Valve seat structure

Abstract

A valve seat structure includes a cylinder head configured to be mounted at an upper part of a combustion chamber, at least one valve port configured to be formed at a part of the cylinder head being opened and closed by a valve, and a valve seat configured to be mounted along an inner circumferential surface of the valve port, wherein a part of the valve seat is provided with a high hardness material portion made from a high hardness material.

What is claimed is: 
     
         1 . A valve seat structure, comprising:
 a cylinder head mounted at an upper part of a combustion chamber;   at least one valve port formed at a part of the cylinder head being opened and closed by a valve; and   a valve seat mounted along an inner circumferential surface of the valve port,   wherein a part of the valve seat is provided with a high hardness material portion made from a high hardness material.   
     
     
         2 . The valve seat structure of  claim 1 , wherein the valve is an exhaust valve. 
     
     
         3 . The valve seat structure of  claim 1 , wherein the valve is an intake valve. 
     
     
         4 . The valve seat structure of  claim 1 , wherein the high hardness material portion is formed in a fan-shaped arc and is positioned to face a spark plug. 
     
     
         5 . The valve seat structure of  claim 4 , wherein a central angle of the fan-shaped arc ranges from 10° to 350°. 
     
     
         6 . The valve seat structure of  claim 5 , wherein the high hardness material portion is made from one material. 
     
     
         7 . The valve seat structure of  claim 5 , wherein the high hardness material portion is made from at least one material including a high hardness material and the high hardness material is formed at a portion contacting the valve. 
     
     
         8 . The valve seat structure of  claim 5 , wherein the high hardness material portion is made from one material into which a copper component is infiltrated. 
     
     
         9 . The valve seat structure of  claim 5 , wherein the high hardness material portion is made from at least one material including a high hardness material and the high hardness material is positioned in an inner side of the valve seat contacting the valve and the inside thereof is infiltrated with a copper component. 
     
     
         10 . The valve seat structure of  claim 1 , wherein the high hardness material portion includes a coupling portion having a protruding shape,
 the cylinder head has a part provided with a groove-shaped mounting portion corresponding to the coupling portion, and the coupling portion and the mounting portion are coupled with each other.   
     
     
         11 . The valve seat structure of  claim 1 , wherein the high hardness material portion has a part provided with a groove-shaped coupling portion,
 the cylinder head has a part provided with a protrusion-shaped mounting portion corresponding to the coupling portion, and the coupling portion and the mounting portion are coupled with each other.