Patent ID: 8011343

Claim:
A multi link type piston-crank mechanism of an internal combustion engine, comprising: an upper link that has one end pivotally connected to a piston of the engine through a piston pin; a lower link that is pivotally connected to the other end of the upper link through an upper pin and rotatably disposed on a crank pin of a crankshaft of the engine; and a control link that has a base end part swingably held by a body of the engine and a leading end pivotally connected to the lower link through a control pin, wherein an axis of the piston pin is offset relative to an axis of the piston in thrust and counter thrust directions, and wherein when the piston comes to BDC (viz., bottom dead center), a part of the piston takes a position below a lower edge of a corresponding cylinder of the engine and the upper pin is offset relative to the axis of the piston pin in the same direction as a pin offset direction in which the axis of the piston pin is offset in the thrust and counter thrust directions relative to the axis of the piston.