Manufacturing Method of Semi-Finished Piston with Inner Cooling Channel through Liquid Extrusion Process

Abstract

This invention has provided a manufacturing method of semi-finished piston with inner cooling channel through liquid extrusion process, including the following steps: a) produce a wear-resistant cast iron ring with coupling hooks and a common salt and corundum dissoluble core with convex edges; b) fix the wear-resistant cast iron ring in the casting moulds after being aluminized; c) fix the dissoluble core after being pre-heated on the wear-resistant cast iron ring with coupling hooks and convex edges; d) fill in the casting mould with aluminum alloy liquid, compressing and molding. The dissoluble core can be accurately fixed in the casting mould through coupling hooks and convex edges. When the semi-finished piston has been manufactured into finished product, it shall be characterized by high compactness and high mechanical property resulted from liquid extrusion technology. Meanwhile, because of the cooling channel, the temperature in the combustion chamber of the head and ring groove is reduced, the load capacity of the piston is greatly improved, and the manufacturability becomes better.

1 . A method of manufacturing semi-finished piston with inner cooling channel through liquid extrusion process comprising: 
 a) producing a wear-resistant cast iron ring with coupling hooks and a common salt and corundum dissoluble core with convex edges;    b) fixing the wear-resistant cast iron rings in a casting mould after being aluminized;    c) fixing the dissoluble cores, after being pre-heated, on the wear-resistant cast iron ring with coupling hooks and convex edges;    d) filling in the casting moulds with aluminum alloy liquid, compressing and molding.    
   
   
       2 . The method of  claim 1  wherein the dissoluble core is manufactured as follows: 
 a) crush the common slat and corundum until they can pass 80˜120 screen, and heat them to 450˜550° C. to remove moisture and other volatile impurities;    b) distribute the corundum 20˜40% weight per share, and the salt 60˜80% weight per share, and then mix them up;    c) put the mixture in a mould, compressing and molding;    d) process the surface of the molded dissoluble core;    e) bake the processed dissoluble core in a baking furnace, and then take it out.    
   
   
       3 . The method of  claim 1  wherein the corundum is barium oxide or zirconia.  
   
   
       4 . The method of  claim 2 , wherein the corundum is barium oxide or zirconia.