Cylinder head for internal-combustion engines

摘要

A cast cylinder head for an internal-combustion engine, in which the charge cycle ducts have a fluctuating duct offset relative to the valve opening caused by the casting technique. Proximate the opening, the charge cycle ducts are provided with a machining allowance which increases toward the duct end and are machined there in a cutting manner so that the interior surface of the charge cycle ducts changes in each case without an offset into the valve opening. In order to achieve a simple tool guiding and nevertheless a machining which is advantageous to the flow, a compensating groove is arranged in the machining allowance of the charge cycle ducts which has a flat V-shaped cross-section and extends in the circumferential direction, specifically-relative to the flow direction-at least in the area of a convex course of the duct wall. The groove flanks have a convex cross-section and are curved to be as free of flow separations as possible. The compensating groove extends at a distance above the upper edge of the valve seat ring which corresponds to approximately 20 to 30% of the inside diameter of the valve opening. The groove base is situated outside the ideal course of the duct surface. The compensating groove extends at least approximately in a plane which is situated approximately at a right angle relative to the duct center line. The depth of the groove measured to the duct tangent corresponds approximately to the maximal core offset.