Patent ID: 7140347
Filing Date: 2006-11-28
Classification: F02B,F02M,Y02T

Abstract:
1. A swirl forming device in a combustion engine having intake and exhaust ports opening into a combustion chamber, which device comprises: an auxiliary passage for introducing an auxiliary gas, which may be either air or an air-fuel mixture, into the combustion chamber from a location immediately upstream of the intake port, the intake part being selectively opened and closed by an intake valve; the auxiliary passage having an open end positioned at the location immediately upstream of the intake port and adjacent the exhaust port, such that when viewed from top in a direction conforming to a longitudinal axis of a cylinder bore, the auxiliary gas is introduced in a direction different from a direction normal to an inner peripheral surface of the cylinder bore to thereby form a swirl along the inner peripheral surface of the cylinder bore, wherein the open end of the auxiliary passage is positioned downstream of an intake passage of the engine with respect to a valve guide for the intake valve, wherein the intake and exhaust ports are positioned substantially symmetrically on respective sides of a diametrical line drawn to pass across a longitudinal axis of the combustion chamber, respectively, and wherein the open end of the auxiliary passage is positioned at the location immediately upstream of the intake port and between, when viewed from top in said direction conforming to the longitudinal axis of the cylinder bore, a first position closest to the exhaust port and a second position displaced 90° from such first position towards an outside of the combustion chamber around the intake port.