Piston having improved cooling characteristics

Abstract

A piston adapted for reciprocal movement within a cylinder of an internal combustion engine. The piston includes a crown and a skirt depending from the crown. A body extends below the crown with the skirt disposed annularly about at least a portion of the body. An inner cooling gallery is defined in the body beneath the crown. An outer cooling gallery is defined between the skirt and the body and located beneath the crown. In addition, at least one bore extends radially between the inner cooling gallery and the outer cooling gallery for providing fluid communication therebetween.

1 . A piston adapted for reciprocal movement within a cylinder of an internal combustion engine, said piston comprising: 
 a crown and a skirt depending from said crown, said skirt defining a lower end;    a body extending below said crown with said skirt disposed annularly about at least a portion of said body, said body defining a longitudinal axis extending in the direction of reciprocal movement of said piston;    an inner cooling gallery defined in said body beneath said crown;    an outer cooling gallery defined between said skirt and said body and beneath said crown; and    at least one bore extending radially and orthogonally relative to said longitudinal axis and between said inner cooling gallery and said outer cooling gallery for providing fluid communication therebetween, said bore disposed longitudinally spaced from said lower end of said skirt and away from said crown to facilitate drilling operations to define said bore.    
   
   
       2 . A piston as set forth in  claim 1  wherein said at least one bore extends radially and orthogonally relative to said longitudinal axis and between said inner and outer cooling galleries.  
   
   
       3 . A piston as set forth in  claim 1  further including a cover plate extending between said skirt and said body so as to define a bottom wall of said outer cooling gallery, said cover plate being operatively attached to said skirt at a location that is longitudinally spaced from the location at which said cover plate is attached to said body so as to accommodate the at least one radial bore extending between said inner and outer cooling galleries.  
   
   
       4 . A piston as set forth in  claim 1  further including a cover plate extending between said skirt and said body so as to define a bottom wall of said gallery, said cover plate defining a serpentine shape in cross-section such that one end of said plate is longitudinally spaced from the other end of the cover plate so as to accommodate the at least radial bore extending between the inner and outer cooling galleries.  
   
   
       5 . A piston as set forth in  claim 1  further including a plurality of bores extending radially between said inner and outer cooling galleries.  
   
   
       6 . A piston as set forth in  claim 1  wherein said outer cooling gallery is disposed annularly about said inner cooling gallery.  
   
   
       7 . A piston as set forth in  claim 1  wherein said body includes a pin bore defined therethrough and adapted to receive a pin to operatively interconnect said piston to a connecting rod, said inner cooling gallery being in fluid communication with said pin bore.  
   
   
       8 . A piston as set forth in  claim 7  wherein said outer cooling gallery is in fluid communication with said pin bore through said at least one bore extending radially between said inner and outer cooling galleries.  
   
   
       9 . A piston and connecting rod assembly for use in an internal combustion engine, said assembly comprising: 
 a piston adapted for reciprocal movement within a cylinder of the internal combustion engine, said piston including a crown and a skirt depending from said crown, a body extending below said crown with said skirt disposed annularly about at least a portion of said body, an inner cooling gallery defined in said body beneath said crown, an outer cooling gallery defined between said skirt and said body and beneath said crown, and a pin bore formed in said body;    a connecting rod adapted to interconnect said piston and a crank shaft so as to translate the reciprocal movement of the piston into rotational movement of the crank shaft, said connecting rod having at least one end with a bore extending therethrough and adapted to be aligned with said pin bore in said piston; and    said at least one end of said connecting rod being in fluid communication with said inner cooling gallery of said piston and including a reservoir formed on said end which is adapted to collect coolant therein.    
   
   
       10 . A piston as set forth in  claim 8  wherein said connecting rod further includes a passage extending between said reservoir and said pin bore.  
   
   
       11 . A piston as set forth in  claim 9  wherein said at least one end of said connecting rod defines a substantial portion of a bottom wall of said inner cooling gallery.  
   
   
       12 . A piston as set forth in  claim 9  wherein said piston further includes at least one bore extending radially between said inner cooling gallery and said outer cooling gallery for providing fluid communication therebetween.  
   
   
       13 . A piston as set forth in  claim 12  wherein said body defines a longitudinal axis extending in the direction of reciprocal movement of said piston, said at least one bore extending radially and orthogonally relative to said longitudinal axis and between said inner and outer cooling galleries.  
   
   
       14 . A piston as set forth in  claim 13  further including a cover plate extending between said skirt and said body so as to define a bottom wall of said outer cooling gallery, said cover plate being operatively attached to said skirt at a location that is longitudinally spaced from the location at which said cover plate is attached to said body so as to accommodate the at least one radial bore extending between said inner and outer cooling galleries.  
   
   
       15 . A piston as set forth in  claim 13  further including a cover plate extending between said skirt and said body so as to define a bottom wall of said gallery, said cover plate defining a serpentine shape in cross-section such that one end of said plate is longitudinally spaced from the other end of the cover plate so as to accommodate the at least radial bore extending between the inner and outer cooling galleries.  
   
   
       16 . A piston as set forth in  claim 9  further including a plurality of bores extending radially between said inner and outer cooling galleries.  
   
   
       17 . A piston as set forth in  claim 9  wherein said outer cooling gallery is disposed annularly about said inner cooling gallery.  
   
   
       18 . A piston as set forth in  claim 9  wherein said pin bore is adapted to receive a pin to operatively interconnect said piston to a connecting rod, said inner cooling gallery being in fluid communication with said pin bore.  
   
   
       19 . A piston as set forth in  claim 18  wherein said outer cooling gallery is in fluid communication with said pin bore through said at least one bore extending radially between said inner and outer cooling galleries.