This invention relates to a rotating valve device for internal combustion engines and, in particular refers to a device comprising a disc-shaped valve which is oositiveJy rotated to permit the opening and closing of fresh gas admitting ports or burned gas e hausting ports into and out of, respecti ely, the cylinder of an internal combustion engine.

Conventional devices based on reciprocating poppet valves Are 1 nown to have several drawbacks, the main one being the inertia and the delays proper to mechanical actuators, whu.h may eventually cause damag.es in an interned ombus.tion enqine when it is running at a comoarati /eJ *- h_ h number ot revolutions.

Actual Iv, the valves and the piston, win 1e moving bad- forth, alternately fill the same space, that is when the piston is πsinq it w ll fill the space previously t* i J lad bv the v.lves when thev were down. Since tha s μπnciμJe of operation is based on precisely synchronized muti \ ι _ of the v lves and the piston, and synchrαnJ .-aL i on s increasingly lost as the engine number of revolutions increases, at the t me rotation exceeds a g Lven speed, the amount of mechanical delay will be such that the piston will nαcl against the valve head and cause it to breal- thus seriously damaging vital parts in the engine.

One further drawback is the functional rigidity of mechanical drive means normally employed to give motion to conventional valves, which is reflected in ^' rigid engine performance characteristics, that is such characteristics cannot be changed in real time- Attempts have been made to overcome those drawbacks by developing improved valves and valve control devices in which the valve return time was shortened by using specially designed springs and devices that forced the valve to return to the closed position.

Those devices, however, have so far failed to signi ican ly increase the maximum useable rotation speed of internal combustion engines while on the other hand requiring a considerable waste of energy to operate.

The main object of this invention is, therefore, to provide a. rotating valve device for internal combustion engines allowing the rotating valve to be moved to the desired position in a very short time, which is negligible as compared with the time needed to move the other engine mechanical parts, the valve to be kept in that position for as long as desired, and then the valve be moved in either direction to reach a new working position, and so on.

Another object of this invention is to provide a rotating valve device requiring negligible power to move.

One further object of this invention is to provide a rotating valve device having a simplified and low-cost structure suitable for mass production.

According to this invention, a rotating valve device for internal combustion engines is characterized in that at least one rotating valve, provided wi h ports for passage of qas, is con rolled by a stepper motor respondi nq to commands received tram a central processing uni and is at e_ch step moved to one of several posi ions where it will either open ar close ports through which fresh gas is admitted into the cylinder ar either open or close burned gas exhaust par ts.

S*_.ver_* ^* L advantages are, therefore, ach e/ed wi h the device acco d ng to h s in.'untion, the main one being -.i the piston and -. ι vf___ da not _1 i d_ -'long th _* ._ same path which prevents the .ilves from being broken because αf delayed motion at an excessively high speed of engine rotation, and consequently the engine useable rotation speed c _ι be increased as required.

Another advantage 3 i*_?_. in the considerable reduction of power nece.sarv to move the valves since the efficiency of the stepper iiiutor _tnd of the linear transmir>*-aion of motion to the rotating val /e is by far greater than that of conventional /aive dri e methods.

A further advantage is that the engine characteristic curve can be easilv modified because all

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relevant data are processed by the central processing unit (CPU) , in order to change the admission and exhaust ports opening times and modes, either in real time or according to predetermined operating modes, since the stepping time of a stepper motor is by all means a negligible fraction of the rotation period of an internal combustion engine.

One further advantage is that the rotating valve can be easily- set to one position or a series of positions to obtain a so—called neutral operation of the cylinder, that is to say no explosive mixture will flow into the cylinder and no compression will occur; by this method, the engine will be running with one or more cylinders in idle mode which will result in lower fuel consumption and less air pollution.

One more advantage of this device is that by using a rotating valve, turbulence areas are easily created. This will facilitate the distribution of fuel—air mixture and eventually speed up the diffusion of explosion in the mixture _^

In the following, the present invention will be further clarified by the description of two practical embodiments of the rotating valve device for internal combustion engines, a description made out in a purely illustrative and not limitative way, with reference to the accompanying drawings, in which: fiqure 1 is a cross-section vi w of an internal

combustion engine provided with a rotating valve device according to this invention; figure 2 is a bottom cross-section view tat en along line 11—11 of figure 1; figure 3 is a partial cross-section view similar to figure 1 showing another embodiment of the rotating valve lev'i o according to th invention; and figu e. ¹ 4 <_■ a bottom cr __≥_.-3eι_t on view tal en along line IV— [V ot fiqi.re 3.

Referring to the accompanying drawings, and in particular to figure 1, an internal combustion engine includes a cylinder 10, in which slides a piston 12 fchat actuates a cranl shaft JL thr ugh a connecting rod 16. The eiiQine can conventional.-/ include several Cylinder in which ,.<_> iii _' - iv piston-;, pli r-o-shifted by appropriate angles,, il l .-_1 i 11&» i-uLh ai ti: ^* n_L. motion.

I'tbovi? : iι idt.i-s 10 Ineru i s a head 13 n which a fuel-dLr mixture admission duct 20 and a burned gas exhaust duct 22 have been iiiach uned.

The fuel-air mixture is combined n a conven ional carburetor 24, _.nd exhaust duct 22 is terminated with conventional mufflers for exhausting the. qa--. into the air.

A rotating valve 28, J oαt-mounLed around a hollow shaft 30, rotates against the precisely Levelled off surface 23 of head 13 that faces cylinder 10.

Rotating valve 28 i s constrained to rotate integral

with shaft 30 by means of transport teeth, however it is free to oscillate around it in order that its precisely levelled off top surface can adhere to surface 23 of head IS, to ensure tightness.

On hollow shaft 30 is mounted a toothed pulley 32, secured to shaft 30 by means of key 34, while a backlash compensating spring 36, working between pulley 32 and a retaining washer 33 kept in place by a locking ring 40, serves to make hollow shaft 30 freely rotate, with no end play, within two guide bushings 42 and 44. An antifriction washer 46 separates pulley 32 from head 18.

Inside hollow shaft 30 there is a spark plug consisting of a dielectric or insulator 48 and an electrode 50, connected to the ignition electric power system through a l af spring 52, attached to head 13 through an isolator 54,.

An electric stepper motor 56, having the function of actuating the rotating valve 23, is provided with a toothed pulley 58 that in turn actuates toothed pulley 32 through a cogged belt 60.

Stepper motor 56 is connected to a central processing unit (not shown) which contains appropriate sensors that constantly detect motor characteri tic values such as the driving sha.ft position, the temperature of various parts, and the like. The CPU also contains one ar more microprocessors to process data and provide commands tα be sent to the actuators. The CPU

is, therefore, able to control stepper motor 56 in order to move, as needed, rotating valve 23 at chosen optimal directions and speeds. The techniques required to implement the CPU are wel l I nown and -.re not described f rther.

As s better shown in Figure 2, rotating valve 23 has three apertures 62 through which the gas is let in, while head 13 has on its surface 26 a total of si:: apertures or ports for the passage of gas.

Of the ports on the head, represented by dashed lines in figure 2, thre-e, .64, Art-. connected with adrni ^• _- ΞJ αii duct 20 ana are useα for admi ting the fuel-air rπr tur_, and three,, 6o , connected with exhaust duct 2c ^" ,, are used far burned gas exhaust.

Apertures c_2 are circular in shape and are located at the vertices of an equilateral triangle.

Ports .-A and 66 Are circular in shape too and are thr ^* -_ ^• _-b/- LIiree located aL the vertico- of -:*n equilateral

The ce.nLeι- of pori-_„ 4 and 66 L ie on _> circle and are -10— and E.-degree al ternately spaced.

By that arrangement, when, for instance, valve 28 is rotating _ Loci wise < a_ sι_en in figure 2) , in 40-degrec- steps, it will -first open admission ports 64, will then set to the position shown in figure 2, i.e. w Lh both ports h and 66 closed, and finallv, at the next stop, it will open *•_*.; a _-t ports 66.

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Let us now refer to figures 3 and 4 which show the second embodiment of the device according to this invention. Here head 18 is provided with injectors 63 for fuel admission, and with conventional spark plugs 70 normally used with Otto cycle engines. In Diesel cycle engines, spark plugs 70 are replaced by heater plugs for starting the engine. In that case only air will flow through the admission duct.

Rotating valve 72 in figures 3 and 4 has two gas ports 74, and head 76 has two admission ports 78 and two exhaust ports SO.

Ports 74 a.re roughly trapezoidal in shape and are diametrically opposite with respect to valve 72 center of rotation. Similarly, ports 78 and 80 are two—by—two di metri ally opposite, have a roughly trapezoidal shape, and are 60— and 120-degree alternately spaced along a circle.

As the valve rotates by one 60—degree step, communications will be established between the cylinder and the outside exactly as was previously described with reference to figures 1 and 2.

Referring to figure 2, let us now suppose that the device is at the beginning of the suction phase with the piston at the top dead center; at that point, the CPU will actuate motor 56 in steps until ports 62 of rotating valve 28 are in line with admission ports 64. In that position, the fuel-air mixture is sucked inside

the cylinder while the piston is moving towards the bottom dead center.

With the piston in that position, Lhe CPU will move rotating valve 28 to the position shown in figure 2 where all ports in head 13 are closed, after choosing v. the proper leads or lags on the basis of sensor-suppl ed data,. The rotating valve will be maintained in that position all along the compression, explosion and expansion phases, up to the next bottom dead center position of the pi ton.

After i t has reached the latter position, the rotating -. e will be oved, with leads or lags determined the CPU, to a position where ports 62 are in line with exh u-L ρo ^ι "-L> _. , and wi ll be maintained in that position throughout the exhaust phase, unti l the piston reaches the top dead center thus al lowing the burned ga':es to escape.

The device has thus been brought bad to the initial condition and the cycle begins again, with rotat ing valve 28 being mo.ώϋ to the position where the nex sueL i on μh_-._e will start,.

If an engine mode of u- erc.t ι on lias been preset such as to have one cylinder inactive, the CPU will move rotating valve 2S to the position where ports 62 are in line with exhaust ports 66, and wi ll maintain it in that position for as long as necessary to permit the cylinder to remain inactive.

If, however, the cylinder should be required to work again for the engine to deliver more power, then the CPU will move rotating valve 28 as previously described, and the engine thermodynarrric cycle will be resumed.

The rotating valve device shown in figures 3 and 4 operates in the same way as that shown in figures 1 and 2, except that, as an additional feature, the cylinder can be made inactive by opening exhaust ports SO during the compression phase, and admission ports 78 during the expansion phase, obviously with no fuel injected through injector 68; this will cause only air to circulate between the admission duct and the exhaust duct, with no fuel supply and no waste of energy as would be necessary to effect compression.

The opening and/or closing lags and/or leads can of course be easily changed dynamically during the internal combustion engine operation so tha.t the engine operating characteristics, especi ly the engine torque, may be such as to meet new engine power requirements in real time.

It should be noted that although two possible embodiments of this device provided with a single rotating valve per cylinder have been shown and described, each cylinder can be provided wi h more than one appropri tely sized valve.

In addition, both the number and shape of the ports

on the head can be changed, and so can the shape and number of por s.

Besides that, the number of ports and apertures can be increased tu form a grid of holes for passaqe of gas, which will be opened and closed by rαtatinq the valve through ju_»t a few degr oes.

It i =_ ub i ϋus that other numerous and different chang<_ ^* iι*J modi ^c -.a! ^** _ _n= t. an be performed bv the si l L I -d i i" die arl. an Lnt* embadimenL of the presen invention ner i nbc-fare du c ^•** . bad , without departing from i ts scope,, It is intended, therefore, that all those changes anu ino i ic&Lioni -v •_ encompassed in the field of thi s in ι-.n I- 1 on „