EP0038781A1 - Distribution device for an internal-combustion engine - Google Patents

Abstract

The internal combustion engine operating at high speed, giving a high output, has a pair of pistons (1,2) reciprocating inside two sleeves with their piston rods parallel and spaced apart. At the bottom of each piston rod (3,4) is attached a swinging arm (12,13) each turning about an axis formed by spindle (11a, 12a) at right angles to the rods. Each rod carries a disc (6) acting as a valve member which is raised and lowered against the wall (7) of the piston, this acting as a valve seating. The two sleeves act as suction and discharge members for the combustion gases. The two swinging arms control the operation of these values as the pistons reciprocate, and are controlled by a rotating cam (106) between them. The rods carry return springs (15,16). The suction sleeve carries a by pass for the piston to prevent excessive build-up of pressure.

Description

Description of the invention

The object of the present invention is to provide a distribution device which allows a positive displacement internal combustion engine to effectively reach a higher number of revolutions than in engines with distribution of the traditional type, while facilitating and coadjuvating, at the same time, the suction and discharge phases of the fuel inside the cylinder, and improving the efficiency of the engine itself.

This object and others still are all achieved by the subject invention which is characterized in that it comprises: a pair of pistons, sliding along corresponding liners, placed in communication respectively with the suction pipe and discharge and, along the outer circumference, with the cylinder of the engine, each piston being movable between two extreme positions, respectively of closing and opening of the inflow light and of deflection to or from said cylinder; means for controlling the translation of each piston in synchronism with the stroke of the piston.

In a preferred solution, this device is characterized in that the sky of said piston, cylindrical, relative to the suction duct, has a valve movable between a first extreme open position when the stele of said piston performs the stroke seen in the opposite direction to the direction of suction of the mixture and a second extreme closed position when said stele runs in the opposite direction to the previous one.

The advantage deriving from this solution is obvious in that the presence of said pistons, as elements for opening and closing the lights to the cylinder of the engine, makes it possible to use lights of larger dimensions, consequently such that can give leads to higher yields throughout the thermodynamic cycle; the particular solution of the sourpape on the piston of the suction duct allows, in addition, a correct opening and closing of the light relative to this duct, without giving rise to discontinuity phenomena in the supply, deriving from the compression exerted in such conduit by the alternating movements of the relative piston.

• - la figure I montre schématiquement le dispositif en objet durant la phase d'aspiration et dans une vue selon une section longitudinale avec quelques parties enlevées pour mieux en évidences d'autres;
• - la figure 2 montre, toujours achématiquement, selon la vue de la figure I, le dispositif en objet durant la phase de compression et explosion;;
• - la figure 3 montre schématiquement, encore selon la vue de la figure I et 2, le dispositif durant la phase d'expansion;
• - la figure 4 montre schématiquement une vue du dispositif dont à figure I dans quelques-unes de ses parties, selon une section transversale, avec la chambre du cylindre moteur en évidence.

Other characteristics and advantages of the invention will emerge even more clearly on the following detailed description, of a preferred, but not exclusive, form of embodiment illustrated for purely explanatory and nonlimiting purposes, in the appended drawings in which:

• - Figure I shows schematically the device in question during the suction phase and in a view in a longitudinal section with some parts removed for better evidence of others;
• - Figure 2 shows, still automatically, according to the view of Figure I, the device in question during the compression and explosion phase;
• - Figure 3 shows schematically, again according to the view of Figure I and 2, the device during the expansion phase;
• - Figure 4 shows schematically a view of the device of which in Figure I in some of its parts, along a cross section, with the engine cylinder chamber in evidence.

With reference to the appended drawings, it can be seen that the device in question comprises a pair of pistons I and 2, sliding along corresponding liners 1a and 2a, in communication respectively with the suction duct Ib and the discharge duct 2b, and communicating, through respective slots AI and A2, obtained along the outer peripheral surface, with the chamber C of the piston P, by means of corresponding pipes Ic and 2c. The steles 3 and 4 and the respective pistons I and 2 are controlled in translation by control means indicated generally by 5, which alternately cause the opening and closing, by means of the said pistons I and 2, of the slots AI and A2.

The stele 3 is not directly connected to the relative piston I; in fact, the sky 6 of the piston I is integral with the stele. 3, but it is separated from the cylindrical body 7 by the same piston I which is closed lower by a disc 8 which allows the connection of the latter with the stele 3 and it is provided with a series of through holes (8'Y.

The sky 6 is complementary shaped to the upper edge 7a of the body 7 of the piston I, in particular it is shaped according to a frustoconical surface whose minor base is directed towards the interior of the body 7.

In this way, when the stele 3 moves in the direction SI of the _f i-gure I, for the opening of the slit AI, the sky 6 "closes" the body 7 held.

Le.stèle 3 is further provided with a flapping element, in this case a ring 9, external to the body 7, designed to effect a flapping on the disc 8, so as to determine a fluctuation of said body 7 parallel to the longitudinal axis of the stele 3 between the final beats of said sky 6 and said ring 9.

At the beginning, in the position of FIG. I, the ring 9 is spaced apart by an amount pre-fixed by the disc 8, while the sky 6 is in the closed position of the body 7; when, as a result of the aforementioned control means 5, the ascent of the piston I is verified, the sky 6 only moves in the direction S2, opposite to the direction SI, by detaching from the edge 7a of the body 7 and "opening", that is to say -to say the body 7 and taking distance between the disc 8 and the ring 9.

Once the said ring ₉ has flapped on the disc 8, the stele _{3 in} t _r groin, in the direction S2, also the body 7 (which is held by means of known segments on the jacket I until the _closure and _u - _r e of the slot AI by the latter, that is to say at closing of the suction light of the mixture to the cylinder of the engine. It can be said, in essence, that the piston I, which by itself constitutes a valve for opening and closing the light AI, is provided with a true and clean valve indicated previously by 6.

This solution of opening and closing between the body 7 and the sky ₆ , with the definition of an annular crown for the passage of the mixture during the translations of the stele 3, became necessary because, during the oscillations of the piston I to open and close, during the different phases of the engine, the slot AI, it was possible to cause as many pressure oscillations on the mixture in the suction duct Ib, if the piston _I slid to hold along it: in particular, the pressure exerted on the mixture filling the pipe Ib, up from the slot _AI , would be extremely harmful when the piston I slides in the direction of the arrow _S 2 to effect the closing of the slot AI itself, while the depression which comes to be created on the melenge, when the piston I slides in the direction SI favors the aspiration.

It follows that in the subject solution in the piston I s "opened" when the mixture is pressurized, that is to say during the translation se- _lon the direction indicated by _S 2, and that it "closes" in the opposite case and we thus obtain a double advantage.

In this connection, in order in any case to exert no harmful pressure on the mixture contained inside the conduit Ib when the piston I slides in the direction S2, the disc 8 is provided, as said, the through holes (8 '' which allow the possible mixture located inside the hollow piston I to propagate val of the latter; this mixture can then be recovered from inside the control chamber of the same steles 3 and 4 and / or recycled in the suction pipe Ib, through a common by-pass, sketched in Figure I, during the sliding in the SI direction of the piston which is closed in this case.

Ultimately, with reference to FIGS. 1, 2 and 3 as well as to the suction piston, it can be seen that this is located in FIG. _I , in the extreme position of opening of the slot AI, it that is to say with the sky 6 in contact and held with the body 7; hardly the stele 3 begins its movement according to the direction indicated by S2, the sky 6, united as said to the same stele 3, detaches from the body 7, freeing from this the annular chamber (7 ') and this during all the race of the piston I at closing of the slot AI during which the mixture undergoes no compression on the part of the piston, but completes the path indicated by the arrow M in FIG. 2.

This for what relates to the piston I. For the piston 2, ie that relating to the discharge, the problem does not arise, since, in the phase of opening (see figure 3) this promotes suction of the burnt mixture from the interior of the engine cylinder through the slot A2, while in the closing phase (see FIG. 2), the piston 2 promotes expulsion of the burnt gases along the duct 2b , as indicated by the arrow in figure 2.

With regard to the control means indicated above overall with 5, these simply consist of a couple of IO cams, wedged above a shaft (IO) in phase with the engine shaft, the first IOa of which causes the triggering of a first assignor II encased in IIa and the second IOb displacement of a second assignor I2 encased in I2a.

The angular displacement of said transferors being rather reduced, to amplify each transferor is integral with a relative arm 12 and 14 framed with the corresponding stele 3 and 4.

In any case, the stroke of the pistons I and 2 in the direction SI or in the direction S2 is quite short, which makes it possible to obtain a high number of revolutions at the engine.

In the illustrated solution the contact between assignors and cammes is guaranteed by elastic means I5 and I6, respectively by steles ₃ and ₄ which constantly exert a force F directed _e in the direction of the arrow SI. it is also possible to use a double pair of cams with "desmodromic" operation, thereby eliminating the use of springs ₁₅ and I6. Naturally, the conformation of the cams and the dimensioning of the device in object are such that they make it possible to comply with the constructive mechanical requirements and with the requirements of the phases to be observed, in relation to the suction, compression and discharge phases of the cylinder of the engine; this solution therefore eliminates the typical drawbacks of normal valve distribution, such as the danger of "flickering" which limits the number of turns.

The invention may assume, in its practical embodiment, forms different from that illustrated above, in particular many modifications of a practical nature may be made thereto without however departing from the protective framework of the present invention.

Claims (5)

1) Distribution device for volumetric internal combustion engines, characterized in that it comprises: a pair of pistons sliding along corresponding liners placed in communication with the suction and discharge conduit and, along the outer circumference , with the engine cylinder, each piston being movable between two extreme positions respectively of closing and opening of the inflow or defluxion light to or from said cylinder; means for controlling the translation of each piston in synchronism with the stroke of the piston. 2) A dispensing device according to the preceding claim, characterized in that the piston crown said cylindrical relative to the suction duct, has a movable valve en- _t re a first extreme position of opening when the said piston stele performs the stroke provided in the opposite direction to the direction of suction of the mixture, and a second extreme closing position when the said stele performs the said stroke in the opposite direction to the previous one. ₃ ) A dispensing device according to claim 2, characterized in that said valve is constituted by the sky of said piston relative to the suction duct, separated from the body of the same piston and integral with said stele; the said body being connected to the said stele with the possibility of relative translation parallel to the own longitudinal axis, the said stele being provided with a flapping element (9) for the said body, capable of defining, in correspondence with the stroke of the stele in the opposite direction to the direction of suction of the mixture, an annular crown (7a) between the sky and the body of the piston for passage of the mixture inside the body of the piston itself. ₄ ) Device according to the preceding claim, characterized in that, in correspondence with the stroke of said stéle in the direction agrees with the direction of suction of the mixture, the sky ( ₆ ) is held on the corresponding body (7). ₅ ) Device according to the preceding claims, characterized in that the suction duct is provided with a by-pass connection of said piston (I).

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