Hollow Valve For An Engine

Abstract

The embodiments of the present invention comprise a coolant-free hollow valve with a cavity and a vacuum being enclosed in the cavity. The valve is used for an engine and one example of an engine is an internal combustion engine. The valve comprises a coolant-free hollow vacuum cavity to reduce the heat conduction such that the combustion heat is used to perform useful work to improve the efficiency of the engine. One embodiment of the present invention is a coolant-free valve with a hollow vacuum cavity and a thermal barrier coating being deposited onto part of the external surface of the valve that comes into contact with the combustion chamber of the engine.

What is claimed is: 
     
         1 . A coolant-free hollow valve for use in an engine having a combustion chamber, the valve comprising:
 a valve stem;   a valve head having a weld-free, combustion-facing surface that is adapted to come in contact with the combustion chamber of the engine;   a cavity in the valve head; and   a vacuum being enclosed in the cavity.   
     
     
         2 . The coolant-free hollow valve of  claim 1 , wherein the cavity is formed in the valve head and in at least part of the valve stem; and
 the vacuum being enclosed in the cavity.   
     
     
         3 . The coolant-free hollow valve of  claim 1 , wherein the cavity is formed in the valve head and the valve stem; and
 the vacuum being enclosed in the cavity.   
     
     
         4 . A coolant-free hollow valve for use in an engine having a combustion chamber, the valve comprising:
 a valve stem;   a valve head having a weld-free, combustion-facing surface that is adapted to come in contact with the combustion chamber of the engine;   a cavity in the valve head; and   a vacuum being enclosed in the cavity; and   a thermal barrier coating being deposited on at least part of the combustion-facing surface of the valve head.   
     
     
         5 . The hollow valve of  claim 4  wherein the engine is an internal combustion engine. 
     
     
         6 . The coolant-free hollow valve of  claim 4 , wherein the cavity is formed in the valve head and in at least part of the valve stem and the vacuum being enclosed in the cavity. 
     
     
         7 . The coolant-free hollow valve of  claim 4 , wherein the cavity is formed in the valve head and the valve stem and the vacuum being enclosed in the cavity. 
     
     
         8 . The coolant-free hollow valve of  claim 1 , wherein the valve head and the combustion-facing surface are made of the same material. 
     
     
         9 . The coolant-free hollow valve of  claim 4 , wherein the valve head and the combustion-facing surface are made of the same material. 
     
     
         10 . The hollow valve of  claim 1  wherein the engine is an internal combustion engine.