2,151,853 INTERNAL COMBUSTION ENGINE Charley Jonville, Neuville-en-Ferrain, and Paul Ferlay, Paris, France Application March 17, 1938, Serial No. 196,508 In Belgium March 22, 1937 7 Claims.

The present invention relates to internal combustion engines of the variable stroke type including an eccentric associated with the connecting rod so as to permit of obtaining a variation of the position of the piston when the latter reaches the end of itsupward stroke, in such manner as to eliminate the clearance space between the piston and the cylinder end at the end of the exhaust stroke.

10 It is a well known fact that in the case of engines such as they are commonly devised,the piston cannot move up to the top of the cylinder because a'certain space must be provided between said piston and said top of the cylinder for 1 receiving the fresh gases which are compressed during the compression stroke. It. follows that a portion of the burnt gases necessarily remains in the cylinder after the closing of the exhaust valve.

20 It has already been endeavoured to obtaina full exhaust from the cylinder by making use, for instance, ,of a connecting rod system including an eccentric mounted either on the wrist pin of the piston or on the crank pin of the crank- 25 shaft. This eccentric turned through an angle of 180 toward the top of the cylinder during the exhaust so as to cause the piston to move up as far as the piston end and thus to drive out the whole of the burnt gases. This eccentric was 30 further intended to keep the piston in its low relative position during the compression stroke. The use of an eccentric alone cannot give the desired result because said eccentric cannot modify the length of the piston stroke without prethus bringing the connecting rod out of axial relation with the piston.

Several means for producing this initial movement of the eccentric have already been sug- 40 gested, such as springs for instance, but the necessity of obtaining a rotation of 180 of the eccentric and the obtainment of a satisfactory lubrication involved problems difllcult to solve and anyway no safe and reliable solution has been 45 found up to this time. v

The object of the present invention is to provide a system which obviates this difficulty.

According to the essential feature of the present invention, this system includes a device for 50 producing this initial displacement of the eccentric which is essentially constituted by a cam associated with the eccentric on which the connecting rod is mounted, and a spring operated 55 push-piece acts in an upward direction on said it acts only through one of its faces.

viously having its movement of rotation started,

cam when the eccentric is moved away from its median position.

The cam may be adapted to make a fullrevolution with a non-uniform motion during one cycle of the engine and in this case both of the opposed 5 faces of said cam are utilized. Such a cam will hereinafter be called double cam. Alternately the cam may be adapted to move with a non-uniform oscillating motion and in this case In the following description, such a cam will be called "simple cam.

Other features of the present invention will result from the following detailed description of some specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafter described, with reference to the accompanying drawing, given merely by way of example, and in which:

Fig. 1 is an elevational view of a double cam employed, according to the present invention, in connection with an eccentric mounted on the wrist pin end of the connecting rod;

Fig. 2 is a sectional view on the line 2--2 of Fig. 1, showing the mounting of this double cam and of the eccentric on the wrist pin of the piston;

Figs. 3 to 6 inclusive are diagrammatical views illustrating different relative positions of the double cam in the course of the working of the system during one cycle of the engine;

Figs. '7 and 8 are views, analogous to Fig. 1, showing embodiments of simple cams accordin to the invention;

Fig. 9 shows a system including the use of two double cams.

In the embodiment illustrated by Figs. 1 and 2, the wrist pin I of piston 2 is mounted on the wrist pin end of the connecting rod 3 through the intermediate of! an eccentric 4 which is 40 adapted to turn freely inside a bearing 5 provided in the little end of the connecting rod. The wrist pin I of the piston extends across eccentric through a hole 6 provided therein and the center 0 of which is at a distance e' from the center 0 of eccentric disc 4. On this disc 4,

I fix in any suitable way, for instance by means of screws I, a cam 8 which, in this embodiment,

is a double cam. A push piece 9 guided in parts Ill and II carried by the connecting rod is subjected to the action of spring I! in such manner as to act constantly on this cam in an upward direction, through the intermediate of a roller l3, which runs along the periphery of said double cam.

' Fig. for the eccentric.

The operation or the system Just above described is the following:

It will be supposed that the piston is at the upper end 0! its stroke, at the end oi. the exhaust. At the beginning of the inlet stroke which follows, the connecting rod pulled by the crank pin exerts a downward eflort on the system, whereas thepiston, under the effect 01' its inertia, exerts an upward eilfort on pin I. Consequently, the eccentric is subjected to the action or a torque which tends to bring it into the position shown by Fig. 3. This position corresponds to that for which the piston is at the end of its upward stroke, against the cylinder end, and isstarting its downward movement in the cylinder.

Near the middle of its downward stroke or inlet stroke, the action of push piece I on the double cam becomes preponderant and the eccentric driven by double cam 8 assumes the position shown by Fig. 4, in which position wrist pin l and the axis of the wrist pin end of the connecting rod no longer occupy axial positions with respect to each other in the cylinder. The push piece is now acting upon the circular concentric portion oi the double cam 8 and, for the present time it is inoperative.

At the end of the inlet stroke of the piston, the acceleration of the motion of the connecting rod becomes zero and its sign changes. The same is true for the movement of the piston, and the, torque that is produced tends to bring eccentric 4 into the position shown by Fig. 5. In the course of the compression stroke the piston remains maintained in its lowest relative position, which corresponds to the position of The same applies to the stroke which follows explosion oi. the gases and which corresponds to expansion of the gases.

when the piston is again moving upwardly so as to effect its exhaust stroke, push-piece 9 acts on double cam 8 and causes it to turn so as to bring it into position shown by Fig. 6, that is to say its median position. Near the end oi. its exhaust stroke the piston keeps exerting an upward effort on'the system under the action of its inertia, but the acceleration of the movement of the connecting rod becomes zero and has its sign reversed. The eccentric is then brought into the position shown by Fig. 3, for which position the piston reaches the top part of the cylinder coming nearly into contact with the cylinder end so as to ensure a full evacuation of the burnt gases.

From the preceding description, it follows that, during the exhaust period, there is no counterpressure to oppose the inertia force that is developed, so that, as a consequence of the relative upward displacement of the piston wrist pin, said piston can move upwardly as far as the top of the cylinder, thus driving out the whole of the burnt gases from the cylinder, whereas, during the compression stroke, the internal counterpressure produced by the fresh gases that are compressed opposes the action of the inertia force so that the piston cannot come into its relative upper position, thus leaving, in the top part of the cylinder, the space necessary for the compressed fresh gases.

The system above described involves no diiiiculty from the point of view of lubrication since the existing usual lubricating device is sufilcient, without requiring modifications.

Of course, the specific mechanism above described for starting the initial displacement of the eccentric has been given merely by wayot example and there are many other possible embodiments of my invention.

In particular, it is obvious that the outline of the cm can be modified according to the thrust action that it is to afi'ect under the efi'ect of a spring or any other source oi. energy. Further the cam rigidly connected to the eccentric can be mounted either on the crank pin oi the crankshaft or on the wrist pin 01 the piston, or again a cam and eccentric group might be fitted on each of these parts, so as to obtain a predetermined variation oi the piston stroke.

Finally, the outline of the cam (double cam) above described (which has the advantage or giving a circular movement ensuring a better balancing of the system than in the case of a reciprocating motion) may be modified as shown by Figs. 7 and 8 of the drawing. In the case of Fig. 7, the cam is of the simple type; it is given an oscillating movement and it is subjected to the thrust of the push-piece from c to d ior being brought into its median position.

The simple cam 01 Fig. 8 is subjected to the action or the push piece only at the ends thereof, no action being exerted between 0 and I. This embodiment is advantageous in that the cam is not so wide and can more easily be housed in the piston.

01 course, we may, in order to obtain a still better balancing of the whole, provide two double cams as illustrated by Fig. 9. For instance, we may fix two cams I and 8' on the eccentric disc, on either' side thereof, and two rollers, I3 and II, urged by the central spring l2, will produce, at the required time, the necessary relative movement oi the disc of the eccentric with respect to the little end of the connecting rod.

Oi. course, the operation of this system is the same as above described.

In a general manner, it should be well understood that, while we have, in the above description, disclosed what we deem to be practical and eiiicient embodiments of the present invention, we do not wish to be limited thereto as there might be changes made in the arrangement, disposition, and form of the parts without departing from the principle of the present invention as comprehended within the scope of the appended claims.

What we claim is:

1. An internal combustion engine including a piston and a crankshaft, a connecting rod interposed between these two parts, an eccentric interposed between one of these two first mentioned parts and said connecting rod, a cam coupled with said eccentric, a push piece carried by said connecting rod adapted to cooperate with said cam, and spring means for urging said push piece toward a predetermined position with respect to said connecting rod.

2. In an internal combustion engine including a piston and a connecting rod for said piston. the combination of a wrist pin for said piston, an eccentric mounted on said wrist pin and journalled in the wrist pin end of said connecting rod, a cam rigid with said eccentric, a push piece slidable along said connecting rod adapted to cooperate with said cam, and spring means for urging said push piece toard the outer end of said connecting rod.

3. In an internal combustion engine including a piston and a connecting rod for said piston, the combination of a wrist pin journalled in said piston, an eccentric mounted on said wrist pin, a circular housing carried by the wrist pin end of said connecting rod adapted to receive said eccentric, whereby said eccentric can turn freely in said connecting rod, a cam rigid with said eccentric, a push piece slidable along said connecting rodadapted to run along the periphery of said cam, and spring means for urging said push piece toward the outer end of said connecting rod.

4. In an internal combustion engine including a piston and a connecting rod for said piston, the combination of a wrist pin mounted in said piston, an eccentric mounted on said wrist pin so as to be rotatable with respect to said piston about the axis of said wrist pin, a circular nousing carried by the wrist pin end of said connecting rod adapted to accommodate said eccentric so that the latter can turn freely therein, a double cam rigidly carried by said eccentric adapted to turn always in the same direction about said axis, a push piece slidably guided along said connecting rod adapted to run along the periphery of said cam, and spring means for urging said push piece toward the outer end of said connecting rod.

5. In an internal combustion engine including a piston and a connecting rod for said piston, the combination of a wrist pin mounted in said piston, an eccentric disc mounted on said wrist pin so as to be rotatable about the aids of said wrist pin with respect to said piston, a circular housing carried by the wrist pin end of said connecting rod adapted to accomodate said eccentric disc so that the latter can turn freely therein, a simple cam carried by said eccentric rigidly therewith adapted to oscillate between two extreme angular positions about the axis of said wrist pin, a push piece slidably guided along said connecting rod adapted to run along the periphery of said cam, and spring means for urging said push piece toward the outer end of said connecting rod.

6. In aninternal combustion engine including a piston and a connecting rod for said piston, the combination of a wrist pin mounted in said piston, an eccentric disc mounted on said wrist pin so as to be rotatable about the axis of said wrist pin with respect to said piston, a circular housing carried by the wrist pin end of said connecting rod adapted to accomodate said eccentric disc so that the latter can turn freely therein, a simple cam carried by said eccentric disc rigidly therewith adapted to oscillate between two extreme angular positions about the axis of said wrist pin, a push piece slidably guided along said connecting rod adapted to run along the periphery of said cam, the outline of said cam being such that said push piece constantly urges said cam toward the median position thereof, and spring means for urging said push piece toward the outer-end of said connecting rod.

7. In an internal combustion engine including a piston and a connecting rod for said piston, the combintion of a wrist pin mounted in said piston, an eccentric disc mounted on said wrist pinso as to be rotatable about the axis of said wrist pin with respect to said piston, a circular housing carried by the wrist pin end of said connecting rod adapted to accomodate said eccentric disc so that the latter can turn freely therein, a simple cam carried by said eccentric disc rigidly therewith adapted to oscillate between two extreme angular positions thereof about the axis of said wrist pin, a push piece slidably guided along said connecting rod adapted to run along the periphery of said cam, the outline of said cam being so traced that said push piece urges said cam toward the median position thereof only when said cam is turned through at least a predetermined angle from its median position, said push piece having no action on the angular position of said cam when the latter is making less than a certain angle with its median angular position, and spring means for urging said push piece toward the outer end ofsaid connecting rod.

CHARLEY' JONVIILE. PAUL FERLAY.

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