Internal combustion engine

Abstract

An internal combustion engine includes including a fuel reformation cylinder for reforming a fuel and an output cylinder for yielding an engine power by combusting a fuel or a reformed fuel, wherein at least a part of the surfaces constituting a volume-variable reaction chamber of the fuel reformation cylinder has a highly heat-insulative material.

1 . An internal combustion engine provided with a cylinder, wherein:
 at least a part of a surface constituting a reaction chamber of the cylinder is made of a different material which is different from a material for a part excluding the reaction chamber of the cylinder.   
     
     
         2 . The internal combustion engine according to  claim 1 , wherein:
 the surface constituting the reaction chamber includes an inner circumferential surface of the cylinder in a cylinder block, a top surface of a piston housed in the cylinder, and a blast surface covering the cylinder in a cylinder head; and   at least one of these surfaces is made of the different material.   
     
     
         3 . The internal combustion engine according to  claim 1 , wherein:
 the cylinder includes a cylinder bore and a piston housed in the cylinder bore; and   the different material is fitted in an inner circumferential surface of the cylinder bore.   
     
     
         4 . The internal combustion engine according to  claim 3 , wherein:
 a space is provided between the inner circumferential surface of the cylinder bore and the different material.   
     
     
         5 . The internal combustion engine according to  claim 4 , wherein:
 the space is provided annularly along the inner circumferential surface of the cylinder bore.   
     
     
         6 . The internal combustion engine according to  claim 1 , wherein:
 the different material is a higher heat-insulative material than the part excluding the reaction chamber of the cylinder.   
     
     
         7 . The internal combustion engine according to  claim 1 , wherein:
 an external reaction chamber having a constant volume is provided outside the reaction chamber and is in communication with the reaction chamber through a communication passage; and   a fuel is supplied to the external reaction chamber.   
     
     
         8 . The internal combustion engine according to  claim 7 , wherein:
 an inner surface of the external reaction chamber is a higher heat-insulative material than the part excluding the external reaction chamber of the cylinder.