Piston crown cooling feature for diesel engines

Abstract

Internal combustion diesel engines require localized cooling methods for the pistons in these engines. The lubricating oil for the engine is also used as a cooling medium. The operating temperature and stresses in the newest models of diesel engines are extremely high and approach the mechanical limits of the engine component materials. Therefore, supplemental methods are required to remove the excessive heat generated during engine operation. In order to increase the amount of heat transferred to the oil from the piston in a given time, a plurality of fins or grooves are formed on some of the heat transferring surfaces of the piston, such as inside the combustion bowl. The increased surface area of the component allows more heat to be dissipated to the oil that is in contact with the surface. The more heat removed from the piston, the more efficiently and economically the engine will perform in service.

What is claimed is: 
     
         1 . A piston for an internal combustion engine, comprising:
 a piston head having a combustion bowl, a circumferential ring belt and a circumferential cooling gallery disposed between the combustion bowl and the ring belt; and   pin bosses disposed below the piston head, said pin bosses each having a pin bore;   wherein the combustion bowl has an interior surface with at least one fin disposed thereon.   
     
     
         2 . The piston according to  claim 1 , wherein the at least one fin extends circumferentially around an upper region of the combustion bowl. 
     
     
         3 . The piston according to  claim 2 , wherein said at least one fin comprises multiple fins. 
     
     
         4 . The piston according to  claim 1 , further comprising at least one fin disposed on an interior surface of the cooling gallery. 
     
     
         5 . The piston according to  claim 1 , further comprising at least one fin disposed underneath the combustion bowl. 
     
     
         6 . The piston according to  claim 1 , wherein the cooling gallery is open at a bottom and further comprising a cover for sealing the bottom. 
     
     
         7 . The piston according to  claim 6 , wherein the cover has an aperture for oil inlet and drainage. 
     
     
         8 . The piston according to  claim 1 , wherein the at least one fin is forged onto the surface of the combustion bowl. 
     
     
         9 . The piston according to  claim 1 , wherein the at least one fin is machined onto the surface of the combustion bowl. 
     
     
         10 . The piston according to  claim 1 , wherein the at least one fin is mounted or affixed to the surface via a mechanical method.