Combustion chamber structure for an internal combustion engine

Abstract

To accelerate a combustion with an entire combustion chamber including the vicinity of an opening portion for air suction to thereby make uniform a flame propagation in a combustion chamber structure for an internal combustion engine, and to provide a technology for preventing the generation of knocks, a longitudinal sectional shape of a top wall surface of the combustion chamber is in the form of a substantially triangular shape in longitudinal section defined and surrounded by a cylinder head, a cylinder and a piston. A projection is provided on a circumferential edge portion of a top surface of the piston, with a surface, facing the top wall surface of the combustion chamber, of the projection being substantially in parallel with the top wall surface of the combustion chamber. A cutaway portion is formed in the vicinity of at least a portion, facing the intake opening portion, of the projection of the top surface of the piston.

What is claimed is:  
     
       1. A combustion chamber structure for an internal combustion engine, in which a longitudinal sectional shape of a top wall surface of a combustion chamber is in the form of a substantially triangular shape in longitudinal section in one direction passing through a center of the combustion chamber defined and surrounded by a cylinder head, a cylinder and a piston, with a spark plug being disposed at an apex portion of the triangular shape and an intake opening portion and an exhaust opening portion on the top surface of the combustion chamber, wherein: 
       a projection is provided on a circumferential edge portion of a top surface of the piston, with a surface, facing the top wall surface of the combustion chamber, of said projection being substantially in parallel with the top wall surface of the combustion chamber; and  
       a cutaway portion is formed in the vicinity of at least a  piston wholly formed within a portion , facing the intake opening portion,  of said  the projection that faces an intake opening of the top wall surface area of the piston  combustion chamber.  
     
     
       2. The combustion chamber structure according to  claim 1 , wherein an intake valve is provided to be openable/closeable in the opening portion for air suction, and said cutaway portion serves also as a valve recess for avoiding any contact between the intake valve and the piston when the intake valve is projected into the combustion chamber. 
     
     
       3. The combustion chamber structure according to  claim 1 , further comprising a swirl flow generating means for generating swirl flows within the combustion chamber, wherein said cutaway portion is constructed by a groove formed in a direction in which the swirl flows generated by said swirl flow generating means are received. 
     
     
       4. The combustion chamber structure according to  claim 1 , further comprising a swirl flow generating means for generating swirl flows within the combustion chamber, wherein said cutaway portion is constructed by a groove formed in a direction in which the swirl flows generated by said swirl flow generating means are not received. 
     
     
       5. The combustion chamber structure according to  claim 1 , further comprising a tumble flow generating means for generating tumble flows within the combustion chamber, wherein said cutaway portion is constructed by a groove formed in a direction in which the tumble flows generated by said tumble flow generating means are received. 
     
     
       6. The combustion chamber structure according to  claim 1 , further comprising a tumble flow generating means for generating tumble flows within the combustion chamber, wherein said cutaway portion is constructed by a groove formed in a direction in which the tumble flows generated by said tumble flow generating means, are not received. 
     
     
       7. A combustion chamber structure for an internal combustion engine comprising: 
       a cylinderical head having an inner wall surface and a cylinder block having an inner wall surface, wherein a combustion is defined by the inner wall surface of the cylinder head and the inner wall surface of the cylinder block, the combustion chamber having a top wall surface area with an intake opening portion and an exhaust opening portion; 
       a spark plug disposed in communication with the combustion chamber; and 
       a piston slidably positioned within the combustion chamber, the piston including a top surface having a circumferential edge with a projection, wherein the projection has a surface that faces, and is substantially parallel with, the top wall surface area of the combustion chamber, 
       wherein a cutaway portion if formed in the piston wholly within a portion of the projection that faces an intake opening portion of the top wall surface area of the combustion chamber, and 
       wherein the combustion chamber has a longitudinal cross-sectional shape that is generally pentagonal. 
     
     
       8. The combustion chamber structure of  claim 7 , wherein the top wall surface area has a substantially triangular shape. 
     
     
       9. The combustion chamber structure of  claim 7  wherein the spark plug is disposed adjacent the top wall surface area of the combustion chamber. 
     
     
       10. The combustion chamber structure of  claim 7  wherein the spark plug is disposed at the top of the combustion chamber. 
     
     
       11. A combustion chamber structure for an internal combustion engine comprising: 
       a cylindrical head having an inner wall surface and a cylinder block having an inner wall surface, wherein a combustion chamber is defined by the inner wall surface of the cylinder head and the inner wall surface of the cylinder block, the combustion chamber having a top wall surface area with an intake opening portion and an exhaust portion; 
       a spark plug disposed in communication with the combustion chamber; 
       a swirl flow generator which introduces swirl flows into the combustion chamber; and 
       a piston slidably positioned within the combustion chamber, the piston including a top surface having a circumferential edge with a projection, wherein the projection has a surface that faces, and is substantially parallel with, the top wall surface area of the combustion chamber, 
       wherein a cutaway portion is formed of the projection in the form of a groove formed in a direction in which swirl flows generated by the swirl flow generator are not introduced into the cutaway portion.