Parent bore cylinder block of an opposed-piston engine

Abstract

A parent bore cylinder block of an internal combustion, opposed-piston engine includes cooling passages that are formed using a 3-D printed casting core. The casting core can include portions that are ceramic. The parent bore cylinder block can include multiple cylinders, each cylinder with cooling passages and turbulence inducing features in those cooling passages, particularly surrounding the central portions of the cylinders.

1 . A method of making a cylinder block of an opposed-piston engine, the method comprising:
 making a printed casting core for a cylinder block with at least one cylinder having a bore, the cylinder being configured to receive a pair of pistons disposed in opposition in the bore;   creating a molding assembly for the cylinder block using the printed casting core;   casting metal into the cylinder block using the molding assembly; and   removing the molding assembly.   
     
     
         2 . The method of  claim 1 , wherein the cylinder comprises intake and exhaust ports separated along a longitudinal axis of the cylinder, each port comprising an array of circumferentially-spaced adjacent port openings in the cylinder block from the cylinder bore to an intake plenum of the engine and to an exhaust plenum of the engine, respectively, and a port bridge between each pair of adjacent port openings. 
     
     
         3 . The method of  claim 1 , wherein making a casting core comprises using a 3-D printing technique. 
     
     
         4 . The method of  claim 1 , wherein the molding assembly comprises a ceramic core portion and one or more sand core components. 
     
     
         5 . The method of  claim 4 , further wherein removing the molding assembly comprises using caustic or an acid to dissolve the ceramic core portion. 
     
     
         6 . The method of  claim 4 , wherein the ceramic core portion of the casting core comprises features near an intermediate portion of the cylinder which form cooling channels in the metal cylinder block. 
     
     
         7 . The method of  claim 1 , wherein the casting core forms an interior surface of the cylinder block defining an annular cooling jacket with cooling features. 
     
     
         8 . The method of  claim 7 , wherein the cooling features comprise turbulence-inducing features. 
     
     
         9 . The method of  claim 8 , wherein the turbulence-inducing features comprise pegs to create turbulent coolant flow of liquid coolant along and around an intermediate portion of the at least one cylinder. 
     
     
         10 . The method of  claim 7 , wherein the cooling features comprise ridges or lands formed to define coolant flow paths 
     
     
         11 . The method of  claim 1 , wherein the casting core forms an intake air plenum. 
     
     
         12 . The method of  claim 1 , wherein the casting core forms exhaust ports and intake ports of the at least one cylinder. 
     
     
         13 . The method of  claim 1 , wherein the cylinder block is a parent bore cylinder block of the opposed-piston engine. 
     
     
         14 . The method of  claim 1 , wherein casting metal into the cylinder block using the molding assembly comprises casting a parent bore cylinder block comprising a crank case portion for an intake side of the opposed-piston engine and a crank case portion for an exhaust side of the opposed-piston engine. 
     
     
         15 . The method of  claim 1 , wherein casting metal into the cylinder block using the molding assembly comprises casting a parent bore cylinder block of an opposed-piston engine comprising one cylinder. 
     
     
         16 . The method of  claim 1 , wherein casting metal into the cylinder block using the molding assembly comprises casting a parent bore cylinder block of an opposed-piston engine comprising three cylinders. 
     
     
         17 . The method of  claim 1 , wherein casting metal into the cylinder block using the molding assembly comprises casting a parent bore cylinder block comprising four cylinders.