Method for the production of a piston pin

Abstract

For the production of piston pins having a hard peripheral area, a relatively inexpensive chill casting method is used. A chill form having a mold cavity for a piston pin is embedded in a casting mold, cast iron is poured into the mold cavity of the chill form, and then the peripheral area of the piston pin that results from this process is cooled by means of the chill form, is white-solidified, and thereby forms a hard wear-resistant surface.

1 . A method for producing a piston pin having a hard peripheral area comprising the following steps: 
 (a) embedding a chill from having a mold cavity for at least one piston pin in a casting mold;    (b) pouring cast iron into the mold cavity of the chill form to form at least one piston pin; and    (c) conducting accelerated cooling of at least a portion of the peripheral area by means of the chill form to form a hard ledeburite structure.    
   
   
       2 . The method according to  claim 1  wherein the cast iron comprises nodular cast iron with graphite mainly in spherolitic form.  
   
   
       3 . The method according to  claim 1  wherein the casting mold is a sand mold.  
   
   
       4 . The method according to  claim 1  wherein the chill form comprises a cylindrical tube.  
   
   
       5 . The method according to  claim 1  wherein the chill form comprises a hollow cylinder having first and second ends and a center region between the ends, the ends and the center region having webs for concentrating the chill effect in the peripheral area of the center region and the ends, the center region forming a contact region piston pin to connecting rod, and each end forming a respective contact region piston pin to pin boss.  
   
   
       6 . The method according to  claim 1  wherein the chill form has a shape of an “8” and comprises two “E”-shaped halves in cross-section.  
   
   
       7 . A device for producing a piston pin having a hard peripheral area comprising: 
 (a) a sand mold; and    (b) a chill form having a mold cavity embedded in said sand mold.    
   
   
       8 . The device according to  claim 7  wherein said chill form comprises a cylindrical tube.  
   
   
       9 . The device according to  claim 7  wherein said chill form comprises a hollow cylinder having first and second ends and a center region between said ends, said ends and said center region having webs for concentrating the chill effect in the peripheral area of the center region to form a contact region piston pin to connecting rod and the ends to form at each end a respective contact region piston pin to pin boss.  
   
   
       10 . The device according to  claim 7  wherein said chill form has a shape of an “8” and comprises two “E”-shaped halves in cross-section.