Patent ID: 6505582
Filing Date: 2003-01-14
Classification: F02B

Abstract:
A variable compression ratio mechanism of a reciprocating internal combustion engine, comprising:a piston moveable through a stroke in the engine and having a piston pin; a crankshaft changing reciprocating motion of the piston into rotating motion and having a crankpin; a linkage comprising: an upper link connected at one end to the piston pin; and a lower link connecting the other end of the upper link to the crankpin; at the top dead center position of the piston, when connecting points between the upper and lower links are able to be supposed on both sides of a line segment connecting a piston-pin center of the piston pin and a crankpin center of the crankpin, and the first one of the connecting points has a smaller inclination angle measured in the same direction as the direction of rotation of the crankshaft from the axial line of reciprocating motion of the piston-pin center and to the line segment connecting the piston-pin center and the first connecting point; as compared to the second connecting point, the first connecting point is set as the actual connecting point between the upper and lower links, wherein the linkage is dimensioned and laid out so that the line segment connecting the piston-pin center and the first connecting point is brought into alignment with the axial line of reciprocating motion of the piston-pin center only during a downstroke of the piston.