Abstract:
The invention concerns a method and an apparatus for optimization of operation and supply of two-stroke endothermic engines, particularly to be employed in the industrial sector relevant to micro engines in the hobby-modellistic field, so as to obtain an improvement of known two-stroke endothermic engines with suction by rotating disc valve, thanks to the use of methods permitting obtaining a better general efficiency of engine, thus obtaining lower consumption along with a better volumetric efficiency and a better mechanical efficiency.

Description:
PRIORITY INFORMATION 
       [0001]    The present application claims priority to International Patent Application No. PCT/IT2008/000648 filed on Oct. 16, 2008 which claims priority to Italian Patent Application No. RM2007A000545, filed on Oct. 17, 2007, all of which are incorporated herein in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a method and an apparatus for optimization of operation and supply of two-stroke endothermic engines, particularly to be employed in the industrial sector relevant to micro engines in the hobby-modellistic field. 
         [0003]    More specifically, the invention essentially consists in improvement of known two-stroke endothermic engines, with a suction by a rotating disc inlet valve, thanks to the application of methods permitting obtaining a better general efficiency of engine, lower consumption along with a better volumetric efficiency and a better mechanical efficiency. 
       SUMMARY OF THE INVENTION 
       [0004]    Operation of engine according to the present invention is that typical of known two-stroke engines with suction from carter-pump and controlled flow from a rotating valve. 
         [0005]    It is therefore specific object of the present invention an apparatus as claimed in the enclosed claim  1 . 
         [0006]    Further embodiments are described and claimed in the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention will be now described, for illustrative and not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein: 
           [0008]      FIG. 1  is a section view of an engine according to the invention; 
           [0009]      FIG. 2  shows a plan view of discs comprising the inlet valve for supply flow; 
           [0010]      FIG. 3  shows a particular of sealing coupling of piston and cylinder of engine of apparatus according to the invention; 
           [0011]      FIG. 4  is an exploded view of a particular of a second embodiment of the apparatus according to the invention; and 
           [0012]      FIG. 5  is an exploded view of a particular of a third embodiment of the apparatus according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    Observing first  FIG. 1 , it is shown a section of an engine, specifically an engine suitable for modellistic field (cars, airplanes, ecc.), representing one of the possible applications, wherein components are those already known, such as output shaft  1 , connecting rod  5 , piston pin  9 , piston  8 , cylinder  10 , head  11 , spark-plug  23 , carburetor  18 , carter  2 , rear carter plug  12 , output shaft bearing  2 , oil reservoir for bench bearings  29 , bench bearing stop  25 , mixture oil recovery channel  4 , ecc. 
         [0014]    Operation occurs for the above components, according to the known two-stroke engine operation, with the exception of rotating disc inlet valve for supply flow (that will be described in greater detail in the following), realized by an innovative method, also fixing of connecting rod to the output shaft and piston ring seal being realized by an innovative method. 
         [0015]    In the exemplificative apparatus shown in  FIGS. 1 and 2 , rotating valve is comprised in an new way within the carter-pump  2 , and according to the direction of the motion drive of output shaft  1 . Said rotating valve is comprised of disc  15 , fixed and integral with carter  2 , and of rotating disc  13 , integral with movement of shaft  1 . Particulars  13  and  15  of  FIG. 1  are shown sectioned mounted on engine, while in  FIG. 2  are singularly shown on the plane. 
         [0016]    Supply flow of engine with suction from carter  2  passes through carburetor  18  within conduct  20 , wherein it is positioned fixed disc  15 , with opening  30  of  FIG. 2  in a position corresponding to suction conduct of  FIG. 1 . Rotating disc  13  rests on fixed disc  15 , and is moved by output shaft  1  shown in  FIG. 1 , to which is fixedly coupled by planes shown in  FIG. 2 , having the suitable shape also provided on shaft  1 ; said disc  13  induces, when rotating according to direction indicated by arrow  37  of  FIG. 2 , opening and closure of passage  30  of flow, thus realizing within carter the same control of rotation of disc  13  on disc  15 , opening and closing the phase by parts  34  shown in  FIG. 2 . 
         [0017]    Rotating disc  13  is kept adhering to fixed disc  15  by thrust of elastic device  34  (see  FIG. 1 ), which integrally rotate with output shaft of  FIG. 1 . Lubrication of valve according to the invention is obtained by oil contained within mixture supplying engine. 
         [0018]    As it can be observed in  FIG. 1 , thickness  38 , blocked by screw  39 , is inserted within carter in order to limit the so called noxious volume. Fixed disc  15  (see  FIG. 2 ) provides suitable projections  31 , blocking the same carter  2 , having the same shape to house it thus preventing rotation of disc  15  due to adhesion rotation to the same rotating disc  13 . 
         [0019]    Connecting rod  5  is constrained to output shaft  1  by a new method providing the use of a stop screw  7 , which, being screwed on shaft  1 , prevents axial exit of rotating connecting rod  5  on output shaft, with interposition of a roll bearing  6 , being thus possible realizing shafts opens toward connecting rod  5 , thus permitting the use of roll bearing in connecting rod and possibility of constraining shaft only by a pair of bearings positioned on a single side of the output shaft. 
         [0020]    Sealing of piston  8  within cylinder  10  is realized by a new method shown in  FIG. 3 , wherein it is possible observing that elastic sealing rings  4  are equal, but symmetric, with respect to the position of cuts  5 ; this permits that, overlapping the same, there is no coincidence of the open points  5  of sealing segments  4 , thus causing closure of juxtaposition of the same in correspondence of discontinuity points  5 . Segments  4  are mounted each other within cavity  2  on piston  1 , and on the same piston it is realized housing corresponding to fixing projection  3  of piston  1  obtained on piston rings  4 . Said projections  3 , entering within cavity  2 , prevent rotation of ring  4  about piston  1 , during operation of engine. 
         [0021]    Observing now  FIGS. 4 and 5 , it is noted that elastic device  14  can be replaced obtaining adhesion of rotating disc  13  on fixed disc  15  by the use of a magnetic field attracting rotating disc  13 , said disc being comprised of ferromagnetic material sensitive to magnetic field in the direction of fixed disc  15 . Particularly, apparatus shown in  FIGS. 4 and 5  provides a series of calamite  41 , integrally provided within carter  2 . On the front portion of the same calamite  41  it is provided fixed disc  15 , on which rotating disc  13  adhering to fixed disc  15  rotates by output shaft  1 . Said disc  13  is kept adhering to the fixed disc  15  by magnetic field created by calamite  41  and is attracted according to the arrows  42 . Both carter  2  and fixed disc  15  are comprised of materials not sensitive to the magnetic field created by calamite  41 . Apparatus of  FIG. 5  is realized with the front insertion of calamite  41  within body  45 , the latter being comprised of material sensitive to magnetic field. Said body  45  permits distributing magnetic field created by calamite  41  in a uniform way on rotating disc  13 , making all calamite cooperating with respect to every angular position taken during the rotation of disc  13 . 
         [0022]    Summarizing, method described in the above permits obtaining uniform adhesion of rotating disc  13  with disc  15  independently from number of revolutions per minute of the same disc. 
         [0023]    Apparatus shown in the figures is suitable for an application in the modellistic field (mini cars, airplanes, ecc.) up to 15 cc. In this application, innovative solution never applied to the field of the two stroke engines for modellistic use have been introduced, such as the rotating valve, for inlet of supply flow, which is not only inside carter but is also provided on the outlet side of the output shaft with respect to the carter; also connecting rod is mounted according to an innovative method, thus rotating on shaft by roll bearing with a stop screw on the same shaft. 
         [0024]    It is further realized oil reservoir separated from the carter by bench bearings; cylinder is comprised of a single cast piece without barrels and is surface treated inside by suitable materials such as “NICASIL” and like. These innovative solutions are specifically suitable for two stroke endothermic engines. 
         [0025]    Present invention has been described for illustrative and not limitative purposes with reference to preferred embodiments, but it is understood that variations and/or modifications can be introduced without departing from the relevant scope defined in the enclosed claims.